1. The importance of surface treatment before industrial spraying

In the process of machining, transportation, storage, etc., the surface of the machined workpiece is often covered with oxide scale, rust molding sand, welding slag dust, oil and other dirt. In order to make the deep layer firmly adhere to the surface of the workpiece, the surface of the workpiece must be cleaned before painting. Otherwise, it will not only affect the bonding force and corrosion resistance of the coating and the base metal, but also make the base metal even in the It can continue to corrode under the protection of the coating, so that the coating peels off and affects the mechanical properties and service life of the workpiece. Therefore, the surface treatment of the workpiece before painting is an important guarantee and measure to obtain a high-quality protective layer and prolong the service life of the product.

2. In order to provide a good workpiece surface, the treatment of the workpiece surface before spraying has the following points:

1. No oil and moisture

2. No rust and oxide

3. No adhesive impurities

4. No residues such as acid and alkali

5. The surface of the workpiece has a certain roughness

Three, commonly used surface treatment methods are:

1. Manual processing: such as scraper, wire brush or grinding wheel, etc. The rust and oxide scale on the surface of the workpiece can be removed by hand, but manual processing is labor-intensive, low in production efficiency, poor in quality, and incompletely cleaned.

2. Chemical treatment: It mainly uses acidic or alkaline solution to chemically react with oxides and oil stains on the surface of the workpiece, so as to dissolve it in an acidic or alkaline solution, so as to achieve the purpose of removing rust, oxide scale and oil stains on the surface of the workpiece. . Chemical treatment is suitable for cleaning thin plate parts, but the disadvantage is that if the time is not properly controlled, even if a corrosion inhibitor is added, the steel can be over-corroded. For more complex structural parts and parts with holes, after pickling with acid solution, it is difficult to completely remove the residual acid immersed in the gaps or holes. If it is not handled properly, it will cause serious pollution to the environment. With the improvement of people's awareness of environmental protection, this kind of treatment method is being replaced by mechanical treatment method.

3. Mechanical treatment method: mainly including shot blasting and shot peening.

①The shot blasting method is a method of using centrifugal force to accelerate the projectile and project it to the workpiece for rust removal and cleaning. However, the flexibility of shot blasting is poor, limited by the site, and it is somewhat blind when cleaning the workpiece, and it is easy to produce dead corners that cannot be cleaned on the inner surface of the workpiece. The structure of the equipment is complex, there are many wearing parts, especially the blades and other parts wear quickly, the maintenance man-hours are long, the cost is high, and the one-time investment is large.

② Shot peening is divided into shot peening and sandblasting.

S uses shot peening for surface treatment, which has a large striking force and obvious cleaning effect. However, the treatment of thin-plate workpieces by shot peening is easy to deform the workpiece, and the steel shot hits the surface of the workpiece (whether shot blasting or shot peening) to deform the metal substrate. Since Fe3O4 and Fe2O3 have no plasticity, they peel off after being broken, and the oil film and the The substrate is deformed together, so for workpieces with oil stains, shot blasting and shot peening cannot completely remove the oil stains. Among the existing workpiece surface treatment methods, the best cleaning effect is sandblasting.

S sandblasting is suitable for cleaning the workpiece surface with high requirements. However, most of the general sandblasting equipment in our country is composed of primitive and bulky sand conveying machinery such as auger, scraper, bucket elevator and so on. The user needs to build a deep pit and make a waterproof layer to install the machinery. The construction cost is high, the maintenance workload and maintenance cost are huge, and a large amount of silica dust generated during the sandblasting process cannot be removed, which seriously affects the health of the operators and pollutes the environment. .

Fourth, the importance of environmental protection With the continuous improvement of science and technology, with people's continuous requirements for product quality, with the continuous application of high-tech equipment in enterprises, with the improvement of people's environmental awareness, the strict requirements of environmental protection departments , it is urgent to control the dust pollution and noise environment. The competition of enterprises is becoming more and more fierce, so how to gain an advantage in the fierce competition has become the key to determine the development of enterprises. Facts tell us that strictly controlling the production process is the premise of ensuring the quality of the company's products, and controlling environmental pollution is the responsibility of each of us.