Forests have played a very significant role to sustain human life on earth from the very beginning. Even today man depends on forest produce, specially wood and bamboo, for variety of purposes. However with the increase in population and consequent increase in demand of wood and resultant indiscriminate felling of trees, the forest cover diminished to a level that it posed problem for saving the environment and the very existence of human being became endangered. This gave birth to the plantation forestry. In the last few decades, lot of plantations of short rotation fast grown exotic species as well as our own important and promising ones have been done so that wood of these plantations could be used for different human needs and natural forests are kept undisturbed and maintained for environmental protection and ecological balance. Under social forestry, farm forestry, agro forestry as well as forest departments normal plantation programmes, large number of trees of species like eucalypt, babul, khair, chir, sissoo, teak, sal, gamari, albizias, casuarina, khasi pine, deodar, poplar, semul, Acacia auriculiformis, Acacia mearnsii, fir, spruce, rubber wood, chandan, bamboo, etc. have been planted. According to an estimate cumulative area put under plantation by all agencies from 1951 to 1999 in more that 30 m ha. The harvest from these plantations has now been started in a big way.

It is expected that if rate of plantation is maintained, the supply of timber from these plantation will continue on sustained basis. The requirement of wood for different activities could thus be met more and more from these plantations and dependence on natural forests will diminish so that they are maintained for posterity.

For a country like India where majority of population live in villages and due to lack of employment in rural areas, there is continuous migration of rural poor to urban areas for search of livelihood and thereby converting cities into slums. The key to sustained development lies in the setting up of cottage industry in rural areas. The cottage industry in the villages can be best developed on forest produce – wood, bamboo, weeds, reeds and grasses.

Wood, being a renewable resource, is an ideal raw material for development of industry on sustained basis. With the development of wood based industry in the rural sector, the farmers growing trees can be assured of remunerative price for their produce at their door step itself, instead of running to city markets and falling under the trap of middle men and commission agents. This will ensure their continued interest in agroforestry. This is necessary for keeping alive the tempo of tree growing which is necessary for the very survival of humanity.

The types of cottage industry which can be developed in rural areas are furniture, door and window, tool handles, agricultural implements, packing cases, match splints, turnery, carving, mat, basket making and variety of handicraft of utility and decorative value made from wood, bamboo, reeds, weeds and grasses. Necessary research support to use plantation wood bamboo and other forest produce for above industries has already been generated in the recent past at Forest Research Institute, Dehra Dun, Institute of Wood Science & Technology, Bangalore, Kerala Forest Research Institute, Peechi, Indian Plywood Industries Research & Training Institute, Bangalore and other organisations involved in wood research and development and utilization including several NGOs.

To quote a few examples, sawing and seasoning technique for Eucalyptus helped its use in furniture, and ammonical copper arsenate treatment technique has enabled inclusion of Eucalyptus as suitable species for door making in Indian Standard specification. Appropriate processing techniques for rubberwood and Acacia auriculiformis has helped their use in furniture and joinery work in a big way specially in South India and even for export. Sissoo and gamari are well known for producing good quality furniture. Ammonia fumigation technique developed at FRI, Dehradun can be of help to improve look and colour of furniture and other handicrafts made from dull looking plantation wood. Poplar splints can be produced and supplied to match industry where big units are purchasing about half of their requirement of splints from the open market.

The production of fruits and vegetables is increasing day by day thanks to agro-horticultural researches. For packing the same for safe transport to city markets, lot of packing cases are needed which can be produced in the village itself from wood of local plantation. Acacias can sustain tool handle and agricultural implement industry needed in the village itself by farmers and other artisans.

Turnery and carving industry can sustain well on the basis of plantation wood. A large number of utility and decorative items can be produced from bamboo and can even be exported if proper quality is maintained as has been successfully done in China. For use of round bamboo for development of lamp stand, flower vase etc., pretreatment processes with urea and poly ethylene glycol can eliminate cracking and deshaping and thus help maintain quality. Bamboo and cane furniture are in great demand now a days.

There are numerous such examples where a profitable cottage industry can be run in the villages and generate gainful employment opportunities in rural sector. Thus plantation wood and bamboo etc. based cottage and small scale industry can help rural masses for their sustainable development and bring prosperity in Indian villages.
________________________
*Formerly Head of Division.

D.P. Khali, Anil Negi and V.K. Jain
Forest Products Division, Forest Research Institute, Dehradun-248 006

Introduction

In the present era of environmental consciousness, more and more material are emerging in construction, furniture and other sectors as substitutes of wood. Wide range of plastics, synthetic material, metals, etc. are being used to substitute wood. However, the real wood substitution and service to environment both are possible if this material is sustainable as well as renewable. Efficient utilisation of plantation species and utilizing the smaller particles and fibres obtained from various lignocellulosic materials including agro wastes to develop ‘panels’ is thus certainly a rational and sustainable approach. Any lignocellulosic waste matter can, therefore, be turned into panels through appropriate R & D work and technology development. These approaches offer much simpler materials for future use in comparison to solid wood logs.

Developmental work on these lines though was already started in Forest Research Institute, Dehradun, in mid forties by Narayanamurti, who covered diverse range of studies in this direction. The utilization of some agricultural wastes for panel products, fibre boards from timbers, building boards from bamboos clearly indicate the awareness towards utilising agricultural and lignocellulosic wastes even at that time.

Subsequently, comprehensive R & D work was done at Forest Research Institute, Dehradun and elsewhere, involving the broader R & D areas essential to improve these products and incorporate the aspects of durability, permeability, lamination, compression, impregnation besides developmental work on glues. Cashew nut shell liquid, black liquor and other phenolic substances from vegetable origin are few examples of this kind. The role of extender was also studied on gross panel properties and products economics. The present paper touches some of the important findings of this field at Forest Research Institute, Dehradun.

Plywood

Plywood is made from thin sheets of veneer that are cross-laminated and glued together with a hot-press. The wood veneer is literally peeled from the log as it is spun. Throughout the thickness of the panel, the grain of each layer is positioned in a perpendicular direction to the adjacent layer. There are always an odd number of layers in plywood panels so that the panel is balanced around its central axis. This strategy makes plywood stable and less likely to shrink, swell, cup or warp. However, the plywood may be the result of combination of the same material from a log or a tree or may be containing different species for different layers with a central symmetry. The plywood thus provides the entrepreneurs or researchers opportunity to try the best combinations from the economic angle (commercial) and from the functional angle (specialty). Such experimentation is more demanding for plantation species to economise the product and improves the quality.

In view of the shortage of plywood logs in the country persistent efforts have been made to study the suitability of different forestry species, such as Adina cardifolia, Araucaria, spp. Betula spp., Dalbergia sissoo, Dillenia spp. Garuga pinnata, Hardwickia piñnata, Jacaranda spp., Juglnas regia, Litsaea monopetala, Machilus spp., Millingtonia spp., Morus alba, Pterocarpus marsupium, Quercus semicarpifolia, Salmolia malabarica, Terminalia tomentosa and Zenthoxylum rhetsa (Jain et al., 1967), Araucaria cunninghamii, Betula monosperma, Calophyllum tomentosum, Cullenia excelsa, Dalbergia latifolia, Dipterocarpus turbinatus, Ficus glomerata, Kayea assamica, Lagerstroemia parviflora, Pinus roxbrughii, Shorea assamica, Vateria indica (Jain and Bisht, 1972a), Abies pindrow, Albizia procera, Calophyllum elatum, Toona cilliata, Cedrus deodara, Cullenia excelsa, Dipterocarpus turbinatus, Ficus racemosa var, Kayea assamica, Mangifera indica, Michelia champaca, Pinus roxburghii, Shorea assamica, Shorea robusta, Tectona grandis and Terminalia myricarpa (Jain and Bisht, 1974), Albizia procera, Cedrus deodara, Calophyllum elatum, Dalbergia latifolia, Dalbergia sissoo, Dipterocarpus turbinatus, Kayea assamica, Mengifera indica, Michelia champaca, Pterocarpus dalbergioides, Shorea assamica, Terminalia alata, Terminalia myriocarpa and Zanthoxylum rhetsa (Gupta and Bisht, 1978 ), Azadirachta indica (Chauhan and Bisht, 1987a), Artocarpus chaplasha, Azadirchta indica, Chloroxylon swietenia, Palaquim ellipticum, Pinus roxburghii, Populus spp., and Terminalia alata (Rajawat and Bisht, 1981), Populus ciliata (Rajawat et al,1989), Artocarpus lakoocha (Rajawat et al.,1990), Melia azadarch (Rajawat et al., 1990), Quercus spp. (Rajawat et al., 1989), Ulmus wallichiana (Shukla et al.,1985), Populus deltoides (Shukla et al., 1986), Dracontomelum mangiferum (Shukla, et al, 1987), Enterolobium contortisiliquum (Shukla et al., 1990), Bauhinia roxburghiana (Shukla et al.,1990), Alnus nitida (Shukla et al., 1988), Lagerstroemia parviflora (Shukla and Shukla, 1989), Millingtonia hortensis (Shukla and Shukla, 1990) for plywood making. Most of the species tested are suitable for making MR grade plywood except Calophyllum tomentosum, Ficus glomerata, Ficus racemosa, Garuga pinnata, Jacaranda spp. and Pinus roxbrughii. Lagerstroemia parviflora found unsuitable (Jain and Bisht, 1972a) is also reported suitable (Shukla and Shukla, 1989) for MR grade of plywood. Timber tested for BWR grades plywood such as Ulmus wallichiana (Shukla et al.,1985), Populus deltoides (Shukla et al.,1986), Dracontomelum mangiferum (Shukla et al., 1987), Enterolobium contortisiliquum (Shukla, et al., 1990), Bauhinia roxburghiana (Shukla et al., 1989), Alnus nitida (Shukla et al.,1988), Lagerstroemia parviflora (Shukla and Shukla, 1989), Millingtonia hortensis (Shukla and Shukla, 1990), Azadarichta indica (Chauhan and Bisht, 1987a), Populus ciliata (Rajawat et al., 1989), Artocarpus lakoocha (Rajawat et al., 1990), Melia azadarch (Rajawat et al.,1990), Quercus spp. (Rajawat et al., 1989), Dalbergia latifolia, Dipterocarpus turbinatus, Kayea assamica, Michelia champaca, Shorea assamica, Shorea robusta, Terminalia myriocarpa and Toona ciliata are suitable for BWR grade plywood except Abies pindrow, Calophyllum elatum and Pinus roxburghii (Jain and Bist, 1973).

The vast amount of data thus collected over the years has formed the basis for the establishment of plywood, block board and flush door making units all over the country. The work carried out on evaluating the suitability of poplar for plywood at this institute has helped in establishing large number of plywood units in Haryana, Punjab, West U.P.,

Uttaranchal, etc. Presently, more than eighty wood species are recommended for plywood manufacture using appropriate quality control measures during manufacturing of plywood (Khali et al., 2003) but most of the species are non-durable and, because a large portion of veneer is from sapwood, the product is liable to be destroyed by fungus and insects and require proper treatment. There are various preservatives and treatment methods for veneers and plywood. The effect of preservative treatment of veneers, glue line and finished plywood of various species are described by Khali et al., (2003) and it is reported that treatment of the finished plywood is the acceptable method.

There are difficulties to get single species for making of plywood. Therefore, the combi plywood may be the solution for this problem. Combi plywood is the combination plywood made of different species veneers. Combi plywood using poplar, eucalypt and paulownia (Paulownia fortunei) were developed for general purpose (exterior grade) (Khali et al., 2004) as well as general purpose (interior grade) (Khali et al., 2005). Combi plywood for general purpose (exterior grade) made of combination of eucalypt – paulownia - eucalypt (EPE) and poplar – eucalypt - poplar (PopEPop) veneers meet the IS specifications at all the three pressure levels viz. 10.5 kg/cm2, 14.0 kg/cm2 and 17.5 kg/cm2 and combination of eucalypt – poplar - eucalypt (EPopE) meets the IS specifications at two pressure level 14.0 kg/cm2 and 17.5 kg/cm2. Combi plywood for general purpose (interior grade) made of combination of eucalypt – paulownia – eucalypt (EPE), eucalypt – poplar - eucalypt (EPopE) and poplar – eucalypt - poplar (PopEPop) veneers meet the IS specifications at all the three pressure levels viz. 10.5 kg/cm2, 14.0 kg/cm2 and 17.5 kg/cm2.

Shortage of wood raw materials could be minimised by utilising vast quantities of lignocellulosic wastes available in the country. By varying the process parameters and binding agents, wide variety of composite wood products could be made from such raw material and can substitute solid wood for various purposes.

The composite wood industries and research in this field seem to have been established in this country almost about the same time. The first match factory was started in 1922. In 1940, the work on wood adhesives and improved wood was taken up in the institute. Work on fiber building boards and particle boards in the country was initiated at FRI, Dehradun in 1950s and large number of raw materials have been evaluated for their suitability for making fiber building boards and particle boards. Agro wastes, bagasse, jute sticks, pine needle, etc. were evaluated for particle board and fiber boards. Large quantities of various grasses are available from the forests, which could be utilised for manufacture of fiberboards. Suitability of spent rosha grass was evaluated for making hardboards and it passed the requirements of specification. Narayanamurthi et al., 1961 carried out some preliminary investigations of evaluating the suitability of Lantana for making hardboards using lime or very small amount of alkali for cooking the raw material. The strength of these boards was low and water absorption was high. Singh et al., 1984 carried out the work on suitability of Lantana camera for building boards and it was observed that satisfactory hard boards and particle boards passing the requirements of IS specifications could be obtained from Lantana.

Suitability of various lignocellulosic wastes has been evaluated for making particle board and fibre board. For fibreboard, suitability of lops and tops from plantation species viz. Eucalyptus hybrid (Shukla et al., 1987), Leucaena leucocephala (subabul) (Shukla et al., 1985) and poplar (Shukla, 1987) with and with out bark have also been evaluated for making fibreboard. Many of these raw materials were found suitable for making fibreboard. For particleboard, suitability of lops and tops from poplar with and without bark and bark alone have been evaluated (Singh et al., 1995). Suitability of lops and tops of Prosopis juliflora and Ailanthus excelsa for particle board have also been evaluated recently (Singh et al., 2002a and 2002b).

The boards can be produced from inferior variety of wood (Singh and Negi, 2001; Singh et al., 1995), which have no commercial utility or from wood wastes from sawmills, plywood plants, other wood based industries (Singh and Rawat, 1990) and other waste lignocellulosic materials (Singh et al., 1995-96; Joshi and Singh, 1996; Singh and Shukla, 1996; Singh, 1993; Joshi and Singh, 1992; Singh and Bhalla, 1987; Shukla and Prasad, 1985; Shukla and Chandra, 1986; Shukla and Prasad, 1986).

Boards can also be prepared as single mat board or multi mats. In multi mat boards veneers, veener mats, saw dust, shavings, etc., can be used as a core material or face in the production of the boards. The boards can also be made in the corrugated form. Stringer type boards can be made using mould and mandrel (Narayanamurti and Bist, 1948, 1963; Narayanamurti, 1956).

Poplar has been grown in a big way in the country and large supplies are available. It is still not finding use in the manufacture of stiles and rails of door/ window shutters, as it is light in weight and low in strength properties specified for such uses. Further, timber from industrial plantation is deprived of quality due to saw milling practices of compromising the strength properties in favour of timber recovery and variability in strength as compared to naturally grown timber.

Laminated veneer lumber (LVL) is a composite wood product manufactured from veneer sheet in which adjacent veneer layers run parallel. LVL has directional properties akin to solid wood, is structurally stable and of predictable quality.

At Forest Research Institute, LVL has been prepared from poplar, process parameters optimized and properties studied (Shukla et al., 1997). Since poplar is non-durable in nature, schedule for treatment of LVL from poplar has also been worked out. It has been noticed that treatment with copper- chrome- arsenic preservative for required level of absorption of 6-8 kg/cm3 does not have significant effect on strength properties and glue bond between veneers (Shukla et al., 1997).

Panel door shutters using poplar LVL, 35 mm thick stiles and rails and 12 mm thick poplar plywood inserts were made. These were subjected to functional test as per Indian Standard IS:1003-1991 & IS:4010-1994. Test results indicate that panel door in general flatness test, local indentation test, edge loading test, shock resistance test, mis-use test, slamming test and screw holding power test meet the requirement of Indian Standard. In impact resistance test the values are slightly lower as expected since the timber itself is light in weight. However, in flexural and buckling test the door does not meet the requirements of Indian Standard. These two tests are rigorous test and panel door prepared from even solid wood of species like hollock and kanju do not meet the requirements (Shukla and Negi, 1998).

LVL can be manufactured in size 10-12 cm wide, 2.5-25 meter long and 7.5 cm thickness. Being dimensionally stable and having uniform strength properties, it is more versatile than sawn poplar wood. Any plywood unit can take up production of LVL without any extra investment in machinery and equipment. Economics of process and manufacturing details have been worked out for the benefit of the industry.

Recently LVL has also been developed from Ailanthus exelsa. The properties of the product developed were studied and compared with solid wood of teak, poplar and ailanthus species (Negi et al., 2000).

b. Laminated core lumber (LCL)

Laminated core lumber (LCL) has been developed at Forest Research Institute, Dehra Dun, from poplar suitable for making stiles and rails of door/window shutters (Shukla, 1997). Successful trials have been made to improve the physical and mechanical properties of poplar through lamination and simultaneous compression.

From the solid core wood laminated with veneer, door and window shutters were made. Inserts were 12 mm thick poplar plywood.

The door was tested as per IS specification of IS:1003 (Part-1- 1993) and IS: 13034-1990. It meets all the test except the impact indentation test which is slightly lower due to soft nature of wood.

Details of the manufacturing process and economics have been worked out (Shukla, 1997). Full size doors shutters have also been made using solid wood core lamination with veneer and plywood insert and fitted in the Scientist Hostel of ICFRE for observing their performance. These shutters are performing well.

Attempts have been made on developing technologies for utilisation of wood residues into value added product to substitute solid wood. The products like particle board and fibre board have been developed. These products though suitable for variety of uses as sheet material lag the directional strength properties required in a product for use as structural material.

Recently structural wood similar to ‘Scrimber’ developed in Australia has been produced at Forest Research Institute from Lantana, bamboo, lops and tops of eucalyptus and poplar (Shukla and Janardan Prasad, 1988; Shukla and Mishra, 1991, Shukla and Negi, 1996; Shukla,1992, Singh, et al., 2001). In this process raw material in the form of sticks are destructured by passing through counter revolving rollers in such a way that their fibre orientation is not disturbed. The reconstituted material is resin treated and consolidated under the influence of heat and pressure. Physical and mechanical properties of reconstituted products were studied and compared with teak. Results indicate that modulus of rupture and other properties of the products are comparable with teak. Structural wood developed is akin to solid wood in appearance. It can be bored, shaped, nailed, screwed with hand and machine tools. It can also be painted and polished with ease.

