PureCycle and StackTeck Produce Living Hinge Cap Using Recycled Polypropylene

PureCycle Technologies and StackTeck Systems have successfully produced a living hinge cap using up to 100% PureFive® recycled polypropylene resin, marking a significant development for the use of post-consumer recycled (PCR) content in high-performance packaging applications.

The companies announced that the caps, manufactured with PureFive Ultra™ and PureFive Choice™ resins, passed a series of customer-related performance tests, including living hinge fatigue testing. Living hinges are widely used in flip-top closures and are considered one of the most demanding applications for polypropylene because they must withstand repeated bending cycles without cracking or failure.

According to the companies, the project demonstrates that recycled polypropylene can meet mechanical performance requirements that have traditionally been associated with virgin resin. The caps also achieved dimensional tolerances comparable to equivalent products made from virgin polypropylene.

StackTeck, a supplier of high-volume injection molds and automation systems, worked with PureCycle to optimize mold design, processing conditions, and part geometry for the recycled material. The resulting closures successfully completed flex-cycle testing and are considered suitable for commercial applications in food, beverage, personal care, and household product packaging.

The development addresses a key challenge facing packaging manufacturers and brand owners as recycled-content mandates expand across North America and Europe. Many packaging applications, particularly caps and closures, require consistent mechanical performance, making it difficult to incorporate conventional recycled polymers without affecting product quality.

John Rego, Senior Market Development Specialist at StackTeck, said the project demonstrates how collaboration across the plastics value chain can help advance sustainable packaging solutions.

“Partnering with PureCycle on this living hinge cap is a testament to what industry collaboration can accomplish. PureFive® resin processed effectively in our tooling, and the final part performance met the requirements of the application,” Rego said.

PureCycle’s PureFive® resin is produced through the company’s proprietary dissolution recycling process, which removes color, odor, additives, and other contaminants from post-consumer polypropylene. According to the company, the resulting resin exhibits performance characteristics similar to virgin polypropylene and has been approved by the U.S. Food and Drug Administration for food-contact applications.

Pete Dias, Senior Director of Market, Application and Product Development at PureCycle, said living hinges represent one of the most challenging performance tests for polypropylene materials.

“The fact that we have demonstrated our recycled resin can meet these requirements expands the range of packaging applications available to customers seeking higher levels of recycled content,” Dias said.

The achievement comes as packaging producers face increasing regulatory requirements related to recycled content. PureCycle noted that PureFive® resin is certified for post-consumer recycled content by the Association of Plastic Recyclers (APR), supporting compliance with emerging recycled-content regulations in several U.S. states.

The companies said the technology could provide converters and brand owners with an additional option for incorporating recycled polypropylene into technically demanding packaging formats without significant changes to existing manufacturing processes.

Source: PureCycle

SUNSHINE Spotlight: The successful production of a living hinge cap using up to 100% recycled polypropylene demonstrates the growing potential for high-performance PCR materials in demanding packaging applications.