Thermoplastic copolyesters injection molding

The wholly aromatic copolyester for injection molding is available in filled and unfilled grades. It can be molded into thin-wall components at high speeds. The high melt flow also enables it to be molded into heavy-wall parts. No mold release is required because of the inherent lubricity and nonstick properties. No post-curing is necessary because the material is completely thermoplastic in nature. The material is expected to have many applications because of its moldability and its resistance to high temperatures, fire, and chemicals. 

Liquid Crystal Polymers Thermoplastic aromatic copolyesters with highly ordered structure. Has good tensile and flexural properties at high temperatures, chemical, radiation and fire resistance, and weatherabil-ity. Processed by sintering and injection molding. Used to substitute ceramics and metals in electrical components, electronics, chemical apparatus, and aerospace and auto parts. Also called LCP. 

Skin/core morphologies are common in blends of LCP s and thermoplastic polymers and they play a significant role in defining the properties of both extruded and injection molded samples. Usually, LCP s in the skin have a higher degree of orientation than in the core when the blends are extruded or injection molded (Husman et al. 1980 Hedmark et al. 1989 Lee 1988). Baird et al. (Baird and Mehta 1989 Baird and Sukhadia 1993) observed a skin/core morphology in blends of PA 66 with HBA/HNA and 40 PET/60 PHB and 20 PET/80 HBA copolyesters. More LCP fibers were present in the skin than in the core for both systems. Isayev and Swaninathan (1994) also reported shell-core structure in the fracture surfaces of injection molded blends of HNA/HBA liquid crystalline copolyesters and poly (etherimide). 

Copolyester elastomers can be processed by conventional thermoplastic melt processing methods such as injection molding and extrusion. They require no vulcanization. These polymers can be processed successfully with low-shear processes such as laminating, rotational molding, and casting. 

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