Extensive research has been done for the development of various types of modified wood viz. compressed wood, impregnated wood, compregnated wood and laminated wood. More than 38 forestry species have been studied for their suitability for compressed wood for improved wooden shuttle blocks for non-automatic looms (Naraynamurti et al., 1961, Jain and Bhatnager, 1963; Jain and Lala, 1966, Shukla and Bhatnager, 1988, 1989, 1993). Similarly, suitability of more than 32 species have been studied for making compregnated wood (Naraynamurti and Kartar Singh 1945; Narayanmurti and Pandey 1948; Jain and Lala 1966; Jain et al., 1967; Lala and Gupta 1977). Similarly suitability of more than 21 species have been studied for making impregnated wood (Naraynamurti and Kartar Singh 1943; Naraynamurti and George, 1948). The studies helped in identifying substitutes for foreign timbers in making several textile mill accessories.

Initial steps were taken at Forest Research Institute, Dehradun to develop indigenous casein glues in mid forties by Naranyanamurti. Glues based on natural products like tannin, cashew nut shell liquid and black liquor lignin from pulp and paper industry were also developed subsequently (Gupta et al., 1978, Singh and Joshi 1988, 1990; Joshi and Singh 1992; Singh and Singh 1993,1993). It was observed that using black liquor lignin it is possible to replace about 50 per cent phenol for preparation of phenol formaldehyde resin for exterior grade plywood. In spite of the above efforts, urea formaldehyde and phenol formaldehyde remained in the centre stage in the field of panel products. The role of fillers and extenders have also been experimented to economise the processes using coconut and walnut shells, silica gel, paddy husk gel beside conventional filler and extenders for manufacture of plywood.

There has been an increasing gap between demand and supply of wood and wood based panel products. This has given birth to a number of wood alternatives from plastic and metal. However, production of wood alternatives from plastic and metal is highly energy consuming and such products, specially from plastic, are not biodegradable and hence not environment friendly. This has prompted the scientists and technologists to develop technology for production of wood alternatives from biodegradable material of natural origin.

Attention has been drawn to agricultural and forest residues which have hitherto been considered as waste material. Rice husk, baggasse, cotton stalk from agricultural residue and pine needle, casurina, lantana, etc. from forest have been successfully converted into panel products. Many such products such as rice husk, baggasse, etc. have been successfully utilized as commercial raw material for particle board.

Coffee husk is one such agricultural residue which has not yet found suitable use for producing value added products. Coffee is grown abundantly in Western Ghats. It also grows in Eastern Ghats of Andhra Pradesh, South Orissa and in small quantity in Bihar, West Bengal and Assam. The main species grown in India are Coffea arabica and Coffea robusta. Area under coffee cultivation is 226,059 ha under small holding and 120,657 ha and large holding. Annual production of coffee seeds in the year 2002-03 was 275,275 mt; annual domestic consumption around 58,000 mt (2001-02) and export to the tune of 53,593 mt (2002-03).

The ripe seeds are sun dried and pounded or hulled to separate the fleshy cotyledons which are then roasted and powdered. The husk remains as waste. Structural details of the husk are given in the material and methods.

Coffee husk obtained from M/s Tata Coffee Ltd., Bangalore having moisture content 7-8 per cent was used as such as raw material. However, for effective gluing, the husks were partially ground.

Conventional urea formaldehyde, phenol formaldehyde or melamine formaldehyde were not found suitable for bonding coffee husk. Bond integrity was poor in the panel made with these resins. A modified phenol formaldehyde resin in which phenol is partially replaced by cardanol (a constituent of cashew nut shell liquid) has been found to be very suitable for bonding coffee husk.

Preparation of cardanol phenol formaldehyde (CPF) resin

Phenol formaldehyde resin was prepared in two stages. Phenol was partially replaced to the extent of 25-30 per cent on weight basis. A typical resin formulation is phenol: cardanol: formaldehyde:

sodium hydroxide = 1: 0.14 : 2.66: 0.54 (molar ratio). Water was added to the extent of 50-70 per cent of phenol in order to control reaction and obtain a resin having solid content 40-43 per cent. Resin having viscosity 80-100 cp was found suitable for bonding coffee husk.

Preparation of coffee seed husk board

Coffee husk were partially ground before mixing resin in order to obtain intimate mix. Boards having weight ratio of coffee husk: resin solid = 100: 6-14 were made. Coffee husks having moisture content 7-8 per cent were mixed with liquid CPF resin manually. Resin coated particles were dried in an oven at around 60oC to moisture content 4-6 per cent. Glue coated particles can be sun dried also; but it requires more time. Dried particles were formed into a mat and subject to hot pressing. Only single layered boards were made. Hot press parameters are: temperature: 140om- 145oC, pressure: 12-13 kgs/cm2, time: 15 mins. for 12 mm thick board. After hot pressing, boards were kept at ambient temperature for 7 days before further processing. Afterwards boards were taken for testing.

Testing of the boards

Boards were tested as per IS: 3087(Bureau of Indian Standards, 1985). Boards made with different resin content (6-14 per cent w/w) were tested separately in order to evaluate the minimum resin requirement for the boards to meet the requirements of relevant BIS specification. Test results are given in Table -1.

Coffee seed husk form a suitable raw material for making panel products. Conventional resins like urea formaldehyde, melamine formaldehyde were not found suitable for bonding coffee husk. Conventional phenol formaldehyde also does not give adequate bond strength; however a modified PF resin where phenol is partially replaced by Cardanol, has been found suitable for bonding coffee husk.

Due to concave shape of coffee husk, glue mixing poses problem as the concave part of the husk either does not receive any resin or if resin happens to fall into concave portion, it remains in excess very often. In order to overcome the problem, coffee husks were partially grinded, when uniform mixing of resin did not pose problem.

It was also found that inner (concave) wall contains a waxy layer which is difficult to get wet by adhesive. Because of the very small size of the husk, it is almost impossible to separate the two layers effectively. Part of the inner waxy layer can be removed by grinding of the husk and winnowing. Presence of this waxy layer may be one reason that 6-8 per cent resin (w/w) does not give adequate bond and higher percent of resin to the dry weight of the substrate is necessary to obtain proper bond.

Moisture content of the glued particles play a vital role in bonding. Initial moisture content in the husk is 7-8 per cent which is suitable for gluing. However, moisture content in the glue coated husk must be brought down to 4-6 per cent before hot pressing; otherwise, there is blister formation in the board during hot pressing.

Although the bond integrity is satisfactory with 6 per cent (weight basis) resin but other properties of the board do not meet the requirement of the IS: 3087. Two important properties viz. water absorption and swelling in thickness and length do not pass the tests below 10 per cent. With resin content 12 per cent (w/w), coffee husk boards meet all requirements of IS:3087 except IB. Further increase of resin content up to 14 per cent shows minor increase in the value, but does not reach the required values of IB as per IS: 3087. Other two properties of the boards i.e., MOR and screw withdrawal strength pass the test at resin content 12 per cent (w/w) and as low as 6 per cent (w/w), respectively. Effect of resin content on properties of boards is shown in Fig. 1 to Fig. 6.

	Fig. 1. Effect of Resin content on water absorption.	Fig. 2. Effect of Resin content on length, width and thickness in 2 hours.
	Fig. 3. Effect of resin content on surface swelling in two hours.	Fig. 4. Effect of resin content on IB.
	Fig. 5. Effect of resin content on MOR.	Fig. 6. Effect of resin content on srew withdrawal strength.

References

The Wealth of India, Vol II, Publication and Information Directorate, CSIR , New Delhi. pp.288-297.

Zoolagud, S.S.; Mohandas, K.K.; Narayanprasad, T.R. 1983. Partial replacement of phenol in phenol formaldehyde resin by cardanol. Bangalore, IPIRTI.

Bureau of Indian Standards. 1985. Specification for wood particle boards (medium density) for general purposes (Specification No. IS:3087-1985). New Delhi, Bureau of Indian Standards

---

WOOD WOOL BOARDS

V.K. Jain and D.P. Khali
Forest Products Division, Forest Research Institute, Dehradun-248 006

Introduction

Wood wool boards made from long wood fibrous strands and inorganic binders originated from Austria. Magnesite bonded boards are reported to be developed in 1914 and cement bonded board in 1928. Because of their versatile nature, the boards found large scale application in low cost housing, shuttering, sandwich type boards for insulation, false-ceilings, etc., in Austria and Germany before the Second World War. Magnesite bonded boards are being used in USA, Federal Republic of Germany, Austria and Italy. Wood wool boards using different binders are marketed under various trade names such as Heraklith, Gypklith, Marlith, Thermacoust, Austrolith, Thermofriz, Ferrolite, Thermolith, etc.

A typical composition for making wood wool boards as followed by Elten Engineering of UK is:

Wood wool =3 kg, portland cement = 6 kg, and water = 3 kg.

For a board of 2.5 cm thickness the weight per square meter is 10 to 11 kg giving an approximate density of 400 kg/ m3. Cost wise, wood wool boards are much cheaper than solid wood or other panels bonded with synthetic and natural adhesives. They are superior in physical properties such as thermal conductivity which is nearly 7 k cals/m2hoC, sound absorption and posses adequate strength and excellent working qualities. Wood wool boards are classified as class-I fire resistant materials based on surface spread of flame tests. All these factors have contributed significantly to the adoption of this material in low cost housing and construction of industrial and commercial complexes. There are three firms in the world namely Elten Engineering, Gever Canalii, and Authon Grimn which manufacture automated wood wool boards. But manufacture of such wood wool board can be done easily in small-scale sector using less sophisticated machinery. Federal Republic of Germany and Japan top the list in manufacture of such boards and fairly good quantities of such boards are being made in France and Czechoslovakia. Plants are also in existence in a number of developed countries like USA, UK, Switzerland, etc., and developing countries like Argentina,

South Africa, Mexico, Brazil, Taiwan, etc. There are presently nearly ten such plants operating in the country with different manufacturing capacities. The production of wood wool boards and their utilization in India is, however very limited as such boards are being manufactured with borrowed or half-baked technology and very seldom these boards meet the necessary requirements. The use of such boards has mostly been confined to false ceiling in airports, cinema halls, cotton and jute mills.

Raw material for the Manufacture of Wood Wool Boards

Basically the raw material requirement for such boards is wood-fibre and the binder. Traditionally, fibres from softwoods have been used as these woods, normally do not interfere with the setting of cement and the resulting board strength. Major manufactures, however, now feel that almost any woody material can be used for manufacture of these boards with some prior treatments to the wood strands. Apart from wood, a large number of agro-wastes like rice-husk, bagasse, hemp-flakes and coconut fibres have been recommended for manufacture of such boards. But the technology being covered by several patents have not been tried extensively. The current practices in India continue to use the traditional softwood species mostly chir (Pinus roxburghii) using cement or magnesite binders because of lack of information of suitability of tropical hardwoods.

Among the binders, Portland cement is the most widely used material, as such boards are water resistant and can be used under outside conditions, Since setting of cement is a very sensitive process, some of the wood species do not make suitable boards with cement. Magnesium oxychloride, magnesite and gypsum have also been used as binders. Supply of industrial wood in general and coniferous wood in particular is not satisfactory in the country. The supplies of softwoods are limited in the Northern Himalayan and Sub-Himalayan ranges of the country. Because of demand of such species for local use such as packing cases for fruit, construction timber, and large scale requirement of these timbers for specialized uses such as in cooling towers, poles, railway sleepers, etc., the cost of softwoods especially chir has gone up very high making its use in wood wool boards manufacture difficult due to economic reasons. Because of transportation cost, the growth of this industry based on pines has been confined to the northern states, with virtually no unit operating in southern states.

Keeping this in view, in Forest Research Institute, Dehradun, timber species belonging to both softwoods (conifers) as well as hardwoods (angiosperms) were investigated. 47 materials in all, comprising 5 softwoods, 35 hardwoods (dicots), 1 monocot (palm), 2 forest waste materials (lantana and pine needles) and 4 agricultural residues (bagasse, rice-husk, rice-straw and wheat-straw) were chosen for investigations because of their commercial availability at low cost or as a waste material (Shukla et al., 1982; Shukla et al., 1984; Jain et al., 1989; Kumar, 1980).

Screening Tests of Materials

Among the various screening tests suggested by earlier workers, compressive strength tests on cylindrical bodies maximum rise and heat of hydration in wood-cement systems were found to be easily adoptable and at the same time capable of giving repeatedly uniform results. These tests were carried out with and without an accelerator. (Kumar, 1980; Jain et al., 1989; Shukla et al., 1984). All the softwoods except suji (Cryptomeria japonica) passed all the tests, with and without the accelerator. In addition 4 hardwoods viz., eucalypt (Eucalyptus camaldulensis), gurjan (Dipterocarpus griffithii), jarul (Laagerstroemia speciosa) and lampati (Duabanga grandiflora) passed all the screening tests. Another 12 hardwoods viz., amari (Amoora wallichii), axlewood (Anogeissus latifolia), benteak (Lagerstroemia lanceolata), champ (Michelia champaca), kuthan (Hymenodictyon excelsum), machilus (Machilus macrantha), needlewood (Schima wallichii), poon (Calophyllum elatum), semul (Bombax ceiba), toon (Toona ciliata), tula (Pterygota alata) and white cedar (Dyoxylum malabaricum) passed all the screening tests on addition of calcium chloride accelerator. Rice-husk also gave all positive indications for suitability on addition of accelerator.

Other 10 materials comprising anjan (Hardwichia binata), mango (Mangifera indica), irul (Xylia xylocarpa), kaim (Mitragyna parvifolia), kala siris (Albizia chinesis), kanju (Holoptelea integrifolia), padri (Sterospermum personatum), bagasse, lantana, rice-straw and wheat straw showed indications of suitability in one of the tests only and needful scale investigations.

Suji (Cryptomeria japonica), chaplash (Artocarpus chaplasha), eucalypt (Eucalyptus hybrid). gurjan, (Dipterocarpus turbinatus), haldu (Adina cordifolia), hopea (Hopea parviflora), kindal (Terminalia paniculata), mahua (Madhuca longifolia), silver oak (Grevillea robusta), teak (Tectona grandis), palymyara palm (Borassus flabellifer), and pine needles failed in all suitability tests.

Types of Boards and Compositions for Their Manufacture

The Indian Standard on wood –wool board IS:3308-1981 specifies two types of boards as follows:

Type 1: Light weight slabs, recommended as non-load bearing members to be used in partitions, ceilings, roof insulation, etc.

Type 2: Heavy duty slabs intended for use in roof construction. Such slabs can also be used for non-load bearing members.

Composition of the boards was so selected as to meet the weight requirement of Type-1, Light weight slabs and Type-II, Heavy duty slabs of the size 2m x ½ m x 2.5 cm and 2 m x ½ m x 4.0 cm respectively as specified in Indian Standard on wood –wool boad IS:3308-1981.

Proportion of the ingredients used in the preparation of Type-I and Type-II boards is as under, (Kumar,1980).

Type-I (size 2 m x 0.5 m x 2.5 cm):

Composition:

	Binder	6.0 kg
	Wood wool	3.5 kg
	Water or solution of the accelerator in water	Quantity absorption  by the wood-wool during 5 min. soaking in water or 2 per cent or 4 per cent solution of accelerator.

Type-II (size 2 m x 0.5 m x 4.0 cm):

Composition:

	Binder	12.0 kg
	Wood wool	7.0 kg
	Water or solution of the accelerator in water	Quantity absorption  by the wood-wool during 5 min. soaking in water or 2 per cent or 4 per cent solution of accelerator.

Suitability Tests of Wood-Wool Boards

The criterion for suitability of wood-wool boards is to meet the deflection requirements under specified loading conditions as per Indian Standard IS:3308-1981. All the four softwoods viz., chir (Pinus roxburghii), kail (Pinus wallichaiana), fir (Abies pindrow) and spruce (Piecea smithiana) passing all the screening tests gave satisfactory boards with cement and two grades of magnesite binders. Out of the four hardwoods tested, semul (Bombax ceiba), toon (Toona ciliata) and poplar (Populus deltoides) gave satisfactory boards with cement on addition of accelerator. The first two species did pass the screening tests only on addition of accelerator. Satisfactory boards were obtained with the above three species with magnesite binder, also Mango (Mangifera indica) which failed in the screening tests, also failed to give suitable boards. Poplar was an exception which gave very low heat of hydration but passed the compressive strength test and formed satisfactory boards with cement as well as magnesite (Shukla et al., 1981).

Other materials viz., lantana-cement, pine needles-cement, pine needles-magnesite, rice husk-magnesite and wheat straw-cement were not found suitable for making boards whereas rice husk-cement along with accelerator showed possibility for use.

Binding between lantana and magnesite also appeared to be satisfactory in preliminary trials. Wood fibres obtained from defibration of boiled wood chips also showed promise for developing board material similar to asbestos sheets (Kumar, 1980).

Wood-wool boards remain dimensionally stable under changing humidity conditions (Shukla et al., 1981). While under wet conditions, the strength decreases considerably and the original strength is regained on redrying the material. The boards were found to be good sound absorbers. These boards were, however, not found to be immune to termite attack in laboratory testing (Shukla, 1977a) but boards put under service trials did not show any incidence of attack during their approximately 3 years of usage. While pretreating wood-wool with inorganic preservatives impaired the strength development in boards (Shukla, 1977b), post treatment with prevalent preservative compositions such as copper-chrome-arsenic and copper-chrome-boron was not as effective as in case of wood (Shukla et al., 1981).

References

Bureau of Indian Standards. 1981. Specification for wood wool building slabs. (Specification No. IS:3308). New Delhi, Bureau of Indian Standards.

Development Association of India, 35(2):19-32.

Kumar, S. 1980. Development of wood –wool boards from indigenous forest materials. Dehradun, Forest Research Institute.

Shukla, K.S. 1977a. Preliminary investigations on the termite resistance of wood-wool boards. Journal of the Timber Development Association of India, 23(1): 21-23.

Shukla, K.S. 1977b. Effect of wood preservaties on setting of wood (chir) cement mixtures. Journal of the Timber Development Association of India, 23(2): 16-18.

Shukla, K.S.; Prasad, L; Bhalla, H.K.L. 1981. Anti-termite characteristics of treated wood-wool boards based on laboratory tests. Holzforschung and Holzverwertung, 33(6): 119-121.

