Several key issues and new products highlighted two March back-to-back meetings, the Plastics Recycling Conference sponsored by Resource Recycling magazine (resource-recycling.org) and SPE’s Global Plastics Environmental Conference (GPEC), both held in Orlando, Florida. Combined attendance exceeded 1700 with 176 exhibitors.
Presentations from Walmart, Bentonville, Ark, and Procter & Gamble, Cincinnati, discussed progress in their sustainability efforts. The giant retailer started its sustainability scorecard efforts two years ago with a focus on increasing recycled content in packaging, which has since been expanded to nearly all product categories, from containers to electronic products.
P&G’s multi-year sustainability effort includes a short-term goal of achieving 25% renewable content and 30% recycled content in its packaging by 2020. It has been working with molders like Currier Plastics, Auburn, N.Y., to reduce material usage in injection stretch-blow molding of PET containers. Lightweighting is also a focus for Amcor Plastics, Ann Arbor, Mich., which utilizes comprehensive life-cycle assessments to measure its plastic products and their recyclability or recycle content. Amcor continues to encourage use of post-consumer reclaim (PCR) in PET and HDPE rigid packaging as one of the most cost-effective means to promote sustainability in today’s market.
A Plastics Recycling Conference session focused on ways to lessen the impact of labels on bottle recycling streams. The Association of Postconsumer Plastic Recyclers said its technical committee has developed design-for-recycling guidelines that discourage use of paper labels and direct printing on packages. APR test methods now include a bleeding-ink test, which looks for the effect of label ink on discoloration of PET flake and molded plaques. APR also reported favorably on one commercial solution—labels that float in water in the sink/float process and have no ink bleed, such as a wrap-around PP sleeve labels in which the ink is laminated between two layers. Tests are underway on developmental shrink-sleeve labels that can be removed in a whole bottle wash.
New pressure-sensitive labels have evolved with adhesives that release from the container and stay with the label. For example, Avery Dennison, Glendale, Calif. offers its CleanFlake portfolio of labels based on clear or white BOPP film facestock and its FassonSR3010 “switchable” water-based adhesive, which can be “turned on” or “turned off” by external stimuli. The adhesive adheres to the PET bottle until the end of its lifecycle, when the cohesive bond is broken in the recycling sink/float process, enabling the label and adhesive to cleanly separate from the PET flake.
Dow Performance Packaging, Midland, Mich., reported on its all-PE recyclable stand-up pouch (SUP) technology, which was jointly developed with a flexible food-packaging converter and a major frozen-foods brand owner in Latin America. The technology boasts high tear strength, puncture resistance, low-temperature tolerance, barrier properties, and excellent optics. It enables recycling in communities with existing PE recycle streams and is suitable for packaging consumer goods from dry and frozen food items to personal-care products. Compared with a paperboard/liner package with equivalent contents, Dow says a PE SUP package offers 88% less total material weight, 54% less total energy consumed in production and transportation, 89% lower greenhouse gas emissions over the package lifecycle, and 90% less post-consumer solid waste.
In a GPEC session on marine plastics waste, Mike Biddle, founder and president of MBA Polymers, Richmond, Calif., discussed recent changes at the company, recognized as the world’s leading multi-national pioneer in recovering plastics from complex waste streams like computers, electronics, appliances, automobiles, and household waste. Last year, MBA closed its 43,000 ft2 pilot-scale facility at its Richmond headquarters and moved its R&D to its three-year old 126,000 ft2 plant in Worksop, U.K.
Biddle said the move was made because Europe does more recycling and offers more R&D opportunities, at least in the near term. The U.K. plant is reportedly the largest and most advanced facility in the world for recovering plastics and rubber from automotive shredder residue. MBA’s proprietary processes there are said to use less than 20% of the energy needed to produce standard virgin resins. The U.K. facility has an annual processing capacity of up to 176 million lb.
MBA has been operating plants that focus on waste electric and electronic equipment (WEEE) in Austria and China since 2006. Moreover, the company now has plans to build full processing plants in the U.S. once it develops sufficient feedstock sourcing. Biddle cited encouraging developments such as the EPA’s approval of “mining” plastics from more than 10 billion lb/yr of auto shredder residue—which translates to nearly 2 billion lb of recoverable plastics; and the continuing growth of electronics recycling despite lack of legislation. He also sees tremendous opportunity in extracting more plastics from municipal solid waste streams beyond the current plastics recycling rate of about 8%.
NEW ADDITIVES & COMPOUNDS
Several fatty-acid-based additives were highlighted by Struktol, Stow, Ohio, for their applicability to reclaimed/recycled plastics. Among them is RP 11, a proprietary lubricant for PP-based resins and compounds that reportedly allows for greater use of regrind or recycled content. It is said to increase melt flow and Gardner impact strength with no adverse effects on other properties at levels as low as 0.2%.
Another Struktol additive is TR251, a multifunctional blend of anionic and ionic surfactants plus lubricant for polyolefins and engineering plastics. It provides significant spiral-flow improvement in both virgin and recycled plastics at loadings as low as 0.5%. New TR219 compatibilizer and lubricant for nylon 6 and 66 compounds has been found to be effective also in PET compounds, especially recycled applications or cases where PET is contaminated with other plastics.
Bioplastics maker Green Dot Holdings, Cottonwood Falls, Kan., discussed a new use for its Terratek GDH-B1 starch-based elastomer. Used up to now for products like cellphone cases and toys, it is now being offered as an impact modifier for PLA. At 10% and 20% levels, it can improve notched Izod impact of PLA by 100-130%, and at 30% addition it boosts impact strength by 450%. An exponential jump in tensile properties, particularly elongation at break, was also cited.
Dow reported on its new Intune PP-based olefin block copolymers (OBCs), which can compatibilize nylon and EVOH with polyolefins, allowing post-industrial barrier-film scrap to be recycled. Intune OBC uses reactive grafting of maleic anhydride (MA) onto ultra-high-flow PP (660 MFR). Other MA-functional compatibilizers have MFRs of only 2 to 3. The Dow compatibilizer has been shown to produce compounds with significantly smaller domains of nylon and EVOH, resulting in better strength and clarity.
Two years ago, Aspen Research Corp., Maple Grove, Minn., was the first company to offer post-industrial recycled PLA, in collaboration with NatureWorks, Minnetonka, Minn. In Orlando, Aspen discussed its development of compounds that upgrade industrial PLA trim scrap into new materials, including higher-end alloys and pigmented compounds. Its first key commercial application is for colored injection molding grades of RPLA made into egg-shaped containers for the EcoEgg div. of chocolate wholesaler Maud Borup, Minneapolis.