Performance comparison of the hottest rubber seals

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Performance comparison of rubber seals

overview of rubber

(I) natural properties of rubber

generally speaking, natural rubber refers to the solid made of natural latex collected from rubber trees through solidification, drying and other processing procedures. Natural rubber is a natural high molecular compound with polyisoprene as the main component. Its molecular formula is (c5h8) n. its rubber hydrocarbon (polyisoprene) content is more than 90%, and it also contains a small amount of protein, fatty acids, sugar and ash

physical characteristics of natural rubber and check the coherent performance of the equipment under 1. Natural rubber has high elasticity at room temperature, a little plasticity, very good mechanical strength, small hysteresis loss, low heat generation during multiple deformation, so its flexion resistance is also very good, and because it is non-polar rubber, its electrical insulation performance is good

chemical properties of natural rubber. Because of unsaturated double bonds, natural rubber is a substance with strong chemical reaction ability. Light, heat, ozone, radiation, flexure deformation, copper, manganese and other metals can promote the aging of rubber. Non aging resistance is the fatal weakness of natural rubber. However, natural rubber added with antioxidant, sometimes exposed to the sun for two months, still can't see much change, and can still be used as usual after three years of storage in the warehouse

medium resistance of natural rubber. Natural rubber has good alkali resistance, but it is not resistant to strong acids. As natural rubber is a non-polar rubber, it can only resist some polar solvents, but it swells in non-polar solvents. Therefore, its oil resistance and solvent resistance are very poor. Generally speaking, hydrocarbons, halogenated hydrocarbons, carbon dioxide, ethers, higher ketones and higher fatty acids can dissolve natural rubber, but its solubility is affected by the degree of plasticization, while lower ketones, lower vinegar and alcohols are non solvents for natural rubber

(II) variety classification and quality standards

natural rubber can be divided into two categories according to morphology: solid natural rubber (film and granular rubber) and concentrated latex. In daily use, solid natural rubber accounts for the vast majority of the proportion

films can be divided into cigarette glue, air dried film, white wrinkle film, brown wrinkle film, etc. according to different manufacturing processes and shapes. Cigarette glue is the most representative variety of natural rubber. It has always been a kind of glue with large dosage and wide application. Cigarette glue is generally classified according to its shape, which is divided into six grades, including super grade, grade 1, grade 2, grade 3, grade 4 and grade 5, and those less than grade 5 are listed as substandard glue

granular gum (i.e. standard gum) is classified according to the internationally unified physical and chemical efficiency and indicators. These physical and chemical properties include seven items: impurity content, initial plastic value, plastic retention rate, nitrogen content, volatile matter content, ash content and color index. Among them, the impurity content is the dominant index, and it is divided into five levels: 5L, 5, 10, 20 and 50 according to the number of impurities

the delivery grade of natural rubber contract in Shanghai Futures Exchange is domestic first-class standard rubber SCR5 and imported cigarette rubber RSS3, of which domestic first-class standard rubber SCR5 is usually also known as No. 5 standard rubber, which implements various quality indicators of natural rubber gb/t8081-1999 version issued and implemented by the State Bureau of technical supervision. Imported cigarette adhesive RSS3 implements the "international standard for quality and packaging of natural rubber grades" (green paper) (1979 Edition) determined by the International Conference on rubber quality and packaging

(III) main uses of rubber

natural rubber has a wide range of uses because it has the above-mentioned physical and chemical properties, especially its excellent resilience, insulation, water resistance and plasticity, and after proper treatment, it also has valuable properties such as oil resistance, acid resistance, alkali resistance, heat resistance, cold resistance, pressure resistance, wear resistance and so on. Such as rain shoes, warm water bags and elastic belts used in daily life; Surgical gloves and blood transfusion tubes used in the medical and health industry; Various tires used in transportation; Industrial conveyor belts, conveyor belts, acid and alkali resistant gloves; Drainage and irrigation hoses and ammonia bags used in agriculture; Sounding balloon for meteorological measurement; Sealing and shockproof equipment for scientific tests; Aircraft, tanks, cannons and gas masks for national defense; It has even become an indispensable raw material for sophisticated scientific and technological products such as rockets, artificial earth satellites and spacecraft. At present, there are more than 70000 kinds of articles partially or completely made of natural rubber in the world

