By Jan H. Schut
News at GPEC 2014 (Global Plastics Environmental Conference), coming up on March 12-14 in Orlando, FL, (www.sperecycling.org), by the Environmental Division of the Society of Plastics Engineers, includes a new lignin-rich degradable filler, a process potentially for food-contact PPC, plus new ways to recycle some of the toughest plastic scrap. GPEC runs back-to-back in the same location with the Plastics Recycling Conference 2014, on March 11-12 by Resource Recycling Magazine, Portland, OR, (www.resource-recycling.com), which brings an astonishing 150-plus exhibitors in addition to its program. Here are some highlights.
NEW GREEN MATERIALS
Robert Aldi, adjunct professor of mechanical engineering technology at Rochester Institute of Technology, Rochester, NY, (www.rit.edu) presents “LENS FBM Biomass Waste Stream from Cellulosic Sugar Production Compounded in LDPE.” LENS FBM (lignin-enriched, non-sulfonated fractionated bio-mass) is a new bio-based filler that imparts degradability to plastic film. “Fractionated bio mass” is plant material separated into cellulose, hemicellulose, lignin and other components. The patent-applied-for filler is a fine dark brown powder (down to 5 um) with a slight sweet smell, made from a byproduct of cellulosic sugar, sourced from a Rochester area producer. Cellulosic sugar syrup is refined from cellulose and hemicellulose from wood waste and used for bio-based oils and fuels.
Aldi compounded the FBM filler into masterbatches with LDPE, then molded test samples at different loadings in LDPE. He presents the properties of a compound of 30/70 FBM/LDPE with 2% compatibilizer, which reportedly shows only minimal (2%) loss in ultimate tensile strength. He also presents preliminary test data for 3-layer coex blown film containing the filler. The new filler is being developed by an RIT incubator company, Cedar Creek Products and Technologies, of which Aldi is a co-founder (email: firstname.lastname@example.org). Samples of the degradable FBM filler should be available this summer for testing, Aldi says.
Bahareh Bahramian, a PhD candidate at the University of Sydney in Australia (sydney.edu.au/engineering/chemical/research/sustainable-technology) presents “Development of an Efficient Process for the Purification of a Renewable Polymer: A Solution for Minimizing Issues in Waste Management.” The reportedly benign process removes zinc catalyst residues from poly (propylene carbonate) to a level that could potentially allow PPC to pass tests for direct food contact. PPC is a biodegradable form of polycarbonate with high oxygen barrier properties, made with alternating CO2 and propylene oxide molecules. If PPC is made with zinc glutarate (or other heavy metal) catalyst, catalyst residues are too high for food contact. U. Sydney’s process reportedly removes more than 80% of zinc residues from PPC to below standard limits. The work is done in collaboration with Cardia Bioplastics in Melbourne, Australia (www.cardiabioplastics.com), which has a subsidiary, CO2 Starch Pty. Ltd., developing degradable blends of PPC and starch. Two U.S. companies also offer PPC, but not as plastic. Empower Materials Inc., New Castle, DE, offers PPC as a niche sacrificial polymer for the electronics industry. Novomer Inc., Waltham, MA, (www.novomer.com) offers low molecular weight PPC polyols (1000-3000 g/mol) for use in PU foams and adhesives. Novomer, however, touts potential use of higher molecular weight PPC as a barrier layer in food packaging to replace EVOH and nylon, but hasn’t so far done food contact testing. Novomer doesn’t use zinc catalyst and says catalyst residues in its polymers are below 1-2 ppm.
RECLAIMING TOUGH SCRAP
Didem Oner-Deliormanli, research scientist at Dow Chemical Company, Freeport, TX, (www.dow.com), presents “Enhancing the Value of Barrier Film Recycle Stream with Dow’s Novel Compatibilizer Technology.” The patent-applied-for new compatibilizer can combine nylon and EVOH fractions with polyolefins, allowing post-industrial barrier film scrap to be recycled. The compatibilizer, which was announced at last year’s K Show in Germany, uses reactive ultra-high-flow grafted maleic anhydride with a very high melt index of 660. The idea is that this very high flow MAH material breaks EVOH up into smaller particles. The new compatibilizer produces compounds with much smaller domain sizes of nylon and EVOH, better strength and optical properties, Dow reports. Conventional MAH compatibilizers, on the other hand, typically have long polymer chains and very low MIs of only 2-3. Dow is also presenting a paper on “Compatibilization and Recycling of Post-Industrial Barrier Film Scrap” on the same compatibilizer at the SPE Polyolefins conference in February.
Paul Rothweiler, VP of Technology Development at contract research firm Aspen Research Corp., Maple Grove, MN, (www.aspenresearch.com) presents “Recycled PLA for Retail Applications.”Aspen was the first company to offer post-industrial recycled PLA (poly lactic acid) biopolymer (RPLA001 and RPLA002) two years ago, working with Natureworks LLC, Minnetonka, MN, (www.natureworksllc.com), the major producer of PLA biopolymer. Aspen developed compounds that upgrade industrial PLA trim scrap into new materials, including higher-end alloys and pigmented compounds. PLA scrap is sourced from NatureWorks and includes card stock and form-fill-seal trim, so the material is mostly opaque with some clear. Aspen’s first major commercial application, launched in February, is for colored injection-molding grades of rPLA for egg-shaped containers for chocolates, made for the Eco Eggs division of chocolate wholesaler Maud Borup Inc. Minneapolis, MN (www.ecoeggs.com). Interfacial Solutions LLC (www.interfacialsolutions.com), River Falls, WI, last year also announced its “hyper-branched” post-industrial rPLA at GPEC and won a GPEC Environmental Award. Interfacial Solutions has a National Science Foundation grant to develop the technology, but has not yet licensed it commercially.
Among the wealth of exhibitors at the Plastic Recycling Conference, are two unusual new recovery technologies. Environmental Recycling Technologies PLC, Oxford, UK, (www.ertplc.com), acquired the rights to a patented process called Powder Impression Molding, originally developed by US car makers. It’s used to mold thermoplastic parts out of commingled recycled plastic powder.
AMUT s.p.a., Novara, Italy (www.amut.it) has set up a new Ecotech Division to supply sortation equipment to MRFs and PRF’s (plastics recovery facilities), including an “elliptical separator,” consisting of planks with an elliptical motion that carry light materials like paper and film up and heavy materials down, while sand and gravel fall through. AMUT has five elliptical separators installed in North America, three at PRFs and two at MRFs, with the goal of improving upstream plastic separation.