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:
Mar. 17, 1992
Filed:
Sep. 06, 1990
Applicant:
Inventor:
Joachim Meyke, Hanover, DE;
Assignee:
Hermann Berstorff Maschinenbau GmbH, Hanover, DE;
Attorney:
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
B29C / ;
U.S. Cl.
CPC ...
264 459 ; 264 51 ; 264 53 ; 26421121 ; 264D / ;
Abstract
A method of producing a foamed thermoplastic plastics material wherein the plastics material is mixed with a pulverulent nucleating agent and is then fused in an extrusion device. A gaseous nucleating agent, generally nitrogen, is then injected into the fused mixture in an amount of from about 0.1% to 0.5% by weight. Thereafter, a liquid propellant is injected into the fused mixture in an amount of from 0.5% to 6.0%, preferably 0.5% to 5.0%, by weight. The mixture is then conveyed to an extrusion head and extruder whereupon foaming occurs.