| 摘要 |
<p>PURPOSE:To form a wooden heat-insulating board by a method in which a dry cellulosic base material is impregnated with an urea resin liquid, dried, neutralized, mixed with a resin material, and molded by expansion to form a skin layer on the surface of the expanded molding. CONSTITUTION:A cellulosic base material (e.g., broken chips, pulp, etc.) is dried to within 15wt%, and impregnated with an urea resin adhesive liquid of emulsion type. The mixture is allowed to stand for 20-30min. The urea resin-impregnated base material in neutralized, dried, and broken into sizes of 100- 150 mesh to obtain an aggregate. The aggregate so obtained is mixed with an expansible resin material 2 (e.g., urethane resin or polystyrene resin, etc.) and then with a blowing agent, a stabilizer and a deterioration inhibitor. The mixture is expanded and molded, and a skin layer 2a is provided on the surface of the molding to form a base board (a) for heat-insulating boards.</p> |
