Polymer for seals and bearings

A low coefficient-of-friction polymer (0.15 to 0.2 @ 33.3 psi, 150 fpm) that has a durable tensile strength (5,500 psi using ASTM D4894 test), and an 8% deformation under load (ASTM D621) works well in high-performance seals and bearings where it's critical to have long component life and low friction. Tetralon 240, from CoorsTek, El Segundo, Calif. (www.coorstek.com) recently received USP Class VI approval.

“USP Class VI approval of Tetralon 240 lets us offer the biotech industry a solution for common seal and wear-component problems,” says John Seubert, Director of Sales for the CoorsTek El Segundo facility.

Silicones for temporary implants

Dow Corning S Series liquid silicone rubbers are tested and supported for implants of 29 days or less. They also are appropriate for disposable applications in IV sets and catheters and for a variety of components, including valves and O-rings. The chemistry of the S Series LSRs is consistent across the three new liquid silicone rubbers — S40, S50, and S70. The materials, (www.dowcorning.com), reach their ultimate physical properties upon initial cure without drift.

Embedded silver and copper fights MRSA bacteria

Fosshield patented technology is 99.99% effective in killing methicillin-resistant Staphylococcus aureus (MRSA) bacteria to below the level of detection within one hour, says developer Foss Manufacturing, (www.fosshield.com). The self-sanitizing fiber provides continuous antimicrobial protection against MRSA, a type of Staphylococcus aureus (staph) resistant to certain antibiotics, and is recognized as a major community-acquired pathogen and growing crisis.

“The key to the effectiveness of Fosshield's antimicrobial agent is the combination of nature's own active ingredients — silver and copper - embedded into the fiber,” says Executive Vice President of Marketing Dave Cicchinelli. “Moisture in the environment, the same moisture required for microbes to grow, initiates the release of silver and copper ions from the fibers. The ions disable the microbes' metabolism, inactivating them. The potential for continuous release ensures long lasting antimicrobial performance.”

Applications for the technology include apparel, footwear, carpets, wall covering, linens, hospitality, filtration, and healthcare.

Implantable polymer detectable by X-ray

An image-contrast grade of PEEK-Optima polymer is now available from Invibio, West Conshohocken, Pa., (www.invibio.com). This grade has the mechanical, physical, and biocompatible properties of unfilled PEEK-Optima polymer with the added advantage of tailored opacity. This lets medical-device manufacturers develop implants that are observed more clearly with X-ray and CT imaging while remaining compatible with MRI. Traditional metallic-implant materials generate imaging artifacts and scatter, preventing a comprehensive inspection of the tissue and bone surrounding the implant.

The company says devices can be produced from the new grade by injection molding, extrusion, or machining. They can also be repeatedly sterilized using conventional methods including steam, gamma irradiation, and ethylene-oxide processes without adversely affecting mechanical properties or biocompatibility.

The polymer's image-contrast grade is intended for implantable medical and pharmaceutical devices and applications requiring blood, bone, or tissue contact of more than 30 days. Invibio says the material is being used or considered in the development of spinal spacers, small joint prosthesis, and ligament-fixation devices.