Coating paint is not only the face of the car but also the base color of the car's anti-rust. Black, white, blue, gray and red are the five main colors of automobile consumption over the years. The local application of coating technology has a history of more than 80 years. The paint has achieved four major upgrades.

Chen Hong, deputy secretary-general of the Paint and Coating Professional Committee of the Chinese Chemical Society, analyzed that the main proportion of Chinese passenger car coatings accounted for 50% of original paint, 20% of refinish paint, 15% of parts paint and 15% of PV stone-resistant paint. Body OEM paints account for the largest share of passenger car paints, followed by refinish paints, with component paints and stone chip resistant paints equal. It will grow at a rate of 7%-8% in the next five years.

Since the 1990s, European and American automobile factories have replaced traditional organic solvent-based automotive coatings with environmentally friendly automotive coatings to meet environmental protection standards. Solvent-based coatings are traditional automotive coatings with organics as the main solvent; The main dispersion medium of the paint, the volatile organic compound emission in the water-based paint is 60%~70% lower than that of the solvent-based paint. The VOC emission of the traditional solvent-based paint is about 125g/m2. In order to meet the environmental protection requirements, the automotive paint is becoming water-based. , high solids, powder coatings are developed in three main directions, and water-based technology is one of the effective ways. Especially the most popular metallic flash coating at present, the VOC emission accounts for 66% of the total. After the coating is water-based, the VOC emission of the whole vehicle can be reduced by more than half. The amount can be reduced to 27g/m2, which can meet the strictest environmental protection requirements.

By 2001, in developed western markets, cars with water-based primers and primers accounted for 7% and 43% of the total output respectively, and 32.5% and 36% in Europe. Among them, Germany has basically achieved water-based paint, with the middle coat accounting for 80% and the base paint accounting for 93%.

The fourth-generation automotive coatings currently used are the fourth- and fifth-generation cathodic electrophoretic coatings, acrylic resin coatings with acid rain resistance and scratch resistance, and the topcoat colors are metallic and natural colors, which are suitable for three-layer coating systems for cars, etc. Represented by the introduction of the local car body coating line in recent years, the world paint company set up factories in China to meet the international car coating standards. Based on the different countries where car products were introduced, this generation of car coatings can be divided into Japanese systems. and the European and American system.

In China, the water-based primer and primer for passenger cars have reached 33%. In 2013, the output of OEM paint for passenger car bodies was 360,000 tons, with electrophoretic paint accounting for the largest share, followed by pigmented paint, and middle paint and clear paint. In the next four years, the proportion of Chinese vehicles using water-based paint will rise from the current 33% to 60%.

Sun Lianying, president of the China Coatings Industry Association, said that last year, the output growth rate of my country's coatings was 6%. The outstanding characteristics of the industry are: In 2014, the total output of my country's coatings industry was about 14 million tons, and the total industrial output value at current prices was 330 billion yuan, an increase over the same period. 12%; the total profit is about 24 billion yuan. The growth rate of output and output value of the whole industry has slowed down, but it is better than the same period of the previous year. The prices of bulk raw materials for coatings have dropped, and corporate profits have generally increased.

She believes that in recent years, the Ministry of Environmental Protection has launched the public welfare "Research on VOC Emission Characteristics and Prevention Countermeasures of Industrial Coating Pollution Sources", "Research on VOC Emission Characteristics and Prevention Countermeasures of Architectural Coatings", "Coating Industry Air Pollutant Emission Standards", VOC consumption tax and sewage charges. , Beijing, Shenzhen and other cities have formulated local standards for the limit of harmful substances in coatings - lead-containing pigments, lead-containing additives, and impurity lead will gradually withdraw from the paint industry.

In the 47 sub-sectors of the petrochemical industry last year, the efficiency index of the coating industry was better than that of upstream products such as petroleum products. The main business income and total profit increased by 13.2% and 25.7% respectively.

Liu Dengliang, director of the Expert Committee of the China Coatings Industry Association, said in an analysis of the industry that there are few state-owned enterprises left, private enterprises are taking the lead, and foreign brands account for 30% to 40% of the market. China is the world's largest consumer of coatings, but the real technological innovation in the coatings industry hardly. Last year, the coating market capacity was 600,000 tons for automotive coatings and 300,000 tons for heavy industry machinery, and called for an integrated production and marketing model for coating and coating, establishing the concept of coating industry processing services, and coating entrepreneurs abandoning their own "local tyrants" who did not grow up. consciousness. Liu Dengliang thinks.

Yang Yuande, secretary-general of the China National Coatings Industry Association, believes that last year, the growth rate of my country's paint production was 6%, which was higher than 3.58% in the previous year, and the growth rate of output value and profit were both 10%. The proportion of high-tech and high value-added products in China's coatings industry is not high, hovering at a low profit level of 5% to 10%, but this means that it will take a long time to increase the concentration of the coatings industry.

