The ultra-soft thermoplastic elastomers (TPEs) known as gels are greatly valued in medical applications for their cushioning properties, but they have challenged device designers because of their surface tack and limited adhesion to polypropylene (PP) substrates. Two new series of Medalist® medical elastomers from Teknor Apex Company successfully address these challenges:
? Medalist MD-16100 low-tack gels exhibit less surface friction than standard TPE gels, providing smooth surfaces and improved haptics. Grades are available with hardness levels from an exceedingly low 20 Shore OO to 65 Shore OO, or 10 Shore A. The compounds can provide padding, support, or cushioning in applications like orthopedic devices and prosthetic liners and can serve in diabetes therapy as insoles, heel cushions, and toe spacers.
? Medalist MD-10100 gels for over-molding onto PP exhibit excellent adhesion to this substrate, providing the design flexibility of parts consolidation and yielding rigid components with built-in cushioning functionality. Grades range from 8 to 18 Shore A. These gels are used in respiratory masks to provide an air-tight, cushioning seal against the face. Other applications include orthopedic devices and grips for handles or hand-held devices.
The new compounds are safe for skin contact, process and demold easily, and are available in clear and translucent grades that are ideal for custom colors, according to Ross van Royen, senior market manager of regulated products. Property data appear in the accompanying table.
“New Medalist 16100 and 10100 Series compounds are unique among TPEs in avoiding much of the tackiness that is typical with gels and overcoming their limitations in PP over-molding,” said Mr. van Royen. “Their outstanding properties as cushions and liners make them cost-effective replacements for silicones.”
Manufactured in ISO 13485 facilities, the new gel compounds comply with FDA requirements for food-grade ingredients, ISO 10993-5 standards for biocompatibility, and REACH SVHC directives. They are free of DEHP and other phthalates, BPA, and latex. Standard grades are ADM-free.