Process for producing glass fiber reinforced thermoplastic compression molded materials and said molded materials

Process of molding fiber reinforced thermoplastic parts having at least one smooth surface, comprising:

• a. preheating laminates of a semicrystalline, thermoplastic polymer, copolymer, terpolymer, blend or alloy having around 50% polybutylene terephthalate, 45% polycarbonate and 5% elastomer that is reinforced with a reinforcing glass fiber strand mat selected from the group consisting of needled continuous strand mat, and chemically bonded mat in an amount in the range of less than 40 weight percent of the laminate at a temperature greater than the melting point of the polymer but less than the decomposition temperature of the polymer to render the polymer to have a flowable viscosity of less than around 20,000 poise and to expand the laminate, and
• b. molding and effective charging of the heated laminate by compression molding to obtain at least 5% flow of the laminate at a pressure of about 500 to about 6,000 psi and where at least one die surface of the mold is maintained at a temperature in the range from about the glass transition temperature of the poly(butylene terephthalate) to a temperature of 60.degree. F. (33.degree. C.) less than said glass transition temperature and greater than the lowest glass transition temperature exhibited by differential scanning colorimetry for the polymer between the primary and secondary glass transition temperature of the resin to produce the molded, reinforced, semicrystalline thermoplastic part.