Manual processing:

Such as scraper, wire brush or grinding wheel. The rust and oxide scale on the surface of the workpiece can be removed by hand, but the manual treatment has high labor intensity, low production efficiency, poor quality and incomplete cleaning.

Chemical treatment:

It is mainly to use the acid-base or alkaline solution to react with the oxide and oil on the surface of the workpiece to dissolve it in the acid or alkaline solution, so as to remove the rust, oxide scale and oil on the surface of the workpiece, and then use the brush roller made of nylon or 304 stainless steel wire (steel wire brush roller made of acid-base solution) to clean up. Chemical treatment is suitable for cleaning thin plate parts, but its disadvantages are: if the time is not controlled properly, even if the corrosion inhibitor is added, the steel can be corroded. For more complex structural parts and parts with holes, after acid pickling, the residual acid immersed in the cracks or holes is difficult to be completely removed. If it is not handled properly, it will become a potential corrosion hazard of the workpiece, and the chemicals are easy to volatilize, The cost is high, and the chemical emission after treatment is difficult. 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 treatment method is being replaced by mechanical treatment.

Mechanical treatment method:

It mainly includes wire brush roller polishing method, shot blasting method and shot peening method. The polishing method is that the brush roller is driven by the motor, and the brush roller rotates at high speed on the upper and lower surfaces of the strip in the opposite direction of the rolling piece movement to brush off the scale. The iron oxide scale is washed away by closed circulating cooling water flushing system. Shot blasting cleaning is a method of using centrifugal force to accelerate the shot and eject it to the workpiece for rust removal. However, due to the poor flexibility of shot blasting and the limitation of the site, there are some blindness in cleaning the workpiece, so it is easy to produce the dead angle on the inner surface of the workpiece that cannot be cleaned. The structure of the equipment is complex, there are many vulnerable parts, especially the blades and other parts wear quickly, there are many maintenance man hours, high cost and large one-time investment.

The surface treatment by shot peening has great striking force and obvious cleaning effect. However, shot peening is easy to deform the thin plate workpiece, and the metal substrate is deformed when the steel shot hits the surface of the workpiece (no matter shot blasting or shot peening). Due to the non plasticity of Fe3O4 and Fe2O3, the oil film will be peeled off after crushing, and the oil film will deform together with its material. Therefore, for the workpiece with oil contamination, shot blasting and shot peening can not completely remove the oil contamination. Among the existing surface treatment methods, the best cleaning effect is sand blasting. Sandblasting is suitable for cleaning the surface of workpiece with high requirements. But at present, the general sand blasting equipment in our country is mainly composed of hinge, scraper, head hoist and other original heavy sand conveying machinery. Users need to build a deep pit and make a waterproof layer to install machinery. The construction cost is high, and the maintenance workload and maintenance cost are huge. A large amount of silica dust generated in the process of sandblasting can not be removed, which seriously affects the health of operators and pollutes the environment.

Sand suction machine is widely used in foreign countries to transport sand. In fact, sand suction machine is a super large vacuum cleaner. The hopper is connected with sand suction machine by a thick conveying pipe to suck sand into the storage tank. The characteristics of sand suction machine are that the construction difficulty and process are simpler than bucket elevator, and it is easy to control, less need to maintain, but the power consumption is large, At present, there are several domestic sand suction machine manufacturers, but the technology is relatively immature, so the vast majority of surface treatment enterprises mainly use bucket elevator.

When selecting sand conveying equipment and dust removal equipment, factories that need to do the shot blasting process must fully consider the actual situation of production, and try to choose the equipment with larger power relative to the production demand. As the equipment in shot blasting industry generally consumes faster, after long-term use, many problems will affect the production, Choosing high-power equipment will greatly reduce the time and cost of maintenance. The insufficient power of dust removal equipment not only damages the health of workers, but also seriously affects the visibility of sand blasting room. The dust can not be discharged, also affects the quality of sand itself and the surface roughness of workpiece.

The manual sandblasting room should be designed according to the actual situation. Compared with the spacious space for the workpiece, it should not be too rigid, otherwise it will affect the manual operation of workers. At the same time, the lighting conditions must be better. For the dry area, the sandblasting can be carried out outdoors.

Plasma surface treatment

Plasma, also known as plasma, is a collection of positively charged positive particles and negatively charged particles (including positive ions, negative ions, electrons, free radicals and various active groups), in which the positive and negative charges are equal, so it is called plasma. It is the fourth state of matter except solid state, liquid state and gas state - plasma state.

The plasma surface processor is composed of plasma generator, gas delivery pipeline and plasma nozzle. The plasma generator generates high-pressure and high-frequency energy, and generates low-temperature plasma in the glow discharge activated and controlled in the nozzle steel pipe. With the help of compressed air, the plasma is sprayed to the surface of the workpiece. When the plasma meets the surface of the object to be treated, the plasma is sprayed to the surface of the workpiece, There are physical changes and chemical reactions. The surface has been cleaned, the hydrogen carbide dirt, such as grease, auxiliary additives, etc. have been removed, or etched and roughened, or dense cross-linking layer has been formed, or oxygen-containing polar groups (hydroxyl, carboxyl) have been introduced. These groups can promote the adhesion of various coating materials, and have been optimized in adhesion and paint application. Under the same effect, a very thin high tension coating surface can be obtained by plasma treatment, which is conducive to bonding, coating and printing. No other machine, chemical treatment and other strong ingredients are needed to increase adhesion.