Patent ID: 8075830

Claim:
A process of forming a blown film comprising: providing a Ziegler-Natta catalyzed polypropylene having a melt flow rate of from 1.8 to 14.0 g/10 min. as measured by ASTM D1238 condition L and a melting point of at least 115° C.; and forming the polypropylene into a layer of a blown film, wherein the layer consists of the polypropylene; and quenching said blown film with air at a temperature of less than 10° C., wherein said blown film has a haze of less than 10% as measured in accordance with ASTM 1003 and a 45° gloss of greater than 70% as measured in accordance with ASTM D523, and wherein said process further comprises internal bubble cooling, stabilizing the external bubble with stabilizers, and the process utilizes a dual lip air ring, and wherein the blown film exhibits a 1% secant modulus (machine direction) measured in accordance with ASTM D882 in the range of 80 to 135 kpsi when the blown film has a thickness of 1.2 mil.