Teknor Apex (Pawtucket, R.I.) plans to introduce a series of Medalist medical-grade thermoplastic elastomer (TPE) compounds for overmolding at MD&M West this year. The new TPEs offer strong adhesion to medical-grade polycarbonate (PC) and PC alloys and include formulations with enhanced resistance to chemicals encountered in wearable applications, according to the company.
Medalist MD-34900 series compounds, available in 50, 60, and 70 Shore A grades, are for general medical overmolding applications, while the MD-36975 grade is a 75 Shore A TPE is designed specifically for overmolding in wearable devices and offers resistance to the lotions and disinfectants that are typically encountered.
In a joint project with Covestro, these materials were overmolded onto various medical grades of Makrolon PC as well as Bayblend and Makroblend PC alloys, using both insert and multi-shot molding. The project included tests to evaluate adhesion, processability and chemical resistance. Peel-strength data showed the Medalist compounds exhibiting excellent adhesion to Covestro’s engineering thermoplastics. At MD&M West, the two companies will present a co-authored white paper with details of the experiments and product performance. Covestro will exhibit at Booth 2221. —NC