Additives: Liquid Strengthening Additive Substantially Boosts Physical Properties of Recycled Polymers

A new liquid ‘strengthening’ additive reportedly reduces the polymer degradation that takes place during melt processing, substantially increasing physical property retention in regrind as compared with unmodified material.

+Restore additive from Riverdale Global, Ashton, Penn., has exhibited positive results with recycled commodity resins such as polyolefins, according to Jared Arbeter, technical sales manager. For example, reground homopolymer PP containing +Restore additive exhibited 65% greater Izod impact strength than unmodified regrind (see chart). Improvements have also been achieved with PP copolymer and HDPE. “This innovation expands end-use possibilities for recycled material, opening new applications in molded or extruded products, including fibers,” says Arbeter.

The new additive can be used alone or in a blend with Riverdale Global’s liquid colors. Typical usage rates are in the 0.1 to 0.5% range. Processors can also use the +Restore additive to enhance the physical properties of virgin materials, though the most dramatic results are exhibited in recycling.