What is the cause of rubber seal deformation?

Rubber seals are our most common rubber products. They are versatile, the production process is relatively simple and many materials are used. Most of the causes of O-ring damage are not caused by the design or pressure of the rubber o-ring. A good design will not cause damage to the O-ring if it just unilaterally increases the pressure. The most fundamental reason is that under the high temperature and pressure of the working environment, the O-ring will undergo permanent deformation, and when the O-ring is pressed into the gap, it will produce bite. Rubber sealing ring is a typical extrusion deformation sealing effect. When installed, it will produce contact pressure with the sealing surface. When the pressure is greater than the pressure of the sealing medium, the sealing effect will be produced, and when the pressure is less than the pressure of the sealing medium, leakage will occur. What is the cause of permanent deformation of rubber seals?

1. Compression and stretching are the basic factors.

Due to the different formulations of rubber O-rings, the compression and stretching of rubber O-rings produced by different companies are also different. Under the condition of long-term compression, the product will produce the imagination of compression stress relaxation. This phenomenon will gradually expand over time. The longer the time, the smaller the amount of compression and stretching, resulting in leakage caused by insufficient elasticity. O-ring manufacturer, rubber ring manufacturer, rubber gasket manufacturer, fluorine rubber ring, sealing ring manufacturer, silicone ring

The most direct method of change is to increase the cross-section size of the product, but it will also lead to an increase in the structure of the product.

2. Temperature is a very important factor.

Temperature is very important for the relaxation of rubber seals. No matter what kind of rubber material, it will accelerate its high temperature aging rate. The higher the ambient temperature, the greater the compression deformation of gas. When the product is deformed by more than 40%, the O-ring will slowly lose elasticity and cause leakage. When installing the rubber O-ring, there will be initial stress, which will slowly disappear due to the relaxation of the sealing ring for a long time and the gradual decrease in temperature. In some cases, it may disappear with a sharp drop in temperature. Even if the rubber material is resistant to low temperature, it will not exceed 25% compared with the stress generated at 20 degrees. Therefore, when installing rubber O-rings, the initial stress should be set and the temperature factor in the working environment should be fully considered.

3. Medium working pressure is the main cause of permanent deformation of rubber seals.

Compared with the above two factors, the medium pressure has a greater impact on the deformation of rubber O-rings, which is the most common situation that leads to the deformation of rubber O-rings under all working conditions. With the development of modern hydraulic devices, the pressure of hydraulic media is increasing. The long-term operation of the rubber O-ring in this high-pressure environment will lead to permanent deformation of the O-ring, which is irreversible. Therefore, different materials should be selected for different working pressures, and rubber materials that are relatively pressure-resistant should be selected. Accordingly, in order to cope with higher working pressure, the degree of hardening of the seal ring of the pressure resistant material will also increase. 

For rubber O-rings, deformation means that air tightness cannot be guaranteed. While this may not seem like a major problem, it often leads to hydraulic system leaks. In severe cases, machine failures may even occur, resulting in property or even human casualties. How do we avoid O-ring distortion? First of all, the selection of rubber seals must be done. Its coefficient of friction must be low and lubrication must be in place. The contact surface must be smooth, free of roughness and stains. In the installation process, it must be ensured that the coaxial installation, the eccentricity should not be too large. At the same time, the rationality of the sealing system must be ensured, and the size error cannot be too large