Optimization of Impact Performance of Injection Moulded Products for Cold Storage Applications: A Case Study on Ice Cream Packaging

AbstractSub-zero mechanical failure of rigid polypropylene (PP) packaging is a major concern in frozen food cold-chain applications operating at temperatures down to −35 °C. This study presents a ten-trial formulation approach using blends of a high-flow PP homopolymer (Borouge HJ333; melt flow rate (MFR) 75 g/10 min) and a propylene ethylene random copolymer (Borouge BJ368MO; MFR 70 g/10 min), together with a metallocene-based propylene ethylene elastomer (ExxonMobil Vistamaxx 6202; MFR 20 g/10 min) at two concentrations. A 1-litre square injection-moulded container was manufactured on a 350-tonne industrial injection-moulding machine and evaluated through 1.2 m flat-bottom drop testing at −35 °C per ASTM D2463, and impact strength testing per IS 2508. Food-contact safety was assessed using overall migration (IS 9845) and specific migration standards (IS 10146, IS 14882, EU 10/2011). Progressive homopolymer replacement with copolymer improved impact strength from 180 gf to 390 gf but failed to ensure consistent drop-test performance. Elastomer addition significantly enhanced toughness, reaching from 430 to 470 gf and meeting drop-test requirements. The optimal formulation was 88 w t% BJ368MO, 10 wt% Vistamaxx 6202, and 2 wt% masterbatch added for white colour appearance, demonstrating superior sub-zero impact resistance and full food-contact compliance.