The race to provide plastic materials for the still-growing medical-devices sector continues and materials firms PolyOne Corp. and RTP Co. are taking their best shots.
PolyOne of Avon Lake, Ohio, and Winona, Minn.-based RTP each touted materials as solutions for medical markets at the Plastics in Medical Devices 2011 conference, held April 11-13 in Huron.
PolyOne's GLS unit has aimed five grades of its Versaflex-brand thermoplastic elastomers at the medical-tubing market. Two of those grades are made with a plasticizer, while the remaining three are not, said Joe Kutka, global market manager. Versaflex can be based on a variety of TPE technologies, including styrenic block copolymers, copolyesters, thermoplastic polyurethanes and thermoplastic vulcanizates.
The health-care market is looking at thermoplastic elastomers because of the search for alternatives, he said. There are concerns with PVC and [plasticizers], and they're looking to replace thermosets like butyl rubber with thermoplastics.
Styrenic TPEs offer options in this area by having the broadest hardness range from gels to flexible tubing of any TPE. In fluid-delivery systems, this has created opportunities for styrenic TPEs to be used in intravenous-infusion sets in applications ranging from IV bags to drip chambers, connectors and tubing. PolyOne also has examined bonds formed between fluid-delivery parts using its materials and other resins such as polypropylene, polycarbonate and ABS.
Any material offered to the medical sector for fluid-delivery systems, however, has to meet customer requirements such as sterilization, weldability and printability, Kutka said. And when plasticizers are needed, PolyOne has avoided materials such as di(2-ethylhexyl) phthalate, or DEHP which has come under scrutiny because of alleged health risks and instead used materials such as paraffinic white mineral oil, which Kutka described as extremely safe.
At RTP, researchers have been focused on finding ways to maximize the use of color in medical devices.
Color selection for medical devices is a critical skill, said Josh Blackmore, global health-care manager. Color can be involved in size, type, function or consumer preference. We're also seeing a consumer crossover effect, where customers prefer a color because they associate it with another brand or company. Color can be a functional requirement as well as appearance.
As a result, RTP looks at commercial color, critical color, sterilization shift and global brand specification, when helping a customer develop a color for a medical application, according to color and additive marketing specialist Mike Chappell.
If a tolerance is too tight, you can set yourself up for more returns, color rejects and more production costs, Chappell said. To prevent this from happening, RTP uses both visual and instrumental color evaluation.
Chappell added that some popular special effects for plastics such as metallic, pearlescent, sparkle or marble looks might not be possible for medical devices. Compounders also need to keep up with the U.S. Food and Drug Administration and the European Union, which Blackmore said are putting increased scrutiny on colorants for plastic to pass biologic testing.
Also at the conference, medical market veteran Len Czuba gave a rundown of different material trends within the sector. Czuba, president of Czuba Enterprises Inc. consulting firm in Lombard, Ill., said there's been a big explosion in the use of plastics and polymers in orthopedic devices.
He also identified implantables, cardiovascular applications, minimally invasive surgery, MRI and imaging, and migration of care from hospital to home as hot growth areas within medical plastics.
And while PVC remains the most widely used medical plastic by volume, the material continues to struggle with DEHP-related concerns, which has opened the door for other materials to compete in IV bags and other applications. The PVC industry hasn't done enough to get the facts out about the material, Czuba said.
PVC makers have responded with non-phthalate PVC grades, but the material still is battling with PP copolymers and blends, styrenic block copolymers, polyethylene copolymers and other materials, according to Czuba.