People who are often in contact with silicone products will find that some silicone products are softer to the touch, and some are harder. The use environment has different requirements for the hardness of rubber and plastic products. For example, in order to achieve the real feeling of the breast, the hardness of silicone breast implants is relatively low.

For the use of silicone seals in different fields, it needs to choose silicone material with different hardness. The conventional low hardness can reach about 10 degrees, or even lower than 3-5 degrees. The hardness of commonly used silicone products is in the range of 30 to 70 degrees. Rubber products are also the reference hardness of most products, but the hardness of silicone products made of specially modulated materials can reach about 80-95 degrees.

The other is ordinary silicone processing technology for solid silicone products. At present, the processing technology of solid silicone products in the entire silicone industry can achieve a lower hardness of 10 degrees, and a higher hardness of 90 degrees. Although it can be done with higher hardness, the defect rate is too high. Product becomes very brittle, the cost is also high, and it is not easy to demold.

The choice of the hardness of the rubber O-ring is also important. For example, the hardness of the water pump and turbine of a power station is 70 degrees. The sealing ring often peels off or even cuts off horizontally. Then 85-90 sealing ring is used instead. The effect is reasonable.