Closing the Loop on Bottle Caps

SEATTLE (Waste Advantage): “Developing a mechanical sorting process to close the loop for food-grade cap-to-cap recycling by consistently separating mixed polyolefins by polymer and color with high purity is a game changer,” comments Joe Castro, president of Greenpath Enterprises, Colton, Calif.

The full-service recycler, processor and manufacturer has partnered with TOMRA Recycling Sorting to install and optimize a plastic flake sorting line designed to identify and separate mixed polyolefin caps from beverage bottles. “We are at the genesis of creating a sorting system for caps similar to what is more common today for the bottle,” adds Eric Olsson, area segment manager, plastics for TOMRA Recycling.

Operating for more than 25 years, the vertically integrated Greenpath accepts a wide range of materials, and the inbound flow can be somewhat inconsistent. Greenpath creates value being a one-stop solution by accepting mixed trailer loads with variable supply streams and producing consistent, quality products.

Considering only the post-consumer polyolefin materials – low-density polyethylene (LDPE), high-density polyethylene (HDPE) and polypropylene (PP) – Greenpath accepts film, rigid plastics and bottle caps. “Polypropylene and polyethylene (PE) are together the most abundant plastic family on earth, but the market is limited for valuable applications for mixed polyolefins,” comments Olsson.

PE and PP have very close density characteristics and are challenging to separate. So, mixed polyolefins are primarily downcycled into more forgiving applications that allow for more contamination.

Courtesy: www.wasteadvantage.com