| 摘要 |
<p>An apparatus for heating and blending highly filled thermoplastic material, such as the PVC compounds used in making plastic pipe, prior to delivering the material into the barrel of an extruder. The apparatus has an elongated housing (34) which contains two intermeshing feed screws (50) that are driven to rotate in the same direction. Controlled heating is provided by electric band heaters (102) which encircle the exterior of the housing (34), and electric cartridge heating elements fitted into aluminum cores that are received by an axial bore in each of the feed screws (50). The use of co-rotating screws and precisely controlled supplemental heat is effective in delivering a constant flow of material to the extruder without localized heating or compacting.</p> |
