NatureWorks (Minnetonka, MN) is making known both the formulation and compounding procedure for the resin, which has the trade name Ingeo 3801X. Full details of the proprietary Ingeo 3801X recipe including impact modifier, crystallization accelerant, and agents for reinforcement and nucleation are openly available to customers.

In answer to questions from MPW, Steve Davies, director of communications and public affairs, explained, "Until now NatureWorks has offered the market the finished resin grade...The difference now is that, for the injection molding market specifically, we've 'drawn back the curtain' on how we've developed this grade, and shared exactly what the technology is (the resin modifiers, the nucleants, the additives package, etc), so that we're not offering just a 'black-box' finished solution, but we've also been completely transparent with how we arrived at that solution (what we used to tailor the resin properties and processing characteristics, and why)."

Those interested in acquiring the Ingeo 3801X formulation and its sister high-heat formulation (without impact modifier), Ingeo HHIM 670-82-01, can email NatureWorks for more information.

Jim Nangeroni, a technical expert at NatureWorks, added that the supplier has taken a similar "pull-back-the-curtain" approach before with its foam grade material, 8051D. "But that grade had such a small group of potential users we did it on a more one-to-one basis," he added.

"With the NatureWorks formulation in hand, independent specialty resin companies and brand owners with captive operations will be in a position to use Ingeo as the foundation for biobased injection molded products and components," added Jed Randall, NatureWorks product manager. "Furthermore, the details of the formulation can serve as a basis for research and development in further tailoring biobased solutions for the semi-durable segment of the plastics market." 

Ingeo 3801X is 80% biobased, using NatureWork's polylactic acid (PLA). This formulation offers thermal dimensional stability up to 120ºC (248ºF), notched Izod impact strength greater than two foot-pounds per inch (107 J/m), and modulus of approximately 450,000 psi (3.10 GPa). Injection molding cycle times are comparable to those for styrenic resins, says the supplier, which recently doubled production capacity of the material to 140,000 tonnes.

During the company's Innovation Takes Root conference in Dallas, TX in April, a number of independent compounders described approaches for achieving a wide range of engineered resin properties with biopolymers. For example, PolyOne gave details on its new reSound biopolymer line, which contains a minimum 30% by weight Ingeo, PHB, or PHBV, for applications requiring improved sustainability and higher overall performance. Teknor Apex described compostable thermoplastic starch (TPS) blend technology for Ingeo modification, and RTP described compounded Ingeo or biobased polyamide (PA) formulations (32-80% biocontent) as offsets to HIPS, PC/ABS, 30% glass-fiber-reinforced polypropylene, or polyamide composites. —Matt Defosse