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. 10, 2004
Filed:
Oct. 03, 1996
John A. Larter, Canandaigua, NY (US);
Robert V. Poirier, Fairport, NY (US);
ExxonMobil Oil Corporation, Fairfax, VA (US);
Abstract
A high density polyethylene (HDPE) film is provided having high-biaxial orieniation. The film includes HDPE having a density of at least about 0.940, and a melt index of from about 0.5 to about 10. The film is stretched in the machine (longitudinal) direction to a degree of from about 5:1 to about 8:1, preferably from about 6:1 to about 7:1. The film is also stretched in the transverse (lateral) direction to a degree of from about 6:1 to about 15:1, preferably from about 9:1 to about 13:1. Preferably, the film has an orientation imbalance, with a higher degree of transverse orientation than machine orientation. Skin layers such as heat seal layers can be provided. Preferably, the film contains one or more layers of a casting promoter material employed to promote casting of a high gauge HDPE sheet subsequently high biaxially oriented to provide the film. The film can also be cavitated, or otherwise modified (e.g., corona-treated, coated, metallized, etc.) to provide films suitable for special applications. The film of the invention has superior properties, including lower water vapor transmission rate, better dead-fold, higher tensile strength, and consistent gauge profile. Also provided is a method for making the biaxially oriented film.