New research on the growing uses of recycled polypropylene in plastic packaging finds it performs well and has the potential to meet environmental goals and reduce raw material costs.
Conclusions suggest both cost optimization of additives can be improved and sustainability goals can be reached by increasing the use of post-consumer recycled (PCR) materials in food packaging.
These findings come as many packagers are relying more on polypropylene and similar plastics than widely-used polyethylene terephthalate (PET) in bottled water and similar beverages.
Polypropylene (PP) has a resin identification code of #5 and a high melting point and is often used in containers for hot liquids. It can also be found in yogurt containers, syrup, medicine bottles, caps and straws.
The new study was conducted by Iowa State University scientists who gathered a small collection of recycled plastics and after testing, found they performed well mechanically in terms of strength, flexibility, integrity and other indicators like heat resistance.
If future performance studies support these findings, and outside chemicals remain below regulatory limits, it could be a win-win for those seeking more sustainable packaging and efficiencies in their packaging recycling programs.
According to the authors, "This study demonstrates the viability of a significant source of polypropylene and its notable long-term impacts, increasing profits by using PCR materials." But the potential upside doesn't end there.
"This approach will produce environmentally responsible food plastic packaging in compliance with legislation in the circular economy," the paper concludes.
According to Iowa State's Drs. Keith Vorst and Greg Curtzwiler, the findings are important because "they demonstrate PCR plastics can have higher value than just sustainability alone. PCR materials can also be used as a source of critical additives that would not need to be added to virgin plastics when blended together."
According to lead author Dr. Ma. Cristine Concepcion D. Ignacio, the research is unique in that it focuses on "determining the compliance and physical performance of extrusion blow molded material recovery facility (MRF)-recovered post-consumer PP bottle for direct food-contact applications."
The article appeared in a recent issue of the peer-reviewed journal Polymers and was supported by IAFNS' Food Packaging Safety and Sustainability Committee.