Polyethylene film and method for the manufacture thereof

摘要

The present invention pertains to a polyethylene film and a process for manufacturing such film. The polyethylene film may have a ratio between the strength in a first direction in the film plane and the strength in a second direction in the film plane perpendicular to the first direction in the range of 0.1-10:1, the strength in at least one direction being at least 0.2 Gpa. The process for manufacturing a polyethylene film may have a starting UHMWPE polymer with an average molecular weight of at least 500,000 grams/mole, an elastic shear modulus determined directly after melting at 160° C. of at most 1.4 MPa, and a Mw/Mn ratio of at most 6 to a solvent-free compacting process and a stretching process under such conditions that at no point during the process the temperature of the intermediate polymer film is raised to a value above its melting point.

主权项

1. A polyethylene film comprising polyethylene and having a ratio between a strength in a first direction in the film plane and a strength in a second direction in the film plane perpendicular to the first direction in a range of about 1:10 to 10:1, the strength in at least one direction in the film plane being at least 0.2 GPa, wherein the polyethylene has a weight average molecular weight (Mw) of at least 500,000 grams/mole and a Mw/Mn ratio of at most 6.