| 摘要 |
865,384. Extruding plastic materials. CABOT Inc., G. L. March 21, 1958 [May 17, 1957], No. 9037/58. Class 87(2). A continuous process for extruding heat curable polymeric compositions comprises heating the composition to a temperature at which it is flowable but not curable, extruding the material through a shaping passage and raising its temperature therein to an active curing level, adjusting the flow rate through the passage in proportion to the temperature attained by the material so that the material emerges from the passage form-sustaining but incompletely cured and then completely curing the composition. Various compositions on temperatures are given. The process may be performed in an extrusion machine comprising a cylinder 10, screw 16 and a breaker plate 28 leading to a shaping passage comprising a mandrel 32 and die 34 which together are coupled to a generator 38 for the production of a high frequency dielectric field across the passage. The extrusion emerges from the passage incompletely cured and is finally cured by its own residual heat before entering a cooling chamber 46. The extrusion may be a tube supported by internal air pressure through a bore in the mandrel or a coated cable. Specification 856,833 is referred to. |