Shukla, K.S.;. Jain, V.K;.Bhalla, H.K.L; Satish Kumar. 1981 Physical and mechanical properties of wood-wool boards, Part-1: Hygroscopicity and dimensional stability. Journal of the Timber Development Association of India, 27 (4): 41-45.

Shukla. K.S.; Agarwal, S.C; Satish Kumar. 1982. Studies on the suitability of toon and mango for the manufacture of wood-wool boards. Kumar, 28(3): 5-13.

Shukla, K.S.; Jain, V.K.; Satish Kumar. 1984. Suitability of lignocellulosic materials for the manufacture of cement bonded wood-wool boards. Journal of the Timber Development Association of India, 30(3): 16-23.

Food and Agriculture Organisation of the United Nations Promotion and Development of Non-Wood Forest Products (NWFP) is one of the priority areas of Food and Agriculture Organisation of the United Nation’s Forestry Department and encompasses many multidisciplinary projects. The website of organization, which is accessible in English, French, Spanish and Arabic, includes information on the work of the NWFP, and details of current activities, news, country profiles and publications. It also provides access to the electronic NWFP Digest, and links to related websites. Website: www.fao.org

---

A WOODEN SPORTS FLOOR

N. K. Upreti and Kishan Kumar
Forest Products Division, Forest Research Institute, Dehradun-248 006

Introduction

A floor of a building generally provides a wearing surface on top of a flat support structure. Its form and materials are chosen for architectural, structural and cost reasons. Wooden floors are generally used in light residential constructions or for indoor sports purposes. Such flooring generally consists of a finished floor of tongue and groove planking or strip installed on a sub-floor. The sub-floor is usually supported on beams that are commonly called joists. Joists are of the order of 5cm x 20cm dimensions and spaced at 40 to 60 cm distances. The wearing surface of such wooden floors can also be of vinyl tiles or hardwood flooring.

There are various types of wooden floorings viz. unfinished flooring which is a product that must be job-site sanded and finished after installation; pre-finished flooring is factory sanded and finished flooring that only needs installation; acrylic impregnated type is a pre-finished wood flooring product. Through a high-pressure treatment, acrylic and colour are forced into the pores throughout the thickness of the wood. The ‘finish’ is inside the wood, creating an extremely hard surface. These floors are highly resistant to abrasion and moisture and appeal most often to commercial customers but are also used residentially. Acrylic impregnated floors are available in the same styles as laminated floors; Laminated wood flooring is produced by bonding layers of veneer and lumber with an adhesive. Laminated wood flooring is available in pre-finished and unfinished forms. These products are more dimensionally stable and are ideal for glue-down installation or float-in installations, basements and humid climates. Solid wood floors have top floors consisting of wooden strips or planks. It is this type which was adopted to construct a sports court in the present case. Construction standards for classic timber floors according to Indian standards are given in IS:3670-1966.

Hard wood flooring is to be preferred for any sports court to take in the pressure it has to withstand during usage. Maintained properly, wood flooring should never have to be replaced. The practical problem with the top surface of a sports wooden floor would be the smoothening of the surface by continuous usage.

Plank and Strip Flooring

A strip floor is different from a plank floor in that they have different fastening and sub-floor requirements. In North America, tongue and groove strip floors in 5 or 8 cm width and 2 cm thickness is probably the most popular hardwood flooring. The most common species used in these parts is red oak. It is moderately durable and its contrasting grain pattern gives a textured look to the floor, which helps disguise scratches and wear and tear. Lengths of the strips are of the order of 91 cm, allowing a randomised joint arrangement. One needs to be careful in choosing the wooden material to be free from internal cracks.

A strip floor requires at least a 2 cm thick sub floor for the nails to be fully engaged. Though plywood might do the job a sub floor, wherever necessary and according to the strength requirements, a hardwood species itself can be chosen for the sub floor especially in heavy-duty floors. However, a softwood sub floor also would be sufficient. It is better to lay the hardwood floor at right angles to the floor joists. This will give a decided firmness to the whole floor.

Strip floors in the range of 1-1.25 cm thickness are also common. But such low thicknesses are to be avoided in tongue and groove jointing systems as they can be sanded only 2 or 3 times before they wear out. (The laminated plank or ‘engineered flooring’ is an exception to these thinner boards. But these have many unique features like having the capacity to get glued directly to concrete). As far as hardwood floorings are concerned, thicknesses of 2 cm and above are to be preferred.

Plank flooring is a very different concept. When 10 cm or wider boards are installed one must have at least a 2 cm thick sub floor (plywood or softwood) if the flooring planks are at right angles to the joists. But if these are going to be parallel to the joists, the sub floor thickness should be increased to more than 2.54 cm. Like strip floor it needs proper flooring nails (preferably every 20 cm) and because the nails are farther apart in this type of floor, screws would be a better choice. This will prevent warping and some of the gapping that occurs with these floors. The wider the boards the larger is the chances for gap formation between planks due to humidity changes.

Constructing a Demonstration Floor

A wooden sports floor of total surface area of 1, 040 sq. ft. was constructed at FRI campus for demonstration purpose. India has vast resources of Eucalyptus and works on its current utilization patterns and level of processing technology developed in the country have helped in projecting this species’ utilization in competition with that in other countries like Australia, Brazil and South Africa.

Using trusses design a total of five beams were made with a length of 14 m and width of 6 inch. These five members were fixed on the ground at equal distances along the length of the court. Above these beams, 24 joists of 5 cm x 10 cm x 6.8m size were clamped at equal distances apart along the width of the court. These joists were made out of eucalyptus hybrid and were seasoned to 12 per cent MC prior to installation.

Eucalyptus has reasonably good drying behaviour especially when modern sawing methods are adopted. Using a modification of quarter sawing a degrade-free recovery of almost 65 per cent could be achieved in the case of Eucalyptus hybrid after seasoning. This is in clear contrast with the deformation and discolouration exhibited by birch during drying (Luostarinen and Luostarinen, 2001). This also compares well with the good degrade-free drying behaviour of 23 mm boards of oriental oak (Du GuoXing et al., 2001)

The sub floor was constructed with Eucalyptus battens of size 2.54 cm x 3.18 cm. These were nailed at about 45 degrees to the joists and at about 2-3 cm apart. Eucalyptus was chosen for this purpose for its good strength properties and with a view to demonstrate the utilization of plantation grown species. The whole sub floor and the joists below were chemically treated on-site by a water-based compound using a spray machine in order to check termite attack.

Classic hardwood flooring is 1.9 cm thick, but 0.95 cm thick versions have been around for many years. In the present case, 20 mm thick flooring tiles made out of different species (eucalypt, toon, teak, etc.) seasoned to 12 percent MC were used for the top floor. The tiles were of uniform width of 10 cm and lengths ranging from 91 cm to 122 cm. The tiles were joined together using tongue and groove jointing system and were screwed to the sub-floor. The use of screws was preferred to nails as this would facilitate replacement of any damaged tiles.

Tongue and groove is a method of fitting similar objects together, used mainly with wood: flooring, panelling etc.Each piece has a slot (the groove) cut all along one edge, and small outcrop (the tongue) on the opposite edge. Two or more pieces thus fit together closely. The tongue was of approximately 7.5 mm length and 4.5 mm thickness. These tiles were prepared by four-side planer cum moulder

Fig. 1. Vertical cross section of a flooring strip showing tongue and groove arrangement.

Description of flooring strips

Length of flooring strips:                                                   91 – 122 cm

Width of flooring strips:                                                    10 cm

Thickness:                                                                         20 mm

Tongue and groove joints description

a :                    7-7.5 mm b :                    4-5 mm c :                    7-7.5 mm d :                    6.7-7.3 mm e :                    4.5-5.5 mm f :                     6.7-7.3 mm g :                    7-8 mm h :                    7.5-8.5 mm

The strength of a floor largely depends not only on the wood that is used. This also depends on the jointing system adopted. The other jointing system most popular is the end gluing system of joining. But it has been reported that this system is usually advisable only in the case of thinner flooring tiles (Elliot et al., 1999). The tongue and groove jointing system is far superior when one uses a standard and traditional floor of 20 cm or more thickness for the top floor as in heavy duty floors For this reason, tongue and groove jointing system was adopted in the construction of the present floor. The use of screws gives the opportunity for replacement of tiles without damaging the neighbouring tiles

Once the top floor was completed, it was coated with linseed oil twice with a gap of 12 hours for surface finish as well as for avoiding hairline cracks on the tiles during dry season.

	Fig. 2. A flooring tile showing tongue and groove.	Fig. 3. Two tiles joined.
	Fig. 4. Four tiles joined together using tongue and grove joints.	Fig. 5. Making of floor - stage 1.
	Fig. 6. Making of floor - stage 2 - Sub floor.	Fig. 7. Making of floor - stage 3 - top floor with tiles.

References

Du, Guo Xing; Cai, Jia Bin; Cao, Xiang. 2001. Drying technology for oriental oak flooring board, China Wood Industry, 15: 12-13.

Elliot, P.W.; Krutz, G.W.; Hodge, M.; Lorett, B. 1999. Evaluation of sports surface system strength: A comparison of engineered flooring strip and traditional tongue and groove random length flooring strips. In: ASE/CSAE-SCGR Annual International Meeting, Ontario, July 1999. Proceedings. The author. pp. 18-21.

Luostarinen, K.; Luostarinen, J. 2001. Discolouration and deformations of birch parquet boards during conventional drying, Wood Science and Technology, 35: 517-528.

---

WOOD PRESERVATION RESEARCH IN FRI : EARLY SCENARIO AND CURRENT TRENDS

Sadhna Tripathi
Forest Product Division, Forest Research Institute, Dehradun-248 006

Despite the advent of other modern metallic materials, wood continues to play an important role in man’s day-to-day life. It is only because of its superior qualities and versatile nature that it still enjoys a superior position as industrial and consumer raw material. In modern society, everyone thinks that wooden products are matchless due to their appearance and durability. Handicraft items, furniture and other products made of wood, specially heart wood of durable species, have specific colour and grains, and articles made of it remain as such for years,. But as there is a shortage in supply of durable wood, people are forced to use non-durable wood. Non-durable woods are mostly plantation grown on short rotation basis. Although they yield faster but the quality is poorer as compared to durable wood. This problem can be solved or overcome by wood preservatives and in the era of agroforestry, wood preservation has attained prime importance. Wood preservation not only imparts adequate life or enhances life 5-8 times but also locks carbon for longer duration, thus reducing greenhouse effect indirectly (Rana et al., 2003). Now preservation is essentially a science in diverse spheres of life and in the field of wood utilisation it has a greater role to play, which could not be visualised in the past. However, the history of preservation dates back to Egyptian era (2000-400 B.C. mummifying using metallic salts and oils) followed by Chinese, who used seawater to preserve structural timber.

Wood preservation practices in India date back to prehistoric times, and on scientific lines Sir Ralph Pearson introduced it in 1908. The next stage in the development of wood preservation in India goes to the credit of S. Kamesam, who gave world’s best known wood preservative of today i.e. CCA. This was patented under the name of ASCU in 1933 later on he developed copper-chrome-boric composition named CCB in 1943.

Kumar (1990) and Dev et al. (1990) started work on modern lines of development. Preservative with higher efficacy, new treatment technologies for wood species, suitable for rural sector and treatability classification of wood on the basis of distribution of preservatives in different cell types are important aspects on which they worked. A methodology to treat green timber was developed (Kumar and Dev, 1993). Extensive field trials to protect bamboo during storage was done (Kumar and Dobriyal, 1990). Several other aspects like permeability, metallic chelates using chir pine resin, cashew nut shell liquor and other naturally occurring resins were developed to replace costly organic solvent type metallic nephthenates preservatives (Purushotam and Tewari, 1958, 1961; Shukla and Tewari, 1970; Shukla et al., 1972).

About thirty years back environmental concerns regarding wood preservatives were virtually non-existent but now heavy metals like arsenic and chromium have undergone, the closest environmental scrutiny spurring effects to replace / reduce their use in waterborne systems. World over research is continued to develop methods for preservation of wood which are eco-friendly and are non-polluting. In India new reagents thioacetic acid has yielded a dimentionally stable, termite and decay resistant wood with improved mechanical properties. Acetylation of wood with acetic anhydride in vapor phase followed by post treatment with aniline solution in xylene has shown excellent results (Singh et.al, 1992, 1997). Another preservative, which has come out very well is copper zinc borate, which was impregnated with double treatment (Rawat and Dev, 2000). But it was difficult to assign any fixed composition to the preservative and reasons were not given for higher leachability of few compositions. Another disadvantage was that double treatment increased cost. Hence, a fixed composition ‘ZiBOC’ has been made and is under field trial (Tripathi et al., 2005). The advantages of the preservative is that it has a fixed composition, single treatment is required and field data show complete protection of wood at very low retention i.e. 3 kg/m3 against control. Regarding cost, it is cheaper than CCA. Hence, it may be tested under most hazardous conditions like cooling towers or marine water to compete and replace CCA. Another preservative copper-lignin A&B was developed from black liquor, an industrial waste of pulp and paper industry and is giving very encouraging results in field trials (Tripathi and Dev, 2003 a & b).

Several biocides of natural origin were also studied for wood protection. Extractives of several durablewood or chemicals derived from natural materials have been examined. Wood of Shorea robusta exhibited excellent results in protecting non-durable wood (Gupta and Dev, 1999).Work on leaf of Ipomoea carnea also concluded that leaf extract can be used for protection of wood and wood products for preventing termite attack (Saxena and Dev 2002). Responsible components were also isolated and characterised (Saxena, 2003). Work on similar lines, utilising neem leaf and oil extractives has been initiated in FRI (Dhyani et al., 2004). Few extractives were found very effective against wood decaying fungi and termites in laboratory trials. Work on oil derivatised products also revealed high protection of non-durable soft and hardwood against termites (Dhyani et al., 2005).

Success of any preservative is also dependent on the depth and distribution of preservative within the wood. Considerable basic work has been done on the effect of ponding, pre-steaming etc. on subsequent preservative uptake and found to improve treatability (Singh et al., 1981a, b). Soaking/hot and cold method with ACA and ACB solution has shown its versatility to treat refractory timbers (Dev et al., 1991). Similarly bamboo is non-durable and needs preservative treatment. It is generally treated by dip diffusion, sap displacement and modified Boucherie techniques. All techniques involve sap displacement. A new method of green bamboo treatment has been developed by FRI Dehradun viz. VAC-FRI (Tripathi and Dev, 2004) which is very fast, easy to operate and involves lower treatment cost. The method is comparable to already known methods. It is the first method reported which works on vacuum operation and gives adequate and uniform retentions of preservative throughout the length of bamboo.

Future needs:

1. Creation of more and more treatment facilities;

2. government departments should evolve some strategy for mandatory use of treated wood;

3. extension and demonstration of already developed technologies to create awareness;

4. more funds should be provided for research to find out new possibilities;

5. proper representation of expertise from forestry fields in all forums of national scientific organizations like CSIR, DST, DBT, etc. to generate funds;

6. research and development on usage of eco-friendly wood preservative should be geared up;

7. small packages on usages of treatment technologies/preservatives should be available/promoted in rural, small scale industry sector;

8. a group research working on problems of wood industry and research and development may be formed for frequent interactions and exchange of views.

References

Dev, I.; Pant, S.C.; Chand, P.; Kumar, S. 1991. Ammonical copper-arsenite – a diffusible preservative for refractory wood species like Eucalyptus. Journal of the Timber Development Association of India, 37(3): 12-15.

Dev. I.; Pant, S.C.; Chand, P. 1990. Ammonical copper-arsenate: A diffusible preservative for refractory wood species. Journal of the Timber Development Association of India, 37(3): 12-15.

Dhyani, S.; Tripathi, S.; Dev, I. 2004. Preliminary screening of neem Azadirachta Indica leaf extractives against Poria monticola wood destroying fungus. Journal of the Timber Development Association of India, 1(1-2): 103-112.

Dhyani, S.; Tripathi, S.; Jain, V.K. 2005. Neem leaves a potential source for protection of hardwood against wood decaying fungi. In: 36th Annual Meeting of the International Research Group on Wood Protection, Bangalore, 24-28 April 2005. Papers. The author.

Dobriyal, P.B.; Kumar, S. 1999. Treatability classification of five heartwood based on penetration indices. Journal of the Timber Development Association of India, 45(1-2): 43-47.

Gupta, P.; Dev, I. 1999. Studies on the fungicidal toxicity of sal (Shorea robusta) heartwood extractives. Journal of the Timber Development Association of India, 45(1-2): 16-24.

Kumar, S.; Dev, I. 1993. Wood Preservation in India. Dehradun, Indian Council of Forestry Research and Education. 263 p.

Kumar, S.; Dobriyal, P.B. 1990. Management of biodegradation of timber logs and bamboos during storage: A review for Indian condition. Journal of the Timber Development Association of India, 36(4): 5-14.

Kumar, S. 1990. Status of wood preservation research and industry in India. In: 19th IUFRO Congress., Montreal, 5-11 August 1990. Proceedings. The author.

Purushotham, A.; Tewari, M.C. 1958. A note on metallic resonates as wood preservatives. Journal of the Timber Development Association of India, 4(4): 19-21.

Purushotham, A.; Tewari, M.C. 1961. A preliminary note on the preparation of copper and zinc preservatives from cashew shell liquor. Journal of the Timber Development Association of India, 7(3): 8-10.

Rana, A.K.; Tripathi, S.; Dev, I. 2003. Role of wood preservation in carbon locking. Indian Forester, 129(6): 707-713.

Rawat, G.S.; Dev, I. 2000. Studies on ammonical zinc borate as an eco-friendly wood preservative. Journal of Timber Development Association of India, 46(1-2): 36-40.

Saxena, P. 2003. Studies on biodical effect of extractives of Ipomoea carnea vis-à-vis wood protection. Ph.D.Thesis, FRI Deemed University, Dehradun.

Saxena, P.; Dev, I. 2002. Preliminary studies on termite resistance of water extracts of Ipomoea spp. Journal of the Timber Development Association of India, 48(1-2): 12-15.

Shukla, K.S.; Jain, V.K.; Tewari, M.C. 1972. A note on the preparation of copper and zinc preservatives from Bhillawan nut shell liquor. Journal of the Timber Development Association of India, 18(2): 27-30.

Shukla, K.S.; Tewari, M.C. 1970. Pilot plant scale preparations of copper resinate. Journal of the Timber Development Association of India, 16(3): 2-4.

Singh, D.; Dev, I.; Kumar, S. 1997. Termite and fungal resistance of chemically modified wood. Journal of the Timber Development Association of India, 43(3): 27-34.

