Extrusion machine for the extrusion of thermoplastic materials.

摘要

920,734. Extrusion machines. S.A.S. LAVORAZIONE MATERIE PLASTICHE (L.M.P.) DI M. I. COLOMBO & C. Dec. 29, 1961 [Feb. 28, 1961], No. 46622/61. Class 87(2). An extrusion press for synthetic thermoplastic materials comprises a barrel 11; a pair of screws 17, 18 with material-tight screwthreads rotating in the barrel and each screw having a smooth intermediate section 27 transversely aligned with a similar smooth section 28 on the other screw; a throttling member 20 of Venturi profile fast with the barrel surrounding the sections 27, 28 of the screws; means e.g. an electric induction winding 41 for heating the barrel and the screw sections 11; means e.g. a cooling jacket 54 for cooling the throttling member; and at least one suction passage e.g. 24, 25 in the barrel 11 directly downstream of the throttling, member 20. Two or more screw sections e.g. 10, 11, 12, may be connected in series with throttling members 20, 21 between them.