METHOD Russian patent published in 2017 - IPC C08L23/06 C08L23/08 F16L9/12 

FIELD: pipes.

SUBSTANCE: invention relates to a polyethylene mixture of high density intended for making articles, preferably, such as pipes. Polyethylene mixture has the melt flow index (MFI₂₁) of not more than 10.0 g/10 min defined according to ISO 1133 at 190 °C and the load of 21.6 kg and the density of at least 940 kg/m³. Herewith the mixture contains from 55 to 95 wt% of a high-density multimodal polyethylene copolymer with the density of at least 940 kg/m³ and from 5 to 45 wt% of an ethylene homopolymer of ultrahigh molecular weight, which has the characteristic viscosity of at least 6 dl/g and the MFI₂₁ less than 0.5 g/10 min.

EFFECT: obtained polymer mixture has higher sag resistance and impact strength without deterioration of its mechanical properties in tension.

17 cl, 3 dwg, 3 tbl, 9 ex