Possibly silicone? Also requires as special liquid injection moldling machine and system. Silicone can be produced in the 70 Sh A but may be too flexible for the application.
I agree that it would be very difficult and expensive to injection mold. I almost positive they are not injection molded as there's no visible gates and are so perfect which is nearly impossible to do with rubber molding.
From examining band that I have that began coming apart, the black...
See below for sample of decorated multicolor rubber that I would like to know how is manufactured. I am a plastics engineer at the beginning few years of my career at an injection molding company and we need to know how this can be done as we have a possible customer with a similar requirement...
