Eastman Chemical Co. (Kingsport, TN) has expanded its Tritan copolyester material into the medical device market promoting it as a bisphenol A (BPA) and halogen-free polymer with better heat stability, chemical resistance, and processability than competitive polycarbonate (PC) and acrylic materials. Making the announcement at Medical Design & Manufacturing West (MD&M; Feb. 9-12; Anaheim, CA; organized by MPW parent Canon Communications), Eastman said the new medical grades of its Tritan material, which was launched for consumer applications in October 2007, offer good lipid and chemical resistance; higher heat stability; easy processing; excellent long-term clarity; and added durability and toughness. In addition, although there has not been an outright ban on materials containing BPA, Eastman did point out that the U.S. Food & Drug Administration (FDA) has entered a “fact-finding” mode with the chemical.

Eastman officials stressed their feeling that processors no longer have to “balance the tradeoffs” with competitive materials, where a PC offers toughness and clarity, but isn’t as resistant to lipids. PCs that do offer improved lipid resistance can be higher molecular weight versions that are generally harder to process. In addition, Eastman pointed out that PCs may add toners to mask yellowing after sterilization, in addition to requiring a secondary annealing step for higher-heat applications.

Eastman will start with two grades – one neat, one compounded with a mold-release agent – and target applications within intravenous systems, respiratory devices, and blood therapy. The company says Tritan retains clarity, hydrolytic stability, and other properties after gamma, electron beam, and ethylene oxide sterilization. The glass transition temperature for the new medical grades is 108°C, compared to a 77°C to 90°C for the heritage material. Eastman is working to expand the portfolio, investigating a sheet-extrusion grade for rigid packaging longer term, with higher melt flow rate (MFR) and opaque grades planned for the third or fourth quarter of this year. The higher flow grade would range from 18-20 MFR compared to 8-10, allowing for thinner walls and greater mold cavitation.

Kenneth Breeding, technical platform manager medical, and Scott Hanson, global industry leader medical, told MPW they believe the greatest near-term opportunities for the material lie in new products, vs. replacing PC or acrylic in existing devices. They estimate that the typical product-development cycle in medical ranges from 18 months to two years. Within the company’s specialty plastics business, medical now represents 15-20% of the market, with good growth year over year. —[email protected]