overview of rubber material characteristics usage nitrile rubber

(NBR) is a copolymer of butadiene and acrylonitrile through lotion polymerization, which is called butadiene acrylonitrile rubber, referred to as nitrile rubber for short. Its content is an important indicator that affects the properties of nitrile rubber. It is famous for its excellent oil resistance. It has the best oil resistance and basically does not swell non-polar and weak polar oils. The heat and oxygen aging performance is better than that of natural, styrene butadiene and other general-purpose rubbers. It has good wear resistance, which is 30% - 45% higher than natural rubber. The chemical corrosion resistance is better than that of natural rubber, but the resistance to strong oxidizing acids is poor. Poor elasticity, cold resistance, flexion resistance, tear resistance, and large deformation and heat generation. The electrical insulation performance is poor, belonging to semiconductor rubber, which is not suitable for use as electrical insulation material. Poor ozone resistance. Poor processing performance. It is used to make rubber hoses, rubber rollers, sealing washers, tank linings, aircraft fuel tank linings and large oil bags that contact oil. It can be used to manufacture conveyor belts for transporting hot materials. Ethylene propylene rubber

(EPDM) is a copolymer synthesized from ethylene and propylene as basic monomers. Rubber molecular chain can be divided into ethylene propylene diene rubber and ethylene propylene diene rubber according to the composition of monomer units. Excellent aging resistance, known as "crack free" rubber. Excellent chemical resistance. Excellent resistance to water, superheat and steam. Excellent electrical insulation. Low density and high filling characteristics. Ethylene propylene rubber has good elasticity and compression deformation resistance. Not resistant to oil. Vulcanization speed is slow, times slower than that of general synthetic rubber. The self viscosity and mutual viscosity are very poor, which brings difficulties to the processing technology. Auto parts: including tire sidewall and sidewall covering rubber strip, etc. Electrical products: including high, medium and low voltage cable insulation materials. Industrial products: acid, alkali, ammonia, and oxidants; Rubber hoses and gaskets for various purposes; Heat resistant conveyor belt and transmission belt, etc. Building materials: rubber products for bridge engineering, rubber floor tiles, etc. Other aspects: rubber boats, swimming air cushions, diving suits, etc. Its service life is higher than other general rubber. Silicone rubber

(VQM) refers to a class of elastic materials with Si-O units in the molecular chain and univalent organic groups as the side groups, which are collectively called organic polysiloxanes. It is resistant to both high temperature and cold, and can maintain elasticity in the range of -100 ℃ ~300 ℃. Excellent ozone resistance and weather aging resistance. Excellent electrical insulation. The electrical insulation of its vulcanizate changes little when it is affected by moisture, water or temperature rise. With hydrophobic surface characteristics and physiological inertia, it is harmless to human body. It has high air permeability, and its air permeability is 10~100 times greater than that of ordinary rubber. The physical and mechanical properties are poor, and the tensile strength, tear strength and wear resistance are much lower than natural rubber and other synthetic rubber. It is used in aviation, aerospace, automobile, smelting and other industrial sectors. It is also widely used as medical materials. It is used in military industry, automotive parts, petrochemical industry, medical and health care, electronics and other industries, such as molded products, O-rings, gaskets, rubber hoses, oil seals, dynamic and static seals, sealants, adhesives and so on. Hydrogenated nitrile butadiene rubber

(HNBR) is a kind of nitrile rubber that removes some double chains after hydrogenation. After hydrogenation, its temperature resistance and weather resistance are much higher than that of ordinary nitrile rubber, and its oil resistance is similar to that of nitrile rubber. Compared with nitrile rubber, it has better wear resistance, excellent corrosion resistance, tensile resistance, tear resistance and compression deformation. It has good resistance to ozone, sunlight and other oxygen conditions. It can be used in detergent for washing clothes or dishes. Seals for automotive engine systems. In the air conditioning and refrigeration industry, it can be widely used as seals in the environment-friendly refrigerant R134a system. Acrylate rubber

