Plate heat exchangers can handle a wide range of materials, from ordinary industrial water to high viscosity liquids, from food liquids and medical materials with high hygiene requirements. The service life of the plate heat exchanger is closely related to the sealing rubber gasket. The sealing rubber gasket inside the plate heat exchanger has excellent aging resistance performance, and is the best one among the existing general rubber materials, and the ozone aging resistance is particularly good, and It has good weather resistance and is exposed to the sun for 3 years without cracks.Hardness is one of the indicators to measure the degree of vulcanization of rubber products, and has a certain influence on the temperature resistance of the gasket. The hardness is higher and the gasket is used at a higher temperature. In China, the Shore (A) hardness is commonly used, while the foreign commonly used IRHD (International Rubber Hardness Unit) is in the range of 30 degrees to 80 degrees, and the two are basically the same.