| 摘要 |
1,024,954. Extruding tubes. SHELL INTERNATIONALE RESEARCH MAATSCHAPPIJ N.V. April 30, 1964 [May 2, 1963], No. 17983/64. Addition to 914,850. Heading B5A. Thermoplastic tubing extruded horizontally is internally cooled by direct contact with a cooling liquid supplied through an insulated duct passing through the mandrel of the die, whilst simultaneously being internally sized. As illustrated, the extruded tubing is passed over an internal sizing device 1 having an external helical groove 4 into the inner end of which opens an aperture 5 through which cooling liquid is supplied via the air insulated duct 2 and the interior of the device 1. The sizing device may alternatively be provided with a number of helical grooves, one or more of which may be of different hand than the remainder. |