Singh, D.; Dev. I.; Kumar, S. 1992. Chemical modification of wood with acetic anhydride. Journal of the Timber Development Association of India, 38(1): 5-8.

Singh. B.; Tewari, M.C. 1981 a. Studies on the treatment of green bamboos by different diffusion processes. Part-I, Dip diffusion of Osmos process. Journal of the Timber Development Association of India, 27(1): 36-41.

Singh, B.; Tewari, M.C. 1981b. Studies on the treatment of green bamboo by different diffusion processes part-II. Steaming and quenching and double diffusion. Journal of the Timber Development Association of India, 27(2): 38-46.

Tripathi, S.; Bagga, J.K; Jain, V.K. 2005. Preliminary studies on ZiBOC- a potential eco-friendly wood preservative. In: 36th Annual Meeting of the International Research Group on Wood Protection, Bangalore, 24-28 April 2005. Papers. The author.

Tripathi, S.; Dev, I 2003b. Patent: New efficacious eco-friendly wood preservative: Lignin copper complex A & B ; filed PAT/ 4.19.14/03046/2003.

Tripathi, S.; Dev, I. 2004. VAC-FRI technology for treatment of green bamboo. Patent NRDC No. 962/DEL/2004.

Websites British Wood Preserving and Damp-Proofing Association http://www.bwpda.co.uk/ The British Wood Preserving and Damp-Proofing Association, founded in 1929, is the largest association of its kind in Europe, and is the nationally recognised authority on timber and damp problems. It sets high standards for its members in technical competence, health, safety and environmental protection and customer service. The members of the association provide answers to a wide range of problems. CSIRO Forestry and Forest Products http://www.ffp.csiro.au/ CSIRO Forestry and Forest Products is the largest single organisation in Australia conducting research into forestry, wood and paper science. Its Web pages, part of the larger CSIRO site, describe the Division, its staff and activities, including research and consultancy services. A ‘News and Events’ section includes an online newsletter ‘Onwood’ and media releases, some downloadable in PDF. The ‘Technical Information’ section provides a direct link to the CSIRO Forestry and Forest Products Library Web site, which give access to its online catalogue. Forest and Wood Products Research and Development Corporation (FWPRDC) http://www.fwprdc.org.au/ FWPRDC provides a national, integrated research and development focus for the Australian forest and wood products industry. Furniture Industry Research Association (FIRA) http://www.fira.co.uk/ The site provides information about FIRA, and its membership, and the services it provides. A searchable index of FIRA publications provides full-text access to free publications, and abstracts of publications which members only can access in full-text. The site also provides news items, access to the FIRA newsletter, and an events calendar. The site search facility allows searching for FIRA members and suppliers of furniture and related products. Indian Plywood Industries Research Institute (IPIRTI) http://www.ipirti.com/default.htm IPIRTI is an autonomous body of the Government of India, Ministry of Environment and Forests. Research areas of the Institute include plywood, solid wood, wood-based composites, non-wood composites, bamboos and wood preservation. Other activities include the assessment of new technologies, training, standardisation and publication of research notes and reports. International Research Group on Wood Preservation (IRG) http://www.irg-wp.com/ The IRG was launched in 1969 as an independent research group. IRG now has over 300 members in 49 countries, comprising scientists with common research interests in wood preservation and biodeterioration, with its secretariat based in Sweden. The IRG holds annual conferences at which the various working parties (Biology, Test Methodology and Assessment, Wood Protecting Chemicals, Processes and Properties, and Environmental Aspects) present papers (IRG Documents). These can be ordered online for a fee. In addition, abstracts of some of the documents, various newsletters, lists of documents and details of reports can be downloaded from the site in PDF. Information about past and forthcoming conferences is also available. International Wood Products Association http://www.iwpawood.org/ Founded in 1956, the International Wood Products Association (formerly the International Hardwood Products Association) is the only association in the United States committed to the promotion and enhancement of trade in the imported hardwood and softwood products industry.

---

BAMBOO PRODUCTS – TECHNOLOGY OPTIONS

C.N. Pandey
Indian Plywood Industries Research and Training Institute, Bangalore-560 022

Introduction

The increasing needs of growing population and environmental awareness have put severe restrictions on management of forest resources in India. This has resulted in shortage of wood required in housing, transport and other sectors. Several non-wood alternatives like metal and plastics also have serious limitations on account of non-sustainability, high-energy requirements and non-bio-degradability. In this situation there is an urgent need for development of sustainable and environment friendly wood alternatives. Bamboo, a fast growing giant grass, found in abundance in India and several other countries in tropics as well in subtropical and temperate regions, except Europe, is emerging as a highly potential natural and renewable material to fill the void.

India has the second largest resource of bamboo both in terms of diversity and distribution (about 13 per cent of the forests or approx. 10 m ha.). India accounts for around 120 of 1, 250 species of bamboo found in the world. Of this, only 30 species are commercially important. Apart from being available in natural forests bamboo is also raised as plantations, both pure and in mixture, and also in homesteads. Bamboo is also suitable for restoration of degraded forest and other wastelands as well as of abandoned shifting cultivated areas.

Bamboo, a fast growing, quick – maturing woody grass is an important cultural feature in many parts of India. Since the beginning of the civilization bamboo has played an important part in daily lives of people in India. Bamboo craft is one of the oldest cottage industries primarily due to versatility, strength, lightness, easy workability of bamboo with simple hand tools. Bamboo has been put to use for various applications ranging from construction to household utilities and have more than 1, 000 documented uses including an important industrial use in paper and pulp manufacture. Due to plethora of essential uses, it has been aptly described as ‘poor man’s timber’, ‘green gold’, ‘friend of people’, ‘the cradle to coffin timber’, ‘green gasoline’, etc.

Relevance of Bamboo Based Panels

Since 1980s, guided by dwindling wood supplies in the tropics, interest on bamboo as a alternative material has intensified resulting in its emergence as potentially the most important non-wood renewable fibre to replace wood in construction and other uses. (Bansal and Damodaran, 1999). The realization that bamboo produces wood biomass faster than many fast growing timber and that some of its physical and mechanical properties are superior to wood available from fast growing plantation species like eucalypt, poplar, acacia, has evoked keen interest in bamboo growing countries and elsewhere on theoretical and applied research on bamboo based products to replace wood in housing, furniture, packaging, transport sectors, etc. (Bansal, 2000). Some earlier studies have revealed that bamboo in panel form is best suited to substitute wood and, therefore, development/refinement of cost effective technologies to produce bamboo based panels is now identified as an extremely important area of research. The environmental and socio-economic implications of bamboo based panel industries also favour their promotion on priority. (Yee et al., 1948; Narayanamurthi and Bist, 1953).

Classification of Bamboo Based Panels

Bamboo based panels can be broadly classified into three groups:

          Bamboo mat composites

1. Bamboo mat board (BMB)

2. Bamboo mat veneer composites ( BMVC)

3. Bamboo mat corrugated sheet (BMCS)

4. Bamboo mat moulded trays (BMMT)

Strip based composites

1. Bamboo curtain board

2. Bamboo strip board (or) bamboo plywood

3. Laminated floor board

4. Parallel glulam

5. Parallel cured gluccam

6. Bamboo net board or bamboo block board

7. Bamboo ‘Zephyr’ board or bamboo ‘Semi fibre’ board

8. Bamboo moulded shuttle

9. Bamboo picking stick

Table 1. Panels based on culms converted into particles, strands and fibre.

	Particles	Strands	Fibre
			Fibre board	Medium density fiber (MDF)
	Particle board bonded with synthetic resins mineral binders	Oriented  strand  board  (OSB)	1. Insulation board 2. Hard board by dry process and  wet process

 In addition to above, technologies are available based on bamboo strips. They are given below:

Stick based products

         1. Agarbathi sticks

         2. Tooth pick

         3. Ice cream sticks

         4. Match splints

Technologies Developed at IPIRTI

The following are the technologies developed at IPIRTI and some of which have already been commercialised and some are in pipeline.

Bamboo mat board

Use of any new material depends upon its suitability for various applications vis-a-vis the materials already in use. Development of appropriate application technology plays an important role in acceptance of any new material. BMB is essentially a layered composite comprising several layers of woven mats having excellent internal bond strength, and are resistant to decay, insects and termite attack. They have physical and mechanical properties at par with waterproof plywood and are fire resistant. Their mechanical properties depend upon the material used for making mats, i.e. bamboo slivers, the weaving pattern and the adhesive used for bonding (Indian Plywood Industries Research and Training Institute, 1983).

However, these properties can be altered by changing the weaving pattern of bamboo slivers used in mat making used for making board in order to get required values for modulus of rigidity (MOR), MOE, tensile strength, etc. (Indian Plywood Industries Research and Training Institute, 1993). Thus, it can be inferred that the strength and stiffness of BMB is related to the weaving pattern of the mats. However, MOR or shear modulus of BMB in the plane of the board is very high and is comparable to the required values for structural plywood as per Indian specifications IS: 10701. It is interesting to note that MOR of BMB far exceeds that of both structural plywood and wood. This is attributable to the herringbone weave pattern. Clearly, BMB has high in-plane rigidity and hence high racking strength and is more flexible than equivalent plywood. (Bamboo Mat Board, 2000; Bansal and Zoolagud, 1999; Zoolagud and Rangaraju, 1991; 1993). This property of BMB can be advantageously used in many engineering applications. In fact, BMB has been found to be especially useful as sheathing material in structural and semi structural uses such as walling, partitions, roof sheeting (Damodaran and Jagdeesh, 1993)., door skins, box furniture, built up hollow beams, gussets, containers (Jagdeesh et al., 1998). Investigations have also been undertaken at the IPIRTI regarding suitability of BMB for manufacture of secondary parts of aircraft and gliders as substitute for speciality plywood made from Dysoxylum malabaricum and Palaquirn ellipticum (Naidu et al., 1998).

BMB meets all the requirements prescribed in the relevant Indian specifications and has in fact much higher cross sectional shear strength compared to plywood (Indian Plywood Industries Research and Training Institute, 2000).

Bamboo mat veneer composite

In BMVC, wood veneers are placed in between the layers of bamboo mats. The properties of BMVC depend upon the mechanical properties of wood veneers that are placed in between bamboo mat layers, in addition to the properties of the bamboo mats and the adhesives used in bonding.

Investigations have shown that strength of a panel made by plantation timber is substantially enhanced when made in combination with bamboo mats. MOE and MOR of BMVC are higher than equivalent plywood and this depends on the number of layers of veneers for a given thickness of BMVC. Due to the presence of woven bamboo mats, BMVC has different mechanical properties along and across the length of the board

The properties are comparable to that of structural plywood. Hence for all practical purposes BMVC can be used in a similar way to plywood for structural applications. BMVC will be economical in higher thickness as compared to BMB.

Bamboo mat moulded products

Considering the flexibility of bamboo mats due to ‘Herringbone’ weave pattern, an idea was mooted to produce moulded products like trays in various forms like rectangular and round, as well in different sizes. A process was developed, including the moulds, to produce such products get them in finished form which can be subsequently finished with coating materials to enhance the appearance and acceptability by the consumers. The moulded products like trays, were found to be highly durable and leak proof which can be conveniently used for various applications like the ones based on metals, plastics etc. The technology for the manufacture of bamboo mat tray has been transferred to two units: one in Pune and the other in Bangalore.

Bamboo mat corrugated sheets

The idea of development of corrugated sheets was a result of development of bamboo mat moulded products like trays to enhance stiffness for the BMB developed through corrugation techniques. Roofing materials such as asbestos cement corrugated sheeting (ACCS), corrugated fiber reinforced plastics (CFRPs). Corrugated aluminum sheeting (CAS) and corrugated galvanized iron sheeting (CGIS) which have been established for more than several decades, are being subjected to scientific scrutiny on several counts, including their impact on workers’ health and environment, the energy requirement for their manufacture, and sustainable supply of raw materials. Of late, priority is being given and rightly so to ‘green’

---

Table2. Strength properties of BMCS in comparison with other existing roofing sheets.

		Thickness	Width	Max load	Load bearing capacity	Weight of sheet
		(mm)	(mm)	(N)	in (N/mm)	(2.44 x 1.05m)in kg.
	BMCS (4 layers)	3.7	400	1,907	4.77	9.78
	GI Sheet	0.6	400	1,937	4.84	10.43
	Aluminium Sheet	0.6	405	669	1.67	3.92
	ACCS	8.0	330	1,880	5.45	21.50

building materials, based on renewable resources. Scaling up of the pilot scale technology for its industrial adoption has been successfully carried out under a project funded by Ministry of Environment and Forests, Govt. of India. The shape and area under the load-deflection curves (Fig.1) of various corrugated roofing materials, namely BMCS, ACCS, CGIS and CAS, clearly bring out the comparative advantage of BMCS over other corrugated materials. The comparative strength properties of BMCS with other existing roofing sheets are given in Table 2. Bureau of Indian Standards has brought out a standard on the specification of bamboo mat corrugated sheets for roofing (Bureau of India Standards, 1999).

A few demonstration structures have been put up in several parts of the country by utilizing BMCS developed and produced at Institute pilot plant. The process of BMCS has been standardised and the plant has been commissioned for commercial production of BMCS. Commercially available coating compositions have also been evolved to ensure the durability of BMCS. Some demonstration structures are under observation and it is reported that the demand for such sheets are steadily increasing presumably based on the advantages over their counterparts. A joint patent with BMTPC has already been applied for.

Bamboo Matchsticks

Development of appropriate process for manufacturing matchsticks from bamboo had also been taken up under a project in collaboration with INBAR. Matchstick making from bamboo is highly relevant due to the scarcity of timbers generally used for this purpose. The lops and tops of the bamboo left over in the handicraft sector can also be used for

Fig. 1. Load bearing strength of BMCS.

making match splints and also the top portion of the bamboo which is discarded in mat making activity can be made use of for match splints. A special treatment is given to improve the burning property. Waxing and head fixing formulations are similar to that of wooden matchsticks The technology developed can replace wooden match splints and the cost of the final product will be cheaper by 20 – 25 per cent. A joint patent with INBAR has already been applied for.

Bamboo mat overlaid particle board

Processes have been developed for overlaying wood/rice husk particle boards with bamboo mats. The overlaying is found to improve physical and mechanical properties of the boards as well as the appearance. The bamboo mat overlaid particle boards may be suitable even for semi-structural applications. The results obtained from bamboo mat overlaid wood particle board in comparison with the data on wood particle boards indicated that water absorption and swelling properties of bamboo mat overlaid wood particle board improved considerably enhancing the durability of such panels even under adverse climatic conditions. Mechanical strength properties of wood particle board increased considerably due to bamboo mat overlaying, eg. MOR over 150 per cent, MOE over 65 per cent and screw holding power by around 50 per cent suggesting the utilisation of BMWPB for enlarged end use applications. Water absorption and swelling properties of BMRHP improved over 100 per cent indicating the durability of such panels even under adverse climatic conditions. Mechanical strength properties of RHPB increased considerably due to bamboo mat overlaying, e.g. MOR: over 115 per cent; MOE: over 60 per cent; screw holding power by 60 per cent suggesting the utilisation of BMRHB for enlarged end use applications.

Bamboo wood

Development of appropriate technologies for the manufacture of both horizontal and vertical laminates using synthetic resin like UF, MUF and PF resins have been developed. Design and development of machinery for exerting side pressure for making laminates has also been made. Preliminary tests carried out on these laminates shows that it is superior to plantation timbers. End use application such as furniture, other household component and flooring have been developed and put to use.

Bamboo strip board

Laboratory scale technology has been developed to make bamboo strip boards from bamboo strips under institute project. The developmental work was limited to laboratory scale of size 45 x 45cm. The panel developed poses high strength, stiffness and rigidity. It is characterised by resistance to deformation, abrasion and weathering. Its bending strength properties are superior to wood panel and therefore application potential, particularly as platform boards, vehicle platforms, transport floorings, etc., are envisaged.

Conclusion

The bamboo based composite technology has attracted attention of a number of entrepreneurs and few industries have already been set up in the country. However, positive policy and technological initiatives

are necessary to accelerate the use of bamboo mat composites including encouraging their use in public sector where currently wood is banned, development of application techniques for various end products evolution of code particularly in housing, construction, transport and dissemination of information about their utility through demonstration and exhibitions.

Considering the vast social and environmental implications and employment potential, a policy thrust at national level is necessary for development of bamboo resources in general and promotion of bamboo composites in particular. As a first step, government has already given a favourable push by exempting bamboo composites from excise duty. Eco-labeling of the products will also help promote exports.

Every new technology requiring further processing to manufacture end products requires continued R&D support during its commercialisation to solve problems which may come up during transfer of technology from lab to factory. The technologies for BMB, BMVC, BMCS and bamboo-based housing are no exception to this. In fact, they need such support even more due to natural variation in the characteristics of the main raw material, bamboo, associated with different species available in different areas/regions and different level of skills in bamboo mat weaving in various tribal/rural groups.

References

Bamboo Mat Board. 2000. Projects around the world of Expo 2000, Vol. 2. International projects. Hannover, EXPO 2000. pp. 738-739.

Bansal, A. K. 2000. Project preparation and appraisal for bio-mass-based industry. In: Training Program on Industrial Project Preparation and Appraisal with Special Focus on Building Materials Sector, Ahmedabad. (Unpublished)

Bansal, A. K.; Damodaran, K. 1999. Wood products research in India: A perspective for the next decade. Wood News, 9(1): 8-12.

Bansal, A.K.; Jagadeesh, H.N.; Guruva Reddy, H. 2001. Bamboo based housing system. In: National Seminar on Waves of the Future – Civil Engineering in the 21st Century, Bangalore, 2001. Seminar document. The author. pp. 25-28.

Bansal, A.K.;.Zoolagud, S.S. 1999. Bamboo based composites ck ground In: All India Seminar on Bamboo Development, New Delhi, 1999. 15p. (unpublished).

Bureau of Indian Standards. 1994. Bamboo mat board for general purposes. (Specification No. IS: 13958). New Delhi, Bureau of Indian Standards. 8p.

Bureau of Indian Standards. 1999.Bamboo mat veneer composites for general purposes. (Specification No. IS: 14588). New Delhi, Bureau of Indian Standards. 8p.

Damodaran, K.; Jagadeesh, H.N. 1993. Potential applications of bamboo mat board. In: National Workshop on Bamboo Mat Boards, Bangalore, 1993. Proceedings. The author. pp 22-26.

Ganapathy, P.M.; Huan-Ming, Z.; Zoolagud, S.S.; Turcke, D.; .Espiloy, Z.B. 1999. Bamboo panel boards: A state of the art review. INBAR. 115p.

