Detailed explanation of seal standards for different materials

Posted by ai on February 29th, 2020

[Introduction] We are all quite familiar with seals. Because every aspect of our life is inseparable from such a small part. Let me give a few examples. There will be some sealing rings on the heating interface in the house, and there will also be some sealing rings on our gas equipment. There is a sealing ring on the water pipe, even for some drinks or bottles. This article mainly talks about the seal standard through the application direction of theseal wholesale.

The seal material is not the same as the application direction, so there will be a variety of seal standards. Below we will specifically talk about a few different use cases for readers' reference.

The first is CR, which is a neoprene seal, which is very resistant to sunlight and weather. It has no effect on refrigerants such as dichlorodifluoromethane and ammonia, and has excellent properties such as resistance to dilute acid and silicone grease. In some mineral oils with a low aniline point, the amount of swelling is large, and it is easy to crystallize and harden at low temperatures. This product is suitable for a variety of environments exposed to the atmosphere, sunlight, ozone and various flame-resistant and chemical-resistant sealing links. Erosion of strong acids, nitro hydrocarbons, esters, chloroform and ketones is not very good. It needs to be noted that it is generally not recommended. The temperature used is -55 ~ 120 ℃.

The second type of IIR, which is what we call butyl rubber sealing ring, has particularly good air tightness and is resistant to heat and sunlight. In addition, it has good ozone resistance, good insulation properties, and good resistance to polar solvents such as alcohol ketone esters. This allows exposure to animal and vegetable oils or oxidizable substances. This product is suitable for standards that are resistant to chemicals or vacuum equipment. Do not use with petroleum solvents, kerosene or aromatics. The temperature range is -50 to 110 ° C.

The third type is ACM, which is the acrylic rubber sealing ring as we know it. Generally has good resistance to oil, etc., and has excellent high temperature and weather resistance. It is not satisfactory from the viewpoint of mechanical strength and compressive deformation rate or water resistance. This is generally used in automotive transmission related systems or power steering related systems. Also remember not to use it in hot water, brake fluid, phosphate ester. Normal temperature is -25 ~ 170 ℃.

The fourth is NR, which is a natural rubber seal. This product has good abrasion resistance and elasticity, and has excellent tear strength and elongation. It is easy to age in the air and becomes sticky when heated. It is easy to expand and dissolve in mineral oil or gasoline. It is resistant to alkali but not strong acid. This type of seal standard is suitable for use in automotive brake fluid, ethanol and other liquids containing hydroxide ions. The normal temperature is -20 ~ 100 ℃.

The fifth is PU, which is a polyurethane rubber seal. We all know that polyurethane rubber has good mechanical properties, and its wear resistance and high pressure resistance are far superior to other rubbers. Very good aging resistance, ozone resistance and oil resistance. However, it is easy to hydrolyze at high temperature and is used for high pressure and abrasion resistant sealing. The application temperature is -45 ~ 90 ℃.