Company Develops Eco-Friendlier Way of Making VOC-Resistant Plastic Industrial Containers
Wal-Mart’s recent announcement of plans to significantly expand its sustainability scorecard program for its titanic supply chain will likely accelerate markets for more sustainable manufacturing technologies as well as industrial packaging used by manufacturers. Over 100,000 suppliers serve the world’s biggest retailer, which alone accounts for 3 percent of U.S. GDP, so its program is bound to have an impact on manufacturing.
The transport of solvent-based chemicals, automotive fluids and foodstuffs have traditionally belonged to the realm of epoxy-coated steel and glass containers and, subsequently, plastics packaging such as polyvinyl chloride (PVC), polyethylene terephthalate (PET) and specially treated high-density polyethylene (HDPE) containers. The use of less-expensive HDPE requires fluorine treatment to give the plastic the barrier properties — namely corrosion resistance – that are needed for the carriage of a wide range of volatile organic compounds (VOCs) and chemicals.
The treatment process involves the use of toxic fluorine gas that could raise concerns under greater scrutiny of environmentally safe and health-friendly production practices being mandated by Wal-Mart as well as other end-users. Treatment also requires packaging manufacturers to ship their HDPE containers, on large long-haul trucks, to only a handful of fluorination plants that exist in the country, entailing costs not excluding stiff carbon-footprint tolls. Meanwhile, PVC has its own share of environmental and human-health challenges with bisphenol A (BPA).
Packaging producer Barrier Plastics Inc., based in Rancho Santa Margarita, Calif., claims that it has developed HDPE containers, marketed under the Baritainer trade name it created, that provide the barrier properties required for a range of VOC shipping applications without polyethylene fluorination. The company uses a proprietary barrier resin, trade-named Quoral, created and manufactured by its sister company, BP Polymers. The resin is based on polyamide (PA), or nylon, and designed to be blended with HDPE before extrusion blow molding of the containers. BP Polymers has specific extrusion screw and head design configurations and material processing settings that yield a permanent structure of overlapping nylon layers within the HDPE matrix for the container wall. But the overall wall structure is monolayer, with the laminar nylon layers reducing permeation of any packaged content.
Kevin Callahan, Barrier Plastics’ vice president of business development, says that the company is targeting any container market that currently employs fluorinated PE, seeing the Quoral and Baritainer technologies as more environmentally friendly options. Citrus oil, used across the food, chemical, cosmetic, perfume and pharmaceutical industries, “is very aggressive and dissolves PE, so [the material] needs to be treated,” cites Callahan, for example. “Companies want to fluorinate, but it’s very toxic. We’re the alternative.”
He also notes that the company’s offerings eliminate shipment of containers to the toll plants or captive facilities of fluorinators, which, in turn, cuts down truck emissions. And he adds, “PVC is going away, especially in green industries,” while “PET does a good job but becomes brittle over time.” The challenge, however, is breaking into established markets, since the industry is “really settled in their ways,” Callahan admits.
Barrier Plastics is touting Baritainer performance benefits including from 60 to 200 times better resistance against solvent-based liquids compared with untreated PE, greater aroma barrier performance as well as 2 to 5 times higher oxygen barrier. Compared with fluorinated PE, barrier efficiency is claimed by the company to be twice as high. Moreover, the company says the mechanical properties of any PE grade used are preserved, including surface printability (e.g., silk-screening), as well as impact and temperature resistance and low weight. Quoral’s concentration can be adjusted (typically from 3 to 15 percent) to meet specific barrier requirements, and it still allows for processing with additives such as flame retardants, anti-stats and colorants.
Initial applications for the Baritainer, which come in bottle sizes up to 32 oz, F-style bottles up to 2.5 gal and jerricans up to 20 L, are the transport of products containing ketones, esters and ethers in the foodstuff, petroleum, agricultural and consumer chemical markets. Barrier Plastics estimates a $124 million potential market just in the replacement of tight head steel containers, and Callahan predicts that pressure for greener manufacturing and packaging from the likes of Wal-Mart and Target will spur conversion. The company is therefore ramping up Baritainer production, now running in Mexico, with two new plants in the United States.