Enhancing the Circularity of PET: Challenges and Solutions

Polyethylene terephthalate (PET) is a widely used plastic, particularly in the food and beverage industry, because of its recyclability, lightweight properties, and durability. As demand for sustainable packaging grows, the focus continues to shift towards improving the circularity of PET, specifically using recycled PET (rPET). This article explores the challenges and solutions to enhancing the circularity of PET, focusing on process optimization, securing quality rPET feedstock, improving consumer experience, and creating value for rPET and PET producers.

Creating Value for rPET and PET Producers

One of the primary challenges in the recycling of PET is maintaining high yield rates for quality rPET. Recycling involves several stages, including sorting, washing, grinding, and extrusion. Each stage can result in material loss and degradation, impacting the overall yield. To address this, advancements in recycling technologies and the use of performance additives are crucial. These additives and stabilizers can enhance the mechanical properties of rPET while reducing yellowing and impurities, thereby contributing to a more valuable, robust material. Additionally, recycle-friendly toners can offset yellowing while improving color consistency across various feedstock.

The production of rPET is inherently more energy efficient than virgin PET production, but there is still room for improvement. The recycling process, particularly the stage of Solid State Polymerization (SSP), can be optimized to further reduce energy consumption. Advanced additives can play a role here as well. For example, molecular chain builders enhance the intrinsic viscosity of rPET while improving the efficiency of the SSP process, reducing the energy required to build intrinsic viscosity (IV).

Process Optimization for Preform Molding and Bottle Blowing

Optimizing the preform molding and bottle blowing processes is essential for reducing energy consumption and improving the quality of PET bottles, especially when incorporating rPET. By using recycle-friendly process aids, manufacturers can reduce the energy required for these processes, minimize bottle blowouts, and mitigate stress cracking. These additives also boost the mechanical and dimensional stability of the bottles, ensuring consistent quality and performance.

Enhancing Consumer Experience

PET bottles offer excellent clarity and transparency, allowing consumers to better see what is inside. This visibility can increase a product’s appeal and convey a sense of purity and quality, which is particularly important for beverages and personal care products. However, a significant challenge with rPET is its aesthetic quality. Recycled PET often exhibits yellowing or color variations due to degradation during the recycling process. This can be a deterrent for brand owners who prioritize the visual appeal of their packaging. To combat this, color-stable toners and additives can be used to maintain the clarity and color consistency of rPET. These additives are developed to withstand multiple recycling loops, helping the recycled material remain visually appealing even after several uses.

Improving the consumer experience is a key goal for PET packaging. This can be achieved by enhancing the shelf life of products and improving the taste and smell of the contents. Oxygen and acetaldehyde scavengers and UV blockers can help preserve the freshness and quality of the packaged product, creating a more pleasing taste and smell for consumers.

Securing Quality rPET Feedstock

Maintaining the quality of rPET feedstock is crucial for the sustainability of PET recycling. Additives that do not degrade the recycle stream are essential in this regard. These additives should not negatively impact the recyclability of PET and should help maintain the integrity of the recycled material. Using Association of Plastic Recyclers (APR) Recognized solutions means that the rPET feedstock remains high-quality, improving the overall efficiency and effectiveness of the recycling process.

Conclusion

The journey towards a more circular economy for PET involves addressing several challenges, from process optimization and enhancing the consumer experience to generating quality rPET feedstock and creating value for rPET and PET producers. By using advanced additives and innovative recycling technologies, these challenges can be mitigated, creating a more sustainable future for PET packaging. Avient offers solutions that address many of these challenges, helping to enhance the circularity of PET and promote a more sustainable packaging industry.