Narayanamurthi, D.; Bist, B.S. 1963. Building boards from bamboo. Indian Forest Records, New Series, Composite wood, 1 (2):48.

Indian Plywood Industries Research and Training Institute, Bangalore. 1983. Development of improved and new products from bamboo mats,. The author. 100p.

Indian Plywood Industries Research and Training Institute, Bangalore. 1993. Bamboo mat board (India) . The author. 188p.

Indian Plywood Industries Research and Training Institute, Bangalore. 2000. Wood substitutes. The author. 105p.

Indian Plywood Industries Research and Training Institute, Bangalore. 2001. Status of bamboo housing technology developed at IPIRTI. The author. 13p.

Jagadeesh, H.N.; Guruva Reddy, H.; .Bansal, A.K. 1998. Affordable and earthquake resistant houses from bamboo. In: International Workshop on Engineered Bamboo Housing for Earthquake Prone Areas, Dehradun, 1998. Proceedings. The author.

Naidu, M.V; Shyamsundar, K.; Aswathanarayana,, B.S. 1998. Suitability of bamboo mat board for secondary structural parts of aircrafts and gliders. Journal of the Aeronautical Society of India, 5: 35-38.

Yee, C. F.; Lo, C. H.; Wang, C. B. H. 1945. Plybamboo. Burma Aeronautical Research., Chengtu, 26: 52.

Zoolagud, S.S.; Rangaraju, T.S. 1991. An improved and economical process for manufacture of bamboo mat board. In: International Bamboo Workshop,4th, Changmai, 1991. Proceedings. The author. pp.1-4.

Zoolagud, S.S.; Rangaraju, T.S. 1993. Bamboo mat board manufacture. In: National Workshop on Bamboo Mat Board, Bangalore, 1993. Proceedings. The author. pp. 1-10.

The Forest Stewardship Council The Forest Stewardship Council (FSC) is an independent, non-profit, non-governmental organisation. It is an association of members founded by a diverse group of representatives from environmental and social groups, the timber trade and the forestry profession, indigenous people’s organisations, community forestry groups and forest product certification organisations from around the world. Membership is open to all who share its aims and objectives. The website of FSC deals comprehensively with certification issues in the UK, offering detailed fact sheets, lists of approved certifiers, forests, suppliers and products. International principles and criteria are described and the full text of the UK National Standard is given. Press releases, a newsletter and links are included, together with membership details. Website: www.fsc-uk.info

---

PROCESSING OF BAMBOO FOR EFFICIENT UTILISATION

V.K. Jain
Forest Products Division, Forest Research Institute, Dehradun-248 006

Introduction

Bamboo is a fast growing renewable forest based resource. It is the single most important forest produce used by mankind. High strength-weight ratio, easy workability and comparative cheapness together with availability in abundance and short period of maturity (about 4 to 5 years) are the reasons for its popularity for diverse purposes. It is used both in the round and split form. Some of the prominent uses are in housing, scaffolding, ladders, agricultural implements, tool handles, sticks, fencing sports goods, fishing industry, basket and box making, pulp and paper industry and for producing beautiful handicraft items. In housing, it has been reported to have been used in foundation, frames, floors, walls, partitions, ceilings, doors and windows, roofs, pipes, troughs and for reinforcement in cement concrete. In a circular cross section, bamboo is generally hollow and for structural purposes this form has many advantages in comparison to rectangular and other solid cross sections. It has a low natural durability so it is amenable to attack by wood decaying fungi and insect pests. In addition, it is also susceptible to mechanical degrade due to splitting at the nodes, collapse and deformation during drying in the round form. It has gained renewed importance in the present day context of shortage of wood due to its fast growing character. In view of all these, it is necessary to evaluate its physical and mechanical properties, classify and grade it for structural and other uses, work out its safe working stresses and develop appropriate processing technology for its efficient utilisation. The results of various studies carried out at Forest Research Institute, Dehradun on different strength aspects of bamboo, its classification, grading, safe working stresses, methods for its seasoning and preservative treatments are summarised in this paper.

Classification of Bamboo for Structural Use

The strength properties of green and air dry condition of 20 species of bamboo tested in round form have been studied. The mean values and ranges of specific gravity (P) and ultimate bending and compressive strength (MOR and MCS) of bamboo vis-à-vis those of wood in green condition are given in Table 1 (Rajput et al., 1991).

Table 1. Specific gravity and bending and compressive strengths of bamboo and wood in green condition.

		P		MOR (kg/sq.cm)		MCS (Kg/sq.cm)
		Mean	Range	Mean	Range	Mean	Range
	Bamboo	0.639	0.515-0.817	559	172-986	401	262-539
	Wood	0.579	0.184-0.976	669	136-1323	334	61-893

An overall classification of bamboo for structural purposes has been attempted on the basis of MOR, MOE and MCS of bamboo tested in green condition (Table 2), different species of bamboo have been classified into three groups based on limits of the above three properties. The limits have been fixed keeping in view the corresponding limits for wood and spread of ultimate bending and compressive strength of bamboo vis-à-vis wood.

Table 2. Classification of bamboo for structural purposes.

		MOR (kg/sq.cm)	MOE (kg/sq.cm)	MCS (kg/sq.cm)
	Group I	700	90	350
	Group II	500-700	60	300
	Group III	300-500	30	250

On this basis sixteen species of bamboo out of those tested so far are classified in the following manner :

Group A: Bambusa glaucescenes (syn. B. nana), Dendrocalamus strictus, Oxytenanthera abyssinica.

Group B: Bambusa balcooa, Bambusa pallida, Bambusa nutans, Bambusa tulda, Bambusa auriculata, Bambusa burmanica, Cephalostachyam pergracile, Melocanna bacciferfa, Thyrosostachys oliveri.

Group C: Bambusa ventricosa, Bamusa vulgaris, Dendrocalamus longispathus, Bambusa bambos (syn .B.arundinacea).

Safe Working Stresses

For structural designing in bamboo, the average strength factors estimated from the laboratory test results cannot naturally be directly employed. For this purpose safe working stresses are required to be used. Safe working stresses are evaluated by applying factors of safety for variability, long-term loading, accidental overloading, location of use and grade on strength factors obtained from the laboratory testing. These factors of safety have been developed on the basis of different studies on properties of bamboo and thus safe working stresses for different species have been evaluated. Minimum safe working stresses for the three groups of species are given in Table 3.

Table 3. Minimum safe working stresses.

		Extreme fibre stress in bending  (kg/sq.cm)	Stiffness  (1000 kg/sq.cm)	Maximum compressive stress (kg/sq.cm)
	Group A	175	20	100
	Group B	125	14	85
	Group C	75	7	70

Factors Affecting Strength

Important factors affecting strength of bamboo viz. locality of growth, age of culm, position within culm, external diameter and wall thickness, position of node and moisture content have been studied. It has been found that strength varies with locality and in certain cases strength of a species from a locality may be even twice that from another locality. Strength increases with age indicating average mechanical maturity around five years. With increase in diameter of bamboo strength falls exponentially. Within the wall thickness, outer portion is stronger than the core. Specimen with node in centre has better bending strength than centre inter-node while compressive strength with node is more than without node. With decrease in moisture content, strength of bamboo increases and there is fibre saturation point at about 25 per cent m.c. Dry bamboo is one and half times stronger than green bamboo (Limaye 1952; Shukla et al., 1988; Rajput et al., 1992).

Grading of Bamboo

Grading is sorting out bamboos on the basis of several characteristics important for utilization. The main characteristics are : 1. dimensions of culm, 2. taper of culm, 3. straightness of culm, 4. international length, 5. wall thickness, 6. density and strength and 7. durability and seasoning. Individual characteristics or sometimes combination of two or three characteristics form the basis of grading. However, the important aspect is to identify and select the correct species required to be used. Unfortunately method of identification of bamboo through anatomical characters has not been perfected so far. Some keys for identification through morphological characters are available but the same are also not very satisfactory. However, the bamboos available in a locality can easily be identified by experienced sorters. The culms should, therefore, be segregated species-wise (Rajput et al., 1992).

Dimension of culms

Four grades are usually made on the basis of diameter viz. Special grade – diameter between 7-10 cm, Grade I – diameter between 5-7 cm. Grade II – diameter between 3-5 cm and Grade III – diameter below 3cm. The minimum length of culms should be 6m.

Taper

The taper affects the firmness of construction and should not be more than 15 per cent per meter length of bamboo in any grade.

Curvature

The deviation from the straightness of the culm is called curvature. The maximum curvature should not be more than 7.5cm in a length of 6m of any grade of bamboo.

Other requirements

Internodal length and wall thickness, etc. play important roles in utilization of bamboo. However, for grading no specific limits of these characteristics are proposed. Some defects like dead and immature bamboos, ghoon holes, decay, collapse, objectionable checks and splits, etc. shall be avoided while using bamboo for structural and utility purposes. Checks more than 3mm in depth are considered as objectionable checks. Nodes should be flushed smooth. Further, bamboo before use should be properly seasoned and treated with preservatives.

Seasoning of bamboo

Green bamboo may contain 50-100 per cent of moisture. As in the case of wood, seasoning of bamboo is necessary before its efficient utilization.

Air seasoning

Air seasoning of split or half round bamboo does not pose much problem but care has to be taken to prevent fungal and insect attack during seasoning. If green bamboo is treated with water soluble preservative as per IS: 1902 or IS: 9096. biodeterioration can be prevented. Fungal and insect attack can be controlled by rapid drying in open sun as usually adopted for several handicraft items like baskets, mats, chicks, etc. without detriment to quality. Seasoning of round bamboo presents considerable problem. A study on seasoning behaviour of Dendracalamus strictus, D.hamiltonii, D.membranaceus, D. calostachyus, D. longispathus, Bambusa nutans, B. tulda, B. arundinacea and B. polymorpha indicated that immature bamboo get invariably deformed in cross section and thick walled immature bamboo generally collapse. Thick mature bamboo tend to crack on surface with the crack originating at the nodes and at decayed points. Moderately thick immature and thin and moderately mature bamboo season with much less degrade. Bamboo with poor initial condition on account of decay, borer hole, etc. generally suffer more drying degrade (Rehman and Ishaq, 1947).

Modified air seasoning

An accelerated hot air seasoning method was recently developed and it has been tried successfully for Bambusa nutans (Jain and Kambo, 1991). In this method the nodal walls are punctured/bored to enable through passage of air from one end of the bamboo to the other. From the butt and hot air generated in a solar air heater is forced through the bamboo tube by a small blower, so that the drying takes place simultaneously from the outermost and innermost wall layers. The cracks developed during drying by this method are much less severe than in normal air-drying method and the drying time is also considerably reduced.

Chemical seasoning

A process for defect free seasoning of round bamboo for handicrafts has been developed. In this method green bamboo is presoaked in 50 per cent by weight solutions of polyethylene glycol 600 maintained at 450C for 4 days before air seasoning. A preservative consisting of 2 per cent by weight of boric acid and sodium pentachlorophenate (1.1) can also be added to the solution to prevent insect and fungal attack. (Sharma et al., 1972). By this method it is possible to achieve total degrade free air seasoning of short length with node intact at one end and other end open of Dendrocalamus giganteus (otherwise very prone to spltiting) for novelty use like flower vase. Even longer pieces of other species like Dendrocalamus strictus with 3-4 intermodes in lengths suitable for lamp stand and similar uses have been successfully air seasoned after puncturing the nodal walls and pre-treating with the above chemical.

Baking over open fire

Round bamboo is often baked over open fire, after applying linseed oil, for primary protection against fungal decay and insect attack during short-term storage. A part from rapid drying of the outer portions, the slight charring caused is believed to provide some protection against biodegradation. It is, however, not a universal technique applicable to all bamboo species without degrade nor is it a method for complete seasoning. Baking should be carried out only over a gently fire, otherwise severe collapse occurs irrespective of the species or the maturity of culms (Rehaman and Ishaq, 1947).

Treatment of bamboo

Although bamboo is one of the strongest structural materials, its natural durability is very low (varying from 1 to 36 months depending on species) specially in tropical countries where biodeterioration is very fast and severe due to stain fungi, rotting fungi and insects. Split bamboo is more rapidly destroyed than round bamboo (Liese, 1980).

Methods of treatment

Bamboo can be treated by brushing (B), dipping (D), modified boucherie (MB), diffusion (Df), open tank/hot and cold (HC) and pressure (P) methods. Hot and cold and pressure methods of treatment of any lignocellulosic material are most versatile and well known. Brushing and dipping have limited efficiency but are useful in many cases. For treatment of green bamboo diffusion or modified boucherie – where treating liquid forces (under air pressure of 1 to 1.4 kg/sq.cm) developed with ordinary foot pump, the sap out of walls and septa of the bamboo through the open end and takes its (sap) place in course of time – methods are most suited (IS: 1902-1961), (IS: 9096-1979). Choice of method depends on type of preservative and condition and end use of bamboo in question.

Preservatives

Coaltar creosotc (CTC), copper chrome arscnic (CCA), acid cupric chromate (ACC), chromated zinc chloride (CZC), copper chrome boric (CCB), copper chrome zinc arsenic (CCZA), boric acid borax (BAB), compositions, copper naphthenate (CN), zinc naphthenate (ZN), benzene hexachloride (BHC) are recommended preservatives under Indian Standards. Choice of preservative depends mainly on end-use of bamboo. Recently another very effective preservative system for treatment of round dry bamboo by soaking treatment has been developed with ammoniacal copper arsenite (Dev et al., 1993).

The details of preferred treatment methods and preservative chemicals for different uses of bamboo are given in Table 4.

Table 4. Treatment methods and preservative chemicals for different end uses of bamboo.

	SI.No.	End use	Preservative chemical	Treatment
	1.	Post, pole, fencing, etc. exposed to weather and in contact with ground :
		a) Dry bamboo	CTC	P, IIC
			CCA & ACC	P
		b) Green round bamboo	CCA & ACC	Df
	2.	Bridges, ladders, scaffolding exposed to weather but not in contact with ground :
		a) Dry bamboo	CTC	D,HC,P
			CCA & ACC	P
		b) Green round bamboo	CCA & ACC	MB(4-6 hrs) Df (20-25 days)
	3.	House components (wall, trusses, purlins, rafters, tent poles) etc. under cover :
		a) Dry bamboo	CTC	D,HC,P
			CCA, ACC, CZC, CCB, CCZA	P
		b) Green round bamboo	CCA & ACC	MB(4 hrs) Df (15-20 days)
	4.	House components (ceiling door and window shutters) :
		a) Dry bamboo	CCA, ACC, CCB, CCZA and BAB	P
		b) Green round bamboo	CCA, ACC, CCB, CCZA and CZC	MB(2-3 hrs) Df (8-10 days)
	5.	Furniture, chicks, Zafri and mats exposed to weather :
		a) Green round bamboo	CCA, ACC, CCB, CZC and CCZA	MB (2-3 hrs)
		b) Green split bamboo	CCA, ACC, CCB, CCB and CCZA	Df (10 days)
		c) Dry split bamboo	CN, ZN, BHC	B (two coats), D (5 min)
	6.	Furniture, chicks, mats and other household articles under cover :
			BAB, CZC
	7.	Basket ware, etc. for packing fruits, vegetable and other edible material :
			BAB
	8.	Basketware for agricultural use other than for edible material :
			CCA,ACC,CZC,CCB	Df (3 weeks)
			CTC	IIC

References

Bureau of Indian Standards.1961. Code of practice for preservation of bamboo and canes for non structural purposes (Standard No. IS. 1902-1961). New Delhi, Bureau of Indian Standards.

Bureau of Indian Standards. 1979. Code of practice for preservation of bamboo for structural purposes (Standard No. IS. 9096-1979). New Delhi, Bureau of Indian Standards.

Dev, I.; Prem Chand; Pant, S.C. 1993. A note on the treatment of dry solid bamboo with ACA. Journal of the Timber Development Association of India, 39(1): 24-28.

Jain, V.K.; Kambo, A.S. 1991. A new approach to seasoning of round bamboo (Bambusa nutans). Journal of Indian Academy of Wood Science, 22(1): 29-34.

Liese, W. 1980. Preservation of bamboo. IDRC.

Limaye, V.D. 1952. Strength of bamboo (Dendrocalamus strictus), Indian Forest Records (New series), Timber Mechanics, 1: 17.

Rajput, S.S.; Gupta, V.K. : Sharma, S.D. 1992. Classification and grading of bamboos for structural utilisation and their safe working stresses. Journal of the Timber Development Association of India, 38(2): 19-32.

Rajput, S.S.; Shukla, N.K., Gupta, V.K.; Jain, J.D. 1991. Timber mechanics: Strength classification and grading of timber. New Delhi, ICFRE.

Rehman, M.A.; Ishaq, S.M. 1947. Seasoning and shrinkage of bamboo. Indian Forest Research, 4(2): 1-22

Sharma, S.N.; Tewari, M.C.; Sharma, R.P. 1972. Chemical seasoning of bamboo in the round for handicraft. Journal of the Timber Development Association of India, 18(1): 17-23.

Shukla, N.K., Singh, R.S.; Sanyal S.N. 1988. Strength properties of eleven bamboo species and study of some factors affecting strength. Journal of Indian Academy of Wood Science, 19 (20): 63-80.

---

CLUSTER TREATMENT PROCESSING OF GREEN BAMBOO AND UTILISATION ASPECTS

S.P. Singh, Sachin Gupta and V.K. Jain
Forest Products Division, Forest Research Institute, Dehradun-248 006

Introduction

Emphasis on bamboo utilisation aspects from a scientific viewpoint is of recent origin in this country. Bamboo has been used in a variety of ways by the traditional craftsmen in particular and others in general from a humble fencing to intricately crafted products of utility and aesthetic value from time immemorial.

From a comparative standpoint between wood and bamboo utilisation, the scientific processing has an edge over the traditional one and now a number of secondary and plantation grown species are in full use for diverse range of products thereby lessening the burden on primary timbers such as teak (Badoni and Rajput, 1997). The large database on various properties has also been generated based on exhaustive R & D work done by Forest Research Institute, Dehradun and other organisations. However, in spite of fast growth of bamboo species in a natural way, the scientific processing occupies a back seat. It is therefore, the need of the hour to explore the area of bamboo utilisation in a big way as this species does contribute in conservation of our natural forests. The wood substitution drive can be more effective and environment friendly in case we switch over to bamboo products than rather going for plastic or metal products (Badoni, 1997).

