| 摘要 |
<p>The tools receive sand which can damage their surfaces by chemical reactions, so a protective porous coating is used on the tools. The coating is pref. dyed with a pigment which has a high resistance to chemical reactions, and is then impregnated with an inert material. The surface of the tools pref. consists of Al or an Al alloy, which is anodised; and the oxide coating is dyed, esp. by carbon. The impregnant is pref. a hydrocarbon, esp. a long chain alkane, e.g. paraffin wax. The coating can be used on any tool with an Al surface, e.g. moulding- or core-boxes, but esp. on patterns. Used e.g. on a pattern made of steel, cast-iron, bronze or resin and covered with Al. The coating is not attacked by sand contg. chemicals such as isocyanate- or phenolic-resins.</p> |
