| 摘要 |
<p>A phenolic foam element having an integral skin of hard, unfoamed thermoset resin is prepared by foaming and curing a phenol aldehyde resin between mold confining members coated with a surface active agent in an amount sufficient that the resin in contact with the mold during foaming collapses, thereby forming the skin. This integral skin protects the foam against abrasion and indentation and eliminates the need for protective coatings, of paper, and the like, on the foam.</p> |
