Copper alloys, Moldmax and Protherm, with high thermal conductivity are frequently specified as mold materials in plastic processes, including injection molding and blow molding. Advantages of such alloys include faster heat transfer and improved mold temperature uniformity leading to shorter cycle times and reduced part warpage. The relative durability of copper alloy molds and mold inserts, compared to traditional tool steels used in plastic injection molds is, however, of concern, since a common perception exists that copper alloys lack wear resistance, particularly in the case of abrasive plastics processing. A methodology of testing the abrasion resistance of copper alloy tooling materials, Moldmax and Protherm, with and without wear coatings, in an actual injection molding environment was developed using an abrasive 33% glass fiber reinforced thermoplastic material. Comparison was made with tool steel. No difference in the wear behavior was observed between the copper alloy and tool steel materials after 35,000 molding cycles. The tests are being continued for a comprehensive evaluation of the relative wear resistance of the tooling materials.
展开▼
