The water-based road of the hottest mechanical coa

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The water-based road of mechanical coatings has a long way to go

the water-based road of mechanical coatings has a long way to go

In the early 1990s, China's construction machinery industry entered a period of rapid development, and a large number of excellent enterprises entered an international, comprehensive and large-scale development. After years of unremitting efforts, today, we can see that China's construction machinery industry has been growing

the rapid development of the construction machinery industry has made the construction machinery coatings gradually in line with international standards in terms of product structure, technical level and coating process, and the production and sales of coatings have also been greatly increased. Since 2011, China has become one of the countries with the largest production and sales of construction machinery in the world. China plans to focus on promoting the construction of 150 major water conservancy projects from 2020 to 2022, with a total investment of about 1.29 trillion yuan and a driving investment of about 6.6 trillion yuan. Under the background of loose monetary policy and the continuous promotion of "two new and one heavy" related projects, the infrastructure and real estate industries are highly prosperous, and the sustainability of the boom cycle of the construction machinery industry is expected to exceed expectations., It can be said that construction machinery coatings have become an extremely important part of China's coating industry

classification of construction machinery coatings

of course, it is necessary for us to understand the classification of construction machinery coatings. If divided by coating, it can be divided into primer, intermediate coat and finish coat

primer is the basic coating applied on the surface of the object for priming. Construction machinery, especially large-scale construction machinery, generally operates in the open air, directly contacts with air, moisture and impurities, and bears the wind and sun. Some construction conditions are poor. The adhesion and corrosion resistance of the coating mainly depend on this primer

intermediate coat is a coating that plays a connecting role between the primer and the dispersed micro crack topcoat through the aggregation and communication. The main function is to fill the bottom base material, isolate the defects of the primer layer, improve the fullness and other decorative properties of the topcoat, enhance the adhesion of the topcoat to the coating, increase the thickness of the entire supporting coating, and improve the water resistance and corrosion resistance of the entire coating. For parts with low decorative requirements and parts with good surface flatness of the substrate, intermediate coating can not be sprayed, so as to reduce the cost of construction machinery products. Commonly used intermediate coating includes epoxy intermediate coating and polyurethane intermediate coating

finish is the "coat" of construction machinery products, which plays a decisive role in appearance and directly affects people's visual senses. It should be noted that at present, the types of construction machinery topcoats have been diversified

characteristics and types of construction machinery primer

primer is the most basic coating in construction machinery coatings. It is directly constructed on the pretreated iron plate surface

the primer on construction machinery must have the following characteristics: good adhesion to the substrate, and the film formed after construction shall have excellent mechanical strength; At the same time, it also needs to have a good compatibility with the upper coating - the primer itself has good construction performance and can adapt to different kinds of coating processes

commonly used construction machinery coating primers include epoxy ester primer, alkyd primer, epoxy primer, acrylic primer, polyurethane primer and cathodic electrophoretic primer. According to different uses of primers, common primers include: oil resistant primer, antirust primer, weldable workshop primer, etc

anti rust primer is used for anti rust protection of common metal parts and has good compatibility with the lower coating: oil resistant primer is mainly used near hydraulic parts, and the coating is required to have good resistance to oil, hydraulic oil and other oils. The weldable workshop primer is used as the primer for temporary rust prevention after the pretreatment of the substrate and before the formal primer is applied. The coating is required to have good weldability. The construction coating is generally in UM

according to the components of the primer, it can be divided into two-component primer and one-component primer. One component engineering primer is prone to undercut and adhesion drop when applying solvent based topcoat. Therefore, two component epoxy primer has become the mainstream supporting scheme at present

requirements of construction machinery for primer

primer is the premise of durability and beauty of finish paint. The quality of primer is an important factor affecting the appearance of finish paint. The primer with poor performance may even peel off and crack. Therefore, the selection and construction of primer are very important. We can select the primer of construction machinery from the following aspects

anti corrosion performance

construction machinery is basically stored and operated in the open air, and some even operate in high humidity, high temperature and high salt environment, so the coating anti-corrosion performance is very important for the service life and good appearance of construction machinery. Its main performance tests include water resistance, oil resistance, heat resistance, salt water resistance and other related standards and methods. For hydraulic parts, the performance of resistance to various hydraulic oils is the most important. Otherwise, after the film is eroded, the film falling off into the hydraulic oil is likely to cause hydraulic system failure, which will affect the daily operation of construction machinery. The primer sprayed on the surface of heated parts must have good heat resistance, otherwise the coating on the heated parts will fall off, causing the parts in this part to be directly exposed to the air, thus accelerating the corrosion rate of construction machinery

mechanical properties

the mechanical properties of construction machinery primer mainly include impact strength, hardness, adhesion, flexibility and other properties. If the mechanical properties of the primer are not very good, the coating can be easily damaged during the production, shipping and working of parts or machinery, thus losing the anti-corrosion performance of the primer


