1. The imported three ethylene propylene rubber O ring, EPDM imported O sealing ring, physical and chemical properties and Application
1) physical and chemical properties
Three Yuan rubber O ring is made by copolymerization of ethylene and propylene into main chain contains no double chain, so the heat resistance, weather resistance and ozone resistance are very good. When the ozone concentration is 100*10-8 (PPHM), there is no cracking in 2430 hours. It also has elasticity, good insulation properties (volume resistance of about 10 breakdown voltage 30-40kv/mm) and low temperature resistance. EPDM (three EPDM) for 150 DEG C ethylene glycol brake fluid, hot water and water vapor (to 150 DEG C), the majority of silicone oil and silicone grease, animal and vegetable oils, most organic or inorganic acid, detergents, soaps and high potassium alkaline environment, polar solvent (ketone, alcohol), phosphate hydraulic oil and refrigerant R134a+PAG, chlorine and chlorine ammonia resistant effect is good, can also be used in acetic acid under 3%-5% environment, but not suitable for mineral oil and grease and aromatic and olefinic solvents. The defect of the O ring of three EPR is slow vulcanization and can not be vulcanized with diene rubber. The self viscosity and mutual viscosity are poor, and the gas tightness is poor.
2) temperature range
Limit temperature: -40~150 C, long term use temperature suggestion: -20~130 C
3) hardness range
Shaw's A40 degree to 90 degrees
4) product color
The default is black, other styles such as brown, green, white, brown, red, yellow, blue, orange, gray and purple can also be made, of course, it can also be customized by customers.
5) application of three meta ethylene propylene rubber and its EPDM O ring
Ethylene propylene rubber (EPR) is widely used in the automotive industry. It can be made into automotive diaphragm, dust-proof rubber sleeve, brake components, radiator and water tank, engine connecting hose, shock absorber, doors and windows, lights and trunk seal. Ethylene propylene rubber can be used as a waterproof material in construction industry and asphalt, and can be made into shock absorbing products in bridge industry, plastic steel doors and windows, high rise buildings, and indoor rubber floor tiles. Ethylene propylene rubber can be used as insulation material of transformer, and can also be made into other high, medium and low voltage insulation products. Ethylene propylene rubber can be made into various chemical corrosion resistant products, such as acid, alkali, ammonia and chloride anticorrosive lining, all kinds of hose, heat resistant conveyor belt, transmission belt, gasket and seal. And the magnetic sealing strip in the household appliances, the parts of the cold and warm air blower, the sealing parts of the washing machine, the vacuum cleaner, the rubber jacket of the cloth and so on.
Two. What is the general representation of the O type ring of the imported EPDM
It is mainly divided into 2 forms, one is the diameter of the inner diameter and the other is the diameter of the outer diameter. At present, the most of the foreign and domestic use is the method of representing the diameter of the inner diameter. Such as AS568, American Standard JIS G/P are expressed with inner diameter of wire diameter *. And GB/T342.1-1982 is also the diameter of the inner diameter d1* line D2. For example, 25*1.8 O-ring, said sealing ring of the inner diameter of 25 mm, 1.8 mm diameter rubber ring is.
Three, install the O-ring, imported three EPDM rubber O ring should pay special attention to what matters
Check work before 1/ installation
A, O ring size (diameter * diameter) and groove size (depth and the width of the notch is correct);
Whether there are burrs, convex and concave points and dust on the surface of B and sealing ring.
C, in order to prevent the seal from being scratched, whether the angle is processed according to the drawing or not, is the sharp edge processed into a chamfering or inverted circle.
Whether D, sealing parts and parts have been smeared with grease or lubricating fluid.
E, no use of solid additives, such as grease, such as molybdenum disulfide, zinc sulfide.
2/ rubber O-ring installation process
A, in order to ensure that the installation is correct, it is recommended to use auxiliary tools to install.
B, installation tools to ensure that no sharp edge;
C, not to distort or overstretch the O ring