Classification of automotive rubber products and their role in automobiles (II)

2 current situation and development trend of automotive rubber products in China
2.1 tyres
In recent years, cars have gradually entered the family, which has stimulated the rapid development of China's automobile industry and promoted the development of automobile supporting industry and rubber products industry. Obviously, rubber tires bear the brunt.
Due to the high speed of automobile, rubber tire products have changed from bias tire to radial tire. Radial tire is the development direction of China's tire industry and the model supported by the state. Since 2001, China's domestic tire factories have been carrying out infrastructure construction and technological transformation around radial tires, with a rapid development rate and great success. In 2004, China's tire output reached 2. 100million, including 1 radial tire. 0.9 billion, with a meridian rate of 52%. In addition to meeting the domestic market demand, nearly 1/3 of the output of tires enter the international market. In 2005, China's tire output reached 2. 300million, including 1 radial tire. 300 million, with a meridian rate of 56%. It is predicted that China's tire output will reach 300million by 2010, including 2 radial tires. 100million, with a meridian rate of 70%. Radial tires will account for about 85% of automobile tires, and strive to achieve 95% of automobile tires by 2015.
In 2004, China's tire consumption of raw rubber was 2.2 million tons, and in 2005, the rubber consumption reached 2.43 million tons, an increase of 10%. 5%。 Natural rubber accounts for about 56. 6%, synthetic rubber accounts for about 43. 4%, synthetic rubber is mainly styrene butadiene rubber and CIS butadiene rubber (outer tube), as well as butyl rubber and chlorinated butyl rubber (inner tube). Due to the limited natural rubber resources in China, the future development direction should appropriately increase the proportion of synthetic rubber. The main increased synthetic rubber is styrene butadiene rubber and CIS polybutadiene rubber. However, at present, the comprehensive properties of these two synthetic rubbers are not as good as natural rubber, and excessive increase in the application proportion of these two synthetic rubbers will reduce the quality of tires. In the future, the physical properties of these two rubbers should be improved or new varieties should be developed.
2.2 sealing products
In recent years, through the introduction of foreign advanced technology, equipment and technological transformation, China's automotive rubber products industry has emerged a number of backbone enterprises with large production scale and high professional level, gradually forming a relatively complete industrial system, which can basically meet and adapt to the needs of China's automotive industry.
At present, there are about 30 skeleton oil seal plants with a certain scale and level in China, with a total production capacity of about 200million pieces. At present, China can produce automotive special skeleton oil seals with various structures, including inner and outer skeleton oil seals, pressure oil seals, and hydrodynamic oil seals with oil lines brought back by the main lip, which can meet the needs of the domestic automotive market. However, due to the high speed of the automobile and the addition of fuel additives, the service temperature, medium resistance and accuracy of the oil seal are increasingly improved. For example, the linear speed of the rear oil seal lip of the crankshaft of some cars can reach 200m / s, and the lip temperature can reach 250 ℃. The structure and material of the original oil seal can no longer meet the requirements of use. Fluorosilicone rubber, acrylate rubber and fluororubber are widely used in automobile engine oil seals abroad. Nbr/ptfe composite oil seal can make the service life of oil seal reach 4000-4500h, that is, the driving mileage reaches 130000 km-180000 km.
However, nitrile rubber is still the main oil seal in China. Although a few manufacturers can produce fluororubber and acrylate oil seals, the output and quality can not keep up with the needs of the automotive industry, and its service life is less than 100000 km. Oil seals in key parts of high-end cars, such as crankshaft rear oil seal and automobile guide rod oil seal, still rely on imported parts, and the localization rate is very low. For the framework oil seal, further improving the heat resistance, dynamic fatigue resistance and compression permanent deformation resistance of the compound, improving the level of tooling and automation, and improving the machining accuracy of the mold are the tasks in the future. The main material of oil seal will be widely used fluorosilicone rubber, Chloroether rubber, hydrogenated nitrile rubber and acrylate rubber.