Bamboo is a fast growing species. The plantation species require a well designed planting and thinning pattern, a suitable seed or clone and additional inputs in terms of nutrients and water to augment their growth. In the case of bamboo the rotation cycle for harvest is just five years. The absence of crown and side branching patterns are other features of this species worth appreciating as compared to timber harvesting. The straight-grained timber is greatly influenced by side branching and leads to wastage at various stages. The bamboo waste during processing is expected to be quite less. In plantation/forest species the additional inputs of thinning and side branch trimming/pruning through silviculture practices are required to be done which are absent in case of bamboo harvesting. The rotational cycle of plantation species is quite longer. Further, the shorter span (5 years) rotation cycle of bamboo harvest also ensures freedom of introduction of new varieties of bamboo in the pattern of agriculture harvesting.

The logs of timber species for various uses are converted to nominal sizes for onward use. Bamboo is naturally occurring in similar sections and in round form, thus economising the primary processing aspects. Therefore, the initial processing from scientific viewpoint has to be incorporated just at harvesting stage and seasoning and preservation assume highest significance.

Wood processing in the broader sense is a linear model that comprises saw milling, seasoning, wood preservation, woodworking and wood finishing. This linear model does not always address the problems of wood utilisation faced by the industry. This model suits only to the mass scale processing lines. Cluster-processing model has been developed to overcome the various limitations of linear model. The cluster-processing model is a fusion of processing parameters concentrated on a product and improves wood utilization in a significant way. There are various benefits of cluster processing model such as -

l better raw material utilisation;

l reduction in drying and treatment cost;

l taming of refractoriness of timber species due to projection of end grain to faces;

l reduction in infrastructural costs;

l improved economic dividends;

l appreciation for the entire range of woody material in place of straight grained only in the same species;

l low-tech solutions that are easy to transfer to rural/cottage operations;

l demonstration of technology is much simpler (Badoni and Pandey, 2001).

The present paper highlights some of the works done at Forest Research Institute, Dehradun and elsewhere. The other aspects of processing have also been presented in brief.

Processing of Bamboo

The primary processing of bamboo utilisation includes harvesting, storage, transportation, preservation and seasoning. The secondary processing line includes fabrication of value added products. The aspects of grading (strength / feature / colour / exterior / interior based) and quality control are nonetheless important including the functional tests on products such as furniture joinery and structures (Badoni et al., 2000).

More and more emphasis has now been placed on conserving wood and developing energy efficient methods for wood processing. It is estimated that about 75 per cent of the total energy (required for making a product) alone is required for timber drying. Further there are a number of areas where wood is utilized in smaller sections such as toys, turnery, handicrafts and utility furniture and considerable scope exist in this area to evolve new concepts of path drying involving simultaneous secondary and primary processing aspects. Some pilot studies done in this regard have already shown encouraging results not only from the energy saving point of view but curbing the drying degrade as well. The dimensional component and related drying behaviour while working with green wood is worth investigating. Drying of shoe last in the form of half wrought is a well-known example in this field.

Mechanisation

The main drawback of efficient utilisation of bamboo for quality products lies in its secondary processing, which is done by the age-old tools. The axe, the wedge and the hammer used to open the timber logs have now been replaced by frame saws, band saws, and associated chipper canters using computerised control. The subsequent wood working techniques have replaced the hand tools by portable power tools. Similar approach is required to be adopted for the bamboo owing to the benefits of mechanisation. (Badoni, 1997). Several bamboo-processing machines have therefore been developed by some countries like Japan, China and other South Asian countries. The introduction of mechanised tools is also essential for handicrafts sector to improve the quality of worked surface on which subsequent region based craft skills can be introduced in the final stage. The arbour saws are quite efficient to cross cut the bamboo in green (harvesting, primary processing) and dry condition (secondary processing).

Research Thrust on Bamboo Utilisation

Bamboo is non-durable in nature; seasoning of bamboo in round form is difficult. The precise dimensions and straightness to produce quality furniture and other products would require sound knowledge of grading through select-sort approach using dimension tables. Putting new ideas into work will definitely pay dividends and work on these lines has just been initiated at Forest Research Institute as described below:

Green dimensioning

The conventional approach for wood and bamboo processing is drying the wood/bamboo first in desired plank round form. In contrast, in the present approach the concept of path drying is being followed. It means the material is first worked in the desired shapes and then allowed to dry. Considerable improvement in drying time has been observed in this approach and the tendency of splitting during drying has been reduced considerably ( Bratkorich, 2000; Gephart John, 1999; Bratkovich, 1998).

Bamboo turnery products

It is possible to turn bamboo in green condition (Fig. 1). Fungi attack the turned piece immediately. In case the turned product is immediately treated after the turning using a simple composition of borax-boric acid followed by a moisture curbing oil treatment as shown in the Fig. 2 it gives promising results. This aspect is presently the most important alternative process being researched at Forest Research Institute, Dehradun for cottage scale wood uses and is known as cluster treatment approach.

The Fig. 3 indicates the potential of green bamboo after cluster treatment to be used as furniture

Fig. 1. Process of turning the green bamboo.

Fig.2. Turnery product with and without cluster treatment.

Fig. 3. Chair made of green bamboo incorporating cluster treatment.

in the form of an upright chair. The Windsor chair in various forms can also be made. The rocking chair, common to every house, is an example of Windsor chair.

Environment friendly wood staining/colouring of bamboo products

Forest Research Institute has evolved an innovative technique of surface improvement of pre-finished products known as ammonia fumigation. Recently this technique has been successfully used to develop a variety of shades in bamboo strips ranging from light golden brown to dark brown and even black shades (Fir. 4 and 5). The ingredients used in the process are ammonia vapours, bark extracts, linseed oil and borax-boric acid. The finishing is a multistep operation and may be grouped under WRPF (water resistant preservative finish) with added advantages of generating a large variety of shades suiting to customers’ demand.

Fig 4. Different eco-friendly shades developed for decorative basketry.

Fig. 5. Stool making using eco-friendly stains in green bamboo.

References

Badoni, S.P.1998. Mechanised processing of bamboo for structures and associated products. In: International Workshop on Engineered Bamboo Housing for Earthquake Prone Areas, Dehradun, 23-26 November 1988. p. 10.

Badoni, S.P.; Pandey, C.N. 2001. Wood processing: Some thoughts. In: Technology Demonstration cum Seminar on Forest Products, Dehradun, 6th Dec. 2001. Papers. Unpublished.

Badoni, S.P.; Pandey, C.N.; Inder Dev. 2000. Utilisation and processing of bamboo. In: Seminar on Bamboo, Tripura, March 2000. Papers. Unpublished.

Badoni, S.P.; Rajput, S.S. 1997. Bamboo: The utilisation scene. In: KVIC Seminar on Bamboo Constitutional Framework, Delhi,. Unpublished.

Bratkorich, S.M.; Gephart, J.S. 2000. Green dimensioning below grade red oak logs: A Minnesota case study. Forest Products Journal, 50 (2): 65-68.

Bratkovich, Steve. 1998. Green dimensioning: A value added opportunity for low-grade logs. In: Oklahoma Timber Utilisation Conference, Eufala, 27 March 1998. Proceedings.

Gephart John, S.; .Peterson, H.D.; Brathovich., S.M. 1999. Green dimensioning review of processing, handling, drying and marketing. Forest Products Journal, 45 (5): 69-73.

FOREST RESEARCH INSTITUTE (DEEMED UNIVERSITY) DEHRADUN – 248 195 ADMISSION ANNOUNCEMENT-2006 I. Master Of Science And P.G. Diploma Courses Issue of application forms starts on : 16th January 2006 Last date for issue of application forms by post : 20th March 2006 Last date for issue of application forms from : 30th March 2006 Institute’s /Bank counter Last date for receiving completed application forms : 7th April 2006 Date of admission test : 14th May 2006 The dates may be changed at the discretion of the university authorities. a) M.Sc. Forestry (25 Seats): Eligibility: Three years Bachelor’s degree in science with at least one of the subjects namely Botany, Chemistry, Geology, Mathematics, Physics, Zoology or a Bachelor’s degree in Agriculture or Forestry. b) M.Sc. Wood Science and Technology (25 Seats): Eligibility: Three years Bachelor’s degree with Physics, Mathematics and Chemistry or B.Sc. degree in Forestry. c) M.Sc. Environment Management (25 Seats): Eligibility: Three years Bachelor’s degree in any branch of basic or applied Sciences or Bachelor’s Degree in Forestry or Agriculture or BE/B.Tech in Environment Science. d) P.G.D in Natural Resource Management (15 Seats): (1 year duration) Eligibility: M.Sc. in any discipline. e) P.G. D in Management of Non Wood Forest Product (22 Seats): (1 year duration) Eligibility: M.Sc. in Botany, Zoology, Forestry, Chemistry II. PERCENTAGE OF MARKS (in the qualifying examination): Candidates having 50 per cent or above marks in general category and 45 per cent marks for Scheduled Castes/Scheduled Tribes may apply. III. CENTRE OF EXAMINATION: (1) Dehra Dun (2) Jabalpur (3) Bangalore (4) Kolkata (5) Chandigarh (6) Delhi (7) Lucknow (8) Jodhpur (9) Shimla (10) Ranchi (11) Coimbatore and (12) Jorhat IV. RESERVATION: Out of the above following seats are reserved for: (a) SC/ST: 15 per cent and 7.5 per cent respectively (b) Handicapped (without mobility restriction and partial deafness): One seat in each M.Sc. Forestry, and M.Sc. Environment Management (c) In-service candidates serving in Govt./Autonomous Bodies of the Central Govt./State Govt.: 5 seats in each M.Sc. Environment Management and PGD Natural Resource Management courses only. V. HOW TO APPLY: Information Bulletin and application form can be obtained by post by submitting a Bank Draft for Rs. 450/- (Rs.400/- as cost of information bulletin + Rs.50/- as postage charges) (Rupees Four hundred fifty only) payable at Dehradun in favour of Registrar, FRI (Deemed University), P.O.I.P.E., Kaulagarh Road, Dehradun–248 195. Application Forms will also be available from the counter of the Union Bank of India (FRI Branch, Dehradun). For details, please refer to ‘Information Bulletin’ 2006. A candidate who wants to apply for two or more courses has to fill up separate form for each course. Application form may also be downloaded from the website www.icfre.org The downloaded forms shall be accepted only if accompanied with a demand draft of Rs. 400/- in favour of Registrar, FRI (Deemed University) payable at Dehra Dun. DIRECTOR F.R.I., (DEEMED UNIVERSITY)

---

CHEMICAL SEASONING OF ROUND BAMBOOS FOR MAKING VALUE-ADDED HANDICRAFT PRODUCTS

N.K. Upreti, Kishan Kumar V.S. and V.K. Jain
Forest Products Division, Forest Research Institute, Dehradun – 248 006

Introduction

Bamboo is a marvellous material bestowed by nature to mankind. Its utility in different areas of life has drawn attention of man to exploit this raw material to the fullest. It is one of the very fast growing plants on earth. Its short rotation period, ease in extraction and workability have rendered this material a special area of interest for mankind. Bamboo is especially used by people in rural areas of the country for their shelter and day-to-day utilities. This is particularly true in the northeastern parts of the country that is why it is described as "poor man’s timber". Because of its varied utility, it is also known as "green gold of the forest" or "friend of the rural people". Bamboo has versatile uses as building material, paper and pulp resources, scaffolding, food, agriculture implements, fishing rods, weaving materials, plywood and particle board manufacturing. Besides these there are nearly two thousand recorded uses of bamboo now such as fuel, fodder, food, laminates, furniture, mats, construction material, chop sticks, toothpicks, musical instruments, vinegar, beer, activated carbon, etc. Bamboos are good soil binders owing to their particular clump formation and fibrous root system and hence also play an important role in soil conservation.

Green bamboo may contain 50-150 per cent of moisture in the form of water. Seasoning of bamboo is essential before it is used as seasoning gives it strength and prevents it from fungal discolouration and decay. Air seasoning of split or half-round bamboo does not pose much problem and demands care to prevent fungal discolouration, decay and insect attacks and can be taken care of by rapid drying after felling or a prophylactic preservative treatment (IS: 1902) before seasoning. Seasoning of round bamboo poses considerable problem in several species of bamboo. Many species of bamboo are more or less liable to surface cracking during drying (Sharma, 1988). Some species like Bambusa nutans and Bambusa tulda crack more than the others. Unlike timbers, drying under mild conditions cannot always prevent cracking in round bamboo. End splitting, surface cracks and cracking at the nodes are common problems faced during air drying even at slow rate of air seasoning and mild weather (Rehman and Ishaq, 1947). Bamboo shows considerable shrinkage in wall thickness as well as in diameter of the culms when dried from green condition. This phenomenon assumes important significance when it is realized that most of the defects, which appear in round bamboo during seasoning are caused by excessive or unequal shrinkage. Again, young immature culms are more likely to have cracks or splits as compared to their matured counterparts. So it is always safer to use matured culms. An accelerated hot air seasoning method was developed and tried on Bambusa nutans (Jain and Kambo, 1991). In this method the nodal walls are bored to enable through passage of hot air from one end of the bamboo to the other. In this method the drying takes place simultaneously from the outermost and innermost wall layers.

An attempt has been made in this study to minimise cracks and splits during seasoning and subsequent use of round bamboo in order to make it fit to be used in novelty handicraft items such as flower vases, pen stand, ashtray, table lamp post, etc. The value addition was done by chemically bulking the bamboo material before forced-air drying. The process of air or kiln seasoning after treatment with anti-shrink chemicals, chiefly with the object of minimizing seasoning degrades, is known as ‘chemical seasoning’. Chemical seasoning of Dendrocalamus giganteus has been tried earlier (Sharma et al., 1972) using poly ethylene glycol-600 (PEG). Urea and common salt have been used in this study and are much cheaper as compared to PEG. Chemical seasoning of green round Bambusa tulda has been tried before (Upreti, 2004) using urea. In the present study chemical seasoning was carried out for three species, viz., Bambusa nutans, Dendrocalamus membranaceus and Dendrocalamus giganteus.

Materials and Methods

About five year old green and freshly felled culms of Bambusa nutans, Dendrocalamus membranaceus and Dendrocalamus giganteus were converted into small pieces of length 40-50 cm with one end open and another end with a node. Their weight, wall thickness and internal diameter were recorded immediately after conversion. Total twenty-five matched pieces of each species were taken for the study. Ten pieces were used for urea treatment, another ten were used for common salt (NaCl) treatment and five pieces were used as controls. The nodal partition was kept intact. These pieces (ten of each species for each solution) were dipped for 72 hours in separately made solutions of urea and NaCl (both 40 per cent w/v) in water maintained at 450C initially for 8 hours. The particular concentration and treatment duration was used based on the preliminary experiments done on these aspects of the species. Temperature was used for creating a partial vacuum inside the bamboo so that absorption of chemicals would be increased. After treatment the treated pieces were wrapped in polyethylene sheets and kept indoor for better diffusion of chemicals. After a week these pieces, along with controls, were forced air-dried initially for three days and later on kept inside an oven at 350C to bring down the moisture content up to 10-12 per cent. Their weight, culm wall thickness and internal diameter were recorded regularly. After drying the samples were immediately coated with polyurethane coating.

Results and Discussion

The properties and their average values for all the three species of bamboo used in this experiment are given in the table 1, 2 and 3. Further the table 4 and 5 are derived from these tables for ease of discussions.

Shrinkages in wall thickness were found to be 27.32 per cent, 20.22 per cent and 42.58 per cent in controls of B. nutans, D. membranaceus and D. giganteus respectively. These were 19.24 per cent, 19.96 per cent and 15.65 per cent in NaCl treated samples of B. nutans, D. membranaceus and D. giganteus respectively and 17.08 per cent, 16.87 per cent and 8.79 per cent in urea treated samples of B. nutans, D. membranaceus and D. giganteus respectively. Thus the shrinkage in wall thickness was observed minimum in urea treated samples of all the species. The best result was observed in D. giganteus.

Table 1. Average values of shrinkage in wall thickness and internal diameter of controls.

			MC (%)	Internal diameter (mm)	Wall thickness (mm)
	B. nutans	Initial	118.2	61.17	9.04
		Final	10-12	55.39	6.57
		Per cent decrease	-	9.45	27.32
	D. membranaceus	Initial	91.5	57.96	9.84
		Final	10-12	47.54	6.57
		Per cent decrease	-	17.98	27.32
	D. giganteus	Initial	65.5	106.78	8.36
		Final	10-12	97.85	4.80
		Per cent decrease	-	8.36	42.58

Table 2. Average values of shrinkage in wall thickness and internal diameter of NaCl treated samples.

			MC (%)	Internal diameter (mm)	Wall thickness (mm)
	B. nutans	Initial	118.2	64.31	9.98
		Final	10-12	60.27	8.06
		Per cent decrease	-	6.28	19.24
	D. membranaceus	Initial	91.5	66.65	10.32
		Final	10-12	58.54	8.26
		Per cent decrease	-	12.17	19.96
	D. giganteus	Initial	65.5	103.32	6.90
		Final	10-12	97.55	5.82
		Per cent decrease	-	5.59	15.65

Table 3. Average values of shrinkage in wall thickness and internal diameter of urea treated samples.

			MC (%)	Internal diameter (mm)	Wall thickness (mm)
	B. nutans	Initial	118.2	51.50	12.76
		Final	10-12	50.01	10.58
		Per cent decrease	-	2.89	17.08
	D. membranaceus	Initial	91.5	68.08	11.38
		Final	10-12	60.78	9.46
		Per cent decrease	-	10.72	16.87
	D. giganteus	Initial	66.0	91.54	7.39
		Final	10-12	89.96	6.74
		Per cent decrease	-	1.73	8.79

Table 4. Shrinkage per cent in wall thickness.

		B. nutans	D. membranaceus	D. giganteus
	Control	27.32	20.22	42.58
	NaCl treated samples	19.24	19.96	15.65
	Urea treated samples	17.08	16.87	8.79

Shrinkages in internal diameter were found to be 9.45 per cent, 17.98 per cent and 8.36 per cent in controls of B. nutans, D membranaceus and D. giganteus respectively. These were 6.28 per cent, 12.17 per cent and 5.59 per cent in NaCl treated samples of B. nutans, D membranaceus and D. giganteus respectively and 2.89 per cent, 10.72 per cent and 1.73 per cent in urea treated samples of B. nutans, D membranaceus and D. giganteus respectively. Thus the shrinkage in internal diameter was also observed minimum in urea treated samples of all the species. Thus between the two treatments, urea was found more effective in minimising the shrinkages in round bamboos studied.

All the controls started developing cracks of varying degree at the nodes as well as surface below 16 per cent moisture content. The length of surface cracks of minimum 1 mm width in untreated controls was recorded up to 11 cms. The treated samples showed absolutely no cracking at the node, especially in urea treated samples, and few samples showed very minor cracks at the outer surface even after drying up to 10-12 per cent moisture content. These results indicate that urea as well as NaCl are working as a bulking agent and are able to impart dimensional stability to the bamboo to some useful extent. Treatment of longer pieces

Table 5. Shrinkage per cent in internal diameter.

