High strength and flexibility are features of a line of thin-walled diaphragms that are injection molded of liquid silicone rubber. These sealing devices, when molded of liquid silicone rubber, improve design function and cost efficiency over similar parts using traditional millable gum processes. The thin-walled diaphragms are used in pneumatic gauges in automotive and truck applications. These component seal applications require long term seal life where temperature variation and resistance to aging are important design considerations. Uninterrupted operation for extended periods is important in these applications. Typical liquid silicone rubber properties for grades ASTM DZZ40 durometer is shore A of 20–80 psi and a tensile strength for ASTM D412 of 1150–1750 psi. These grades have heat resistance to 180°C and flexibility down to -45°C. They have electrical insulating characteristics and resist UV radiation and weathering. Additional advantages of liquid silicone rubber include a clean molding process with no material pre-processing. Depending on part complexity, parts can be molded with minimal flash extension and with very little gate or flash material waste. Compared to other materials and processes, this means lower labor content due to reduced manufacturing steps.
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