New liquid additive to increase physical properties of recycled polymers

A new liquid additive from Riverdale Global LLC (Aston, PA) reduces the polymer degradation that takes place during melt processing, substantially increasing physical property retention in regrind compared with unmodified material, according to the company. Riverdale Global specializes in liquid color management for the plastics industry through its sealed color delivery system, computerized color technology and global service network. 

Riverdale Global’s +Restore additive has exhibited positive results with recycled commodity resins such as polyolefins, according to Jared Arbeter, Technical Sales Manager. For example, reground homopolymer polypropylene containing +Restore additive exhibited 65% greater Izod impact strength than unmodified regrind, as shown in the chart below. Improvements have also been achieved with PP copolymer and HDPE.

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

"+Restore enables recyclers to obtain physical properties much closer to those of virgin polymer than with unmodified regrind," said Arbeter. "This innovation expands end-use possibilities for recycled materials, opening new applications in molded or extruded products, including fibers."