		B. nutans	D. membranaceus	D. giganteus
	Control	9.45	17.98	8.36
	NaCl treated samples	6.28	12.17	5.59
	Urea treated samples	2.89	10.72	1.73

Fig. 1. Shrinkage in wall thickness.

Fig. 2. Shrinkage in inner diameter.

Bn = Bambusa nutans , Dm = Dendrocalamus membranaceus, Dg = Dendrocalamus giganteus

having two or more inter nodes can be tried after puncturing the nodal partition to allow free flow of chemicals to the interior wall. Urea and NaCl, being hygroscopic, cause problem during rainy season when humidity is high for a prolonged period by making the finished product sweat. The problem of sweating is avoided by coating the finished product by polyurethane wood finish immediately after its seasoning.

Conclusion

B. nutans, D. membranaceus and D. giganteus in round form can be seasoned free of drying degrades like cracking and splitting after giving it an anti-shrink treatment in green, freshly felled condition. The treatment makes it possible to air-dry bamboo defect free. A solution of urea as well as NaCl (40 per cent w/v) in water can be used to get satisfactory results. But urea gives better results compared to NaCl. After drying the treated product should be coated by polyurethane finish in order to avoid sweating in prolonged humid atmosphere, as urea is hygroscopic. The treatment offers the possibility for handicraft manufacturers to use these bamboos in round form for novelty items.

The study should prove helpful in treating the round bamboo with urea in order to avoid cracks in seasoning, however, it is suggested that anyone planning to use the treatment commercially should make a series of tests on the species size and shape of specimens to be used, varying the chemical concentration and the treatment time in order to attain an optimum bulking concentration of the chemical.

References

Bureau of Indian Standards. 1961. Code of practice for preservation of bamboo and canes for non-structural purposes (Specification No. IS:1902-1961). New Delhi, Bureau of Indian Standards.

Jain, V.K.; Kambo, A.S. 1991. A new approach to seasoning of round bamboo (Bambusa nutans). Journal of the Indian Academy of Wood science, 22 (1): 29-34.

Rehman, M.A.; Ishaq, S.M.1947. Seasoning and shrinkage of bamboo. Indian Forest Reord, 4 (2): 1-22.

Sharma, S.N. 1988. Seasoning behaviour and related properties of some Indian species of bamboo. Indian Forester, 114(10): 613-621.

Sharma, S.N.; Tewari, M.C.; Sharma, R.P. 1972. Chemical seasoning of bamboo in round for handicrafts. Journal of the Timber Development Association of India, 18 (1): 17-23.

Upreti, N.K. 2004. Chemical seasoning of round Bambusa tulda. Journal of the Timber Development Association of India. 50(3-4): 28-31.

Calendar of Meetings 15-16 Mar 2006 IPGRI-IUFRO Workshop on Climate Change and Forest Genetic Diversity: Implications to Sustainable Forest Management in Europe Email: secretariat@cgiar.org 20-31 Mar 2006 VIII Meeting of the Conference of the Parties to the Convention on Biological Diversity, Canada Secretariat of the Convention on Biological Diversity, 413 St-Jacques Street, 8th Floor, Office 8ooo, Montreal, Quebec, Canada, H2Y 1N9 Tel: 1-514-2882220, Fax: 1-514-2886588 Email: secretariat@biodiv.org Website: www.biodiv.org 21-22 Mar 2006 National Conference on Forest Biodiversity Resources: Exploitation, Conservation and Management, Madurai, India Dr. K. Muthuchelian, Organizing Secretary, National Conference on Forest Biodiversity Resources, Centre for Biodiversity and Forest Studies, Madurai Kamaraj University, Madurai - 625 021, Tamil Nadu (India) Tel: 0091 - 452 – 2458020, Fax: 0091 - 452 - 2459181 Email: kmcbiodiver@yahoo.co.in 21-23 Mar 2006 National Symposium on Tree Improvement for Sustainable Forestry, Jabalpur, India Dr. N.N. Pathak, Head, Department of Forestry, Jawaharlal Nehru Kirshi Vishwa Vidyalaya, Jabalpur-482 004, India Email: hodforjnkvv@yahoo.com Website: www.jnkvv.nic.in 22-29 Mar 2006 IV International Tree Squirrel Colloquium and Ist International Flying Squirrel Colloquium. Including Conservation Priorities Workshop: Tree and Flying Squirrels in the Developing World, Bangalore, India R. Nandini, National Institute of Advanced Studies, Indian Institute of Science Campus Banglore 56012, India, Tel: 91-9443142296 Email: nandinirajamani@yahoo.co.in Website: www.squirrelcolloquia.co.in and www.iisc.ernet.in/its.htm 8-10 Jun 2006 Pan Pacific Conference, Seoul, Korea Korea Technical Association of the Pulp and Paper Industry, Dr. Hye Jung Youn, Department of Forest Sciences, Seoul National University San 56-1, Sillim-dong, Gwanak-gu, 151-921 Seoul, Korea Tel: +82-2-786-8620, Fax: +82-2-786-8621 Email: panpac06@plaza.snu.ac.kr 9-11 Jun 2006 International Symposium on Introduction and Spread of Invasive Species www.phytomedizin.org/meetings/meet.hym www.hcpc.org/invasive 19-25 Jun 2006 IX Latin American Congress of Botany on Contributing to the Global Knowledge of the Latin American Native Flora www.botanica-alb.org/www.botanica-alb.org/CongresoPreins.pdf 8-10 Aug 2006 IUFRO: Forest and Water in a Changing Environment www.caf.ac.cn/newcaf 22-26 Aug 2006 First European Congress of Conservation Biology (ECCB) "Diversity for Europe" www.eccb2006.org 10-16 Sep 2006 Forests under Anthropogenic Pressure-Effect of Air Pollution, Climate Change and Urban Development (IUFRO) www.fs.fed.us/psw/rfl/ 26-29 Sep 2006 Patterns and Process in Forest Landscape: Consequences of Human Management, Bari, Italy Prof Giovami Sanesi, Dip Scienze delle Produzioni Vegetali, Faculty of Agricultural Science, Program in Forestry and Environmental Science, University of Bari Via Amendola 165/A, Bari, Italy Tel: 39-80-5443023, Fax: 39-80-5442976 Website: www.greenlab.uniba.it/events/iufro2006 14-15 Nov 2006 XII National Symposium on Hydrology with Focal Theme on Groundwater Governance: Ownership of Groundwater, Roorkee, India National Institute of Hydrology, Jal Vigyan Bhawan, Roorkee-247 667 (Uttaranchal) Tel: 01332 - 272906-09 Extn. 219 Fax: 01332 - 272123 Email: ncg@nih.ernet.in

 

---

Bibliography on Forest Products (2000-2005)

 

1. Abdurrohim, S.; Djarwanto. 2000. Cold soaking treatment of mangium (Acacia mangium Willd.) using boron compound. Buletin Penelitian Hasil Hutan, 18(1): 19-26.

2. Abdurrohim, S.; Martono, D. 2002. Cold-soaking treatment of five wood species using CCB preservative for housing purposes. Buletin Penelitian Hasil Hutan, 20(4): 303-312.

3. Abdurrohim, S.; Sudika, D.A. 2004. Treatability of 41 wood species with CCB preservatives. Jurnal Penelitian Hasil Hutan, 22(3): 167-174.

4. Ahmed, B.M.; French, J.R.J.; Vinden, P. 2004. Evaluation of borate formulations as wood preservatives to control subterranean termites in Australia. Holzforschung, 58(4): 446-454.

5. Ajmal Samani; Tripathi, Sadhna; Gazwal, A.K. 2005. Laboratory screening trials for protection of timber against sapstain fungus. Journal of the Timber Development Association of India, 51(1-2): 72-77.

6. Akande, J.A. 2003. Environmental education on wood preservatives and preservative-treated wood products. Journal of Environmental Extension, 4: 55-58.

7. Akbulut, T.; Kartal, S.N.; Green, F. 2004. Fibreboards treated with N’-N-(1,8-naphthalyl) hydroxylamine (NHA-Na), borax, and boric acid. Forest Products Journal, 54(10): 59-64.

8. Aleon, D. 2004. Phytosanitary heat treatment of wood. Bulletin OEPP, 34(1): 133-138.

9. Alexander, J.; Alexander, P. 2000. From kinship to contract? Production chains in the Javanese woodworking industries. Human Organization, 59(1): 106-116.

10. Almeida, R.R.; Bortoletto Junior, G.; Jankowsky, I.P. 2004. Veneer production from Eucalyptus grandis x Eucalyptus urophylla hybrid clones wood. Scientia Forestalis, 65:49-58.

11. Anderson, M.E.; Leichti, R.J.; Morrell, J.J. 2000. The effects of supercritical CO2 on the bending properties of four refractory wood species. Forest Products Journal, 50(11-12): 85-93.

12. Anderson, R.C; Hansen, E.N. 2004. The impact of environmental certification on preferences for wood furniture: A conjoint analysis approach. Forest Products Journal, 54(3): 42-50.

13. Andrews, M.; Lausberg, M.; Nakada, R.; Walker, J. 2003. Singing softwoods - sorting logs with sonics. Scottish Forestry, 57(4): 199-202.

14. Arda, M. 2004. A general picture of the world commodity economy. Unasylva, 55(219): 11-18.

15. Asghar Omidvar; Ruddick, J. 2004. The influence of low styrene content on the decay resistance of an aspen wood polymer composite. Forest Products Journal, 54(10): 57-58.

16. Aviara, N.A.; Oluwole, F.A.; Haque, M.A. 2005. Effect of moisture content on some physical properties of sheanut (Butyrospernum paradoxum). International Agrophysics, 19(3): 193-198.

17. Awoyemi, L. 2004. Effects of borate impregnation on the mechanical hygroscopic and swelling properties of birch (Betula pubescens) wood. Journal of the Timber Development Association of India, 50 (3-4): 6-11.

18. Awoyemi, L. 2004. Effects of microwave modification on the swelling properties of Pinus radiata heartwood. Indian Forester, 130(3): 267-272.

19. Azizi, M.; Amiri, S.; Faezipour, M. 2002. Determination of effective criteria for location selection of plywood and veneer units by AHP method. Iranian Journal of Natural Resources, 55(4): 543-557.

20. Azizi, M.; Amiri, S.; Yazdi, M.M. 2004. Decision making for selection of suitable location for plywood and veneer manufacturing units in Iran. Iranian Journal of Natural Resources, 57(3): 523-536.

21. Baeza, M.; Briones, R.; Hernandez, G. 2002. Minimum retention with CCA salts on radiata pine timber that protects against subterranean termite attack. Maderas: Ciencia y Technologia, 4(2): 186-192.

22. Bailey, D.S.; Smith, R.L.; Araman, P.A. 2004. An analysis of the physical properties of recovered CCA-treated wood from residential decks. Wood and Fiber Science, 36(2): 278-288.

23. Baileys, J.K.; Marks, B.M; Ross, A.S.; Crawford, D.M.; Krzysik, A.M.; Muehl, J.H.; Youngquist, J.A. 2003. Providing moisture and fungal protection to wood-based composites. Forest Products Journal, 53(1): 76-81.

24. Ball, J.; Carle, J.; Lungo, A. Del. 2005. Contribution of poplars and willows to sustainable forestry and rural development. Unasylva, 56(221): 3-9.

25. Bamaca Figueroa, E.E.; Kanninen, M.; Louman, B.; Pedroni, L.; Gomez, M. 2004. Carbon content of forest products and residues generated by timber harvesting and sawmilling in the Mayan Biosphere Reserve. Recursos Naturales y Ambiente, 41: 102-110.

26. Bansal, A. K. 2004. Indian timber imports - an analysis. Indian Forester, 130(9): 963-976.

27. Bansal, A.K.; Narayanaprasad, T.R.; Mathews, K.C. 2002. Plywood from plantation species - Populus deltoides (poplar). Indian Forester, 128(1): 75-80.

28. Bansal, A.K.; Prasad, T.R.N. 2004. Manufacturing laminates from sympodial bamboos - an Indian experience. Journal of Bamboo and Rattan, 3(1): 13-22.

29. Bansal, A.K.; Rangaraju, T.S.; Shankar, K.S. 2002. Matchsticks from bamboo. Journal of Bamboo and Rattan, 1(4): 333-340.

30. Bansal, A.K.; Zoolagud, S.S. 2001. Bamboo composites: Material of the future. Journal of Bamboo and Rattan, 1(2): 119-130.

31. Bao, Fu Cheng; Jiang, Ze Hui; Liu, Sheng Quan. 2000. A modeling approach to the relationships between plantation poplar wood properties and qualities of veneer and plywood. Scientia Silvae Sinicae, 36(1): 91-96.

32. Bao, Fu Cheng; Liu, Sheng Quan. 1999. Studies on the relationships between wood properties and the quality of veneer and plywood of plantation poplars. Australian Forestry, 62(1): 21-26.

33. Bao, Fu Cheng; Liu, Sheng Quan. 2001. Modeling the relationships between wood properties and quality of veneer and plywood of Chinese plantation poplars. Wood and Fiber Science, 33(2): 264-274.

34. Barbosa, A.P.; Mano, E.B.; Andrade, C.T. 2000. Tannin-based resins modified to reduce wood adhesive brittleness. Forest Products Journal, 50(9): 89-92.

35. Barnes, H.M.; Amburgey, T.L.; Sanders, M.G. 2004. Performance of zinc-based preservative systems in ground contact. Wood Design Focus, 14(2): 13-17.

36. Barnes, H.M.; Amburgey, T.L.; Sanders, M.G. 2005. Performance of copper naphthenate and its analogs as ground contact wood preservatives. Bioresource Technology, 96(10): 1131-1135.

37. Barnes, H.M.; Brient, J.A; Freeman, M.H.; Kerr, C.N. 2002. Performance of copper-naphthenate-treated poles in service. Forest Products Journal, 52(4): 60-63.

38. Barnes, H.M.; Murphy, R.J. 2005. Bending and tensile properties of vapor boron-treated composites. Wood and Fiber Science, 37(3): 379-383.

39. Baysal, E.; Yalinkilic, M.K. 2005. A comparative study on stability and decay resistance of some environmentally friendly fire-retardant boron compounds. Wood Science and Technology, 39(3): 169-186.

40. Baysal, E.; Yalinkilic, M.K. 2005. A new boron impregnation technique of wood by vapor boron of boric acid to reduce leaching boron from wood. Wood Science and Technology, 39(3): 187-198.

41. Baysal, E.; Yalnklc, M.K.; Colak, M.; Goktas, O. 2003. Combustion properties of Calabrian pine (Pinus brutia Ten.) wood treated with vegetable tanning extracts and boron compounds. Turkish Journal of Agriculture and Forestry, 27(4): 245-252.

42. Bhavanisanker, K.; Swaminathan, C.; Hann, J. 2004. Studies on the penetration of CCA and boric acid preservatives in treated red gum wood. Indian Forester, 130(4): 464-466.

43. Biblis, E.J. 2000. Rolling shear modulus of sweetgum plywood and unidirectionally laminated veneer. Wood and Fiber Science, 32(1): 2-6.

44. Biblis, E.J.; Carino, H.F. 2000. Flexural properties of southern pine plywood overlaid with fiberglass-reinforced plastic. Forest Products Journal, 50(4): 34-36.

45. Bigsby, H.; Ozanne, L. K. 2002. The purchase decision: Consumers and environmentally certified wood products. Forest Products Journal, 52(7-8): 100-105.

46. Bigsby, H.R.; Ozanne, L.K. 2001. Consumer preference for environmentally certified forest products in New Zealand. New Zealand Journal of Forestry, 46(3): 36-41.

47. Binbuga, N.; Chambers, K.; Henry, W.P.; Schultz, T.P. 2005. Metal chelation studies relevant to wood preservation. 1. Complexation of propyl gallate with Fe2+. Holzforschung, 59(2): 205-209.

48. Blanchet, P.; Beauregard, R.; Erb, A.; Lefebvre, M. 2003. Comparative study of four adhesives used as binder in engineered wood parquet flooring. Forest Products Journal, 53(1): 89-93.

49. Bolkesjo, T.F.; Tromborg, E.; Solberg, B. 2005. Increasing forest conservation in Norway: Consequences for timber and forest products markets. Environmental and Resource Economics, 31(1): 95-115.

50. Bortoletto, G.; Belini, U.L. 2003. Veneer and plywood production of guapuruvu wood (Schizolobium parayba Blake.) coming from a mixed plantation of Brazilian tree species. Cerne, 9(1): 16-28.

51. Borysiuk, P.; Jabonski, M.; Zado, A. 2003. Modification of chosen plywood properties with Ahydrosil K preservative. Annals of Warsaw Agricultural University, Forestry and Wood Technology, 53: 8-13.

52. Borysiuk, P.; Mankowski, P.; Apinski, K.; Nowak, K.; Omen, J. 2003. The use of polyethylene waste to coat plywood. Annals of Warsaw Agricultural University, Forestry and Wood Technology, 53: 19-22.

53. Borysiuk, P.; Zado, A.; Sosinska, K.; Gowin; Mrozik, M.; Nowakowski, M. 2003. Flexible plywood made of Polish timber. Annals of Warsaw Agricultural University, Forestry and Wood Technology, 53: 23-27.

54. Bos, F. ; Magorou, L.; Rouger, F. 2005. An approach to viscoelastic behaviour analysis of wood-based panels by an inverse method of characterisation. Holzforschung, 59(5): 546-551.

55. Bosunia, A.K.; Islam, M.A; Hannan, M.O; Lahiry, A.K. 2003. The present status, characteristics and problems of wood based turning handicrafts industry in Bangladesh. Journal of the Timber Development Association of India, 49(3-4): 42-49.

56. Boussaguet, P. 2000. Exterior wood decking: Anti-slip measures. CTBA Info, 84: 10-13.

57. Bowe, S.A; Bumgardner, M.S. 2004. Species selection in secondary wood products: Perspectives from different consumers. Wood and Fiber Science, 36(3): 319-328.

58. Brandt, C.W.; Fridley, K.J. 2003. Effect of load rate on flexural properties of wood-plastic composites. Wood and Fiber Science, 35(1): 135-147.

59. Brelid, P.L.; Simonson, R.; Bergman, O.; Nilsson, T. 2000. Resistance of acetylated wood to biological degradation. Holz als Roh und Werkstoff, 58(5): 331-337.

