Is a Fear of Plastics a Concern in the Medical Device Industry?

At the recent Plastics in Medical Devices conference held in Westlake, Ohio, Elliott Pritikin of Teknor Apex Company highlighted the problem of increased negative perceptions of plastics. Health-risk concerns have led to companies such as Kaiser Permanente to ban PVC and its plasticizers. It has been claimed that PVC, or polyvynil chloride, has the tendency to leach into its environment.

“If we take a step back and look at the macro market trends and regulations, there’s an increasing set of regulatory requirements, growing concern for the environment, company bans on traditional materials, life-threatening allergens, safety and shelf life of consumable goods, and public perception,” Pritikin, senior medical market manager for the Pawtucket, R.I.-based plastics company, said during the conference. “This all combines to add pressure to the design engineers as they search for true viable candidates and alternative solutions addressing some of these materials of concern.”

Pritikin said that Teknor has been adapting to the pressurized environment by developing thermoplastic elastomer (TPE) medical polymers as an alternative to PVC. TPEs are a mix of plastics and rubbers. They require little to no compounding, with no need to add reinforcing agents, stabilizers or cure systems. Hence, batch-to-batch variations in weighting and metering components are absent, leading to improved consistency in both raw materials and fabricated articles. TPEs easily can be colored by most types of dyes. Their manufacture consumes less energy and allows for closer and more economical control of product quality—a chief concern in the device sector.

Potential disadvantages of TPEs include the relatively high cost of raw materials and their poor chemical and heat resistance.

In comparison testing, Pritikin said Teknor’s 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 percent to 35 percent weight savings.

According to Putnam, Conn.-based biomedical polymers and compounds supplier Foster Corporation, polymers used in orthopedic implants can be grouped into two families: long-term implantable and bioresorbable. Long-term implantable polymers commonly include polyethylene, urethane, and polyketone while bioresorbables consist of polycaprolactone, polylactide, and polyglycolide.