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. 22, 2006
Filed:
Dec. 30, 2002
Christopher K. Haas, Cottage Grove, MN (US);
Mark D. Gehlsen, Eagan, MN (US);
Sara B. Mortenson, Somerville, MA (US);
Joan M. Strobel, Maplewood, MN (US);
Ravi K. Sura, Woodbury, MN (US);
David L. Vall, Woodbury, MN (US);
Christopher K. Haas, Cottage Grove, MN (US);
Mark D. Gehlsen, Eagan, MN (US);
Sara B. Mortenson, Somerville, MA (US);
Joan M. Strobel, Maplewood, MN (US);
Ravi K. Sura, Woodbury, MN (US);
David L. Vall, Woodbury, MN (US);
3M Innovative Properties Company, St. Paul, MN (US);
Abstract
The present invention is directed to a process for producing a polypropylene foam by mixing a high melt strength polypropylene and a blowing agent to form a melt mixture, reducing the temperature of the melt mixture at the exit of the apparatus to an exit temperature that is no more than 30° C. above the melt temperature of the neat polypropylene while maintaining the melt mixture at a pressure sufficient to prevent foaming; passing the mixture through said exit shaping orifice and exposing the mixture to atmospheric pressure, whereby the blowing agent expands causing cell formation resulting in foam formation, and orienting said foam. The foam is useful as tape backings, thermal and acoustical insulation and as a diffuse reflector for use in optical applications such as computer displays.