WEB EXCLUSIVE: A new family of polyolefin “bio-composites” with 10% to 40% renewable content based on plant matter is new from Biobent Polymers, Marysville, Ohio. Biobent is a new division of Univenture in Marysville, an injection molder and fabricator of document binders, mailers, disc packaging, and other plastic storage products. Biobent’s new Panacea blends of PP, HDPE, and LDPE with finely ground soy meal are intended to overcome two previous hurdles to renewable plastics. One is the relatively high cost of existing biopolymers; the other is the tendency of biobased fillers, when blended with conventional plastics, to reduce the performance properties of the host resins. Battelle Memorial Institute in Columbus, Ohio, received funding from the Ohio Soybean Council, to try to solve these problems. Battelle reportedly came up with a compatibilizer for soy-meal powder and polyolefins so as to achieve a molecular bond that preserves or even enhances the original properties of the PP or PE. One advantage, for example, is said to be increased flowability for the bio-composite compared with neat polyolefin. Univenture acquired from Battelle exclusive worldwide sales and sub-licencing rights to this technology. Univenture has used the material commercially in its UniKeep binders (photo).
Panacea compounds are a translucent golden-brown color. They require predrying, because the soy content absorbs moisture. Temperature must be controlled in processing to avoid overcooking the compound, which causes darkening, but Biobent sources say the high flow of the material allows use of lower-than-normal melt temperatures. Battelle’s tests reportedly show that Panacea compounds can be reprocessed and show no warpage from exposure to humidity. Because of the possibility of microbial attack, these materials are not currently recommended for food-contact or medical uses.
Although commercial pricing has not been set, Biobent is currently selling Panacea products for a premium over unfilled polyolefins. Since soy meal costs 10¢ to 12¢/lb, and is more stable in pricing than polyolefins, Biobent believes the long-term price can come down to a level comparable to or below that of polyolefins. Panacea materials are made for Biobent by a toll compounder, so production can be scaled up as needed. Biobent’s long-term goal is to sub-licence the technology to other compounders. It also aims to explore agricultural biomass (waste-product) sources as alternatives to soy meal for these blends.