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:
Jun. 22, 2010
Filed:
Jan. 18, 2007
William Ward Merrill, White Bear Lake, MN (US);
Jeffery N. Jackson, Woodbury, MN (US);
Andrew T. Ruff, Mendota Heights, MN (US);
John A. Wheatley, Lake Elmo, MN (US);
Dennis L. Krueger, Hudson, WI (US);
William Ward Merrill, White Bear Lake, MN (US);
Jeffery N. Jackson, Woodbury, MN (US);
Andrew T. Ruff, Mendota Heights, MN (US);
John A. Wheatley, Lake Elmo, MN (US);
Dennis L. Krueger, Hudson, WI (US);
3M Innovative Properties Company, St. Paul, MN (US);
Abstract
A stretcher for substantially uniaxially orienting a film includes a plurality of gripping members to hold opposing edge portions of the film, paths along which the gripping members travel to stretch the film in a stretching region, and a drive mechanism to convey the film and gripping members along a machine direction. At least a portion of the paths in the stretching region define diverging, curvilinear courses disposed in-plane. The paths are configured such that during the stretching an extent of uniaxial character, U, is between zero and unity and a minimum value of an extent of uniaxial character, U, is at least 0.70 over a final portion of the stretching after achieving a TDDR of 2.5. U is defined as U=(1/MDDR−1)/(TDDR−1), wherein TDDR is greater than 4 at an end of the stretching region.