Blends of Starch and Recycled Polypropylene Enable Processors to Offer Products with up to 95% 'Green' Content
New blends of thermoplastic starch (TPS) and polypropylene (PP) developed by Teknor Apex Company enable processors to incorporate high levels of both bio-based and recycled content into their products while obtaining physical properties comparable to those of virgin PP, it was announced today by the Bioplastics Division.
The new blends are available in the Terraloy® BP-13020 series of ready-to-process compounds, each with a combined 95% content consisting of TPS and recycled PP; and as Terraloy® MB-13020 masterbatches, which can be let down at a 1:1 ratio in virgin PP for a combined 47% bio-based and recyclate content.
Teknor Apex manufactures the blends using a patented process that incorporates high levels of starch without the usual substantial falloff in the physical properties of the host polymer, noted Edwin Tam, manager of strategic initiatives. “Many processors are looking for ways to help customers meet sustainability goals by incorporating ‘green’ content but are discouraged by the property tradeoffs often involved,” Tam said. “Our Terraloy products can help them meet sustainability goals while still obtaining performance comparable to those of standard polypropylene.”
Teknor Apex recommends the new blends for use in injection molded consumer products, extruded sheet, profiles, and tubing, and blow molded jars and bottles.
Terraloy® BP-13020 ready-to-process compounds are blends of 25 to 30% TPS and 70 to 75% PP, of which 70 to 75% is recyclate. Terraloy® MB-13020 masterbatches have 35 to 50% TPS content and up to 50% recyclate. Customers can use the masterbatches in a 1:1 letdown with either virgin or recycled PP.
Data in the accompanying table show how two Terraloy compounds, based on homopolymer and copolymer PP, respectively, compare with virgin PP in terms of physical properties. Teknor Apex can custom formulate compounds to maximize specific properties such as impact strength or flexural modulus.