The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Jan. 23, 1979
Filed:
Oct. 04, 1976
Eberhard Kertscher, Romanel, CH;
Maillefer S.A., Ecublens, CH;
Abstract
An installation is provided for extruding plastic material comprising a screw extruder having a cylinder provided with a hopper near the rearward end of said cylinder and with an extrusion head secured to the forward end of said cylinder, and at least one pump having a delivery pipe connected to at least one port disposed in the wall of said cylinder for delivering an additional fluid product to said extruder through said port or ports during the extrusion operation, the inner surface of said cylinder including a zone provided with grooves extending downstream starting from said hopper over a limited distance, said port or ports opening out into one or more of said grooved zone, said grooved zone being followed by a smooth zone, the inside diameter of which is less than the maximum diameter measured from the bottoms of said grooves, and wherein said screw extruder is of essentially uniform dimensions at the point of said zone and the portion of said screw extruder immediately upstream thereof.