First of all, everyone should know that whether it is silicone or rubber, soft colloidal products have to rely on kneading and deformation to produce a sealing effect. Therefore, when the pressure is greater than the pressure of the sealing medium, the sealing effect will occur, and when it is less than the pressure of the sealing medium, leakage will occur. The reason is because of the permanent deformation of the silicone rubber ring under the high pressure of the working environment and the bite formed when it is squeezed into the gap, so this is the core element, and there are several unavoidable elements on the basis of this element. .
One: The working pressure causes the deformation and failure of the silicone rubber ring; pressure kneading is the main culprit for the permanent deformation of the silicone rubber ring. The pressure of the medium has a greater impact on the deformation of the silicone rubber ring, and it is also a common cause of the deformation of the silicone rubber ring in all occupations. In this situation, with the development of modern hydraulic equipment, the pressure of the hydraulic medium is increasing, and the silicone rubber ring will be permanently deformed in this high-pressure environment for a long time. This deformation is irreversible, so for different Different raw materials should be used for the working pressure, and silicone or rubber materials that are relatively pressure-resistant, wear-resistant and temperature-resistant should be selected. Correspondingly, in order to cope with higher working pressure, the hardness of the silicone rubber ring of pressure-resistant materials will also increase accordingly.
Two: temperature causes failure; temperature is very important for the relaxation of the silicone rubber ring. No matter what kind of raw material, it will speed up its aging speed at high temperature. When the temperature in the environment is higher, the deformation of air compression will The bigger it is, when the deformation of the product exceeds 40%, the silicone rubber ring will gradually lose its elastic ability and cause leakage. When the silicone rubber ring is installed, there will be initial stress, which will gradually disappear after the long-term relaxation of the silicone rubber ring and the gradual decrease in temperature. In some cases, it may disappear with the sharp drop in temperature. Even if the silicone rubber product material is resistant to high and low temperature, it will not be greater than 25% of the stress generated at 20 degrees, so the initial stress should be set when installing the silicone rubber ring, and the temperature in the working environment should be fully considered. elements.
Three: the elements of shrinkage and stretch; because the formula of silicone rubber rings is different, the shrinkage and stretching strength of silicone rubber rings produced by different companies are also different. When the product is in a long-term compression state, the phenomenon of stress relaxation will occur. This phenomenon will gradually expand with time. The longer the time is, the smaller the amount of compression and stretching will be, resulting in lack of elasticity and leakage. The direct change method is to increase the cross-sectional size of the product, but it will also lead to an increase in the structure of the product.
Post time: May-07-2022