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Natural Fibre Composites -
a new application in bamboo technology Bamboo has a long and well established tradition as a building material
throughout the world’s
tropical and sub tropical world. It is widely used for many forms of
construction , specially for housing in rural areas. It is a fast
growing, renewable and versatile resource, characterized by high
strength and low weight, and is easily worked upon using simple
tools. Bamboo constructions are easy to build and with correct
details are resilient to wind and earthquake forces with correct
details. Yet, the use of bamboo has been largely restricted to
temporary structures and lower grade buildings due to limited
natural durability, difficulties in jointing, flammability and lack
of structural design data. Moulded in different shapes…. Perhaps, one of the biggest advantages of bamboo is the versatility in the forms and the composites it can be used in. It can be used in conjunction with other materials while offering excellent structural properties. One such application is the use of bamboo in Natural Fibre Composites (NFC). Bamboo forms the core material which is encased within resin to give monolithic structural elements. The intermeshing of fibre to resin combination gives a dense matrix of high strength and a relatively light composite material. The bamboo core can be customized to different applications- small bamboo culms, split bamboo, flattened bamboo, bamboo mats,etc. After cutting the bamoo in the required shape and size, it is placed in the mould, similar to laying a reinforcement cage and the resin is poured into the forms to encase it. The resin is mixed with accelerators and hardeners according to specifications to make it ready for use.The demoulding time varies from 40 minutes to 2 hours.
By using moulds of different geometries, a series of shapes and sizes for different applications can be achieved. NFC materials can be moulded into sheets, boards, gratings, pellets, frames, trench covers, stair treads etc. Many structural sections can also be fabricated like beams, columns, trusses, purlins and rafters. This makes it possible to use them in prefab housing, cubicles, kiosks, sheds and even geodesic domes and pyramids. They can also be used as a substitute for wood, metal or masonry for partitions, false ceilings, fences, railings and even as flooring roofing and walling tiles.
The use of resin imparts resistance to chemicals like acids and solvents, thermal and electrical resistance and makes the composite water proof, termite proof, rot proof . This makes the product ideal for use in wet environments and other extreme conditions like industries.
The material can be potentially very cost effective since a large proportion of the end product comprises of bamboo or other natural fibres or agro based biomass of different varieties. The use of resin is the influencing factor in determining the cost of the material. The percentage of resin in the finished product depends on its shape and size. In smaller and thinner products like gratings and tiles, the proportion of resin can be 50- 60 %, whereas in structural elements like trusses and beams, it can be 25- 30 %. Since, resin is the only industrial product used in the technology, the rationalized use of resin in the elements will not only further bring down the cost of the technology but also make it more environment friendly. qReported by Pankaj Khanna For more information on the technology contact Mr. Khare
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