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    Home > Coatings News > Paints and Coatings Market > Automotive maintenance industry environmental protection policy requirements and repair coating technology status quo

    Automotive maintenance industry environmental protection policy requirements and repair coating technology status quo

    • Last Update: 2020-11-13
    • Source: Internet
    • Author: User
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    1, China's auto repair industry pollution and control overview
    With the rapid development of China's economy, automobiles have become an indispensable means of transport in people's daily life. While cars bring great convenience to people, they also cause many environmental pollution problems. Among them, the paint exhaust gas produced by the auto repair industry is one of the causes of air pollution

    . Auto repair spray exhaust gas contains paint mist particles and VOCs and other components, with high wind volume, low concentration, intermittent, complex process and so on.
    To Beijing as an example, the current number of cars in Beijing is huge, corresponding to the auto repair industry has also been rapid development, the current Beijing auto repair list of auto repair enterprises a total of about 2480, including brands of 4S stores, other General Motors repair shops, mainly concentrated in Haidian District, Chaoyang District, Fengtai District, Fangshan District. In the process of car repair painting produces a large number of VOCs gas emissions, toluene and xylene, etc. , at present, most 4S shop paint paint using oil-based coatings, which as solvent volatile organic matter (VOCs) with photochemical activity, is the formation of fine particles (PM2. 5) and ozone important prescive substances. The exhaust gas emitted by the auto repair industry has the characteristics of large fluctuation of pollutant concentration in spray paint exhaust gas and the unsethical and intermittent fumes. Unlike other industrial exhaust gases, paint exhausts contain not only organic pollutants such as VOCs, but also a large amount of over-spraying fog. At present, there are many pre-treatment methods for paint mist at home and abroad, and the types of processing materials are also very diverse, including dry and wet treatment methods. For VOCs exhaust gas, at present, according to the concentration of VOCs in the exhaust gas using different types of treatment technology, for high concentration (>5000mg/m3) should be used absorption method, condensation method to recover; For the medium concentration (500-5000mg/m3) of organic exhaust gas using direct combustion, catalytic combustion, biofiltration, etc. , for low concentration (<500mg/m3) of organic exhaust gas generally use adsorption, plasma, photo catalysis and other technologies.
    the current car 4S shop spray paint exhaust gas are basically used activated carbon adsorption method. Activated carbon adsorption capacity is limited, when it is adsorbed saturated will lose exhaust gas processing capacity, need to be replaced regularly. In addition, activated carbon compared with other adsorption materials fire point is low, when heat concentration in the adsorption tank is prone to fire phenomenon, resulting in safety problems. In today's auto repair market environment, most auto repair enterprises can not be in strict accordance with the requirements of the replacement of activated carbon, resulting in the failure of activated carbon materials, paint exhaust gas can not be treated in a timely manner and direct emissions, causing serious air pollution. Adsorption of saturated activated carbon is a hazardous waste, for its management needs dangerous waste qualification, most enterprises can not carry out this work, to a certain extent, also caused a safety hazard. The above-mentioned problems not only cause the VOCs to deal with the effect is not ideal, cause serious environmental pollution problems, bring economic losses to enterprises, but also bring a lot of problems to the supervision of government departments.
    2, some provinces and cities local automobile maintenance environmental protection policy requires
    01
    Guangdong Province
    motor vehicle maintenance enterprises should gradually use water-based, high-solidity and other low VOCs content of environmentally friendly coatings, restricting the use of solvent-based coatings. Encourage motor vehicle maintenance enterprises with painting technology to conduct business and cooperation with rice spray centers to promote the centralized, economical and environmentally friendly development of rice-gold painting in the industry. Motor vehicle maintenance enterprises painting and baking operation should be completed in the paint room, the production of volatile organic matter centralized collection and import of volatile organic matter treatment facilities, emission standards. Investigate and rectify open-air and open-type auto repair spraying operations in accordance with the law.