There are more than 60 sealant strip manufacturers in China, with 49 production lines of various automobile sealing strips, with a total annual production capacity of 200 million meters.
Sealing strip is one of the fastest growing industries of rubber products in China in recent years. No matter the output, output value or profit, it has increased significantly, and has basically formed a professional system. The manufacturer has introduced the production technology, equipment and testing instruments of the Italian Saiya seal company respectively. The technology and product quality are equivalent to the international level of the 1990s. It can design and develop products by itself, basically meeting the needs of the domestic car industry. Rubber varieties are mainly EPDM. In the future, TPE will be used as the sealant strip, TPV as the glass guide groove, and the new process of multi-faceted flocking and extrusion lamination will be adopted.
2.3 shock absorbing products
China has more than 20 rubber shock absorption products factories with a considerable scale, with a production capacity of about 70million pieces, which can basically meet the needs of domestic automobile production, maintenance and replacement.
At present, foreign advanced countries have successfully developed a new generation of rubber shock absorbers, such as liquid sealed shock absorbers, electronically controlled shock absorbers, torsional shock absorbers, etc., which are still in the development stage in China. In China, natural rubber is still used in automotive shock absorber products, as well as the combination of natural rubber and CIS polybutadiene rubber or CIS polybutadiene rubber. The development direction of materials should be EPDM, butyl rubber and other rubber types with good heat resistance and excellent damping performance. Developing new shock absorbing materials with more heat resistance and dynamic fatigue resistance and developing liquid sealed shock absorbers are research topics that China should invest more in the future.
2.4 safety products
There are more than 30 manufacturers of brake film (diaphragm) and brake cup for automobiles in China. After years of transformation, the product performance basically meets the requirements of the automotive industry. The service life of domestic high-strength rubber diaphragm has reached the technical mark of 1million times. The production capacity of membrane is 35million pieces, and the production capacity of diaphragm is 15million pieces. The main raw rubber used is natural rubber or the combination of natural rubber and synthetic rubber. In the future, high-strength rubber diaphragms such as EPDM and TPE should be further developed and applied.
The production of airbag in China has just started, with only 6-7 manufacturers and a total production capacity of about 200000 sets / year. The national automobile safety law stipulates that the total weight is 2. Vehicles with a capacity of less than 5 tons (category M1) must undergo a crash test before being listed in the catalogue. In the future, all vehicles must meet the standard and must be equipped with safety capsules. The air bag is generally made of neoprene with nylon as the framework. Looking forward to the next development direction is to use thermoplastic elastomer to manufacture airbag.
2.5 rubber hose products
In recent years, the automobile rubber hose has increased at a rate of about 25%. There are more than 20 automobile rubber hose factories with a certain scale in China, with a total production capacity of 200million standard meters. Braided rubber hose and winding rubber hose are the main ones, and the proportion of resin composite rubber hose, including brake rubber hose and cooling water pipe, is increasing; Short fiber rubber hose is valued for its simple process and good performance. From the perspective of rubber materials, it has developed from a single kind of rubber in the past to the use of different kinds of rubber in the inner, middle and outer layers to adapt to different working environment conditions. It is generally composed of 2-3 kinds of rubber. In recent years, the development of automotive hose in China has begun to take shape. Many enterprises have introduced foreign advanced technology and equipment, and the product quality has been greatly improved. However, compared with foreign countries, there is still a large gap, and medium and low-grade products can meet the market requirements. High end products such as fuel pipes, thin braided rubber hoses, heat-resistant pipes and so on still rely on imports. The matching rate of domestic cars for such products is only 40%, and that of high-end cars is only 5-10%. In addition to nitrile rubber, nitrile rubber / PVC blend rubber is also used as rubber materials, and hydrogenated nitrile rubber, Chloroether rubber, chlorosulfonated polyethylene and ethylene propylene diene monomer are further applied.
