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AssigneeApplied Extrusion Technologies, Inc.
InventorsWilliam J. Ristey, George A. Senich, William J. Hill, Harry S. Anderson
Estimating the term…
A shrink film comprising a biaxially oriented polymer film comprising polypropylene having a machine direction shrinkage and a transverse direction shrinkage that is less than or equal to 50% of the machine direction shrinkage, and wherein the machine direction shrinkage is greater than 15% and the transverse direction shrinkage is less than 10% at about 140.degree. C. The shrink film is formed by a process comprising subjecting a biaxially oriented polymer film to a treatment which comprises the heating the film to a temperature of about 100.degree. C. to 180.degree. C. The heated film is drawn under conditions to extend it by at least 1.05 times its original length in the machine direction. The drawn film is cooled under tension to produce a shrink film having the specified ratio between the machine direction shrinkage and the transverse direction shrinkage in addition to having a kinetic film-to-film coefficient of friction of about 0.05 to 0.40. The shrink film is suitable for wrapping contoured articles.
A shrink film comprising a biaxially oriented transparent polymer film, the polymer being selected from the group consisting of polypropylene homopolymers, polypropylene copolymers and blends thereof, said polymer film having a machine direction shrinkage and a transverse direction shrinkage that is less than or equal to 50% of the machine direction shrinkage and wherein the machine direction shrinkage is greater than 15% and the transverse direction shrinkage is less than 10% at about 140.degree. C.
A biaxially oriented shrink film produced by heating a biaxially oriented transparent polymer film to a temperature within the range of about 100.degree. C. to 180.degree. C., the polymer being selected from the group consisting of polypropylene homopolymers, polypropylene copolymers and blends thereof;
An article having a non-uniform contour which is at least partially covered with at least one shrink film comprising a biaxially oriented transparent polymer film, the polymer being selected from the group consisting of polypropylene homopolymers, polypropylene copolymers and blends thereof, said polymer film having a machine direction shrinkage and a transverse direction shrinkage that is less than or equal to 50% of the machine direction shrinkage and wherein the machine direction shrinkage is greater than about 15% and the transverse direction shrinkage is less than 10% at about 140.degree. C.
A shrink film comprising a biaxially oriented transparent polymer film, the polymer being selected from the group consisting of polypropylene homopolymers, polypropylene copolymers and blends thereof, said polymer film having a machine direction shrinkage and a transverse direction shrinkage that is less than or equal to 50% of the machine direction shrinkage and wherein the machine direction shrinkage is greater than 15% and the transverse direction shrinkage is less than 10% at about 140.degree. C., wherein the shrink film has a kinetic film-to-film coefficient friction within the range of about 0.05 to about 0.40.
An article having a non-uniform contour which is at least partially covered with at least one shrink film comprising a biaxially oriented transparent polymer film, the polymer being selected from the group consisting of polypropylene homopolymers, polypropylene copolymers and blends thereof, said polymer film having a machine direction shrinkage and a transverse direction shrinkage that is less than or equal to 50% of the machine direction shrinkage and wherein the machine direction shrinkage is greater than 15% and the transverse direction shrinkage is less than 10% at about 140.degree. C., wherein the polymer shrink film has a kinetic film-to-film coefficient of friction within the range of about 0.05 to about 0.40.
Dependencies are inferred from the claim text.