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:
Sep. 01, 1992
Filed:
Dec. 28, 1989
Robert J Blemberg, Appleton, WI (US);
John P Eckstein, Neenah, WI (US);
Mark E Nordness, Appleton, WI (US);
American National Can Company, Chicago, IL (US);
Abstract
Apparatus and method for fabricating films and packages, especially films and packages containing a layer of vinylidene chloride copolymer. The preferred apparatus includes a coextrusion feedblock (20) in combination with an annular extrusion die (10) having an internal crosshead mandrel (11), and intervening spacing means for conveying the melt stream (24) from the feedblock to the die. The mandrel (11) has a cross-head groove (14), whose preferred design resembles elements of a rectangle. The inner surface of the outer die wall (19) preferably has an offset portion, including one of a pair of ramps (33A, 33B) traversed by the melt stream (24) as it leaves the groove. The die (10) maintains the melt stream in a single basic shape as the melt stream traverses the die. The VDC copolymer is shielded from the equipment surfaces beyond the VDC copolymer extruder. Equipment surfaces beyond the VDC copolymer extruder are protected from the VDC copolymer. The effective shielding enables use of a die (10) greater than 85 cm. circumference at its exit (31).