| 摘要 |
<p>A layer of mouldable material containing a hardening synthetic resin is applied by heat and pressure to a compressible base by first applying a high pressure for such a short time as to liquefy the material and then applying a considerably lower pressure while heating is maintained until the material has hardened. A wooden plate is covered with a thin layer of a mixture comprising 50 per cent by weight of phenolformaldehyde condensation product and 50 per cent of wood dust. A layer of paper impregnated with resin may be inserted between the wood and the resin powder. The plate is then pressed for three minutes at a temperature of 150-160 DEG C. under a pressure of 70 kg/cm2 and afterwards for 7-10 minutes under a pressure of 10 kg/cm2. The base may also be made of cork, synthetic wood, or the material known under the Registered Trade Mark "Celotex."</p> |
