Particle board is cheaper, denser and more uniform than conventional wood and plywood and is substituted for them when cost is more important than strength and appearance. Particleboard can be made more appealing by painting or the use of wood veneers on visible surfaces. Though it is denser than conventional wood, it is the lightest and weakest type of fiberboard, except for insulation board. Medium-density fibreboard and hardboard, also called high-density fiberboard, are stronger and denser than particleboard. Different grades of particleboard have different densities, with higher density connoting greater strength and greater resistance to failure of screw fasteners.
A significant disadvantage of particleboard is its susceptibility to expansion and discoloration from moisture absorption, particularly when it is not covered with paint or another sealer. Therefore, it is rarely used outdoors or in places where there are high levels of moisture, except in bathrooms, kitchens and laundries, where it is commonly used as an underlayment shielded beneath a moisture resistant continuous sheet of vinyl flooring.
Particleboard or chipboard is manufactured by mixing particles or flakes of wood or jute-stick together with a resin and forming the mixture into a sheet. The raw material is fed into a disc chipper with between four and sixteen radially arranged blades. The chips from disk chippers are more uniform in shape and size than from other types of wood chippers. The particles are then dried, and any oversize or undersized particles are screened out.
In dry environments, veneered particleboard is preferred over veneered plywood because of its stability, lower cost, and convenience.
Resin is then sprayed as a fine mist onto the particles. Several types of resins are used in the procces. Amino-formaldehyde based resins are the best performing based on cost and ease of use. Urea melamine resins offer water resistance with more melamine offering higher resistance. It is typically used in external applications, with the coloured resin darkening the panel. To further enhance the panel properties, resorcinol resins can be mixed with phenolic resins, but that is more often used with marine plywood applications.
