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:
Aug. 16, 1983
Filed:
Feb. 20, 1981
Applicant:
Inventor:
Juris Walter, Schaffhausen, CH;
Assignee:
Swiss Aluminium Ltd., Chippis, CH;
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
B29D / ; B29F / ;
U.S. Cl.
CPC ...
264 455 ; 264 461 ; 264 48 ; 264321 ; 264D / ; 425325 ; 4258 / ;
Abstract
The invention relates to a process for the continuous manufacture of foamed sheets of thermoplastic material having an extreme width to thickness ratio, small thickness tolerance, a uniform cell structure and, over the whole cross section on both sides of the sheet a thin, non-foamed outer skin. The plastic, which already contains the foaming agent is, on emerging from a wide-slit nozzle, allowed to foam freely without any restriction and cool. The sheet or strip formed in this manner is then heated locally at the surface and calibrated to final dimension.