Biodegradable PGA Resin For Barrier Bottles

Kureha PGA LLC, Charleston, W.Va., a new unit of Japan’s Kureha Corp., broke ground in April for a plant that will make polyglycolic acid (PGA) resin, a biodegradable thermoplastic polyester that offers exceptional oxygen and CO2 barrier for multilayer PET bottles. The facility in Belle, W.Va., is scheduled for completion in early 2010 and will have a capacity of 8.8 million lb/yr. Kureha currently has a pilot plant in Japan. Before now, there has been no cost-effective, high-production technology for PGA, which has been limited to high-value uses like medical sutures. PGA is based on glycolic acid, which occurs naturally in plants and the human body. However, Kureha’s PGA is made from natural gas. The new resin, tradenamed Kuredux, boasts 100 times greater gas barrier than PET and is targeted for three-layer bottles for carbonated soft drinks and beer. Bottles reportedly can use as much as 20% less PET and retain barrier performance with just 1% to 2% by weight of PGA, according to Kureha. So although PGA will cost 10 times as much as PET, cost reductions may be possible. No tie layers are required in the PET/PGA/PET construction. PGA also provides two to three times greater barrier than MXD6 amorphous nylon. And unlike EVOH, it reportedly doesn’t exhibit a dramatic fall-off in barrier performance under high humidity. PGA reportedly will not interfere with PET recyclability because PGA degrades quickly and completely during reprocessing. PGA also is claimed to meet European compostability requirements. In Europe and Asia, Kureha sees opportunities to replace MXD6 nylon in barrier beer bottles. Other possibilities are films and thermoformable sheet. (304) 344-3317 • www.kureha.com