60. Broman, N.O. 2001. Aesthetic properties in knotty wood surfaces and their connection with people’s preferences. Journal of Wood Science, 47(3): 192-198.

61. Brunecky, P.; Svancara, F.; Chladil, J.; Polasek, J. 1999. The problem solution state of organic substance emission in wooden products. Drevarsky Vyskum, 44(3-4): 75-82.

62. Bucket, E. 2001. Analysis of life cycle: A tool of marketing ecology for products based on wood. CTBA Info, 88: 33-38.

63. Bull, D.C; Harland, P.W.; Vallance, C.; Foran, G.J. 2000. EXAFS study of chromated copper arsenate timber preservative in wood. Journal of Wood Science, 46(3): 248-252.

64. Bumgardner, M.S.; Bowe, S.A. 2002. Species selection in secondary wood products: Implications for product design and promotion. Wood and Fiber Science, 34(3): 408-418.

65. Bustos, C.; Beauregard, R.; Mohammad Mohammad; Hernandez, R. E. 2003. Structural performance of finger-jointed black spruce lumber with different joint configurations. Forest Products Journal, 53(9): 72-76.

66. Cao, Jin Zhen; Kamdem, D.P. 2004. Microwave treatment to accelerate fixation of copper-ethanolamine (Cu-EA) treated wood. Holzforschung,58(5): 569-571.

67. Cao, Jin Zhen; Kamdem, D.P. 2004. Moisture adsorption characteristics of copper-ethanolamine (Cu-EA) treated Southern yellow pine (Pinus spp.). Holzforschung, 58(1): 32-38.

          68. Cao, Jin Zhen; Zhao, Guang Jie. 1999. Humidity-conditioning of wood and wood-based
          interior decorative materials during water vapor changing process. Forestry Studies in China,
          1(1): 54-60.

69. Cao, Jin Zhen; Zhao, Guang Jie. 2000. Humidity conditioning function of wood and wood-based interior wall materials III. Scientia Silvae Sinicae, 36(4): 55-58.

70. Cao, Zhong Rong. 2002. Difference analysis of plywood product standard between America and China. China Wood Industry, 16(4): 7-9.

71. Carino, H.F.; Willis, D.B. 2001. Enhancing the profitability of a vertically integrated wood products production system. Part 1. A multistage modelling approach. Forest Products Journal, 51(4): 37-44.

72. Catallo, W.J.; Shupe, T.F. 2003. Hydrothermal treatment of creosote-impregnated wood. Wood and Fiber Science, 35(4): 524-531.

73. Catallo, W.J.; Shupe, T.F.; Gambrell, R. P. 2004. Hydrothermal treatment of CCA- and penta-treated wood. Wood and Fiber Science, 36(2): 152-160.

74. Cavanagh, G. 2002. House framing - present and future durability issues. New Zealand Journal of Forestry, 47(4): 34-36.

75. Chang, Shang Tzen; Wu, Jyh Horng; Yeh, Ting Feng. 2002. Effects of chromated-phosphate treatment process on the green color protection of ma bamboo (Dendrocalamus latiflorus). Journal of Wood Science, 48(3): 227-231.

76. Chao, W.Y.; Lee, A.W.C. 2003. Properties of southern pine wood impregnated with styrene. Holzforschung, 57(3): 333-336.

77. Chauhan, S.S.; Entwistle, K.M.; Walker, J.C.F. 2005. Differences in acoustic velocity by resonance and transit-time methods in an anisotropic laminated wood medium. Holzforschung, 59(4): 428-434.

78. Chen, H.; Rhatigan, R.; Morrell, J.J. 2003. A rapid method for fluoride analysis of treated wood. Forest Products Journal, 53(5): 43-45.

79. Chen, K.; Ohmura, W.; Doi, S.; Aoyama, M. 2004. Termite feeding deterrent from Japanese larch wood. Bioresource Technology, 95(2): 129-134.

80. Chen, Zhi Lin; Wang, Qun; Mao, Qian Jin; Zuo, Tie Yong; Fu, Feng; Ye, Ke Lin. 2002. A new kind of developing material - woodceramics. China Wood Industry, 16(5): 10-13.

81. Cheng, Fa; Qi, Hong Juan; Li, Hou Ping; Wei, Yu Ping. 2004. Study on the technological conditions of preparing polyurethane resins from liquefied benzylated wood. Chemistry and Industry of Forest Products, 24(2): 39-42.

82. Cheng, Wan Li; Liu, Yi Xing; Qi, Hua Chun; Toshiro, M.; Misato, N. 2004. Shrinkage stress of wood during drying under superheated steam (I): The characteristics of radial shrinkage stress. Journal of Northeast Forestry University, 32(6): 32-34.

83. Chiu, Chih Ming; Lin, Cheng Jung; Tang, Sheng Lin; Tang, Shyh Chian; Lo, Cho Chen Nan. 2004. Effects of different chemical dressings on wound areas of pruned Taiwan Zelkova (Zelkova serrata Hay.) trees against discoloration and decay. Taiwan Journal of Forest Science, 19(3): 177-186.

84. Choi, Sung Mee; Ruddick, J.N.R.; Morris, P. 2004. Chemical redistribution in CCA-treated decking. Forest Products Journal, 54(3): 33-37.

85. Christiansen, A.W.; Vick, C.B.; Okkonen, E.A. 2003. Development of a novolak-based hydroxymethylated resorcinol coupling agent for wood adhesives. Forest Products Journal, 53(2): 32-38.

86. Chuang, Chin Shen; Ko, Chun Han; Leu, Shao Yuan. 2003. Impact of polyvinyl acetate application on combustion characteristics of wooden surface linings. Journal of the Experimental Forest of National Taiwan University, 17(1): 49-60.

87. Chui, Y.H. 2000. Strength of OSB scarf joints in tension. Wood and Fiber Science, 32(1): 7-10.

88. Chung, D.H.; Chen, HisYuan. 2000. Study on consuming market for wood flooring products in Northern Area of Taiwan. Journal of the Experimental Forest of National Taiwan University, 14(4): 185-200.

89. Chung, Min Jay; Wu, Jyh Horng; Chang, Shang Tzen. 2005. Green colour protection of makino bamboo (Phyllostachys makinoi) treated with ammoniacal copper quaternary and copper azole preservatives. Polymer Degradation and Stability, 90(1): 167-172.

90. Clausen, C.A. 2000. CCA removal from treated wood using a dual remediation process. Waste Management and Research, 18(5): 485-488.

          91. Clouston, P.; Civjan, S.; Bathon, L. 2004. Experimental behavior of a continuous metal  
          connector for a wood-concrete composite system. Forest Products Journal, 54(6): 76-84.

92. Colakoglu, G.; Aydn, I.; Colak, S. 2002. The effects of waiting time of alder (Alnus glutinosa subsp. barbata) veneers before drying on shear and bending strength of plywood. Holz als Roh und Werkstoff, 60(2): 127-129.

93. Colakoglu, G.; Colak, S.; Aydin, I.; Yildiz, U. C; Yildiz, S. 2003. Effect of boric acid treatment on mechanical properties of laminated beech veneer lumber. Silva Fennica, 37(4): 505-510.

94. Constant, T.; Badia, M. A; Mothe, F. 2003. Dimensional stability of Douglas fir and mixed beech-poplar plywood: Experimental measurements and simulations. Wood Science and Technology, 37(1): 11-28.

95. Cooper, P.A; Jeremic, D.; Ung, Y.T. 2004. Effectiveness of CCA fixation to avoid hexavalent chromium leaching. Forest Products Journal, 54(3): 56-58.

96. Cown, D.; Van Wyk, L. 2004. Profitable wood processing - what does it require? Good wood. New Zealand Journal of Forestry, 49(1): 10-15.

97. Creemers, J.; Meijer, M.De; Zimmermann, T.; Sell, J. 2002. Influence of climatic factors on the weathering of coated wood. Holz als Roh und Werkstoff, 60(6): 411-420.

98. Cui, W.; Kamdem, D.P. 2000. Wood products and wood protection in China. Holz als Roh und Werkstoff, 58(5): 387-391.

99. Dai, Chun Ping; Troughton, G.; Wang, B. 2003. Development of a new incising technology for plywood/LVL production. Part I. Incising at the lathe and its effect on veneer quality and recovery. Forest Products Journal, 53(3): 73-79.

100. Damodaran, K. 2000. Coconut (Cocos nucifera) wood - a potential source of wood raw material. Wood News, 10(3): 39-43.

101. Dawson Andoh, B.E.; Slahor, J.J.; Osborn, L.; McDonald, L. 2002. Effect of pre-extraction by different solvent systems on leaching of CCA components from treated Appalachian hardwoods. Forest Products Journal, 52(10): 62-66.

          102. Dawson, B. S. W.; Kroese, H. W.; Hong, S. O. 2004. Modelling the rate of loss of light
          organic solvent from a stack of radiata pine timber. Holz als Roh und Werkstoff, 62(3): 184-
          188.

103. Dawson, B.; Gallagher, S.; Singh, Adya. 2003. Microscopic view of wood and coating interaction, and coating performance on wood. Forest Research Bulletin, 228: 53.

104. Dawson, B.S.W.; Kroese, H.W.; Hong, S.O. 2002. Primer blocking and pre-service adhesion of acrylic coating systems applied to light organic solvent preservative (LOSP) treated radiata pine sapwood boards. Holz als Roh und Werkstoff, 60(3): 210-218.

105. Dawson, B.S.W.; Kroese, H.W.; Hong, S.O; Lane, G.T. 2002. Resin bleed after painting from radiata pine boards treated with tributyltin naphthenate (light organic solvent preservative) or copper, C.hromium and arsenic compounds (water-borne preservative). Holz als Roh und Werkstoff, 60(1): 18-24.

106. Deka, Manabendra; Saikia, C. N. 2004. Assessment of chemically treated wood for dimensional stability, strength property and termite resistance. Indian Forester, 130(11): 1286-1298.

107. Denizli Tankut, N.; Tankut, A.; Eckelman, C.; Gibson, H. 2003. Improving the deflection characteristics of shelves and side walls in panel-based cabinet furniture. Forest Products Journal, 53(10): 56-64.

108. Devi, R.R.; Ilias Ali; Maji, T.K. 2003. Chemical modification of rubber wood with styrene in combination with a crosslinker: effect on dimensional stability and strength property. Bioresource Technology, 88(3): 185-188.

109. Dhamodaran, T.K.; Gnanaharan, R. 2001. Optimizing the schedule for CCA impregnation treatment of rubber wood. Holz als Roh und Werkstoff, 59(4): 294-298.

110. Dhamodaran, T.K.; Gnanaharan, R. 2002. Treatability of under-water stored rubberwood with boron preservative. Journal of Tropical Forest Products, 8(1): 66-71.

111. Dhamodaran, T.K.; Gnanaharan, R. 2004. Boron impregnation treatment of Eucalyptus grandis wood; commercial scale treatment of green timber. Journal of the Timber Development Association of India, 50(1-2): 14-18.

          112. Diaz, B.; Murace, M.; Peri, P.; Keil, G.; Luna, L.; Otano, M. 2003. Natural and
          preservative-treated durability of Populus nigra cv Italica timber grown in Santa Cruz
          Province, Argentina. International Biodeterioration and Biodegradation, 52(1): 43-47.

113. Dickson, M. 2002. Timber a growth material for construction. Journal of the Institute of Wood Science, 16(2): 78-86.

114. Dickson, R.; Joe, B.; Johnstone, D.; Austin, S.; Ribton Turner, F. 2005. Pre-processing prediction of wood quality in peeler logs grown in northern New South Wales. Australian Forestry, 68(3): 186-191.

115. Dinwoodie, J.M.; Enjily, V. 2003. Wood-based panels: Particleboard (chipboard). BRE Digest, 477(2): 8.

116. Dinwoodie, J.M.; Enjily, V. 2004. Wood-based panels: Plywood. BRE Digest, 477(4): 8.

117. Dinwoodie, J.M.; Enjily, V. 2004. Wood-based panels: Selection. BRE Digest, 477(7): 16.

118. Diouf, P.N.; Delbarre, N.; Perrin, D.; Gerardin, P.; Rapin, C.; Jacquot, J.P.; Gelhaye, E. 2002. Influence of tropolone on Poria placenta wood degradation. Applied and Environmental Microbiology, 68(9): 4377-4382.

119. Dobriyal, P.B.; Chauhan, K.S.; Indra Dev. 2001. The durability and treatability of Populus deltoides Marsh. Indian Forester, 127(2): 207-212.

120. Dobriyal, P.B.; Indra Dev. 2002. Durability and treatability of some Indian bamboo species - a review. Indian Forester, 128(9): 981-990.

121. Dobriyal, P.B.; Satish Kumar. 1999. Treatability classification of five hardwoods based on penetration indices. Journal of the Timber Development Association of India, 45(1-2): 44-47.

122. Donath, S.; Militz, H.; Mai, C. 2004. Wood modification with alkoxysilanes. Wood Science and Technology, 38(7): 555-566.

123. Donkor, B.N.; Kallioranta, S.; Vlosky, R.P.; Shupe, T. F. 2003. A regional comparison of US homeowner perceptions about treated wood. Forestry Chronicle, 79(5): 967-975.

124. Druz, N.; Andersone, I.; Andersons, B. 2001. Interaction of copper-containing preservatives with wood. Part 1. Mechanism of the interaction of copper with cellulose. Holzforschung, 55(1): 13-15.

125. Duan, Xin Fang; Li, Yu Dong; Wang, Ping. 2002. Review of NDE technology as applied to wood preservation. China Wood Industry, 16(5): 14-16.

126. Eastin, I.; Perez Garcia, J. 2003. Discrepancies in forest products trade statistics. Forestry Chronicle, 79(6): 1084-1092.

127. Eastin, I.L; Roos, J.A; Boardman, P. 2004. A technical assessment of the market for wood windows in Japanese post and beam construction. Forest Products Journal, 54(6): 23-30.

128. Eckelman, C.; Haviarova, E.; Zui, H.I.; Gibson, H. 2001. Considerations in the design and development of school furniture for developing regions based on local resources. Forest Products Journal, 51(6): 56-63.

129. Eckelman, C.A.; Erdil, Y.Z.; Zhang, J.L. 2002. Withdrawal and bending strength of dowel joints constructed of plywood and oriented strandboard. Forest Products Journal, 52(9): 66-74.

130. Edwin, L.; Pillai, A.G.G. 2004. Resistance of preservative treated rubber wood (Hevea brasiliensis) to marine borers. Holz als Roh und Werkstoff, 62(4): 303-306.

131. Ejechi, B.O. 2003. Tropical field assessment of combined Trichoderma viride Proteus sp. and urea protective treatment of wood against biodeterioration. International Biodeterioration and Biodegradation, 51(2): 109-114.

132. Enayati, A. A.; Bezaatipour, P. 2000. A study on the possibility of applying used sleepers as a raw material for particleboard manufacturing. Iranian Journal of Natural Resources, 53(2): 141-153.

133. Erdil, Y. Z.; Eckelman, C. A. 2001. Withdrawal strength of dowels in plywood and oriented strand board. Turkish Journal of Agriculture and Forestry, 25(5): 319-327.

134. Erdil, Y. Z.; Zhang, J.; Eckelman, C. A. 2003. Staple holding strength of furniture frame joints constructed of plywood and oriented strandboard. Forest Products Journal, 53(1): 70-75.

135. Erdil, Y.Z.; Zhang, J.L.; Eckelman, C.A. 2002. Holding strength of screws in plywood and oriented strandboard. Forest Products Journal, 52(6): 55-62.

          136. Erdil, Y.Z.; Zhang, J.L.; Eckelman, C.A. 2003. Withdrawal and bending strength of
          dowel-nuts in plywood and oriented strandboard. Forest Products Journal, 53(6): 54-57.

137. Eriksson, P. 2003. Foreseeing the forest value of wood mechanical products. Skogand Forskning, 4: 3-6.

138. Evans, P. 2003. Emerging technologies in wood protection. Forest Products Journal, 53(1): 14-22.

139. Fan, Hui Fang. 2000. Current situation and manufacturing technology development trend of container flooring. China Wood Industry, 14(4): 19-21.

140. Fang, Gui Zhen; Ren, Shi Xue. 2002. Comparison on decay- and leach-resistances among three quaternary ammonium salts as wood preservatives. Chemistry and Industry of Forest Products, 22(2): 61-64.

141. Fang, Gui Zhen; Ren, Shi Xue; Jin, Zhong Ling. 2001. Envolvement of research on wood preservatives. Journal of Northeast Forestry University, 29(5): 88-90.

142. Fang, Gui Zhen; Sun, Yao Xing; Shi, Lian Jie; Chen, Guang Sheng. 2000. The dimensional stability and resistance to decay of wood [treated] with fire retardant DPB. Journal of Northeast Forestry University, 28(4): 57-59.

143. Feio, S.S.; Barbosa, A.; Cabrita, M.; Nunes, L.; Esteves, A.; Roseiro, J.C; Curto, M.J.M. 2004. Antifungal activity of Bacillus subtilis 355 against wood-surface contaminant fungi. Journal of Industrial Microbiology and Biotechnology, 31(5): 199-203.

144. Fisher, T.H.; Jin, Y.Y.; Schultz, T.P. 2001. Fungicidal activity of 3'-substituted-3-stilbenols. Holzforschung, 55(6): 568-572.

145. Fleming, M.R.; Hoover, K.; Janowiak, J.J.; Fang Yi; Wang, Xin; Liu, Wen Min; Wang, Yue Jin; Hang, Xiao Xi; Agrawal, Dinesh; Mastro, V.C; Lance, D.R.; Shield, J.E.; Roy, R. 2003. Microwave irradiation of wood packing material to destroy the Asian longhorned beetle. Forest Products Journal, 53(1): 46-52.

146. Fojutowski, A.; Kropacz, A. 2003. Anti blue stain chemical preservation of pine wood from different age classes. Drewno, 46(170): 27-40.

147. Forbes, C.L; Jahn, L.G; Araman, P.A. 2001. An investigation of hardwood plywood markets. Part 2. Fixture manufacturers. Forest Products Journal, 51(6): 25-31.

148. Fouquet, D. 2003. Factors of timber preservation and deterioration in humid tropical regions. Bois et Forets des Tropiques, 277: 19-34.

149. Franklin, A.; Canniere, C.De; Gregoire, J.C. 2004. Can sales of infested timber be used to quantify attacks by Ips typographus (Coleoptera, Scolytidae)? A pilot study from Belgium. Annals of Forest Science, 61(5): 477-480.

150. Freeman, M.H.; Shupe, T.F.; Vlosky, R.P.; Barnes, H.M. 2003. Past, present, and future of the wood preservation industry. Forest Pr