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. 13, 1984
Filed:
Nov. 09, 1981
Applicant:
Inventor:
Thomas W Winstead, Baltimore, MD (US);
Assignee:
Maryland Cup Corporation, Owings Mills, MD (US);
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
B29D / ;
U.S. Cl.
CPC ...
264 403 ; 264 406 ; 264 407 ; 264 50 ; 264 53 ; 264 54 ; 264D / ; 425 / ; 425144 ; 425145 ; 4258 / ;
Abstract
A method and apparatus for entraining gas as a blowing agent in a thermoplastic melt to provide a foamed thermoplastic extrudate wherein an annular sheet-like flow of gas under pressure is impinged on a tubular configuration of melt to entrain the gas in the melt is disclosed. Also disclosed is an improved method and apparatus for controlling the pressure in the thermoplastic melt.