Liquid silicone makes them strong, durable
Minnesota Rubber's sealing diaphragms are made out of injection-molded silicone rubber, as opposed to regular millable gum processes. They are made for applications that have varying temperatures and demand resistance to aging, such as pneumatic gauges in cars and trucks. They are good insulators and resist UV radiation and weathering. The ASTM DZZ40 grades have silicone rubber properties of shore A of 20-80 and the ASTM D412 grades have a tensile strength of 1150-1750 psi. They resist heat up to 180 C and are flexible down to -45 C. The molding process has no material pre-processing, and molded parts have little gate or flash waste. The rubber's repeatable, short cycle times and less or no secondary operations make for fewer manufacturing steps, and therefore less labor content.
Minnesota Rubber QMR Plastics Group