Patent ID: 8168112

Claim:
A process of forming blown film comprising: providing a bimodal ethylene based polymer, wherein the bimodal ethylene based polymer is formed from a Ziegler-Natta catalyst system, wherein the Ziegler-Natta catalyst system is formed by contacting an alkyl magnesium compound with an alcohol to form a magnesium dialkoxide compound and contacting the magnesium dialkoxide compound with successively stronger chlorinating agents, wherein the bimodal ethylene based polymer exhibits a density of at least about 0.940 g/cc; blending the bimodal ethylene based polymer with at least 100 ppm peroxide to form modified polyethylene; and forming the modified polyethylene into a blown film, wherein the modified polyethylene exhibits a stability ranking of at least 2; wherein the polymer article exhibits a transverse strength that is at least about 85% lower than a polymer article prepared via an identical process absent the peroxide.