MATERIALS / RECYCLING PETplanet Insider Vol. 24 No. 01+02/23 www.petpla.net 30 Sustainablility - enabling additives for food and beverage packaging by Marco Schaefer, Sr. Marketing Manager Food & Beverages Packaging EMEA, Avient Corporation Functional additives are crucial to making PET a versatile packaging material. Additives can extend the performance of PET by protecting against food spoilage caused by oxygen ingress, UV radiation, visible light, and/or by-product migration. They can also help with retaining packaging material’s mechanical properties. The circular use of PET will significantly reduce reliance on fossil fuels and reduce carbon emissions. The use of mechanically recycled PET yields 79% less CO2 emissions than virgin PET. This circular use of PET will significantly reduce reliance on fossil fuels in the manufacturing process as recycled PET use yields 79% less CO2 emissions than virgin PET. However, the recycled material has different qualities than virgin PET, often darker or yellow in colour with lower intrinsic viscosity (IV), and is also more challenging to process. To address the increased use of rPET and the multiple processing loops it will undergo, manufacturers will require additives that meet these additional challenges. As rPET content increases, additives need to adapt so that: 1) they do not negatively impact rPET aesthetically or during processing; 2) they function as intended when used in conjunction with rPET; 3) they have no negative impact on non-intentionally added substances (NIAS) through the recycling process. A shift from functional additives to sustainability-enabling functional additives will be required in this rapidly changing market. Additives that provide the necessary functionality have no negative impact on rPET, and show improvements in rPET quality, processability, or performance, are currently available. If adopted globally, additives like these would enable improved quality and availability of bottle-grade rPET in the future, enabling the continued circularity of PET through multiple recycle loops. Colour When PET is recycled, degradation reactions can lead to yellowing. In addition, degradation reactions of PET additives can also occur, potentially leading to additional yellowing and colour variation. As the levels of rPET used in PET packaging are set to increase, the number of heat exposures of rPET will increase; hence, the yellowing and colour variation of rPET resin will increase. To overcome these issues, Avient developed a range of solutions that will have a minimal impact on the additional discolouration of rPET even after repetitive recycling steps. And to mimic more realistic conditions, Avient has set up an internal recycling protocol that is evaluating colour stability as MATERIALS / RECYCLING
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