Cement-bonded particleboard (CBPB) was first commercially manufactured in the early 1970s. The panel is a mixture of wood particles and Portland cement together with mineral additives. The first impression of the panel is that it is grey in color, has a smooth almost polished surface and is heavy. This initial assessment of the panel fails to appreciate its outstanding merits especially in terms of reaction to fire, durability, stability, sound insulation and stiffness.
Following storage for at least 3 months, the debarked softwood logs of selected species are reduced to flakes some 10mm to 30mm in length and 0.2mm to 0.3mm in thickness using drum-knife flaking machines. After passing through a hammer mill, the flakes are separated into surface and core material by screening, and are then mixed with Portland cement and water in the ratio by weight of:
Small quantities of chemicals are added to the wet mix; one of their purposes is to accelerate cement setting.
Careful storage and handling is important to maintain panels in their correct condition for use; therefore CBPB must be protected from rain and accidental soaking. During transport, it is particularly important to keep edges well covered. Panels should be stored flat in an enclosed, dry building. When handling panels, the edges and corners should be protected against damage and care should be exercised in the carriage of thin panels.