Processing, thermoplastics mold design

Multiblock Copolymers. Replacement of conventional vulcanized mbber is the main appHcation for the polar polyurethane, polyester, and polyamide block copolymers. Like styrenic block copolymers, they can be molded or extmded using equipment designed for processing thermoplastics. Melt temperatures during processing are between 175 and 225°C, and predrying is requited scrap is reusable. They are mostiy used as essentially pure materials, although some work on blends with various thermoplastics such as plasticized and unplasticized PVC and also ABS and polycarbonate (14,18,67—69) has been reported. Plasticizers intended for use with PVC have also been blended with polyester block copolymers (67). 

Injection Molding Guide for Thermoplastic Rubber—Processing, Mold Design, Equipment, Advanced Elastomer Systems LP, Akron, Ohio, 1997. 

Compression molding is used primarily to process thermosetting systems and difficult-to-process thermoplastics, such as flber-fllled systems or thermoplastic elastomers. We first describe some of the basic features of the process and the areas where design is needed. This is followed by discussion of the elementary ideas in the modeling of compression molding. 

Newer resins include polysulfone, polyethersulfone, polyetherimide, and polyetherketone. Some of these newer materials are high temperature thermoplastic, not thermoset, resins. They are being promoted for the design of injection-molded printed circuit boards in three-dimensional shapes for functional appHcations as an alternative to standard flat printed circuit boards. Only semiadditive or fully additive processing can be used with these devices. 

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