26

13Th Five Year Plan For The Coatings Industry: Focus On Reducing Vocs

In 2014, the total production of coatings in China reached 16.4918 million tons. Behind such a huge output lies significant environmental pollution and energy consumption, and such a large number of coating products also emit millions of tons of VOCs into the atmosphere during the coating process. Reducing the pressure that production and painting processes bring to the environment and energy should be a key task in the coatings industry during the 13th Five Year Plan period. At present, the growth rate of low pollution coatings in China is far lower than the growth rate of the total production of coatings in the country. In recent years, only the proportion of water-based building coatings has grown significantly, while the overall proportion of low pollution coatings is still in negative growth. The promotion of low-carbon environmental protection, energy conservation and emission reduction work cannot be separated from the development of coating technology. During the 13th Five Year Plan period, environmentally friendly and resource-saving coatings such as water-based coatings, high solid coatings, solvent-free coatings, UV cured coatings, radiation cured coatings, functional new exterior wall insulation coatings, as well as products and production lines with a single production capacity of 30000 tons/year or more, should be encouraged and supported. In the research and development, production, and application of various coatings, many problems have been encountered at present and need to be solved during the 13th Five Year Plan period. For example, during the drying and film-forming process of water-based wood coatings, the bound water is not easily discharged, ultimately leading to phenomena such as water absorption and bursting of the wood. The drying of water-based wood coatings in the later stage should promote technologies such as cold infrared drying and microwave drying to facilitate the discharge of bound water. China's automotive coating technology has reached or even surpassed the international advanced level, but the main production lines that have been put into operation are low to medium solid solvent based coatings. If all production lines are changed to water-based production lines, it is not practical to invest funds or stop production and sales of the production lines. In the later stage, production line upgrades and construction can be carried out synchronously. On the one hand, investment will be increased in the fields of coating utilization and paint mist recovery technology, and the production line of low to medium solid coatings will be improved into a high solid coating production line. On the other hand, water-based coating lines will be built in parallel without affecting production, gradually replacing solvent based coating lines in stages. The construction of ship coatings mainly relies on spraying, with a small amount of pre coating using brushing technology. Due to the large volume of the ship, a segmented painting process is generally used, and finally closed, which can achieve a completely enclosed spray painting construction of 80% to 95% of the paint. However, the painting operations after the entire ship is closed are mostly completely open-air, so emission reduction must be achieved by controlling the VOC content and diluent dosage of the coatings. At present, there are problems with steel structure coatings and painting, such as unorganized VOC emissions caused by outdoor painting, high VOC content and diluent ratio caused by solvent based anti-corrosion coatings, and the need for regular painting and maintenance of steel, which result in a large amount of VOC emissions from the steel structure coating itself and the painting process. During the 13th Five Year Plan period, low VOC coatings should be used as much as possible for anti-corrosion coating, environmentally friendly construction methods should be promoted, and the anti-corrosion quality of coatings should be improved to reduce the maintenance frequency of coatings. Overall, the coating industry must promote industrial upgrading through technological upgrades, gradually moving from high pollution and high energy consumption to low-carbon and environmentally friendly direction. It is necessary to increase investment in the research and development of green and environmentally friendly coating technologies, improve and upgrade coating production lines that cannot be eliminated temporarily, achieve organic emissions of VOCs, and improve the coating process of coatings to increase coating utilization, reduce paint mist waste and VOC emissions.