Nithin Raikar, SABIC Specialties Senior Business Manager for LNP Resins and Compounds, explains the impact LNP ELCRES CRX PC copolymers have had in the medical field.
How has the increased use of disinfectants in healthcare changed the way plastics are used?
Device manufacturers and material suppliers have worked hard to better understand the compatibility of new chemical agents with plastics. The COVID-19 pandemic has accelerated the focus on the types of materials used to address infection control challenges. In particular, device manufacturers are considering newer material solutions with improved chemical resistance to withstand the cumulative effects of cleaning, harsh disinfectants, and the increased frequency of cleaning protocols.
How do SABIC products help maintain the structural integrity of surfaces?
SABIC recognizes the need to develop materials with improved chemical resistance to extend the useful life of critical plastic medical products. With respect to traditional polymer chemistry, repeated exposure to harsh chemicals over time can result in either physical deterioration (stress cracking, hairline cracking, swelling and discoloration) or chemical attack (negative reaction of the chemical with the polymer).
SABIC has innovated to help hospitals mitigate this risk by developing a new family of LNP ELCRES CRX polycarbonate copolymers that have improved chemical resistance over existing materials. Compared to traditional PC, ABS and polyester and co-polyester resins and blends, which may not be compatible with highly aggressive disinfectants, the new LNP ELCRES CRX copolymers can help prevent stress cracking and reduce crack propagation. This means that hospitals can continue to use the most aggressive and effective forms of the disinfectant without compromising device functionality.
How rigorous were the tests that prove the technology works?
SABIC follows a well-established Environmental Stress Cracking (ESC) test procedure (ASTM D543) to test chemicals and environmental conditions that mimic the typical exposure of a part. We conducted this study to evaluate the compatibility between established materials and twelve leading surface disinfectants commonly used to clean equipment. This includes many of the disinfectants published on the United States Environmental Protection Agency’s list that meet their criteria to fight SARS-CoV-2, the novel coronavirus that causes COVID-19.
To test compatibility with various chemicals, SABIC used a quantitative ESC test that rates retention of tensile properties for three to seven days at a percentage load and at room temperature. Without an established industry standard, this exposure area was selected to bring the material to its test limits. The test sticks are kept saturated with the chemical agent, ie they are wrapped in disinfectant wipes. This test method is one of the strictest of protocols and serves as a highly accelerated version of normal exposure to disinfectant wipes in healthcare. *
How complex is the process of bringing these polymers / copolymers to market in Europe?
Healthcare and medical device applications place unique and stringent demands on thermoplastic materials. Proper selection of plastics for medical devices and device housings will continue to be a focus to ensure better patient safety and lower operating costs.
It is important for OEMs to involve material suppliers early in the design process in order to identify suitable materials that meet both the mechanical requirements (such as flowability, impact resistance, creep resistance) and the growing requirement for chemical resistance to withstand harsh disinfectants. As designers explore the benefits of using new plastic technologies during product development, SABIC provides support beyond material selection for part design and mold processing. A proactive and collaborative approach to material selection supports the ability to bring new materials to market that meet product performance and meet applicable legal requirements for medical devices.
* The compatibility criteria may vary as there is currently no agreed industry standard. SABIC defines compatibility as ≥90% retention in tension at extension and 80-139% retention in tension at break.
This article is featured in the March / April issue of EPPM magazine