Compression stamping, glass fiber

Figure 5.54 Processing sequence for compression stamping glass fiber reinforced thermoplastic sheets...

In use are stamping compression molding presses. Plastic used can be TS sheet molding compounds (SMCs) and stampable reinforced thermoplastic sheet (STX) material (STX is a registered tradename Azdel Inc., Shelby, NC). It is usually composed of a glass fiber-thermoplastic RTP (Chapter 15). 

GE Plastics markets a range of composites (Azloy ) based on glass hber reinforced PC, PC/PBT (Xenoy ) or PPE alloys. The glass fiber reinforcement is in the form of mats or chopped fibers. Parts with these materials are formed by compression molding. The materials are commercially available in the form of precompounded sheets from which blanks are cut and stamped into the final shape following the standard rules for glass filled materials. For example, better flow is obtained with the reinforcement in the form of chopped fibers than with mats. The type of reinforcement determines the ability to hll complex parts, such as parts with ribs. 

A single-part windshield wiper cowl plenum compression molded from 32 percent Crastin glass fiber reinforced vinyl ester SMC, replaces 11 steel stampings welded together for DaunlerChrysler minivans. All critical system components are directly mounted to the cowl plenum, which was not possible with the steel assembly, because it did not have the necessary precision fit. ... 

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