LONG BEACH, CALIF. — Plastics could make significant inroads into medical containers now made from glass because of improvements in how oxygen and moisture barriers are coinjection molded.
At least that's according to Kortec Inc., a Beverly, Mass., maker of coinjection equipment that says it recently succeeded in a two-year effort to make barriers thin enough to be used in medical molding.
Such oxygen barriers have been used in food packaging for years, but the more-demanding performance requirements and thinner walls of medical products made it difficult to coinject a barrier in those applications, said sales manager John Kermet. Kermet presented a paper on the process at the Western Plastics Expo, held Jan. 6-8 in Long Beach.
The process could see its strongest application in bottles, vials, collection devices and testing devices, Kermet said, adding that plastics now could be substituted for 80 percent of the glass used in medical applications.
``Medical has not been seen as a viable market for coinjection molding,'' Kermet said. ``This [process] will allow medical to convert a lot of packaging to plastic because this will give you the oxygen- and moisture-barrier capability.''
Kortec commercialized the process about two months ago, and is testing it on one unidentified medical product, Kermet said. The Kortec process designs the coinjection into the mold, rather than into the molding machine, as more traditional coinjection molding is done.
Injection molder Nypro Inc. is looking at the Kortec process for a personal and health-care application since the company saw the technology at NPE 1997 in Chicago, said Barry Potter, corporate director of strategic marketing for the Clinton, Mass.-based molder.
Nypro has not looked at the technology for medical applications, however, because most makers of medical devices are reluctant to change and put another device through complicated Food and Drug Administration scrutiny, Potter said.
Kermet said getting FDA approval of the technology in medical applications will not be insurmountable because the agency has approved coinjected food applications.
Husky Injection Molding Systems Ltd. in Bolton, Ontario, manufactures molding machines that do coinjection, but has focused on food applications and is not targeting the medical market, said Michael Smith, general manager of Husky's technical center in Costa Mesa, Calif.
Medical applications have performance and quality requirements that make coinjection difficult, he said.
Another machinery company, Welltec Machinery Ltd., based in Hong Kong, introduced coinjection equipment to the U.S. market at the WPE show, but sees it mainly used in thick-wall markets, said Gary Edington, vice president of the company's Elkhart, Ind., subsidiary. Welltec introduced coinjection machines with clamping forces of 385-1,700 tons.
The process also could be used in recycling because plant scrap or post-consumer regrind could be used as the filler layer, cutting costs, Kermet said.