| 摘要 |
PURPOSE:To improve the release property of particle board during hot pressing by a structure wherein vegetable fragments impregnated with aqueous solution of urea or related substance are employed at both the front and the back layers of the particle board manufactured by using organic polyisocyanate as binder. CONSTITUTION:Particle board with excellent humidity resistance and durability is manufactured by hot-pressing forming mat, which is formed by adding organic polyisocyanate to vegetable fragments having water content of about 30% or less. Mat layer, which forms the front layer and the back layer of the particle board, is formed by employing vegetable fragments, to 100 parts by absolute dry weight of which several parts of 5-50% by weight aqueous solution of ureal substance such as urea, thiourea, dicyanamide, aliphatic amines, aromatic amines or the like is impregnated by spraying or the like. The organic polyisocyanate vapor developed by heating is caught by urea, resulting in preventing the fragments from adhering to a cold plate and a heating platen. Cellulosic material can be employed as a fragment. |
