First of all, everyone should know that whether it is s […]
First of all, everyone should know that whether it is silicone or rubber, soft colloidal products must rely on the sealing effect of extrusion deformation, so when the pressure is greater than the pressure of the sealing medium, the sealing effect will be produced, and the leakage will occur when the pressure is less than that. The reason is due to the permanent deformation of the silicone rubber ring under the high pressure of the working environment and the bite caused by being squeezed into the gap, so this is the main core factor, and there are several inevitable factors on the basis of this factor.
First: the working pressure causes the deformation and failure of the silicone rubber ring; pressure extrusion 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 the most common cause of deformation of the silicone rubber ring in all industries. In one case, with the development of modern hydraulic equipment, the pressure of the hydraulic medium is increasing, and the silicone rubber ring will work in such a high-pressure environment for a long time, which will lead to permanent deformation, which is irreversible. Therefore, different materials should be selected for different working pressures, 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 pressures, the hardness of the silicone rubber ring of pressure-resistant materials will also be As it goes higher.
Second: temperature causes failure; temperature is very important for the relaxation of the silicone rubber ring. No matter what kind of material, it will accelerate its aging speed at high temperature. When the temperature in the environment is higher, the deformation of air compression will be reduced. When the deformation of the product exceeds 40%, the silicone rubber ring will slowly lose its elastic ability, causing leakage. When the silicone rubber ring is installed, there will be initial stress, which will gradually disappear with the long-term relaxation of the silicone rubber ring and the gradual decrease of the 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, compared with the stress generated at 20 degrees, it will not be greater than 25%, so the initial stress should be set when installing the silicone rubber ring, and the stress in the working environment should be fully considered. temperature factor.
Third: the factors of compression and stretching; due to the different formulas of silicone rubber rings, the compression 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 compressive stress relaxation will occur. This phenomenon will gradually expand with time. The longer the time, the smaller the amount of compression and tension, and the lack of elasticity will lead to leakage. The most direct way to change is to increase the cross-sectional size of the product, but it will also lead to an increase in the structure of the product.
Therefore, in the early use process, the selection of silicone rubber should be done well. Its friction coefficient must be low, and the lubrication must be in place. The contact surface must be smooth, not rough or stained. During the installation process, it is necessary to ensure the coaxiality of the installation, and the eccentricity must not be too large. Today, the editor and I will explain it to you here. I believe that you have a new understanding of the main reasons for the failure of the sealing performance of the silicone rubber ring. If you have any questions, you can call us.