Living in a medical materials world at MD&M West

The co-located Medical Design & Manufacturing (MD&M) West and PLASTEC West events in Anaheim, CA, last week scored a trifecta, with more attendees, more exhibitors and more exhibition space (the show, in fact, sold out) than the previous year, according to Stephen Corrick, Senior Vice President at UBM Canon, which organizes the event (and produces PlasticsToday). The largest medical manufacturing event in North America, MD&M routinely highlights advances in medical materials. This year was no exception, and polymers suppliers, compounders and convertors, in particular, showed their industrious side on the show floor. Here are some innovations in medical materials that caught my eye as I walked the show.

New silicone PSAs from Dow Corning

Dow Corning launched a new family of silicone pressure-sensitive adhesives (PSAs) designed to address issues commonly associated with acrylics. The MG-2XXX series of PSAs enable strong, conformable adhesion of medical devices over extended wear periods without irritating the skin. The new PSAs are also gas and water permeable.

Available in a range of tack and peel-adhesion values, solvent types and solid contents, the four material grades have successfully passed biocompatibility testing for cytotoxicity, skin irritation and skin sensitization, per U.S. FDA guidelines.

The MG-2402 and MG2502 PSAs can be processed using conventional roll coating equipment for solvent-based systems. The MG-2410 material can be applied by means of hot melt coating equipment, and the MG-2401 grade is designed for applications where the liquid adhesive is brushed or sprayed onto the skin.

Dow Corning also introduced three advanced biomedical-grade liquid silicone rubber (LSR) materials at the event in Anaheim. The silicone elastomers share a uniform chemistry at the molecular level, ensuring reproducible processing and performance across various medical device designs, says the company. The Silastic Q7-78XX elastomers are available in 40, 50 and 70 Shore A hardnesses. The company has also launched the C6-7XX LSR series for short-term and non-implant applications.

Foster Corp.: And then there were five

Compounder Foster Corp., which serves the medical device industry from facilities in Putnam, CT, and Las Vegas, NV, was saving it up for MD&M West. The company introduced no fewer than five new products designed to support medical device manufacturers by delivering processing improvements and to accelerate regulatory approvals and time to market. This embarrassment of materials riches was no accident, according to Larry Acquarulo, President. "MD&M West has become our primary show for introducing new technology," he told PlasticsToday. "It's definitely our biggest show and will continue to be our platform for product introductions."

A highlight at the Foster booth was the ProFlex SEBS line of thermoplastic elastomers, which are designed to "fill a niche for injection molding and extrusion applications," says Acquarulo. Available in small lots, the polymers combine elastomeric properties with processing ease. The ProFlex materials are available in a range of durometers; standard, tear-resistant and ProPell formulations are also available. "Eighteen standard grades are in stock, and customized hardness and melt flow properties are available," adds Acquarulo.

The company also introduced PureEase medical-grade thermoplastic polyurethane (TPU) polymers, which are modified with proprietary additives to increase production yields in tube extrusion applications. Unmodified TPUs may exhibit undesirable characteristics such as curling, resin agglomeration, tackiness and dimensional instability, explains Acquarulo. PureEase modified TPUs are designed to eliminate these concerns.

Foster also chose MD&M West as a platform to introduce medical-grade heat- and light-stabilized (HLS) TPUs; MediBatch color concentrates that are formulated and manufactured using medical device pigments to expedite the approval process; and an extension of its Nanomed line, Nanomed MAX, which features increased polymer stiffness through the addition of nano-clay fillers in MX-nylon resins.

Eastman's copolyester joins the (chemicals) resistance

Eastman Chemical Co. (Kingsport, TN) chose to focus on its broad portfolio of products for medical applications and its in-house materials expertise at MD&M West 2016. The company placed particular emphasis on its Tritan copolyester MXF 121, an opaque material that offers chemical resistance, sterilization stability and toughness in handheld and other electronic medical device housings.

Hospitals are using more aggressive disinfectants to prevent hospital-acquired infections, but these chemicals can cause environmental stress cracking, hazing and unwanted color changes in materials. Moreover, advanced medicines like oncology drugs and carrier solvents are challenging the chemical resistance of polymers used in delivery devices.

"Devices are wiped down more aggressively than ever before, and that's especially true as they are designed for greater mobility," says Ellen Turner, Global Market Development Manager, Specialty Plastics, Medical, at Eastman. "Plastics have to withstand this treatment, and it's especially important that the materials are tested based on the environment in which they will be used." Tritan MXF121 can withstand rigorous use and disinfectants, while offering increased durability and product failure reductions, says the company.

Eastman also makes a laudable effort to educate molders on the processing of these and other materials it supplies for medical applications. The materials mold differently and may require some design adjustments, says Turner, and Eastman has created the www.tritanmoldit.com website specifically to provide molders with a direct resource for processing solutions. An expert is available to answer questions within 24 hours, and the site provides technical expertise in injection molding with Eastman Tritan copolyester to medical applications and devices.

We covered a number of other medical materials-related news from MD&M West in articles published in PlasticsToday last week, including:

Medical-grade Veradel HC A-301 polyethersulfone (PESU), the newest material from Solvay Specialty Polymers (Alpharetta, GA), retains transparency and stiffness at high temperatures and offers processing advantages over other commercial high-heat, transparent polymers. Read more

Putnam Plastics (Dayville, CT) profiled a proprietary extrusion process that produces advanced tri-layer tubing with markedly improved tensile and burst strength, as well as reduced elongation, compared with conventional tri-layer tubing technology. Read more

Covestro (Leverkusen, Germany) presented a three-way medical stopcock made with its Makrolon material along with a prepolymer that provides advanced properties for wound-care applications. Read more