(ACM) is an elastomer polymerized with alkyl ester acrylate as the main component. It has good petrochemical oil resistance, high temperature resistance and weather resistance. Suitable for automotive transmission oil. It has good antioxidant and weather resistance, and has the function of resisting bending deformation. It has excellent resistance to oil products. In terms of mechanical strength, compression deformation and water resistance, it is weak, slightly worse than the general oil resistant adhesive. Automotive transmission system and power system seals. Styrene butadiene rubber

(SBR) is a copolymer of styrene and butadiene. Compared with natural rubber, it has uniform quality and less foreign matters, but its mechanical strength is weak. It can be mixed with natural rubber. Low cost non oil resistant materials. Good water resistance, good elasticity with hardness below 70 °. With poor compression deformation at high hardness, most neutral chemicals and dry and nourishing organic ketones can be used. It is widely used in rubber products such as tires, hoses, tapes, rubber shoes, auto parts, wires, cables, etc. Fluorine rubber d) the determination results and production date of this batch of products

(FPM) is a kind of synthetic polymer elastomer with fluorine atoms on the carbon atoms of the main chain or side chain. With the goal of building a powerful country with materials, it has excellent high temperature resistance and oxidation resistance. In order to make this thin material more suitable for clothes, it has oil resistance and chemical resistance, and its high temperature resistance is better than that of silicone rubber. It has excellent high temperature resistance (it can be used for a long time below 200 ℃ and can withstand a high temperature above 300 ℃ for a short time), which is the highest among rubber materials. It has good oil resistance, chemical corrosion resistance, aqua regia corrosion resistance, and is also the best among rubber materials. It is non combustible and belongs to self extinguishing rubber. At high temperature and high altitude, the performance is better than other rubbers, and the air tightness is close to butyl rubber. Resistance to ozone aging, weather aging and radiation are very stable. It is widely used in modern aviation, missiles, rockets, aerospace and other cutting-edge technologies, as well as automotive, shipbuilding, chemical, petroleum, telecommunications, instrumentation and machinery and other industrial sectors. Fluorescein silica gel

(FLS) is silicone rubber, which is fluorinated. Its general performance has the advantages of fluororubber and silicone rubber. It has good oil resistance, solvent resistance, fuel oil resistance and high and low temperature resistance. It is suitable for special purposes, such as chemicals that can resist oxygen, solvents containing aromatic hydrogen, etc. Chloroprene rubber

(CR) on space and aerospace parts is a kind of high molecular elastomer polymerized from 2-chloro-1,3-butadiene. It has excellent characteristics of weather resistance, fire resistance, oil resistance, chemical corrosion resistance and so on. It has high mechanical properties and high tensile strength, which is equivalent to natural rubber. Excellent aging resistance (weather resistance, ozone resistance and heat resistance). Excellent flame retardancy. It has the characteristics of non spontaneous combustion. Excellent oil and solvent resistance. Good adhesion. Poor electrical insulation. Poor low temperature performance, low temperature makes rubber lose elasticity, even fracture, and poor storage stability. It is used to manufacture R12 refrigerant resistant seals such as rubber hoses, tapes, wire sheaths, cable sheaths, printing rollers, rubber plates, gaskets, and various gaskets and adhesives. It is suitable for making parts in contact with atmosphere, sunlight and ozone. Butyl rubber

(IIR) is polymerized from isobutene and a small amount of isoprene, and a small amount of unsaturated groups are retained for sulfur addition. It is impermeable to most general gases. It has good resistance to sunlight and ozone. It can be exposed to animal or vegetable oils or oxidizable chemicals. It should not be used with petroleum solvent, gum kerosene and aromatic hydrogen at the same time.

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