New Copolyester for Rigid Medical Packaging
At MD&M West 2010, Eastman Chemical Co. (Kingsport, TN) announced the launch of Eastman Tritan copolyester MP100 for rigid medical packaging. At an industry unveiling event February 9, Gregory W. Nelson, senior vice president and chief technology officer of Eastman Chemical Co., called the launch of Tritan “the fastest introduction of any polymeric material by Eastman or any others we could find.”
“We believe that the [healthcare products] industry is looking for innovation,” he told the audience. “It is looking to reduce hospital-acquired infections and to reduce healthcare costs.”
Tritan copolyester MP100 offers the same properties offered by Eastar copolyester 6763, including chemical resistance, clarity, and toughness. “In fact, it may offer higher heat resistance and greater inherent toughness than 6763,” reports Scott Hanson, global industry leader, medical market segment, specialty plastics business, Eastman. “It offers manufacturers of expensive medical devices or devices with a long shelf life a new packaging option.”
Tritan copolyester MP100’s high heat resistance provides sterilization and durability advantages. Tritan allows higher sterilization chamber temperatures, allowing faster ethylene oxide (EtO) cycle times and a reduced risk of warping and sticking, Eastman reports. Compared with other competitive materials, Eastman Tritan copolyester MP100 provides post-sterilization clarity and color. It quickly returns to glasslike transparency and original color after gamma sterilization. It is not suitable for use with autoclave methods, however.
In addition, Eastman claims that such heat resistance permits more rapid accelerated-aging protocols that result in faster validation and more reliable shelf-life qualifications, reducing time and labor. Plus, it says, the higher heat resistance of Tritan reduces the impact of aging and increases a package’s shelf life compared with that of other materials.
As part of Eastman's commitment to supplying innovative materials and solutions for packaging and injection molded device applications, Eastman worked with DD Studio (Carlsbad, CA), a respected design and prototyping firm, to develop a medicine-dosing cup that could act as a sample chip for material evaluation. According to Scott Clear, product development director of DD Studio, the design firm “validated Eastman’s claims and discovered a few other characteristics.” The multiple-part dosing cup was able to be assembled without undercuts, ultrasonic welding, or screws, he told the audience.
Parts can be joined using cold swaging, a technique that involves bending and crimping a plastic part without heat to join two parts, saving energy and avoiding the use of chemicals, adhesives, and mechanical fasteners. In addition, “the material is resistant to chemicals such as MEK and more, so it does not crack or haze.”
“As the medical marketplace increasingly values safe, durable, and reliable devices that make an emotional connection with users and recognizes design as a competitive advantage, it’s grown more important for materials suppliers and designers to work together,” says Hanson. “Through our collaboration, we can help designers who are creating state-of-the-art medical devices to bring them to market easier and faster, and also consider next-generation materials to solve industry issues.”
Given its toughness, Tritan copolyester MP100 offers the potential for package lightweighting and downgauging to reduce thickness, thereby requiring less source material and resulting in reduced energy usage and shipping costs. “It can be used at a thinner gauge than 6763,” says Hanson. “Cost savings may also be achieved by eliminating the need for secondary packaging.” It also can be thermoformed with less wasted material and time because the material does not stress-whiten or increase particulate or angel hair compared with sheet made from acrylic, acrilonitrile, or polyvinyl chloride polymers.
Eastman Tritan copolyester MP100 offers moderate oxygen and moisture barrier, explains Hanson. To increase such properties, it can be coextruded with high-barrier materials.
One potential challenge is that Tritan copolyester MP100 is not as stiff as 6763, which could limit its use for long, narrow trays or other packages required to be particularly stiff.
Eastman has worked with a major medical device manufacturer (MDM) and tested the material in accordance with ASTM D4169 in a simulated protocol determined to be appropriate by the MDM. "We tested trays manufactured from both Eastman Tritan copolyester MP100 and Eastar copolyester 6763 with a 3-lb simulated device using 40-mil sheet. Under this simulated protocol, the packages made from Eastar copolyester 6763 passed 97% of the time from a drop height of 30 in., while the packages made from Tritan copolyester MP100 passed 100% of the time. For demonstration purposes, the drop height was raised to 60 in., and the packages made from Tritan copolyester MP100 continued to pass 100% of the time," reports Eastman Chemical.