Pawtucket, Rhode Island – Teknor Apex Co. developed a new series of medical-grade thermoplastic elastomer compounds for overmoulding applications to produce wearable devices.
The TPE compounds, which are sold under the brand name Medalist, offer strong adhesion to polycarbonate and PC alloys as well as "enhanced" resistance to chemicals, depending on the formulation, a company news release said.
The Medalist line includes compounds in 50, 60 and 70 Shore A grades (MD-34900 series) for general medical overmoulding applications.
Additionally, 75 Shore A (MD-36975 series) have been designed specifically to resist chemicals encountered by wearable devices, such as those found in lotions and disinfectants.
Teknor Apex recommends the compounds for wearable devices where TPEs can contribute comfort; soft-touch or cosmetic grips for handheld devices as well as and seals and gaskets.
The TPEs have been billed as “excellent alternatives” to liquid silicones in overmoulding as they do not require a primer, have a shorter cycle time without lengthy curing process, and can be processed on conventional injection moulding equipment.
Teknor Apex worked with Covestro to test the compounds by overmoulding them onto various medical grades of Covestro brand PC Makrolon and PC alloys Bayblend and Makroblend, using both insert and multi-shot moulding.
The joint project involved tests to evaluate processability in addition to adhesion and chemical.
“Peel strength data showed the Medalist compounds exhibit excellent adhesion to Covestro's engineering thermoplastics,” the release added.
The two companies will present a co-authored white paper with details of the experiments and product performance at MD&M West in Anaheim, California, 9-11 Feb.
Teknor Apex will exhibit at Booth 2121and Covestro will be at Booth 2221.
Founded in 1924, Teknor Apex operates 13 manufacturing plants in the US, Belgium, Germany, China, and Singapore.
The company intends to increase TPE compounding capacity by 15% between its production units in Germany and Singapore, company president Suresh Swaminathan told ERJ sister publication Plastics News in November.
"With these strategic initiatives, we will become one of the few compounders globally who will have local capabilities to provide TPEs and TPVs (thermoplastic vulcanisates) in the three major world regions," he said.