| 摘要 |
An extrusion pelleting process and apparatus is disclosed wherein the outermost portion of an extrusion orifice is surrounded by a heat reservoir maintained at a temperature significantly higher than the softening temperature range of the polymer being extruded. The high temprature heat reservoir constitutes a heat source from which individual extrusion orifices may be heated above the polymer's softening range to assist in melting frozen plugs of polymer which may block the orifice from time to time. Also disclosed is a heat flow control mechanism, in effect, for slowing the heat release from the reservoir to the individual extrusion orifices for economy of operation while still making available such high temperature source for unfreezing such plugs. The presence of a combination coolant and lubricating film at least partially comprised of nonvaporized liquid coolant between the material being extruded and the inner surface of its extrusion orifice which produces an extrusion in rod of strand-like form having a partially solidified exterior shell prior to cutting into individual pellets is believed to enable the operation of the outer platen of the subject device at significantly higher temperature than prior are devices without the adverse effects of polymer overheating. |
