| 摘要 |
977,955. Reclamation of scrap synthetic resin. E. I. DU PONT DE NEMOURS & CO. Aug. 1, 1963 [Aug. 1, 1962], No. 30633/63. Heading B5A. In a process for the reclamation of thermoplastic synthetic resin scrap, particles of the scrap are compacted in a tapered screw compactor 4 and issue into a melt screw extruder 7 and are extruded as molten resin. The screw 3 of the compactor is driven by motor 1 through coupling 2 at a controlled torque so that compacted synthetic resin passes into the extruder at a constant pressure of from 75 p.s.i. to just below the pressure at which the compacted resin would be converted into melt. A cutter 10 cuts the extruded resin into pellets. By this process particles having relatively high bulk density are obtained from particles of low bulk density and can be used in extrusion processes for forming films &c. Non-thermoplastic material such as hemp or asbestos may be added to the thermoplastic resin before compaction. Two examples are described of the treatment of scrap polyethylene film. |
