Polypropylene is a popular, widely used packaging resin, but often faces challenges when it comes to being recycled. Still, its properties make it very desirable. The resin is durable, lightweight and can deliver the high clarity so much in demand for food and beverage packaging. It also is one of the least energy-intensive polymers to make and recycle compared to other clear polymers.
Global demand for polypropylene (PP) is about 90 million metric tons, with its usage having grown on average by 3.5 to 4 percent per year over the past decade, according to Esteban Sagel, principal of Houston-based Chemical and Polymer Market Consultants. Other analysts forecast similar growth continuing in the years to come.
Brazilian chemical engineer Victor Sanfins Cecon, who is currently pursuing a Ph.D. in food science and technology at Iowa State University in the U.S., revealed a startling statistic in his recent talk at the Society of Plastics Engineers’ ANTEC conference in Denver, Colorado. He was disclosing findings from his ongoing study about the types of plastics found in various material recovery facilities (or MRFs) in the Midwestern U.S.
Citing U.S. Environmental Protection Agency data about the resins being recycled from municipal solid waste streams, he noted that PET and HDPE plastics are recycled at the highest rates –– 17.2 percent and 8.9 percent, respectively. Comparatively, the EPA data show, just 8.5 percent of all plastics being generated are recycled, and the popular PP packaging resin is being recycled at a paltry rate of only 0.6 percent.
This is in part because PP often is used in combination with other resins and barrier layers that make the overall package incompatible with most recycling streams.
Brand owners and packaging processors are working hard to address this issue by finding ways to make mono-material PP constructions that can be more easily recycled. Several companies showcased their efforts at the interpack 2023 fair.