the anti-corrosion, mechanical properties and other properties of the primer must be constructed through the primer and realized after drying and film forming. Its workability will also affect the production efficiency, cost and appearance quality of construction machinery. The construction performance of the primer is mainly manifested in surface drying, solid drying, leveling, covering power of the coating and construction adaptation period. The drying time of primer is too long or high drying temperature is required, which will affect the spraying time of the lower coating, thus increasing the construction cost: poor leveling of primer will lead to uneven surface of the film after drying, and it is likely to suffer from low gloss and poor orange peel when spraying the top coating

requirements of construction machinery for intermediate paint

intermediate paint is a coating that plays a connecting role between primer and topcoat. The main function is to fill the bottom base material, isolate the defects of the primer layer, improve the fullness of the finish coat and other decorative properties, and enhance the adhesion of the finish coat to the coating, increase the thickness of the entire supporting coating, and improve the water resistance and corrosion resistance of the entire coating

requirements of construction machinery for intermediate paint: good compatibility with primer and finish paint, and strong adhesion with upper and lower coatings; The hardness of the coating shall be moderate. The solvent of the finish coat shall not "bite" the coating. It shall have good water and humidity resistance, and shall not cause blistering of the finish coat. It shall have good grinding performance, and can be dried at an appropriate high temperature. When it is dry, it must not stick sandpaper and have good dryness. The commonly used intermediate coating is epoxy intermediate coating and polyurethane intermediate coating. The selection of polyurethane intermediate coating mainly considers that the coating has better weather resistance

requirements for surface paint of construction machinery

the top coat can make construction machinery have high gloss, rich colors and give people aesthetic feeling. The finish effect directly affects customers' judgment on the quality of construction machinery products, so the appearance color and effect are paid more and more attention. Commonly used solvent based topcoats include alkyd, acrylic, chlorinated rubber and polyurethane topcoats. Requirements for surface paint of construction machinery are as follows

protection performance

construction machinery is generally constructed and stored outdoors, with poor working conditions. It is faced with wind and sun, dust pollution and washing by rain and cement water. Therefore, construction machinery needs coating protection to make its surface coated with a certain thickness of film, so as to isolate oxygen, moisture, dust and other corrosive substances in the atmosphere, avoid corrosion within a certain period of time, and ensure the service life of the equipment. It can be said that the protective function is the basic function of the construction machinery coating, so the coating is required to have good mechanical properties such as adhesion, impact resistance and flexibility

decorative performance

at the beginning of the development of the domestic construction machinery industry, the work efficiency is high, and the coating is mainly used for rust protection. After entering the 21st century, as the industry cake becomes bigger and bigger, and the competition is becoming increasingly fierce, the coating appearance has also become an important factor in the competitiveness of products. Higher gloss, fullness and pleasing coating color matching naturally make it easier to win the market. Similarly, with the development of the market, PMMA is widely used as intraocular lens transplantation material in surgery, but its contact with corneal epithelial cells will cause permanent damage to corneal epithelial cells. Construction machinery enterprises also realize the importance of brand building and corporate image visual identification (VI). Therefore, coating the product surface with paint plays an important role in brand communication

construction machinery is huge and complex in structure, so it is difficult to achieve high appearance effect on all surfaces. For this reason, the construction machinery industry has put forward the concept of covering parts, that is, the parts covered outside the machinery and equipment, including the oil tank, cab, hood, cover plate, etc. on these covering parts, the decoration of coating is highlighted, and the surface coating is required to be smooth, uniform, full, high gloss, disease-free, and have certain weather resistance. In a certain period of time, its loss of light and fading are within the specified range. Since 2000, the construction machinery industry has paid more and more attention to the appearance quality of products. The biennial Beijing construction machinery exhibition also specially held appearance evaluation activities. The decorative function of construction machinery coating has become more prominent, and users and manufacturers have paid more attention to the overall visual effect of product coating


when selecting the top coat of construction machinery, attention must be paid to the compatibility with primer, intermediate coat or putty, otherwise the whole coating may be wrinkled and undercut during coating. During the construction of the finish paint, it is required to have good leveling, high gloss, high freshness and good fullness, but no sagging. Poor leveling performance of finish paint may lead to sagging, orange peel, poor freshness and poor fullness

at present, most of the domestic and foreign construction machinery products still use solvent based coatings for pouting. The use of low construction solid solvent based coatings will produce a large amount of volatile organic compounds (VOC) emissions and cause serious pollution to the environment

in recent years, China has promulgated and implemented a series of policies and regulations restricting solvent based coatings. The market of traditional solvent based construction machinery coatings has been greatly impacted, and the voice of waterborne construction machinery coatings is rising

in September, 2013, the State Council issued the action plan for the prevention and control of air pollution, which clearly defined the implementation of comprehensive treatment of volatile organic compounds in petrochemical, organic, surface coating, packaging and printing industries, improved the limit standards for volatile organic compounds in coatings and other products, promoted the use of water-based coatings, and encouraged the production, sale and use of low toxic and low volatile organic solvents

on January 26, 2015, the Ministry of Finance and the State Administration of Taxation jointly issued the notice on Levying consumption tax on batteries and coatings, announcing that the consumption tax on coatings will be levied from February 1, 2015. Consumption tax in production, entrusted processing and import

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