Abstract: An ethylene polymerization process is disclosed. Ethylene is polymerized in two slurry reaction zones with a C6-C10 alpha-olefin in the presence of a single-site catalyst capable of making a high molecular weight polyolefin. The process yields medium density and linear low density polyethylene having a bimodal molecular weight distribution and a melt index from about 0.10 to about 0.80. Films from the polyethylene have superior impact properties.

Abstract: A process for preparing polyethylene thin films is disclosed. The process comprises extruding a blend that comprises a linear low density polyethylene (LLDPE) and a high molecular weight, high density polyethylene (HMW-HDPE) or high molecular weight, medium density polyethylene (HMW-MDPE). The blend has an LLDPE/HMW-HDPE or HMW-MDPE weight ratio at least 50/50. The blend is extruded through an annular die to form a molten material tube. The molten material tube is then pulled around a fixed internal orientation device (FIOD) to form the film. The FIOD makes it possible to prepare polyethylene thin films from LLDPE-rich LLDPE/HMW-HDPE or HMW-MDPE blends on a high stalk film line. The films have increased machine-direction (MD) tears.