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, 1977
Filed:
Jan. 23, 1976
Stephen Olney Cook, Mill Valley, CA (US);
Crown Zellerbach Corporation, San Francisco, CA (US);
Abstract
Tubular multilaminate film having four or more layers can be made by A. combining two or more streams of dissimilar resins to form a first stream of parallel layers of the resins and feeding the stream into a first annular space wherein the stream divides into two substreams which flow laterally in opposite directions about the axis of the space and then join to form a first annular stream in which the layers are coaxial, B. combining two or more other streams of resins to form a second stream of parallel resin layers and feeding the stream into a second annular space which is concentric with the first annular space and wherein the second stream divides into two substreams which flow laterally in opposite directions about the axis of the space and then join to form a second annular stream in which the layers are coaxial, and C. combining the first and second annular streams to form a composite annular stream, and D. expressing the composite annular stream through an annular orifice to form the tubular multilaminate film.