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Patent Searching and Data

Document Type and Number:
Japanese Patent JPH0418326
Kind Code:

PURPOSE: To reduce the degree of dispersion in the radial direction by substantially supplying a gas replenished in a blank tube from the mouthpiece of an extruder at a fixed temperature after heating.

CONSTITUTION: A thermoplastic resin is extruded in a tubular shape from a mouthpiece 1, a tube 6 under a softened state is held by two pairs of pinch rolls 2 and 3, introduced into a heating apparatus 4 and heated at a temperature higher than the softening point of the resin and lower than the melting point in the heating apparatus 4, and a diameter is enlarged by the pressure of air incorporated into a diameter enlarging section 7, and the tube is oriented and oriented up to desired diametral size. Since air filled in the tube in the diameter enlarging section 7 slips out with time, air is replenished from the introducing pipe 9 of air in order to supply the air. Compressed air fed from a supply source is stabilized by a regulator and a reducing valve and introduced into the introducing pipe 9, and heated by a heater 10. A temperature detector 11 and a temperature regulator 12 are annexed to the heater 10, and air is heated substantially at a fixed temperature, thus preventing the effect of atmospheric temperature on the tube 6 under the softened state immediately after extrusion.

Torii, Tamotsu
Application Number:
Publication Date:
January 22, 1992
Filing Date:
May 14, 1990
Export Citation:
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International Classes:
B29C55/22; B29C61/08; B29K105/02; (IPC1-7): B29C61/08