| 摘要 |
<p>1533956 Cement bonded wood chips BERBAUELEMENTE GmbH & CO KG 23 Feb 1977 [23 Feb 1976] 07553/77 Heading C3N [Also in Division B5] Boards or constructional members of cement bonded wood chips are made by extruding a mixture of cement slurry with wood chips which, prior to mixing with the cement slurry, have been provided with a waterproof skin of water glass and cement by wetting the chips with an aqueous solution of the water glass by mixing, and then extracting the water by mixing the wetted chips with cement powder, so that the cement is at least partially set to form the waterproof skin with the sodium silicate. Preferably, the skin is formed by mixing in volume parts of 87% wood, 8% water glass, and 5% cement, and the cement slurry comprises 100 parts volume parts cement to 40 to 80 parts water, with the mixture to be extruded preferably comprising 60% volume parts of wood chips provided with the skin, 20% of cement slurry, and 20% of a filler such as perlite. The extruded boards may be made porous by the inclusion of air pockets.</p> |
