New developments in powder coatings at the beginning of this century

< br / > Hu Ningxian (Fenghua Nanhai pharmaceutical and chemical group) < br / > 1 development trend of powder coating < br / > one of the important issues of the World Summit on Sustainable Development (also known as the Earth Summit) recently held in Johannesburg, South Africa is how to implement the Kyoto Protocol on greenhouse gas emissionsIn fact, this is also an important topic closely related to our coating industry, because greenhouse gases also include volatile organic compounds (VOC) emitted to the atmosphere every day< br / > with the development of the world economy, the annual VOC emission to the atmosphere is increasing, which has reached 20 million tons / yearThese emissions not only pollute the environment and affect human health, but also destroy the ecological balance, leading to greenhouse effect and endangering human survivalTherefore, controlling VOC emissions has become a worldwide environmental protection issueAccording to the Kyoto Protocol, countries with different levels of development must undertake corresponding reduction tasks during 1990-2008< br / > coating is the second largest source of VOC emission (about 25% of the total), so it is very important to control the emission of organic solventsAlthough it can be achieved through many ways, such as the so-called green (environmental protection) coatings such as high solid coatings, electrophoretic coatings, water-based coatings, radiation curing coatings and powder coatings, etc., but because the powder coatings are 100% solvent-free, the recycled powder can be reused, its utilization rate is almost 100%, there are no problems such as the disposal of flying objects, cleaning water treatment, etc., and its environmental burden is the lightest, And through decades of efforts, the performance of the coating film has been very superior, which makes it occupy a special position in the green (environmental protection) coatingIt is estimated that powder coatings will be the second largest in the total industrial coatings by 2010 (see Table 1), but it is also believed that the market share of powder coatings will exceed that of water-based coatings by 2007 based on the solid fractionIn short, by the end of the first decade of this century, powder coating will become the main coating< br / >Since 1992, because of the increase of base number, the average growth rate has decreased, but there is still more than double-digit growthIn 2000, it reached 96000 tons, 1200 times of that in 1982 (see Figure 2)In terms of absolute output, it has become the second largest country in the world after the United States< br / >In 2000, the output of the United States was 176000 tons, with an annual growth rate of 6%The growth rate may decline due to the events of September 11 and the economic recessionEven if these factors are not taken into account, the output in 2005 was only 220000 tonsSo at that time, we are likely to surpass the United States in absolute production and take the first place in the world< br / > in addition to the development of powder coating itself, the corresponding resins, additives and basic chemical raw materials have also been developedFor example, the world-famous DSM and UCB companies all set up factories in China, and the domestic companies with comparable scale are Hangzhou Zhongfa, Anhui Shenjian, Fenghua Nanhai, etcThere has also been considerable progress in pulverizing equipment and coating equipmentGeneral unit equipment, even a complete set of assembly lines, have realized localizationOne of the most prominent is the rise of a powder equipment industry in YantaiThe coating equipment enterprises are mainly concentrated in Shanghai and southern Jiangsu< br / > but the development is unbalancedThe first is the production scaleAt present, there are more than 1000 powder factories in China, with an average annual output of only 100 tons, including foreign-funded, Sino foreign joint venture, state-owned, private and other economic componentsAccording to the latest statistics, there are 10 enterprises (such as ferro ferro, DuPont Huajia, Akzo Red Lion, Akzo Changcheng, Qingdao Meier, etc.) with an annual output of more than 4000 tonsTheir total output accounts for about 50% of the national outputThere are about 35 enterprises with an annual output of 1000-4000 tons and about 50 enterprises with an annual output of 500-1000 tonsAlthough there are also 200-300 tons / year enterprises in the rest, most of them are small factories with dozens of tons or even family workshops with dozens of tons< br / > followed by regional distribution, most of these enterprises exist in the eastern part of China, such as Guangdong, Fujian, Zhejiang, Shanghai, Jiangsu, Shandong, Hebei, Beijing, Tianjin, Liaoning and other provinces, especially in the Pearl River Delta and the Yangtze River Delta Except for Anhui, Hubei and Sichuan, there are few enterprises of high scale in the central and western regions, some of which are even blind spots < br / > again, it is the technical level and quality In some large-scale enterprises, the production equipment is advanced (such as a complete set of imported equipment), the testing equipment is perfect, and the personnel quality is high, so the product quality can be guaranteed However, some enterprises have outdated equipment, lack or no testing instruments, no professional personnel, and all rely on experience to judge In addition, with the fierce competition now, the phenomenon of Jerry building and shoddy manufacturing does exist < br / > in addition, we should also be aware that although we are now known as the second largest in the world, it is only 0.1kg in terms of per capita powder consumption, which is far from the United States (0.8kg / person) It is far behind the developed countries in product development, technological upgrading and advanced equipment On the one hand, we should not be blindly optimistic and narcissistic On the other hand, it also points out that there is still a lot of space for us to develop and occupy < br / > 3 hot spot of application and development of powder coating < br / > 3.1 automobile powder coating < br / > automobile manufacturing industry is one of the largest users of coating Since the 1980s, developed countries have formulated more and more strict control indicators for the emission of organic solvents in automobile production From 15.5 lbs / car in the late 1970s to 1.5 lbs / car in the early 21st century, i.e the current emission index is less than 1 / 10 of the