Patent ID: 7256247

Claim:
A polymer produced using a polyethylene two-stage polymerization process, comprising: (a) polymerizing ethylene in the presence a Zeigler-Natta catalyst and a co-catalyst for a period of time to produce a lower molecular weight polyethylene with a melt flow index (M15) of from 100 to 3000 dg/min; (b) adding a metallocene component and continuing the polymerization for an additional period of time to produce a higher molecular weight polyethylene with a melt flow index (M15) of from greater than 0.2 to 10 dg/min, wherein the addition of the metallocene component adjusts the hydrogen response of the Zeigler-Natta catalyst; wherein the polymerization process produces high-density polyethylene with a bimodal molecular weight distribution of from 10 to 35 and wherein said bimodal polyethylene has a density of from greater than 0.930 to about 0.970 g/cc.