    02
    Henan Province
    to promote the auto repair industry VOCs management, promote the use of electrostectronic spraying and other high-efficiency coating process, painting, leveling and drying process operations should be placed in the paint room, the use of solvent-based paint spray gun should be closed cleaning, resulting VOCs exhaust gas centralized collection and introduction into the treatment facilities, to achieve the standard emissions, low concentration of organic exhaust gas or odorous gas using low-temperature plasma technology, UV photo catalytic oxidation technology, activated carbon adsorption technology, such as two or more combined processes, prohibit the use of single adsorption, catalytic oxidation and other treatment technology.
    01
    Suscum guangzhou
    maintenance enterprises should complete the relevant rectification tasks by June 30, 2019, the rectification tasks include four points:
    1, the full promotion of the use of low volatile organic matter content paint, the proportion of use of more than 80%, where the primer must be fully used low volatile organic matter content paint.
    2, coatings and organic solvents, cleaning agents and other raw materials containing volatile organic matter in the transport, transfer, storage and other processes should be kept closed, the use of the process with open, timely after use closed.
    Spraying, repainting, leveling, drying and other maintenance work should be carried out in the closed paint room, painting, cleaning spray gun and other organic exhaust emissions-related operation should be set up closed space or equipment, the volatile organic pollution exhaust gas should be set up exhaust pipe centralized collection and import pollution prevention facilities treatment, to ensure that the VOCs operating places and exhaust pipes near no obvious odor.
    exhaust pipes shall be installed in accordance with the "Regulations for standardized setting of sewage outlets for pollution sources in Guangdong Province" (Guangdong Ring (2008) No. 42) and other requirements, and set up before and after the purification device can be closed automatic and manual sampling port.
    3, deepen the end volatile organic matter pollution control. Installation of pollution control facilities that handle paint mist, filter dust, remove odors, efficiently purify organic exhaust gases, and reflect exhaust gas flow rates and VOCs removal rates. Volatile Organic Emission Limits are implemented in accordance with the Surface Coating (Automotive) Volatile Organic Compound Emission Standard (DB44/816-2010). When working with solvent-based coatings, the removal rate of volatile organic matter is more than 90%, and the removal rate of volatile organic matter should not be less than 50% when working with low volatile organic matter content.
    4, standardize internal management, establish a bill management system, record the use of raw materials and products containing volatile organic matter, waste, activated carbon, filter cotton and other volatile organic pollution treatment supplies acquisition, after use of activated carbon, filter cotton and other hazardous waste disposal. The account shall be kept for a period of not less than three years.
    02
    Xi'an
    City Transportation Bureau issued a notice that may 1 to August 31 during the summer prevention period, the city strictly control the spraying of organic emissions, prohibit our city's automobile maintenance enterprises in the daily 10 to 16 o's day to carry out painting operations.
    the summer prevention period, the Municipal Transportation Bureau will strengthen the auto repair industry VOCs (volatile organic matter) rectification. The new auto repair enterprises and key auto repair enterprises pilot the use of water-based or high solid sub-paint, auto repair enterprises painting, drying and other processes should be carried out in the paint room, the use of solvent-based paint spray gun should be cleaned in a confined space, the resulting VOCs exhaust gas should be collected and imported into the treatment facilities, to achieve the standard emissions.
    03
    Foshan
    focus on the supervision of VOCs annual emissions of more than 10 tons of auto repair enterprises.
    supervision and management as stipulated in the plan, and by the end of June 2019, all districts will have completed the inspection of auto repair enterprises within their jurisdictions. By the end of September 2019, clean up and eliminate all kinds of incomplete procedures, serious pollution engaged in spraying, paint repair operations auto repair enterprises. Each district will be VOCs annual emissions of more than 10 tons of auto repair enterprises gradually into the city-level key supervision of enterprise management.
    at the same time, increase support. The enterprises that take the initiative to change the water-using paint, phase out the painting room and move into the spraying center should be properly subsidized to promote the intensive and green upgrading of the auto repair enterprises. Insurance companies are encouraged to give priority to the adoption of regular and "environmentally friendly" auto repair enterprises for maintenance.
