New liquid additive improves postconsumer regrind

Physical property tests carried out by Riverdale Global, Aston, Pennsylvania, in cooperation with a molder of packaging containers, has demonstrated that +Restore liquid additive is even more effective than was originally claimed for improving the performance of postconsumer plastics regrind.

The test results indicate that, at relatively low usage levels, the +Restore liquid additive enables processors running 100 percent postconsumer polypropylene (PP) or high-density polyethylene (HDPE) to obtain products with virgin-like properties, according to a company news release.

According to test results comparing 100 percent virgin PP with 100 percent PP regrind containing 0.4 percent +Restore additive, the regrind tested at 99 percent of virgin PP in the first step of the bending process.

“These test results and similarly encouraging data for HDPE show that plastics processors can use the +Restore additive to meet sustainability goals by actually upcycling postconsumer waste, eliminating most, and in some cases, all, of the property losses typically incurred in recycling,” says Jared Arbeter, technical sales manager.  

+Restore also improves part consistency in comparison with untreated recycled material, Arbeter adds. As measured by standard deviation in a range of physical property tests, for example, HDPE regrind with 3 percent white concentrate exhibited 50 percent or more decreases in part variation when it contained 0.4 percent of the +Restore additive.

Other benefits are provided by the +Restore additive, Arbeter says, “Because the additive has an affinity for the base polymer, it acts as a lubricant, enhancing melt flow. In addition, the +Restore molecule has a functional group that readily reacts with pigments, fibers or fillers in the resin, while a different segment of the same molecule is designed to couple with the polymer. As a result, it forms a strong bond between resin and filler without compromising flexibility.”

The +Restore additive can be used in all thermoplastic processes, alone or in a blend with Riverdale Global’s liquid colors, the company says.