MANUFACTURE OF STAMPING MOLDABLE LAMINATE OF GLASS FIBER REINFORCED POLY(ETHYLENE TEREPHTHALATE) AND STAMPING MOLDED SHAPE

摘要

Glass fiber reinforced poly(ethylene terephthalate) laminates having good flowability in the mold are useful in producing molded articles having additional or complex features and shapes. The glass fibers reinforcing the modified poly(ethylene terephthalate) are in the form of a needled mat which can be produced directly from forming glass fibers or from packages of glass fibers. In either situation, the glass fibers have a chemical treatment of a dried aqueous chemical treating composition having one or more poly(ethylene terephthalate) compatible thermoplastic film forming polymers that are dispersible, emulsifiable or soluble in water, one or more organic-inorganic glass fiber coupling agents in an effective coupling agent amount, a cationic lubricant in an effective lubricating amount and a carrier in an effective amount to allow application of the chemical treating composition to the glass fibers. The continuous glass fiber strands are formed into at least one layer of continuous glass fiber strands ultimately having a moisture content of less than 1 weight percent for needling. After needling, the needled mat is dried to have a moisture content of less than around 0.3 weight percent. One or more layers of the needled mat are laminated with one or more overlays and/or extrudates of modified poly(ethylene terephthalate). The poly(ethylene terephthalate) is modified to have a rate of crystallization from melt to produce at least 30 weight percent crystallization at a temperature in the range of 120 to 220°C in a time from about 5 to about 60 seconds. The lamination is conducted at a temperature to melt the poly(ethylene terephthalate) under pressure and for sufficient time to allow the melted poly(ethylene terephthalate to penetrate into around and through the needled mats. Subsequently the heated materials are cooled at a rate to produce at least 30 weight percent crystallization in the PET, when the cooled temperature of the laminate is around 150_.F. The laminates are dimensionalized to meet the volume and configurational requirements for a molded part. One or more dimensionalized laminates are heated to melt the modified poly(ethylene terephthalate) at a rate to remove any moisture from the laminate before melting the PET. The heated laminates are molded in a hot die at a temperature in the range of 120 to 220°C for a time in the range of about 5 to about 60 seconds to produce the reinforced PET molded part having at least 30 weight percent crystallization.