2.6 adhesive tape products
The production of transmission belts for cars, especially synchronous belts, started late in China. After the reform and opening up, in order to cooperate with the introduction of car localization, some joint ventures have successively introduced foreign advanced technology and equipment, developed corresponding products, and basically met the needs of cars; However, there is still a certain gap in product quality and performance compared with similar foreign products. The production process of V-belt for automobile has been replaced by trimming belt. In terms of materials, hydrogenated nitrile rubber is mainly used abroad; Chloroprene rubber is still the main type in China, and ethylene propylene diene monomer and chlorosulfonated polyethylene elastomer are used in a few cases. Hydrogenated nitrile rubber cannot be used because of its high price, so the service life of domestic V-belt is only about 100h. Foreign V-belts can be used for 180000 km, which can be synchronized with automobile overhaul. There are about 300 automobile transmission belt manufacturers in China, with a production capacity of 500million standard meters of V-belts and 20million synchronous belts.
2.7 other products
The rubber strip of automobile wiper is one of the most problematic varieties of automobile rubber products in China. The main problems are high noise, poor wear resistance and poor wiping efficiency. Neoprene is the main material of wiper strips in China. Foreign countries have conducted in-depth research on materials and structures. Such as replacing neoprene with EPDM and silicone rubber, adding solid lubricant to the rubber, or spraying wear-resistant materials on the surface. The quality problem of automotive wiper strip has attracted the attention of Chinese people, and some manufacturers have carried out relevant research and achieved good results.
Automobile sealant is mainly used for sealing the welds of car body and door steel plates and connections. Automotive adhesives mainly include PVC hot melt adhesive, asphalt primer and neoprene adhesive.
3. Ideas for improving the technical level of automotive rubber products in China
3.1 first of all, the government should attach great importance to guiding enterprises to increase investment in technology research through policy support.
Relevant government departments should pay attention to the quality of auto parts as a key factor related to the quality of automobiles. Seriously organize the technical elites in relevant domestic industries to selectively target several key technologies for research. We can learn from the experience mode of "Guangdong Hong Kong key material technology research" adopted by Guangdong Province in recent years. Organized by the Provincial Department of science and technology, experts from enterprises, research institutes and colleges and universities will screen, demonstrate, approve and bid on major materials and technologies encountered in the current economic construction of the provincial port. The research funds are partly allocated by the provincial government and relevant functional departments, supported by a certain proportion of corresponding funds from enterprises, and jointly developed by the bid winning enterprises and colleges. After several years of experiments, it has indeed achieved results.
3.2 develop urgently needed special raw materials and change the current situation of "making bricks without straw".
3.2.1 synthetic rubber varieties
High quality EPDM for composite sealing strips and brake films, fluororubber varieties for skeleton oil seals with high temperature resistance above 200 ℃, high pressure resistance, wear resistance and good adhesion, fluorosilicone rubber, wear-resistant acrylate rubber, hydrogenated carboxyl nitrile rubber, oil resistant silicone rubber and acrylic rubber with excellent low temperature performance, etc.
3.2.2 new vulcanizing agents, additives and framework materials
Catch up with and surpass international advanced countries, and develop a new generation of environmentally friendly crosslinking agents, accelerators and additives, high-strength skeleton materials, such as polyester with excellent adhesion, high-strength glass fiber, aramid with good stability, etc.
3.3 enterprises, together with scientific research institutes and colleges and universities, organize capable scientific research forces to focus on accelerating the development of high-precision products in a short time and improve the localization matching rate of high-end vehicles.
1. The car crankshaft high-speed oil seal and crankshaft oil seal meet the requirements of 8000km, temperature resistance of 250 ℃, and working life of 4000-5000h;
2. Liquid sealing composite shock absorber, torsional shock absorber, electronic shock absorber, temperature resistance 300 ℃;
3. Heat resistant fuel hose and thin-wall hose (wall thickness ≤ 2mm);
4. Multi channel special-shaped rubber hose;
5. High strength rubber film is required to be resistant to high and low temperatures, with a service life of 50 under normal temperature × 10000 normal operations.