White paper: Kynar^® PVDF polymer processing and recycling aid (PPRA) for film processing of recycled polyethylene resins

Post-industrial and post-consumer film recycling

Efficient mechanical recycling of post-industrial and post-consumer film remains a challenge in the industry today in part due to the variability of incoming film feed streams. This paper measures the effect that a Kynar® PVDF polymer processing and recycling aid (PPRA) has in improving the film processing of recycled polyethylene resins. Both melt fracture elimination and pressure reduction were observed when a Kynar® PPRA was added to a recycled polyethylene film process. This data suggests that film converters looking to increase recycled polyethylene output, or the percent of recycled polyethylene content in their process, can consider adding a Kynar® PPRA to increase
their processing efficiency.

Mechanical recycling challenges

The polyethylene industry is increasingly focusing on sustainable solutions. Mechanical recycling specifically is generating industry attention for its ability to extend the life cycle of plastics that were initially considered to be “single use.” In the area of mechanical recycling, polyethylene film presents unique challenges when it comes to recycling. The challenges arise due to the variability in the composition of the feed streams, the need to wash and pretreat the film, and the possible degradation of the polyethylene from additional heat histories. Polymer processing aids (PPA) have been proven to increase processing efficiency in various polyethylene base resins by eliminating melt fracture, and increasing output (by reducing extruder pressure).1,2,3,4 Prior to this study, to the knowledge of the authors, no technical analysis on PPA performance in recycled polyethylene base
resins had been conducted. The objective of this study was to determine if a Kynar® PPRA maintains its effectiveness in improving processing efficiency when added to a recycled resin.

Download the white paper