Bimodal polyethylene blend showing good blend quality

摘要

Bimodal polyethylene blends are made from a high-molecular-weight ethylene copolymer and a low-molecular-weight ethylene homo- or copolymer and have a melt flow rate MFR 190/21.6 of from 6 to 14 g/10 min, a density of from 0.94 to 0.97 g/cm3, an environmental-stress-cracking resistance ESCR150 h and a value of less than 3 when the quality of blending in the blend is measured to ISO 13949. A process prepares polyethylene blends of this type by melting and homogenization in a mixing apparatus and discharge via a gear pump. The blends are used to produce moldings, in particular hollow articles and pressure pipes.