    1 Encourage the use of pollutant removal efficiency technology
    In the standard control, it is necessary to standardize the exhaust gas collection system, install pollution prevention and control facilities with the function of handling paint mist, filter dust, remove odor, efficient purification of organic exhaust gas, treatment technology recommends not to use plasma, photocatalytic oxidation and other single-stage treatment technology, encourage the use of pre-treatment adsorption desorption, catalytic combustion, combustion, activated carbon adsorption and desorption devices and other high efficiency removal technology.
    according to the "Guangdong Province to win the blue sky defense war three-year action plan", failed to complete the bottom, medium paint environmental protection paint replacement auto repair enterprises to install VOCs online monitoring (monitoring) facilities, and with the ecological environment sector network.
    2 vigorously promote the construction of shared spraying mode
    According to the plan, continue to vigorously promote the auto repair industry to implement centralized spraying center construction, last year to carry out auto repair centralized spraying pilot construction work, by the end of 2019, each district completed at least one auto repair shared spraying center. Encourage the use of oily coating operations into the centralized spraying center. Banning open-air and open-air steam repair spraying.
    at the same time, strengthen the regulatory management. Water-based (low volatile) coatings and solvent-based coatings of auto repair enterprises shall be used separately from different spray guns and clearly marked. Coatings, organic solvents, cleaning agents and other raw materials containing volatile organic matter in the transport, transfer, storage, deployment and other processes should be kept closed, the use of the process with the open, after use in a timely manner closed.
    program stipulates that spraying, repainting, leveling, drying and other maintenance work should be carried out in the closed paint room, painting, cleaning spray gun and other operations related to organic exhaust emissions should be set up closed space or equipment. Enterprises should use the workshop environment negative pressure, installation of high-efficiency gas collection devices and other ways to collect VOCs exhaust gas and import into treatment facilities, and ensure that VOCs-related operating sites and near the exhaust cylinder there is no obvious odor.
    3, environmental protection repair paint technology status quo and development direction
    the main application of water-based repair paint in color paint:
    (1) paint is the most important source of VOC emissions during the repair spraying process.
    can reduce VOC emissions by about 80% by converting the paint layer into a water-like product. The use of water-based paint for repair operations can fully meet the current VOC emission standards.
    (2) high-solid varnish is currently the most widely used technology on the market.
    can reduce VOC emissions by up to 1/3 compared to conventional varnishes compared to their solids. Therefore, high-solid varnish in carbon emissions, energy consumption and production costs can be comparable to water-based varnish. At present, the most environmentally friendly choice is water-color paint plus high solid hooded varnish.
    (3) water-like primer, medium coating and varnish product promotion still have certain technical limitations.
    such as water-type primer and medium coating drying time, early grinding performance can not meet the requirements, construction efficiency and film-forming performance has yet to be improved. According to the large-scale production of water-based primer, medium and varnish there is still a certain distance.
    Water-based primer development direction: acrylic and water-based polyurethane mixing system
    early repair paint with water-based acrylic resin as the main film-forming substance, with good construction, decorative, weather resistance, light preservation, color preservation, fast drying and low cost. With the improvement of formulation, the comprehensive properties of water-based acrylic repair paint, such as chemical resistance and friction resistance, have been gradually improved and are widely used in the market. For example, hydroxypropyl acrylic coatings have become popular automotive patches due to their fast drying speed, excellent performance and moderate price. However, acrylic patch paint also has some obvious disadvantages. For example, due to the characteristics of water-based acrylic emulsion, sometimes water-based acrylic resin prepared by the side of the paint with blue or white light, so that the water-based paint before and after drying color is not consistent, not suitable for color adjustment, can not meet the requirements of rapid color adjustment of the repair paint. In order to improve the overall performance, water-based primers began to use acrylic and water-based polyurethane mixing systems.
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