Graded density particle board

Graded density particle board is based on the same principle as three-layer particle board, just with coarser particles to the outer edges and a softwood centre. It makes a denser product than standard particle boards but lighter than three-layer particle boards, which is likely to have higher levels of resin.

Standard particle board was originally made in late 19th century Germany, then produced commercially around the Second World War. The earlier board products were often made using blood albumin glue, whilst later commercial products used phenolic resins, amino formaldehyde-, urea formaldehyde-, or urea melamine-based, today there are also particle board products that use glues with lesser environmental impacts. Graded density as well as three-layer particle boards were introduced some time later, as a method to reduce the volumes of glue and wood used, whilst retaining similar characteristics with a lighter board.

All particle boards comprise of a small chips and flakes of softwood of varying sizes and density that are impregnated with adhesive (usually amino formaldehyde-, urea formaldehyde-, or urea melamine-based) and subjected to high temperature(up to 220°C) and pressure (2-4MP). When cooled, the boards are cut and sanded, sold either as plain board or faced with laminate.

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