METHOD AND APPARATUS FOR FORMING A MOLDED PLASTIC PART

摘要

A method and apparatus for forming a molded plastic part such as a body side molding for a motor vehicle in which a ribbon of plastic material is extruded through a shaping die of an extruder and is thereafter moved through a runner and into an elongated closed end mold cavity having a size and shape conforming to the body side molding. The cross-sectional area of the extruded ribbon, the runner, and the mold cavity are substantially equal and the entire path of the plastic material moving through the extruder, runner, and mold cavity is maintained at a temperature above the melting point of the plastic material so that the plastic material moves smoothly and quiescently along the path under relatively low pressure and with minimal disturbance. The invention process substantially eliminates swirling and streaking of metal particles which are commonly dispersed in the plastic material to give the body side molding a metallicized, glossy appearance.