There are four main categories of particle composites: parallel strand lumber, particleboards, fibreboard, and woodwool slabs.
Parallel strand lumber, particleboards and OSB are fabricated with small fragments of wood produced by cutting or mechanical fracture of timber, while the fibre in fibreboards is produced by pulping the wood to produce bundles of fibres or separated fibres. Woodwool slabs are made with long, thin, thread-like, strands of woodshavings.
Parallel strand lumber (PSL) is manufactured from long strands of dried timber oriented with the grain parallel and glued together under heat and pressure into a continuous billet which is cut into standard structural lengths.
The best-known particleboard type is chipboard, made from chips produced by mechanically fracturing wood, such as forest thinnings and industrial wood waste, into small fragments. After drying, the graded chips are mixed with resin and formed into boards by curing in a heated press. Cement bonded particleboard comprises small particles of wood bonded with either Portland or magnesite cement, and formed and cured into panels.
Oriented strand board (OSB) is made from strands of wood aligned in layers throughout the thickness of the board, the strands having a length of at least twice their width. This produces a cross-ply effect, emulating plywood with similar strength and stiffness.
Woodwool slabs are made from long strands of wood shavings, tangled, coated in cement and lightly compressed together. They have an open texture, and are very permeable to water vapour and moisture absorbent
