PTI is one of only two U.S. companies approved by the Association of Postconsumer Plastic Recyclers (APR) to provide testing services in conjunction with the organization's critical guidance documents. The voluntary screening guidelines help companies understand the approximate effect that their material or container might have on the quality of the rPET stream. Further, the APR's objective is to enhance the quality and quantity of postconsumer plastic packaging materials.
Brand owners are continuing to push performance boundaries by working with new resins, additives and multilayer structures to achieve longer shelf life and other attributes. The downside is that very little is known about what happens to the recycling stream when many of these innovations enter it.
“The only way for brand owners to really be able to claim that their package is fully recyclable and meets APR guidelines is to subject it to testing that can support their position,” Schloss said.
Typically, once PET containers have been sorted out of the mixed bottle stream they are chopped into small flakes and washed in a hot very caustic aqueous solution. A “sink or float” water separation process removes any non-PET materials (polyolefins, labels, etc.) with densities 1 can remain and potentially contaminate the rPET flake.
“The demand for recycled PET resin very often outstrips supply. When you look at what comprises the PET recycling stream today, its primarily soft drink and water bottles. When you broaden collection efforts to include full shrink wrap labeled containers, plus vitamin water, juice, cosmetic, and household chemical bottles, you now introduce complications that can lower the quality of the cleaned and washed rPET material,” Schloss said.
To help better manage backend concerns, Schloss also encourages suppliers to get involved. Ideally, the recycling stream audit process should begin before the raw material or packaging component is sold to the brand owner.
Companies also can choose to engage in a preliminary “quick test” which typically takes one to two weeks. This can yield valuable information on the yellowing and hazing tendencies of these new materials. As the recycling confidence in the innovation material increases, companies may opt to conduct more in depth testing. Critical guidance testing typically requires a month, with end use application studies adding another month to the timeline. In addition to material composition, attributes such as color, haze, intrinsic viscosity, black specks, etc. are also analyzed for waste stream impact.
“The question that we all need to address is what is going to happen to that bottle when it is time to dispose of it? Should the consumer include it with their recyclables? Can it be easily sorted using today's manual and automated processes? Can it be turned into high quality rPET or will it contribute to the degradation of the recycled material supply? The answer to that lies in what decisions are made well before the raw material gets converted into a finished package,” Schloss said.