POLYETHYLENE FILMS AND METHOD OF MAKING THE SAME

摘要

The instant invention is a polyethylene film, and method of making the same. The polyethylene film according to instant invention includes at least one heterogeneously branched ethylene/α-olefin copolymer having a density in the range of about 0.910 to about 0.930 g/cm3, a molecular weight distribution in the range of about 2.8 to 3.8, a melt index (I2) in the range of about 0.3 to about 4 g/10 min, and an I10/I2 ratio in the range of 6.5 to about 7.8. The film has a normalized dart impact strength of equal or greater than (6666-7012*density) g/mil, a normalized tear strength of equal or greater than (440*e−(density−0.915)2/2*(0.00949)2) g/mil, and a haze in the range of 3 to 10 percent. The method of making the polyethylene film according to instant invention includes the following steps: (1) providing at least one heterogeneously branched ethylene/α-olefin copolymer having a density in the range of about 0.910 to about 0.930 g/cm3, a molecular weight distribution in the range of about 2.8 to 3.8, a melt index (I2) in the range of about 0.3 to about 4 g/10 min, and an I10/I2 ratio in the range of 6.5 to about 7.8; (2) processing the heterogeneously branched ethylene/α-olefin copolymer via blown film extrusion process or cast film extrusion process; and (3) thereby forming a film having a normalized dart impact strength of equal or greater than (6666-7012*density) g/mil, a normalized tear strength of equal or greater than (440*e−(density−0.915)2/2*(0.00949)2) g/mil, and a haze in the range of 3 to 10 percent.