| 摘要 |
<p>The process consists of (a) preparing several kraft papers of 100-250 g./sq.m. weight, impregnated with 24-35% plasticised phenol-formaldehyde varnish; (b) drying and partially curing the impregnated paper in a hot air oven at 130-150 deg. C; and (c) placing several of the layers over a core of cellulosic material and pressing and curing by heat.</p> |