Environmentally friendly paint

Zhao Jinbang, a professor-level senior engineer at the Shanghai Institute of Coatings, believes that traditional coatings use organic solvents as diluents, which contain a large amount of volatile organic compounds (VOCs). About 2.2 million tons of VOCs are emitted into the air every year in my country, equivalent to 1.3 billion The sum of the air inhaled by the Chinese for 16 consecutive hours increases at an average annual rate of 9%. Data shows that industrial solvents account for about 30% of the total VOC emissions, becoming one of the main sources of emissions, while the VOC emissions of paint and adhesives account for about 70% of industrial solvents. The total annual emissions reach 4 million tons, which is about the total annual VOC emissions of 60 million vehicles. This is equivalent to the total emissions from burning 270 million tons of coal.

At present, the proportion of low-pollution coatings in developed countries such as the United States and Japan has reached 65% to 70%, Germany is as high as 80%, and my country is still less than 50%, so the development of environmentally friendly coatings is an inevitable trend.

Qian Borong, chief engineer of CNOOC Changzhou Coating Chemical Research Institute, said that there are many reasons why my country's solvent-based high-polluting coatings are still dominant. One is the cost problem; the second is the concept problem; the third is the use habit problem; the fourth is because the environmental protection paint is not as good as the solvent-based paint in some performances; the fifth is the process problem.

The Secretary-General of China Environmental Protection Association believes that an important source of PM2.5, the main source of pollution in haze weather, is VOC. The VOC emissions of the paint coating industry account for about 1/5 of the total VOC emissions. The paint industry has become a source of haze. One of the main culprits is the heavy responsibility of industrial upgrading.

According to data, in China, the major customers of the world-renowned automotive coatings manufacturer PPG include Volkswagen, GM, Mercedes-Benz, BMW, Dongfeng Peugeot, Citroen, Chery and Hainan Mazda. Almost every automaker in the world uses PPG's automotive coating products or technologies.

On the whole, the current development problems of my country's automotive coatings are the lack of innovative technology, the backward production control technology, and the low level of coating equipment. my country's domestic famous brand automotive coatings companies control a small market share, and the homogenization competition in the coatings industry is very serious, which makes the profit margins of my country's automotive coatings companies smaller. When the new year is approaching, Shanghai subway trains are hurriedly trimmed between operations and transported with a new look passenger. The reporter visited the Meilong base of the subway a few days ago to reveal the process of the subway maintenance personnel changing the "new clothes" for the train.

It takes two days for a train to be refurbished

In the paint room, one carriage of the No. 102 train on Line 1 has been "wrapped", and only the white body wall is exposed. The original straight red ribbon line has been polished off, and the line is temporarily outlined by red paint, only to be repainted.

Jiang Hua, the person in charge of painting, told reporters that after 10 years of operation, many vehicles on Line 1 and Line 2 entered the overhaul cycle, so a batch of trains on Line 1 were scheduled to be repainted on the occasion of the New Year. After a car is split, it is painted with a new wet-on-wet process, which will shorten the time for the paint to dry and dry, and shorten the train's new clothes by 2 days, further reducing the impact on daily operations. "The aluminum plate of the car body will be coated with 6 layers of paint on the front and back to ensure the color is stable and firm." Jiang Hua said, first polish the car body with degreaser, and then the painter will paint it accurately again and again, never changing the original appearance of the car body. Painters wearing protective clothing revealed that the paint is not easy to dry in the low temperature environment in winter. They strengthened the control of the constant temperature and humidity workshop and worked overtime to paint. The key is to control the thickness of the paint, otherwise the adhesion of the paint will be reduced or it will be more prone to dust. The 8-car group 1 train can control the paint job in 2 days.

All trains will be cleaned

The reporter learned that in addition to the repainting of the trains, the overall cleaning plan of the trains has also been encrypted for each line. The normal cleaning cycle for trains is 3 months, but on the occasion of the New Year, almost all trains will be cleaned in the middle of the night.

The person in charge of the train cleaning of the subway maintenance vehicle branch said that at 22-23 o'clock at night, after the trains returned to the warehouse one after another, the "bath" time for a train was strictly controlled within 3 hours. According to reports, it is the most difficult to clean under the seats in the car, especially under the love seat next to the door.

The subway side said that for the cleaning of subway trains, it is necessary to use some large-scale equipment, or manually use wet mops, dry mops, and detergents. At present, we are exploring more efficient cleaning methods, and strive to make the train look like a new car when it comes back online the next day.

At present, the driving factors for the growth of local passenger vehicle water-based coatings are policy-driven. The second is the social responsibility of OEMs, and their understanding of the concept of green environmental protection has been recognized by most OEMs. The third water-based paint technology has matured. At present, large foreign companies that master the technology of automotive water-based original paint have many years of application experience abroad. Fourth, benefits, water-based paints have shown more and more benefits - in line with the general trend of environmental protection, promoting technological progress, improving corporate competitiveness, and creating business opportunities. It is more common to use water-based paint technology from the water-based coating technology system of the main engine factory to the coating line. The new lean coating process with shorter process flow, low energy consumption and lower operating cost will be the mainstream in the future.