The main raw material for the production of bamboo ply/mat board is bamboo, which is the fastest growing plant and occurs naturally in the forests and is also suitable for plantation even over degraded lands. For manufacturing boards, bamboo is to be converted into mats. The sheets have been found to be resistant to water, fire, decay, termites, insects, etc.[1]
The manufacturing process consists of the following:
1. Procurement of bamboo slivers in mat form from the farmers. Mats are woven from bamboo slivers. Mostly women in rural or tribal areas do the weaving manually, as part time vocation to supplement family income. From split bamboo epidermal layer is removed and slivers of thickness ranging from 0.6mm to 1.8 mm are made and dried in air to moisture content of around 15%. Three types of mats are required for the ply board (normally a couple of cms longer and wider than the size of the finished ply board)
2. The mats are dried to a moisture level not exceeding 15%
3. Bamboo mats are dipped in modified phenol formaldehyde resin mixed with a preservative to increase resistance to termite and decay. Resin coated mats are dried to a moisture content of around 10% in steam heated drying tunnels.
4. Dried resin coated mats are assembled in 10 to 15 plies and hot pressed to produce bamboo mat ply board of desired thickness. The mats are assembled in a manner that cross layers are on top and bottom while the longitudinal and transverse mats alternate till the desired thickness.
5. This combination is now pasted on either side with resin coated impregnated paper or wood veneer as desired.
6. The composite is now pressed in hot press for half an hour to the required thickness.
7. The ply board is now ready to be trimmed from the edges to the required dimension using rotary cutters.
8. After trimming the edges the ply board is inspected for dimensions, thickness, surface finish and sent for packing.
Market Size: Factory-produced, these bamboo boards represent a significant new market for rural bamboo producers. Wafer board and OSB are widely used in the US and Canada, with 95% houses being made of these. Bamboo is an ideal raw material for the production of wafer board and OSB due to its strength and dimensional stability. The price of wafer board/OSB made of bamboo is approximately US$8/ft3, which is equivalent to US$0.40/ft2 approx. of 15 mm thick boards – approximately half the cost of treated wood boards of same dimensions. Technology has been developed to produce roofing sheets from wafer board that also insulate thermally, which makes it a very competitive product as against those from bamboo mat board, which has failed to impact the market owing to high prices.
[1] INBAR, 2002
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