original Over the past 20 years, the great decline of each emission is related to the use of new coatings: for example, the introduction of high solid coatings in the early 1980s, the use of water-based coatings in the late 1980s, and the application of powder coatings in the 1990s In fact, powder coating has been used in the research of automobile for more than 20 years, but because automobile coating not only has high corrosion resistance, but also has high decoration, it is quite difficult to make a breakthrough in a short period of time Powder coating was only used in auto parts, auto primer, stone hammer resistant primer, etc until the end of 1990s, it was used in batch for car top coat and finishing coat, becoming the real automotive coating At present, DuPont, BASF, Kansai, Nippon and PPG, the five largest automotive coatings Companies in the world, are further developing automotive powder coatings, with an estimated annual growth rate of more than 12% Among them, the fastest-growing is the powder coating for the whole body < br / > it is not too late to start using powder coating for automobile parts in China The first automobile factory has established a powder coating line as early as the mid-1990s, and other automobile manufacturing companies have roughly cooperated in the powder coating process of automobile parts in the same period But up to now, it is still in place and has not been further developed According to the current situation of large amount of foreign investment, the growing situation of domestic automobile industry and the strength of domestic powder industry, we should and have the ability to develop this precious land < br / > 3.2 wood powder coating < br / > wood and furniture manufacturing industry is also one of the largest users of coating < br / > although the report that powder coating can be used in wood has been published for more than ten years However, the real industrial application is in recent years, that is, the low temperature curing powder coating and ultraviolet (UV) curing powder coating can only be realized after the manufacturing process is improved For the powder coating of wood, people used to worry about two things: how to electrostatic coating insulated wood, how to avoid wood wing curve caused by high temperature In fact, as wood contains a certain amount of water, as long as the water is well controlled, its electrostatic adsorption is not a problem At present, the low-temperature curing method is 140oC curing; the UV curing method is 100oC melting and curing at room temperature, which will not cause wood wing curl MDF, which is widely used in wood industry, is the main part of assembled furniture The powder assembly line that has been put into operation is used for MDF coating < br / > the annual output of MDF alone in China is millions of square meters At present, urea formaldehyde paint or polyethylene film are still being used Both of them have environmental protection problems (the former is more serious), and the process is complex, the operation steps are many, and the quality is difficult to guarantee It is imperative to use powder coating So there is a huge potential business opportunity < br / > 3.3 pipeline powder coating < br / > pipeline powder coating has been used in foreign countries for more than 30 years and laid for more than 100000 km However, we still introduced the coating process of solvent coating 10 years ago, so that when it is found that the service life of powder coating is more than double today, in turn, we should not only introduce the coating equipment of powder, but also import the powder coating for pipeline Although the quality of domestic powder coatings has basically passed the customs and occupied part of the market after several years' efforts, the imported products still dominate the market at present < br / > according to the calculation, only the trunk line of the west east gas pipeline under construction at present needs more than 11000 tons of powder coating In addition, the total amount of powder coating used for the branch pipeline is estimated to be about 15000 tons China has agreed with Russia to lay an oil pipeline from Siberia to Daqing and then to Dalian The country expects to develop several oil and gas pipelines from Kazakhstan to Xinjiang and China in the next few years, with a powder consumption of at least 50000 tons In addition, domestic pipeline construction enterprises also contract foreign outsourcing engineering business, and their powder consumption is also considerable Therefore, the domestic powder coating manufacturing industry will compete for it more fiercely < br / > 3.4 powder coating for building < br / > since 1990s, powder coating has played a huge role in building engineering with its unique decoration and protection functions Especially in the coating of aluminum alloy profiles, products and steel bars, it has good economic and social benefits For example, glass curtain wall used to be a very popular exterior wall decoration, but it will cause light pollution, and the fragile glass has great danger Since the appearance of aluminum alloy curtain wall panels, these hidden dangers have been eliminated, and its soft color has become a new fashion in Europe < br / > steel bar is the skeleton of all large buildings, and the life of steel bar dominates the life of buildings The acidity and alkalinity of cement itself may pose a threat to steel bars Moreover, the water penetrating through concrete accelerates the corrosion of acid, alkali and salt, which can be seen clearly in some chemical factories and salt alkali areas Since 1973, the United States used epoxy powder coating steel bars in the construction of Pennsylvania bridge, now it is found that it greatly improves the service life of steel bars, effectively protects the building, and the expected service life can be more than doubled This practice has been confirmed by legislation in many developed countries < br / > at present, the construction area of 500 million square meters per year in China is undoubtedly a huge opportunity for the powder coating industry Although powder coating has entered the construction field in the 1990s, most of them are used for aluminum alloy profiles, aluminum alloy ceilings, steel doors and windows, anti-theft doors, etc For aluminum alloy curtain wall panels, steel bars and other bulk users almost no one involved, I believe that in the near future this field will cause people's strong concern < br / > 4 new powder coating types < br / > except epoxy, epoxy polyester, polyester / TG