What are the requirements of automatic sandblasting machine for workpiece processing?

Material adaptability

Metal workpiece: automatic sandblasting machine can handle a variety of metal workpieces, such as steel, aluminum alloy, stainless steel and so on. For steel workpieces, whether ordinary carbon steel or alloy steel, sandblasting machine can effectively remove impurities such as rust and scale on the surface. For example, in the manufacture of automobile parts, after welding or forging, steel parts such as automobile frame and wheel hub will have scales and welding slag on their surfaces. These impurities can be quickly removed by automatic sandblasting machine, so that the surface can reach the roughness required for subsequent processing (such as painting and electroplating). The texture of aluminum alloy workpiece is relatively soft. In the process of sandblasting, it is necessary to pay attention to selecting appropriate sand materials and sandblasting parameters to avoid excessive erosion on the surface of the workpiece. For example, in the processing of aluminum alloy parts in aerospace field, using fine sand and low sandblasting pressure can not only clean and roughen the surface, but also damage the workpiece.

Non-metallic workpieces: also applicable to some non-metallic workpieces, such as glass, ceramics, plastics, etc. For glass products, the automatic sandblasting machine can perform sanding treatment, change the transparency and gloss of the glass surface, and make decorative frosted glass. In ceramic processing, it can be used to remove defects on the surface of ceramic body or to make special texture patterns on the surface of ceramic. However, due to the particularity of its material, plastic workpieces are sensitive to sandblasting strength. Some plastics with low hardness, such as polyvinyl chloride (PVC), may cause surface deformation or damage if the sandblasting parameters are not properly controlled, so it is necessary to choose milder sand and lower sandblasting pressure.

Workpiece size and shape restrictions

Size range: automatic sandblasting machine has a certain processing size range. Small sandblasting machines can generally handle smaller workpieces, such as small precision mechanical parts, and their processing chambers may be tens of centimeters square, which is suitable for processing watch parts and small electronic components. The large-scale automatic sandblasting machine can handle large-scale workpieces, such as large-scale metal plates for architectural decoration, and the length of its processing room may reach several meters, which can accommodate large-scale workpieces for sandblasting. However, the oversize workpiece may affect the uniformity of sandblasting effect, so it is necessary to adjust the parameters such as sandblasting angle and spray gun position reasonably.

Shape complexity: For workpieces with simple shapes, such as flat plates and cylinders, automatic sandblasting machine can easily process them. However, for workpieces with complex shapes, such as those with complex cavities, deep holes or finely carved surfaces, the machining difficulty will increase. For example, some molds with complex internal passages need special spray guns and sandblasting processes during sandblasting to ensure that the sand can reach all the surfaces to be treated. At the same time, it is necessary to avoid the accumulation of sand in the complex shape of the workpiece, which will affect the sandblasting effect and subsequent cleaning.

Workpiece surface state requirements

Pretreatment requirements: Before automatic sand blasting, the surface of the workpiece should be as flat as possible. If there are large bumps, depressions or cracks on the surface of the workpiece, the uniformity of sandblasting may be affected. For the workpiece with oil, grease and other pollutants, it is necessary to clean and pretreat it first, because these pollutants will affect the contact between sand and the surface of the workpiece and reduce the sandblasting effect. For example, there are often cutting oil residues on the surface of machined metal workpieces, which need to be cleaned with organic solvents or alkaline cleaning agents before sandblasting.

Compatibility requirements for subsequent processing: the surface state of the workpiece processed by automatic sandblasting machine should match the subsequent processing technology. If the workpiece needs to be machined with high precision, the surface roughness after sandblasting should be controlled within a certain range to avoid affecting the machining accuracy. In case of coating treatment, the surface of the workpiece after sandblasting should have appropriate roughness to enhance the adhesion between the coating and the surface of the workpiece. Generally speaking, it is appropriate to control the surface roughness (Ra) of the workpiece for painting at about 3-7 μ m..

Workpiece strength requirements

The workpiece needs to have enough strength to withstand the impact force during sandblasting. For workpieces with low strength, such as some brittle materials (such as some ceramics, glass, etc.) or thin-walled workpieces, it is necessary to carefully select the sandblasting parameters. If the blasting pressure is too high or the sand particles are too large, it may lead to cracks or even breakage on the surface of the workpiece. For example, in the sand blasting process of glass crafts, it is necessary to use lower sand blasting pressure and finer sand, and strictly control the sand blasting angle to prevent glass products from being damaged. For workpieces with high strength, such as thick-walled metal castings, they can withstand relatively high sandblasting strength, and more aggressive sandblasting parameters can be adopted in removing surface impurities and roughening the surface.