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.
