| 摘要 |
PURPOSE:To reduce the weight of a pattern and to improve machineability, etc. by packing a waste material into the cavities of a skeleton, embedding the mixture composed by compounding adequate amts. of lightweight aggregate, furan resin or urea resin and acid into the cavities and molding the surface. CONSTITUTION:Skeletal materials 1-4 for a pattern are made of wood and a prototype is formed. Left-over pieces such as wooden pieces and styrene balls are put into the spaces in such skeleton and thereafter the mixture composed by adding 20-60pts. a furan resin or urea resin (liquid) and 1-10pts. acid such as sulfuric acid as a catalyst to 100pts. granular lightweight aggregate is embedded therein. The surface thereof is then cut away to the specified size, by which a solid pattern is perfected. The similar result is obtd. by adding further 5-10pts. a polyester resin or epoxy resin (liquid) and 0.5-1pt. curing agent to 100pts. the lightweight aggretate. Since the light material and plastic material are used, the weight and cost are both reduced. |
