Several new medical grades of plastics are directly
targeting flexible PVC, which has been criticized
for potential health risks.
Companies introducing new thermoplastic elastomers aimed at medical vinyl applications, such as IV bags, include DuPont, PolyOne and Teknor Apex. The new materials were introduced at Medical Design & Manufacturing West, Anaheim Convention Center, Anaheim, CA.
"DuPont(TM) Hytrel(R) thermoplastic polyester elastomer is a versatile engineering material with potentially significant advantages in performance and part costs over alternative flexible materials, including plasticized PVC, conventional rubbers and several other TPEs (thermoplastic elastomers)," said John Gavenonis, global health care manager - DuPont Performance Polymers. Potential uses for the DuPont material include soft-touch/grip surfaces, valves, seals, springs, shock absorbers, tubing and noise management parts for medical products and pharmaceutical equipment.
PolyOne's NEU Specialty Engineered Materials LLC subsidiary is offering GLS Versaflex(TM) grades that are said to feature excellent clarity, flexibility and non-plasticized formulations with exceptionally low leachables and extractables for enhanced patient safety. PolyOne is also offering non-phthalate flexible Geon(TM) HC vinyl compounds.
"We use a collaborative approach to help customers reduce the risk inherent in product design, material selection and manufacturing start-up, which in turn speeds time to market and ultimately, drives marketplace success," said Larry Johnson, global healthcare marketing director for PolyOne.
Teknor Apex said its new Medalist(R) MD-500 Series compounds exhibit crystal clarity and mechanical properties comparable to those of PVC; provide similar clamp resilience and resistance to kinking and necking; have a PVC-like "feel"; and are substantially more flexible and significantly less dense. A typical compound in the series, Medalist MD-575, exhibits 70 percent less heat-aged color shift than a gamma-stabilized PVC compound of comparable hardness.
"Medalist MD-500 Series products outperform traditional PVC-alternative technologies by mirroring many of the performance and handling characteristics of flexible PVC tubing compounds, while providing distinct advantages in some key capabilities," said new business development specialist Elliott Pritikin.
Medalist MD-500 Series elastomers have been tested for compliance with ISO 10993-5 cytotoxicity standards and are free of animal-derived materials, phthalates, latex, silicones and additives not directly required for medical applications. Standard formulations include five grades, with Shore A hardness (15 sec.) ranging from 53 to 86.
Some suppliers consider the composition of their new elastomers to be proprietary, and describe them as using a "broad range of chemistries."
The European Union's Scientific Committee on Emerging and Newly Identified Health issued a report in 2008 stating that some medical procedures may create significant exposure to DEHP-type plasticizer used in PVC compounds to make them more flexible.
Other new materials introduced at the MD&M West include:
- New anti-static compounds for inhalation devices from SABIC Innovative Plastics. The new transparent materials are said to provide permanent anti-static properties, eliminating the need for secondary operations.
- A newly developed curable coating that NuSil says decreases the coefficient of friction of the underlying silicone surface by a minimum of 50 percent when compared to a non-coated silicone surface. Silicone elastomers inherently have a high degree of surface tack and a tendency for blocking (sticking to themselves by virtue of chemical affinity), which may cause problems in applications where they come in contact with each other or other surfaces.
- Teknor Apex also introduced a new gamma-stable rigid PVC injection molding compound that provides the clarity and toughness required for tubing connectors, luer locks, valves, drip chambers, instrument handles and similar medical components.