Why Your Label May Not Be Improving PET Recycling 

When end-use labels are not properly washed off from PET material and enter the recycling stream, they have the potential to increase haze percentage or yellowness seen in PET material once it is broken down and extruded back into an application such as bottles or trays.  

Overtime, this can mean that PET is not able to be recycled back into PET once again. 

In particular, the APR Critical Guidance testing protocol states haze percentage must be less than 10 percent in PET control material in order for it to still “pass” and be recycled into PET again, and yellowing levels must be less than 1.5 degrees from the control material. Exceeding these limits can lead to: 

• Reduced clarity: It can be difficult to identify PET material during sorting via FTIR scanners in recycling facilities once the PET flakes have been processed. The scanners search for color during sorting, which includes clear; however, if the PET quality is no longer clear, it will be rejected from the PET stream.  

• Decreased circularity yield: While haze or color-impacted PET can be turned into other recycled items including clothing fibers or carpets, it can no longer contribute to PET circular recycling, which decreases the overall yield being utilized for multiple generational usage. 

• Increased degradation: The haze or yellowness within PET material causes stress and irregularities, weakening its overall strength and structure. This can allow it to degrade at a faster rate. Additionally, the PET’s crystallinity levels may decrease, making it less stable over time and more susceptible to moisture absorption, which can further cause degradation.

However, not all PE applications are ideal for wash-off label adhesives 

While a wash-off label adhesive may pass the APR Critical Guidance testing, formulations typically cannot offer high performance in applications exposed to temperatures of 40 °F (4.4 °C) or lower, such as freezer-grade or cold-fill applications. This is because the polymer in a general-purpose wash-off label adhesive is not soft enough to sufficiently wet out and adhere at low temperatures. Due to this limitation, brand owners typically opt to either experience performance failure while using general-purpose wash-off label adhesives on cold applications, or resort to non-wash-off label adhesives that do not provide recyclability.  

Until now.