Teknor Apex Company has yielded a new series of thermoplastic elastomers (TPEs) for over-moulding that exhibit excellent adhesion to engineering plastic substrates while meeting the stringent requirements for use in medical devices.
Medalist MD-30000 Series medical TPEs bond effectively to polycarbonate, ABS, PC/ABS, CoPe, PET, PBT, ASA, SAN, PMMA, POM, PA, and PS.
The compounds are for use in wearable devices, ‘soft-touch’ or cosmetic grips for device housings, handheld devices, instruments, and seals and gaskets, and are processable in either multi-shot or insert moulding,
The new series includes grades with enhanced softness, translucence, low compression set for effective sealing properties, and resistance to lotions and other chemicals encountered by wearable devices.
Unlike liquid silicones, over-moulded TPEs do not require the use of a primer, have a shorter cycle time due to avoidance of a curing process, and can be processed on conventional injection moulding equipment.
Three of the Medalist MD-30000 Series compounds were introduced earlier this year after successful completion of a joint project with Covestro LLC, in which the materials were over-moulded onto medical grades of polycarbonate and PC alloys and tested for adhesion, processability, and chemical resistance.
Ross van Royen, senior market manager for Teknor Apex, said: “Over-moulding Medalist TPEs onto rigid substrates enhances the ergonomic and aesthetic properties of medical devices, adds new functionalities such as moulded-in seals and cushions, and provides the design freedom and cost savings associated with parts consolidation.”