Process and apparatus for manufacturing molded parts from granulated

Abstract

A process of manufacturing molded parts using a mold with relatively movable parts enclosing a mold cavity which is fed with plasticizable material, comprises directing grains of the plasticizable material into a vertically elongated vestibule having a lower end connected to the feed of the mold cavity and directing hot gases into the lower end of the vestibule and upwardly through the plasticizable material therein to make the material weldable and, thereafter, directing the weldable material into the cavity under pressure. The device for carrying out the process includes a feed conduit which is connected into the cavity which is disposed below a vertically elongated vestibule which has a closed top and a bottom opening into the conduit. The vestibule includes an upper substantially cylindrical first zone portion, a lower substantially cylindrical third zone portion, of a smaller diameter than the upper first zone portion, and an intermediate second zone portion interconnecting the first and third zone portions which is of frusto-conical configuration. The granular material is fed into the intermediate zone of the vestibule and hot gases are circulated to the lower end of the bottom third zone portion and upwardly through the material in each of the zones and out through the top of the first zone portion. A ram is movable in the feed conduit to direct the weldable plastic material into the mold cavity defined between the two mold parts.