| 摘要 |
<p>Shell process foundry resin compositions containing novolak resins are improved by incorporating therein from about 0.5 to about 10 percent, based on the weight of the resin, of a finely divided, siliceous material such as fumed silica, bentonite, kaolin clay and attapulgus clay. The presence of the siliceous material provides resistance to peelback during the formation of sand shells and increases the stripping strengths of the incompletely cured molds.</p> |
