Patent ID: 8790106
Filing Date: 2014-07-29
Classification: B29B,B29C,B29K

Abstract:
1. An apparatus for processing thermoset cross-linked elastomeric scrap material, comprising: a batch-operated high shear mixer for receiving said thermoset cross-linked elastomeric scrap material and configured to induce chemical reactions to partly devulcanize the material in a first devulcanizing stage wherein the material retains some cross-linking; and a continuously-operated multi-screw cooled extruder including elements for rolling and elements for milling and configured to receive the partly devulcanized material consisting of a granule liquid mix from the high shear mixer and further devulcanize the material by mechanical shearing action in a second stage to produce an extruded product for revulcanization, said continuously-operated multi-screw cooled extruder rotating at speeds no greater than 100 rev/min and comprising in sequence: a first zone configured to limit the temperature of the material to no higher than 90° C. and to perform a high shear process with an approximate 0.015″ gap between moving components and about 500 passes of milling at a 2:1 ratio, said first zone including milling elements for performing a milling action; a second zone configured to cool the material to less than 40° C.; a third zone cooled to about 40° C. and configured to provide a medium shear milling action of about 250 passes of milling at about a 1:1.25 ratio; and a fourth zone configured to compact the material and feed the compacted material to a discharge orifice ready for use as a source material in a vulcanizing process.