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Analysis of the status quo of industrial coating equipment technology and future development planning

I. Current Situation: China is a big manufacturing country. In the industrial production process, industrial coating equipment processes involve many industries, including all industries involved in the coating process, such as motor vehicle manufacturing and maintenance, furniture, household appliances, and metal products. Processing, color steel plates, containers, shipbuilding, electrical equipment, pipe industry, etc. The coatings industry is in the field of new materials. Environmentally friendly coatings include: waterborne coatings, powder coatings, radiation curable coatings and high solids coatings. As environmentally friendly coatings are still in the early stages of research and development, some key technical issues are still far from being resolved. Therefore, the use of solvent coatings accounts for 50-60 of the total amount of coatings. China's industrial coatings production in 2009 was 9.114 million tons, of which solvent-based coatings accounted for 60.2010 coating production output (China Coatings Industry Yearbook, 2011), 9.7 million tons, Among them, solvent-based coatings account for 52.1. About 3.5 million tons of VOCs per year (including the diluent used in coating) are volatilized into the atmosphere during the use of the coating (only hundreds of thousands of tons of xylene), and the waste is very wasteful. serious. Due to the rapid development in recent years, the average growth rate is 15%. In 2012, the output reached 12 million tons (the import and export volume is negligible), of which industrial coatings account for about 70, or about 8.4 million tons. VOCs emit about 6 million tons or more. It has become the largest source of industrial VOCs emissions in China, and has the greatest impact on China's industrial VOCs emissions.

Environmental hazards during production and application: such as VOC emissions, formaldehyde and heavy metal residues, free TDI volatilization. China has formulated a series of mandatory national standards for coatings. In 2009, only five mandatory coating standards represented by GB24408-2009 Limits for Hazardous Substances in Exterior Wall Coatings for Buildings were revised. At the same time, foreign stricter environmental regulations (such as HAPs regulations, VOCs regulations, REACH regulations, etc.) have set a higher threshold for the export of China's coating products, raw materials and even downstream products such as home appliances, toys and furniture. Barriers and technical barriers). To this end, under such an increasingly strict regulatory situation, strengthening coating technology innovation, developing and upgrading environmentally friendly coatings is the general trend of development. At the same time, users of conventional solvent coatings need to strengthen VOCs processing technology innovation.

  1. Painting process, equipment status. China's coating equipment and technology development is relatively fast. There is a big gap in environmental protection, energy conservation and emission reduction and resource utilization. Many coating lines VOC emissions are not up to standard, energy consumption per unit of painted area, water consumption and coating materials consumption are high, there is no corresponding mandatory policy. For example, although China is a big automobile producing country, it is not a strong country, and automobile painting is no exception.

    1) Conventional automotive technology (complete process) Body-in-the-field pretreatment Electrophoresis electrophoresis drying (lysate discharge) Electrophoresis polishing (dust particle discharge) Weld seal (VOCs discharge) PVC vehicle bottom spray (VOCs discharge) Medium spray coating ( VOCs emissions) intermediate coating leveling (VOCs emission) medium coating drying (VOCs emission) in the application of painted topcoat spray (including varnish) (VOCs discharge) topcoat leveling (VOCs discharge) topcoat drying (VOCs emissions) Checkpoint supplement (VOCs emission) finishing warranty cavity spray wax (VOCs discharge) assembly shop

    2) Conventional auto parts process (complete process) pre-treatment (electrophoresis electrophoresis drying) or (dehydration drying) medium coating spraying medium coating leveling coating drying topcoat spray topcoat flow flat paint drying

    3) Conventional container process (complete process) blasting zinc spray medium coating spraying medium coating leveling coating drying topcoat spraying topcoat flow flat paint drying

    4) Conventional home appliance process (complete process) pre-treatment equipment (electrophoresis electrophoresis drying) or (dehydration drying) medium coating spraying medium coating leveling coating drying topcoat spray topcoat flow plane paint drying, pre-treatment dehydration drying powder Spray powder drying (no VOCs emissions)

