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:
Feb. 05, 1991
Filed:
Nov. 09, 1987
Christopher W Macosko, Minneapolis, MN (US);
Thierry G Charbonneaux, New Brighton, MN (US);
Kirk J Mikkelsen, Piscataway, NJ (US);
Regents of the University of Minnesota, St. Paul, MN (US);
Abstract
An extrusion die is described for extruding a polymer from a reactive precursor mixture without plugging of the die. The extrusion die includes a die inlet leading to at least one channel having dimensions which produce a wall shear stress value that exceeds the critical wall shear stress value for the particular reactive precursor mixture to prevent occlusion of the die. The preferred configuration of the die channels is a tree-like structure to obtain a coating width which is greater than the dimensions of the individual channels. Other features of the invention include a method for determining the critical wall shear stress value and a method for extruding reactive precursor mixtures.