Blow-Up Ratio's Effect on LLDPE Film's Properties with Different Material Types

This research explores producing high-impact LLDPE films for flexible packaging, focusing on the influence of the blow-up ratio (BUR) in the blown film extrusion process. LLDPE films with varying material grades were produced using a mini-blown film extrusion process, with BUR systematically ranging between 1.5 and 2.45. Standardized tests evaluated mechanical properties. The best sample, with material and ratio variation 1.3 and BUR 2.0 (LLDPE/n-Hexene Copolymer & Plastomer mixture), showed outstanding impact strength and tearing resistance among the references sample and other material types and variations. The research also aims to identify optimal parameters for high-impact LLDPE films suitable for mono-material applications in flexible packaging. LLDPE's outstanding mechanical and thermal properties have drawn attention across industries. A mini-blown film extrusion process produced LLDPE films with varying material grades, while BUR ranged from 1.5 to 2.45. Mechanical properties were evaluated, including tensile strength, elongation, impact resistance, and tearing strength. Compared to references as a normal ratio, the best optimization sample achieved an impact strength of 2,808 J/mm² with a 25% increase in outer/inner positions. Tensile strength values were 50/48 N/mm² in MD/TD positions, with elongation reaching 870/825% in MD/TD positions. Tearing strength measurements resulted in 872/843 gram-forces in MD/TD positions, highlighting the best material and BUR combination LLDPE for flexible packaging. The research also investigated film sealing strength using the sealing initiation temperature (SIT), confirming excellent sealing integrity at lower temperatures. In conclusion, this research identifies optimal parameters for high-impact LLDPE films, enhancing their suitability for flexible packaging applications and contributing to sustainability in the flexible packaging industry.