Rubber seals are the most common thing. It can often be seen in daily life, the production process is relatively simple, and a lot of raw materials are used. So what is the cause of the rubber seal deformation? There are mainly the following points:
1. Medium level pressure is the key reason for the permanent deformation of rubber seals
Compared with the two elements, the material working pressure has a higher damage to the deformation of rubber O-rings, and it is the most common condition that causes rubber O-rings to change under all working conditions. With the development trend of contemporary hydraulic control valves, the working pressure of hydraulic press materials is increasing. The long-term operation of the rubber O-ring in such a high pressure natural environment will cause permanent deformation of the O-ring, which is irreversible. Therefore, different raw materials should be selected for different pressures, and rubber raw materials with relative pressure resistance should be selected. Comparatively, in order to better solve the higher pressure, the hardening level of the compressive raw material seal ring will also be increased.
2. Downsizing and Rashen are foundational elements
Because the secret recipe of rubber O-rings is not the same, the reduction and Rashen of rubber O-rings produced by different companies are not the same. Under the criteria of long-term shrinkage, the commodity creates the illusion of reduced stress relaxation. This kind of situation will slowly expand with the change of time. The longer the time, the smaller the shrinkage and pull amount, resulting in leakage conditions caused by insufficient ductility. The most immediate way to change the fluorine rubber sealing silicone ring is to improve the section specifications of the product, but it will also cause the structure of the product to improve.
3. Temperature is a critical factor
Temperature is critical to the relaxation of the rubber seal. No matter what kind of rubber raw material, it will accelerate its high temperature embrittlement rate. The higher the working temperature, the larger the shrinkage deformation of the steam body. When the product deformation exceeds 40%, the O-ring will gradually lose ductility and cause leakage. When the rubber O-ring is installed, the original ground stress will appear, because the sealing ring is relaxed for a long time and the temperature is slowly reduced, the original ground stress will gradually subside. In some cases, it is likely to subside with a sharp drop in temperature. Even if the rubber raw material is cold resistant, the contrast with the ground stress caused by 20 degrees will not exceed 25%. Therefore, when installing rubber O-rings, the original ground stress should be set and the temperature factor in the office environment should be taken into account.