Alliance Films, Wisconsin, has developed a 12.7-micron power pre-stretch (PPS) film using a 67-layer NanoLayer coextrusion structure in collaboration with ExxonMobil Signature Polymers and Cloeren.
The film was produced on a 6-up SML SmartCast line equipped with Cloeren’s 67-layer NanoLayer feedblock, running at a line speed of 460 m/min. According to the case study, the structure incorporates multiple metallocene polyethylene grades and performance polymers across core and skin layers, with most layers using neat polymers rather than blends.
Alliance Films stated that the objective was to create a film delivering high holding force and stretchability while maintaining puncture resistance and tear propagation. “Our commitment to the customer is to offer a line of stretch film unmatched in the marketplace by outperforming in performance, quality, and service,” said Troy Wolf, President of Alliance Films.
Testing using the ESTL stretch film performance tester (FPT-EVO) recorded ultimate elongation of 490% and force at break of 131 N. Stretch force measured 105 N at 250% pre-stretch. The natural draw ratio occurred at 325% strain.
Tear propagation resistance exceeded 25 seconds at 250% pre-stretch and 15 seconds at 300% pre-stretch. Dart puncture resistance remained consistent across 200%, 250% and 300% pre-stretch levels.
Wrapping trials were conducted on a Robopac 708 wrapper at pre-stretch levels of 200%, 250% and 300%, using three wraps on the top and bottom of the pallet at 10 RPM. Containment force was measured at multiple pallet positions.
At 300% pre-stretch, the film maintained strong containment force and reduced film usage per pallet by approximately 10% compared with 250% pre-stretch, according to the reported test data.