Development of a Rapid Injection Mold for Liquid Silicone Rubber

• Main Authors: LIN,JIUN-SHIAN, 林君憲
• Other Authors: KUO,CHIL-CHYUAN
• Format: Others
• Language: zh-TW
• Published: 2019
• Online Access: http://ndltd.ncl.edu.tw/handle/n97qu4

碩士 === 明志科技大學 === 機械工程系機械與機電工程碩士班 === 107 === Liquid silicone rubber (LSR) parts are used in biomedical products and daily commodities due to their stable properties. In order to compress time to market for a new product, it is necessary to develop an injection mold for LSR injection mold swiftly and effectively. Rapid tooling (RT) technology can reduce time to market compared to the conventional machining methods. The aluminum-filled epoxy resin mold is capable of replacing the conventional steel mold for small batch production using injection molding. In this study, an injection mold with heating element was developed using RT technology for LSR injection molding. It was found that the replication rate for the average microgroove depth and width of the Al-filled epoxy resin mold is about 90.5% and 98.9%, respectively. The transcription rate for the average microgroove depth and width of the LSR molded parts is about 91.5% and 99.2%, respectively. The variations in dimension of microgroove depth and width of the LSR molded parts can be controlled within ± 1 μm. The average surface roughness of the Al-filled epoxy resin mold was only increased by about 12.5 nm after 200 test runs of LSR injection molding. This study furthermore developed epoxy resin tooling allowing the addition of aluminum powder to reduce the manufacturing cost of metal resin rapid tooling. With the optimum mixing ratio, the epoxy resin mold developed in this study, exhibiting mechanical properties close to those of its commercial counterpart, was capable of achieving approximately an 87% reduction in rapid tooling manufacturing cost compared to its commercial metal resin counterpart.