NBR, a nitrile rubber O-ring, import import NBR seals
NBR nitrile butadiene rubber is obtained from emulsion polymerization of butadiene and acrylonitrile. Nitrile rubber is mainly produced by low temperature emulsion polymerization. It has excellent oil resistance, high wear resistance, good heat resistance and strong adhesion. Ding Qing rubber O-ring aging synthetic rubber with good performance. There are five kinds of acrylonitrile content (%) in NBR 42~46, 36~41, 31~35, 25~30 and 18~24. The more the content of acrylonitrile is, the better the oil resistance is, but the cold resistance decreases accordingly. In addition, it has good water resistance, air tightness and good bonding properties. Its disadvantages are low temperature tolerance, poor ozone resistance, low electrical performance and low elasticity.
It is widely used in all kinds of oil resistant rubber products, various oil resistant washers, gaskets, bushings, soft packaging, soft rubber pipes, printing and dyeing cots, cable adhesive materials, etc., and it has become an essential elastic material in automobile, aviation, petroleum, duplication and other industries.
The basic performance of nitrile rubber has excellent oil resistance, its oil resistance is second only to polysulfide rubber and fluoro rubber, and has the wear resistance and gas tightness. The defects of Ding Qing rubber are ozone and aromatic, halogenated hydrocarbons, ketones and ester solvents, which are not suitable for insulation.
The main purpose of nitrile rubber is mainly used for the production of oil products, such as the oil pipe, tape, Ding Qing rubber O-ring rubber diaphragm and large oil sac, commonly used in the production of various types of oil resistant molded products, such as O ring, oil seal, rubber bowl, diaphragm, valve, bellows, is also used to make blankets and wear parts. Ding Qing rubber has excellent performance and high life. The service life of dynamic pressure seal is 5 to 10 times higher than that of conventional rubber sealing product, and it can reach up to tens of times. Under certain conditions, it can be life as sealing matrix. The friction resistance is small and the dynamic and static friction is equal. It is the 1/2 - 1/4 of the friction force of the "0" shape rubber ring, which can eliminate the "crawling" phenomenon of the movement at low speed and low pressure. Ding Qing rubber is high wear-resistant, and the seal face has the function of automatic elastic compensation after wear. Ding Qing rubber has good self lubrication performance. It can be used as oil free seal. The structure is simple and easy to install. Working speed: 15m/s; working temperature: -40-120 degrees. Applicable medium: hydraulic oil, gas, water, mud, crude oil, emulsion, water - ethylene glycol, acid. The import of nitrile rubber O-ring is suitable for all kinds of mechanical equipment, in terms of temperature, pressure, and different liquid and gas medium, the sealing function under static or motion. Various types of sealing elements are widely used in machine tools, automobiles, ships, aerospace equipment, metallurgical machinery, chemical machinery, construction machinery, construction machinery, mining machinery, petroleum machinery, plastic machinery, agricultural machinery and various instruments. It is mainly used for static seal and reciprocating motion seal. When used for rotary motion seal, it is limited to low speed rotary seal. Generally installed in the outer circle or the inner circle is a rectangular groove in the groove to play a seal. In oil resistant, acid and alkali, grinding, chemical erosion and other environment still play a good seal and shock absorption. Therefore, it is one of the most widely used seals in hydraulic and pneumatic transmission systems.
Two. Series standard and line diameter of imported NBR sealing ring
The O type ring is a standard piece. It is widely used. In the process of development, it has gradually formed the standards of various countries.
The representative of the following are the following:
The 1/ standard is divided into old and new national standard GB, GB is to old O-ring diameter * wire diameter to represent the new national standard to the inner diameter of the rubber ring; * diameter represented by the current domestic enterprises mainly in the new national standard.
Old national standard: the national standard GB1235-76--- line diameter is: 1.9, 2.4, 3.1, 3.5, 5.7, 8.6;
New national standard: the national standard GB3452.1-92--- line diameter is: 1.8, 2.65, 3.55, 5.3, 7;
2/ daily standard JIS B2401--- line diameter is: 1.9, 2.4, 3.1, 3.5, 5.7, 8.4;
The R--- line diameter of the 3/ method was 1.90, 2.70, 3.60, 5.33 and 6.99.
4/ American Standard AS568A, British standard BS 1806--- wire diameter: 1.78, 2.62, 3.53, 5.33, 6.99;
5/ de standard DIN3771 GB3452.1-92--- line diameter is: 1.80, 2.65, 3.55, 5.30, 7;
6/ BS standard BS 4518 Rui standard SMS 1586--- line diameter: 1.6, 2.4, 3, 5.7, 8.4.
Three. After vulcanization of rubber O ring and imported NBR sealing ring
After being vulcanized, the seal can not immediately become a qualified product that can be sent to the customer. It will also be completed by some other corresponding work.
1) in order to meet the performance requirements of some characteristics, the surface of the product needs to be treated by a special process.
2) in order to ensure the stability and performance requirements of some products, it is necessary to cool the corresponding products by hot drawing and cooling after inflation.
3) in order to increase the aesthetic feeling of the product and improve the seal, the product needs to be trimmed.
The flash or Flash edges will be generated in the process of molding, it is the overflow glue edge formed when the product flows out at the time of vulcanization delay and the parting surface of the die.
1/ manual trimming: This is the earliest use of a trimming method. This method requires a higher level of manual proficiency, and the quality of the product varies from person to person. Due to the use of scissors, scrapers and other tools to remove the edges, there are often scratches, scratches and deformations. In a word, the quality of the trimming of the product is not stable.
2/ mechanical dressing: it is a kind of high efficiency and high quality trimming method.
A and low temperature shot blasting
The trimming methods used in this process generally require high precision of the product. It is to rapidly cool the product to liquid nitrogen or dry ice to below the brittleness temperature, and then spew out metal pellets or plastic projectiles to break the flex and finish the trimming.
B, mechanical grinding and trimming
The trimming method is of low precision and is usually used for die rubber with inner holes and outer circles.O type ring. The cutting tool for grinding particles of certain thickness, so the surface of the product may be with residual sand effect
C, low temperature drum trimming
It is the friction between the impact force generated by the rotation of the drum and the products, has been frozen to brittle temperature following flash products break and fall off, the drum shape is octagonal, in order to increase the product impact force in the drum, the drum speed should be moderate, people can improve the efficiency of abrasives.
D, cutting and trimming punching machine
This method applies the product and its rubber edge can be put on the mold or the model product on the bottom of the punching knife. The punching is also divided into cold cutting and hot cutting.
F, low temperature vibration trimming
It is also known as vibration, freezing and trimming. The products do spiral vibration in the circular seal box. There is a strong impact between products and products and abrasives, resulting in the brittle edge of rubber crumble. Low temperature vibration trimming trimming drum than low temperature, low failure rate of products, the production efficiency is relatively high.
G, mechanical cutting trimming
It is suitable for the trimming of the larger dimensions, and the cutting tools are used.
H, low temperature brush grinding trimming
It is by using two nylon brushes rotated around the horizontal axis to remove the rubber edge brush of the frozen rubber O ring.