Polyesters prepreg sheets

Figure 5.1 7 Automated-integrated RP vacuum hand lay-up process that usesTS polyester prepreg sheets...

Mat and continuous glass fibre reinforcements theoretically all the thermoplastics are usable in these forms, but up to now developments have concentrated on polypropylenes (PP), polyamides (PA) and thermoplastic polyesters (PET) fibre-reinforced PEEK, polyetherimide (PEI) and polyphenylene sulfide (PPS) are used for high-performance applications. They are presented in a range of forms from stampable sheets to pellets, prepregs, ribbons, impregnated or coated continuous fibre rods. More rarely (as in the case of PA 12, for example), the thermoplastic is provided in liquid form. 

Prepregs, in the strict sense of the term, are therefore limited to certain resin systems and are usually employed in higher-performance materials. An alternative form, which has been used very widely for almost a half century, is sheet molding compound (SMC) and bulk molding compound (BMC), which are fully-formulated materials ready for molding by compression or injection, mainly based on TS polyesters and glass fibers (Table 4.1). 

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