    5) Conventional spray booth equipment. The spray booths larger than 95 use fresh air to force air and exhaust, and VOCs are directly discharged at low concentration and high air volume. For processing VOCs, it is necessary to increase the concentration of VOCs. 5 The spray booth adopts a circular form to forcibly supply air and exhaust air. The concentration of VOCs is relatively high and can be discharged after treatment. This form is only suitable for automatic spray booths and is not suitable for manual spray booths. 6) The VOCs concentration of conventional flow chamber equipment is relatively high and can be discharged after treatment. However, only 5-10 devices in the country are equipped with VOCs processing devices, and the use of the processing devices during normal production is unknown. 7) The concentration of VOCs in conventional paint drying room equipment is relatively high and can be discharged after treatment. However, only 5-10 devices in the country are equipped with VOCs processing devices, and the use of the processing devices during normal production is unknown. 8) Conventional VOCs processing equipment Domestically used VOCs processing equipment is activated carbon adsorption, catalytic combustion, high temperature incineration (RTO, TNV), medium temperature incineration (expansion of drying room heating equipment, such as quaternary unit), radiation VOCs processing (CIR ). Activated carbon adsorption, catalytic combustion, low investment, high cost of use, poor processing effect, generally used for small production lines, low equipment utilization rate. High-temperature incineration (RTO, TNV) has a high investment, low cost of use, high treatment effect, generally used in medium and large production lines, and the equipment utilization rate is relatively high, especially the waste heat of TNV is used in the drying room, and the equipment utilization rate Very high. 2. Existing problems 1) Unbalanced technology development, environmentally friendly coatings, new processes, new equipments need to be improved Although China has become the largest paint producing and consuming country, it is not a coating technology, a coating engineering powerhouse, and domestic companies producing coatings. The technical level of the varieties is not uniform, and the technical level of domestic painting projects is not uniform, and there is still a relatively large gap. In particular, technologies for environmentally friendly coatings, new technologies for energy conservation and emission reduction, and new equipment in various fields are in urgent need of improvement. Because China does not have a mandatory energy conservation and emission reduction policy for painting projects, the company has no incentive to renovate existing coating production lines, and the application of new coatings, new processes and new coating equipment for energy conservation and environmental protection is not promoted. 2) Many enterprises, small scale, weak environmental protection technology, and poor environmental awareness According to statistics, there are about 8,000 paint manufacturing enterprises in China, mostly small and medium enterprises. Low-level redundant construction is very serious, overcapacity, and inefficient use of human resources, there is a great waste. For high-level, high-tech environmentally friendly coatings and environmental protection equipment, there are few investments, and some companies use environmentally friendly equipment but rarely use them. Therefore, strengthening corporate specialization, specialization guidance, expanding the scale of enterprises, concentrating resources to develop environmentally friendly coatings, and cost-effective environmental protection equipment are important issues for sustainable development. 3) The situation of non-environmental coatings has yet to be improved. 50-60 is a solvent-based coating in China's coating production. Nearly 3.5 million tons of volatile organic compounds (VOCs) are emitted into the atmosphere every year, and the waste of pollution is very serious. In the enterprises using solvent-based coatings, about 95 VOCs in the spray booth are directly discharged at low concentration and high air volume, and the VOCs in the 90 drying chamber and the leveling chamber are directly discharged at a high concentration and small air volume, and the rest are provided with VOCs processing devices. However, the technology of VOCs processing devices is uneven, and because there is no long-term supervision system, the utilization rate of VOCs processing devices during normal production is not high. 4) The system for promoting the healthy development of the coating industry and environmental protection equipment by standards and regulations has not yet been formed. China's environmental protection coating standard system, VOCs emission system and related important basic standards have only been initially established, yet to be improved, and the backwardness of standards has slowed down China's coatings. The process of industrial and environmental protection equipment and international integration has affected the improvement of the international competitiveness of China's coatings industry and environmental protection equipment. 2. Characteristics of coating (spraying) process waste gas: (1) It is usually accompanied by a large amount of overspray paint mist particles; (2) There are many kinds of paints, different solvents are used, and the organic components are complex (organic solvent in paint) Including: benzene, ethers, lipids, ketones, alcohols, alcohol ethers, hydrocarbons, etc., some low-molecular additives may be restored to the atmosphere, some benzenes, alcohols and fats belong to the double High yield and three substances); (3) Forced delivery and exhaust operation are mandatory in the spraying process, and the air volume is large and the concentration of organic matter is low. Therefore, the treatment of the exhaust gas of the coating equipment is difficult, the treatment cost is high, and the treatment effect is poor, which is a difficult problem in the emission control of industrial VOCs in China. At present, some key industries involved in the coating process in China, such as motor vehicle manufacturing and maintenance, furniture, home appliances, machinery and equipment manufacturing, pipe industry, shipbuilding, containers, etc., the treatment of spraying waste gas has just started in recent years, only very A small part of the exhaust gas has been treated, and the existing treatment equipment has low operating efficiency, poor operating conditions, and poor emission reduction effects. Since China is a big manufacturing country, in the heavily polluting industries where VOCs emit large amounts of products, such as furniture manufacturing, containers, shipbuilding, automobiles, home appliances, etc., they all have a high share in the world. Therefore, in the future emission reduction of industrial fixed source VOCs in China, the treatment of painted exhaust gas is the top priority.

Second, the development plan of coating equipment is based on structural adjustment and development mode, implementing the strategy of adjustment, transformation, innovation and upgrading. Under the guidance of relevant national policies, efforts are made to adjust the industrial technology structure and organizational structure, strengthen independent innovation and form independent technology. , standards and brands, increase the development of new environmentally friendly coatings, promote new processes, new equipment applications, and accelerate the transformation of existing coating production lines with energy saving and environmental protection. 1) Accelerate the development of environmentally friendly coating products Solvent coatings: In the coating process of automotive products, the cost of coatings is less than 20% of the total coating cost, and the remaining 80 is the cost of the coating process. Therefore, reducing the volatile organic compound (VOC) content in the coating, shortening the coating process, optimizing the layout of the coating line, rationally arranging the production, and improving the first pass rate of the product can reduce the cost of the whole vehicle and save energy and environmental protection. Environmentally friendly coatings: Promote the application of new technologies such as water-based, solvent-free (powder coatings, radiation-curing coatings) and high solids differentiation.

2) Promote new processes and new equipment applications. For example, for the whole vehicle coating, the whole vehicle coating process is promoted and the intermediate coating process is eliminated. At the same time, the middle coating polishing process is eliminated, the coating production line is reduced, the environmental pollution is reduced, and the waste discharge is reduced. Promote the use of automatic coating equipment , reduce the amount of paint overspray (reduced paint consumption), use a circulating air supply and exhaust device and configure VOCs processing equipment. Promote energy-efficient VOCs processing devices to reduce the cost of use.

3) Accelerate the transformation of existing coating production lines . Most of the coating production lines in China currently have relatively poor process and coating equipment technology, and there is no VOCs treatment device. The environmental pollution is very large. Through the relevant national policy guidance, the production line is upgraded and upgraded, which is to reduce VOCs. The top priority of emissions.

4) Accelerate the formulation of relevant national policies, have clear regulations on the handling and discharge of VOCs, and establish a long-term supervision system for the use of VOCs processing devices.

Tiankun Coating specializes in the production of automatic spraying lines .