Closures are critical to the plastic packaging system because they can protect the contents of the package and provide safety aspects for the consumer. The closure can be the most essential part of the package for the consumer experience.
Bottles and closures have traditionally been made using virgin resin. However, manufacturers are incorporating more post-consumer recycled (PCR) content to meet sustainability goals. This is true not just for bottles, but also for closures such as caps and lids. There is also a shift from polypropylene (PP) to high-density polyethylene (HDPE) closures, where post-consumer resin is more readily available. This shift is improving access to PCR for closures specifically and, as a result, increasing the amount of PCR used across all plastic packaging, including in more challenging situations such as food-contact packaging. This can help brands and retailers reach 2025 sustainability targets and beyond.
There are, however, complexities when using PCR in closures. It can adversely affect quality and performance, impacting functionality and safety. This article will explore these key challenges and offer potential solutions.
Moving away from virgin resin to using the same grade of PCR, you can expect both processing conditions and product performance to change. This includes specific areas related to viscosity, color and dimensional stability, stress cracking, and organoleptic properties.
Color and Dimensional Stability
Organoleptic Properties (Odor)
Incorporating PCR into closures is reported to reduce greenhouse gas (GHG) emissions by 71% over the use of virgin resin¹. The challenges to do so, however, can seem insurmountable. Fortunately, there are a number of options available to help you effectively use PCR in closure applications. Contact us if you would like to learn more, or talk with one of our product experts about your own PCR challenges.
¹Source: Life Cycle Impacts for Postconsumer Recycled Resins, December 2018 https://plasticsrecycling.org/images/library/2018-APR-LCI-report.pdf