Abstract: A polyethylene molding composition having a multimodal molecular mass distribution and comprising from 45 to 55% by weight of a low molecular weight ethylene homopolymer A, from 20 to 40% by weight of a high molecular weight copolymer B comprising ethylene and another olefin having from 4 to 8 carbon atoms and from 15 to 30% by weight of an ultrahigh molecular weight ethylene copolymer C can be prepared in the presence of a Ziegler catalyst in a three-stage process and is highly suitable for producing pipes having excellent mechanical properties.

Abstract: A polypropylene composition for injection-molded drainage systems comprising 78-84 wt % of a crystalline propylene polymer, 8 to less than 13 wt % of an elastomeric copolymer and 8 to less than 13 wt % of polyethylene. The said composition exhibits a flexural modulus value higher than 1400 MPa, a melt flow rate (MFR), determined according to ISO method 1133 (230° C. and 2.16 kg), of from 1.5 to 5.0 g/10 min, and a value of Izod impact resistance at 0° C. of more than 6 kJ/m2 according to ISO method 180/1A.

Abstract: A polypropylene composition for injection-moulded drainage systems comprising 78-84 wt % of a crystalline propylene polymer, 8 to less than 13 wt % of an elastomeric copolymer and 8 to less than 13 wt % of polyethylene. The said composition exhibits a flexural modulus value higher than 1400 MPa, a melt flow rate (MFR), determined according to ISO method 1133 (230° C. and 2.16 kg), of from 1.5 to 5.0 g/10 min, and a value of Izod impact resistance at 0° C. of more than 6 kJ/m2 according to ISO method 180/1 A.