Coating knowledge: current situation and development direction of coating technology of construction machinery in China

Core tip: as the first link of product competition, coating of construction machinery products is attached great importance; baking process is adopted to adapt to the market (3) adhesion Film adhesion is an important index to measure the mechanical strength The key of adhesion is pre-treatment, and the most reliable pre-treatment process is shot blasting Therefore, shot blasting is generally used for structural parts of construction machinery products (4) weather resistance Generally, construction machinery works in outdoor environment, which requires coating materials with good weather resistance Luster The glossiness of the coating depends on the fineness of the atomization of the spraying equipment The finer the atomization is, the better the glossiness is The atomization ratio should be used as much as possible Paint knowledge | precautions for wall paint color selection Recommended introduction: when painting the wall, the owner sometimes has difficulty in choosing what color of the wall paint to paint In fact, there is no ugly color in the wall paint, only the disharmonious color matching The use of wall color contains the knowledge of health Too strong color will stimulate people's perception, make people have a sense of fidgety, affect people's mental health Grasp the basic principles of wall color and paint a colorful space 1、 Wall paint color selection notice 1 Light color is generally used for the top surface Light colors make people feel light, dark colors make people feel heavy Usually, the treatment of rooms is from top to bottom, from shallow to deep For example, the ceiling and walls of rooms are white and Coating home news: as the first link of product competition, coating of construction machinery products is attached great importance to; in order to adapt to the market, baking process is adopted (3) adhesion Film adhesion is an important index to measure the mechanical strength The key of adhesion is pre-treatment, and the most reliable pre-treatment process is shot blasting Therefore, shot blasting is generally used for structural parts of construction machinery products (4) weather resistance Generally, construction machinery works in outdoor environment, which requires coating materials with good weather resistance Luster The gloss of the coating depends on the fineness of the atomization of the spraying equipment The finer the atomization, the better the gloss The airless spraying with better atomization should be used as far as possible 2 The characteristics of coating process engineering machinery products are miscellaneous varieties, many specifications, large volume and heavy weight Different products have different production characteristics and use environment, different production programs, and different coating processes Since the production program of construction machinery was small before the 1990s, and it could not be mass produced, its typical process flow is: structural parts: shot blasting (or shot peening) → cleaning → primer spraying → drying → putty scraping → drying → assembly Complete machine: cleaning → drying with water trace → puttying → drying → polishing and wiping → surface coating 1 → drying → surface coating 2 → drying → finished product (water drying and putty drying are mostly self drying ）With the development of construction machinery coating, the typical process flow has changed greatly The typical process flow is: structural parts: (1) common process: shot blasting → cleaning → primer spraying → drying → putty scraping → polishing and cleaning → intermediate coating → drying → surface coating → drying → assembly (2) The latest technology: shot blasting → cleaning → (degreasing, phosphating, pure water washing and spraying) → moisture drying → bottom coating → volatilization leveling → surface coating → leveling → drying → assembly The whole machine: cleaning → water trace drying → putty finishing and bottom spraying → drying → finished product 3 Low temperature drying self drying coating is widely used for the finishing coat of coating materials and engineering machinery, mainly including modified alkyd enamel, acrylic engineering machinery enamel, polyurethane enamel, etc., which meet the requirements of different customers The coating is dried at low temperature, mainly to improve its adhesion and hardness The top coat must be matched with primer, putty and intermediate coat system The top coat material is the main factor for the difference of coating quality between domestic and foreign products It is necessary for domestic coating manufacturers to develop products with high quality and low price to meet the demand of domestic market 4 Process layout engineering machinery structure parts and whole machine coating production line are mainly composed of structure parts shot blasting cleaning room, whole machine cleaning room, moisture drying room, grinding room, paint spraying room, paint film drying room, finishing room and conveying equipment The layout of process equipment is closely related to the characteristics of the product and the coating process used Factors such as whether the product is wheel type or crawler type, what kind of putty is applied, and whether the intermediate coating process is used affect the overall process layout The process layout is closely related to the transportation mode of the production line At present, the self hoist transportation with accumulation function is widely used for the coating of structural parts in China There are three main modes of the whole coating production line: double plate chain transportation, transfer vehicle transportation and self-propelled mode The two modes of equipment are arranged according to the assembly line, and each process is completed in a separate room 5 Coating equipment 5.1 the automatic shot blasting process is adopted for the surface pretreatment of structural parts in the shot blasting chamber Shot blasting is an efficient surface treatment method that shoots abrasive at a certain speed to the treated steel surface, and removes oxide skin, rust products and other dirt on the steel surface by the impact and grinding effect of abrasive on the steel surface The passing type shot blasting (blasting) cleaning room is composed of cleaning room body, shot blaster, shot tank, spray gun, shot circulation system, ventilation and dust removal system, bottom structure, electrical control system, etc (1) Generally, the best position of the cleaning chamber body is equipped with a shot blasting machine (the quantity is determined according to the shot blasting quantity) The inclined arrangement of the shot blasting machine ensures that every part of the workpiece can be cleaned, that is, the longest part, the widest and the highest part should be considered The workpiece must move at a constant speed when it is shot blasted in the shot blasting area, and the door of the chamber must be closed to ensure that the shot does not fly out of the room The high manganese cast steel guard plate is used as the lining guard plate of the chamber in the shot blasting area, which has good universality, interchangeability and long wear-resistant life (2) The exit end of the peening chamber is equipped with a peening cylinder and two spray guns The inner wall is protected by wear-resistant rubber plate, which not only ensures the reliability of the equipment, but also reduces the cost of the equipment The inlet and outlet of the chamber are equipped with electric doors, which can be controlled automatically or manually 5.2 the spray booth of water spinning spray booth is composed of chamber, air supply and exhaust system, lighting system, paint mist treatment system, control system, combustible gas concentration alarm device, etc (1) The upper part of the chamber body is provided with a static pressure chamber, which is integrated with the framework of the spray booth The static pressure room is equipped with high-efficiency filter non-woven fabric, so that the clean air sent into the room is pressed down along the top of the room according to the laminar flow state, effectively controlling the diffusion of paint mist (2) The air supply system shall be equipped with primary and medium efficiency filter sections and heating sections (the heat source is steam, and the indoor hot air in winter shall be ≥ 15 ℃) The wind speed of each section is required to be uniform to avoid paint mist escaping (3) The paint mist purification efficiency is required to be more than 99%; the exhaust system is equipped with air-water separation device, which is discharged into the atmosphere after treatment (4) The treatment of organic waste gas meets the national comprehensive emission standard of air pollution The exhaust gas monitoring and alarm device monitors the concentration of combustible gas in the room at any time When the concentration of solvent reaches 25% of the lower explosion limit, it will alarm immediately 5.3 the bottom (surface) paint drying room adopts the forced hot air convection circulation mode The energy in the drying room mainly includes steam, electricity, liquefied gas, light diesel oil, etc the equipment is mainly composed of the room body, hot air circulation system and exhaust gas purification equipment At present, the hot air circulation system adopts the quaternion heating furnace (plug-in fan, fuel oil heating system, high temperature filter, exhaust gas treatment integrated structure) The heating speed is fast, the indoor temperature is even, and the temperature difference is less than + 5O ℃ Home of coatings is specialized in coatings, diatom mud, paint coating, coating technology, fire retardant coating news and coating, diatom mud, paint coating, coating technology, fire retardant coating decoration knowledge and decoration renderings,