Improvements in the manufacture of tubes of thermoplastic materials

摘要

626,945. Extruding tubes. SOC P.A. LAVORAZIONE MATERIE PLASTICHE. May 2, 1946, No. 13.343. Convention date, June 21, 1944. [Class 87 (ii)] [Also in Group XXVIII] A tube is formed of two or more helical portions 1, 2 of thermoplastic material of different properties, colours, &c., by a rotary distributer 6 having conduits 9, 10 fed respectively with two different thermoplastic materials by extrusion presses P, P1 and annular chambers 4, 41 opening into the conduits by means of annular slots. The distributer is driven by a pinion 12.