The attraction of the medical market remains a strong one for plastic materials firms. You can put PolyOne Corp., Daikin America Inc. and Teknor Apex Co. on the list of companies looking to expand their presence in that market.
Officials with those firms spoke at Plastics in Medical Devices 2012, a June 12-13 conference hosted by Plastics News in Westlake.
PolyOne in Avon Lake, Ohio, is finding opportunities for its Geon HC rigid PVC compounds as a result of the startling trend of hospital-acquired infections, or HAIs.
“Steps are being taken to handle HAIs, and that's having a big impact on material selection,” said Joe Kutka, global business development manager for PolyOne's Geon line.
The incidence of HAIs has increased 36 percent in the last 20 years. HAIs have a 5 percent fatality rate, resulting in 100,000 deaths annually and costing medical systems $28 billion.
Adding to the challenge is that Medicare hasn't reimbursed for HAIs since 2009, placing 95 percent of related costs on patients or hospitals.
As a result of higher HAI rates, hospitals are using stronger disinfectants and using disinfectants more frequently in general. This can have an adverse impact on plastic materials used in medical devices, Kutka said.
“Disinfectants can cause polymer cracking and crazing in device housings,” he said. “This can lead to fires, burns and equipment failure. [Disinfectants] can corrode electrical circuitry. All of these things can lead to more service calls, warranty claims and product returns.”
Kutka added that in many cases, Geon HC has performed better in medical-device material testing than such commonly used materials as polycarbonate, ABS and blends of PC with ABS, PET or polybutylene terephthalate.
Geon HC also can be alloyed with other materials to match specific applications. Kutka said PolyOne is testing the material with several medical customers.
Fluoropolymer resins also are gaining ground in the medical area through applications such as catheters, heat-shrink tubing, sutures, biocontainment vessels, pre-filled syringes and inhaler components, according to John Felton, Daikin market development manager in New York.
Fluoropolymers are on the high end of the price scale, but offer excellent performance with low water absorption, biocompatibility, chemical resistance and barrier properties, Felton said. He disagreed with the commonly held idea that fluoropolymers are difficult to process and should only be used for special applications.
One processor who doesn't need to be convinced of the value of fluoropolymers is Ken Kelly, general manager of injection molder Performance Plastics Ltd. of Cincinnati. Performance made a commitment to work with fluoropolymers several years ago and now generates more than 40 percent of its sales from parts made from those materials.
But the project required some effort, Kelly said. New types of metal had to be used for high-volume mulitcavity molds, partly because of the corrosive nature of fluoropolymers. Equipment and tooling also had to be made to fluoropolymer standards. And critical safety systems had to be put in place to handle toxic gases that can be emitted during fluoropolymer molding.
The effort has paid off for Performance Plastics, which now uses fluoropolymers in numerous products, including as a glass replacement in drug-delivery systems. Fluoropolymers “are a new option for product design engineers,” Kelly said.
At Teknor Apex, officials believe their firm's role in the medical-device market is “to simplify the process for device manufacturers,” said Elliott Pritikin, senior medical market manager for Pawtucket, R.I.-based Teknor.
“We want to make it easy for material selection to be made and for [device makers] to meet requirements,” he said.
Teknor has been positioning its Medalist compounds made from thermoplastic vulcanizates and other types of thermoplastic elastomers as alternatives to PVC in some medical applications.
Concerns about health risks alleged for PVC and its plasticizers have led to bans from medical firms such as Kaiser Permanente and commercial giants like Wal-Mart Stores Inc. and Apple Inc.
In comparison testing, Pritikin said Medalist TPEs — which contain no phthalates, as some types of PVC do — have shown similar clarity and kink resistance to PVC in tubing products, while offering better elongation and 30-35 percent weight savings.
Medalist also showed better color-change performance than PVC in films, pouches and bags, according to Pritikin. In medical cable jacketing, Medalist can provide excellent electrical and flame-retardant performance, he added. Medalist TPEs also are being marketed as an alternative to natural-rubber latex and thermoset rubber, offering cost and scrap reduction and faster cycle times. Unlike rubber latex, Medalist has no issues with allergies, extractables or odor, Pritikin said.
“There's been negative momentum for some traditional materials, and that's put undue pressure on the medical-device industry,” he added.