POLYETHYLENE MOULDING COMPOSITION FOR MAKING FILMS THROUGH EXTRUSION BLOWING, HAVING IMPROVED PROCESSING PROPERTIES

摘要

FIELD: chemistry.;SUBSTANCE: invention relates to a polyethylene moulding composition having multi-modal molecular-weight distribution, especially suitable for films made via extrusion blowing, having thickness between 8 and 200 mcm. The polyethylene moulding composition has density between 0.953 and 0.960 g/cm³ and MFR_190/5 of the end product after extrusion between 0.10 and 0.50 dg/min. The composition contains 42-52 wt % of a first fraction of ethylene polymer made from a homopolymer A, having a first molecular weight, 27-38 wt % of a second fraction of ethylene polymer made from another homopolymer or a first copolymer B of ethylene and at least one first comonomer from a group of olefins having 4-8 carbon atoms,whereby the first copolymer B has a second molecular weight greater than the said first molecular weight, and 15-25 wt % of a third fraction of ethylene polymer made from a second copolymer C having a third molecular weight greater than the second molecular weight.;EFFECT: disclosed polyethylene moulding composition enables to obtain thin films with improve processing properties without deterioration of mechanical properties.;12 cl, 2 tbl, 3 ex