POLYMER COMPOSITION AND METHOD FOR PRODUCING PLASTIC BOTTLES The two-stage process of injection-blow molding

摘要

FIELD: process engineering.;SUBSTANCE: invention relates to polymer composition and method of plastic bottle production by two-stage injection-blowing. Plastic bottle is produced by drawing at second stage, separated in time and space, after heating to 115°C-135°C, from the blank with 2.1-2.9 mm thick walls at forming with blowing and drawing axially and radially. Blank is produced at first stage by injection moulding or by injection moulding with additional injection of polymer composition. Note here that said polymer composition contains at least 60 wt % of HDPE that features density of 0.941-0.965 g/cm³ and first melt index at 190°C/2.16 kg of 0.1-0.9 g/10 min, to 40% of calcium carbonate as a filler and to 4% of dye based on titanium oxide and/or zinc sulphide. Note here that said HDPE represents mono- or multimodal HGPE with second melt index at 190°C/21.6 kg making 5 g/10 min to 50 g/10 min.;EFFECT: sufficient strength, wall thickness variation smaller than ±0,5 mm.;10 cl