Composite Materials
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PlywoodPlywood is probably the most widely available manufactured board material. It is made by bonding together a number of thin veneers of softwood or hardwood - or a combination of each. There is always an odd number of veneers and the direction of the grain runs alternately to give the material strength; the more veneers used, the stronger the plywood. Both the type of glue and veneers determine the suitability of a sheet for a particular application. The finish quality of plywood varies enormously, some have attractive grains while others can have a large number of knots.
HardboardHardboard is a compressed, composite board. Fibre residuals are saturated in a wet process and then compressed to a sheet. A fine fibre overlay is applied (normally to one side) to provide smooth face.
ParticleboardParticleboard is made by bonding together wood particles with an adhesive under heat and pressure to form a rigid board with a relatively smooth surface. Particleboard is available in a number of densities; normal, medium and high-density. Normal density is fairly soft and 'flaky', high-density is very solid and hard (often used for worktops and fire doors) - medium density is somewhere in between.
Medium Density Fiberboard (MDF)MDF is a type of hardboard which is made from wood fibres glued under heat and pressure. MDF has many qualities that make it an ideal alternative to plywood or chipboard. It is dense, flat, stiff, has no knots and is easily machined. Its fine particles provide a material without a recognisable "grain". Unlike plywood and blockboard, MDF contains no internal voids, and will produce better edges providing that it is correctly machined.
Oriented Strand Board (OSB)Sterling board is a wood-based panel manufactured from softwood strands compressed and bonded together with exterior grade, water resistant resins. It is readily identified by the random pattern of flattened, softwood strands which make up the surface.
It can be used in place of other sheet materials but due to the surface finish, it is generally restricted to areas where appearance does not matter. Tongue and Grooved is also available for use on flat roof decking and flooring applications. |