Custom molded FDA seals for prosthetic heart valves use liquid silicone rubber (LSR) with 40 Shore A hardness. Precision molding tolerances of ±0.05 mm ensure perfect fit within titanium housing. After post-cure at 200°C for four hours, these seals withstand 40 million cycles (equivalent to 30+ years) without leakage in accelerated durability testing. https://globalsealstech.com/medical/