Generally speaking, the blasting effect is mainly determined by the material of the part and the blasting abrasive. Depending on the material of the part, the abrasive blasting abrasives can range from strong metal abrasives to soft resin abrasives. Dry blasting and liquid blasting are also important considerations. The production efficiency determines the type of equipment, and the automatic blasting production line, semi-automatic blasting equipment, press-in blasting machine, and suction blasting machine are selected according to the processing capacity. The size of the workpiece determines the equipment specifications, and the size of the cabin is selected according to the size of the workpiece so that there is enough space to complete the processing work. Compressed air requirements. Determine the capacity of the air compressor according to the equipment specifications, and leave a 20% margin to protect the life of the air compressor. Xiefan sand blasting machine is introduced to you in detail as follows:
Function or use of sand blasting machine
1.Cleaning of workpiece surface
Can be used as rust layer on metal, residual salt and oxide layer on the surface of heat treated parts, oxide layer on the surface of rolled parts, oxide layer on the surface of forged parts, oxide layer on the surface of welded parts, molding sand and oxide layer on the surface of castings, machining Residual dirt and tiny burrs on the surface, and the surface of old parts are processed to remove the surface adhesion layer, reveal the original color of the substrate, and the surface cleaning quality can reach Sa3 level.
2.Pretreatment of workpiece surface before coating
It can be used as a pretreatment process for various electroplating processes, brush plating processes, spraying processes and bonding processes to obtain active surfaces and improve the adhesion between plating, coatings and bonding parts.
3. Change the physical and mechanical properties of the workpiece
It can change the surface stress state of the workpiece, improve the lubrication conditions of the mating parts, and reduce the noise during the movement of the mating parts. It can harden the surface of the workpiece and improve the wear resistance and fatigue resistance of the part.
4. Finishing of workpiece surface
Can change the surface roughness Ra value of the workpiece. Can produce matt or diffuse reflection of the surface of the workpiece to achieve the purpose of finishing.
Second, the main parameters of sand blasting equipment
The main parameters that affect the blast processing: the type of abrasive, the size of the abrasive, the concentration of the abrasive, the spray distance, the spray angle, the spray time, the compressed air pressure, etc.
Environmental protection characteristics of sand blasting equipment
1. Greatly improves the pollution of dust to the environment and the harm to workers' health;
2. It can be directly installed on the production line, saving production area and facilitating workpiece turnover;
3. Flexible working methods, variable process parameters, and can adapt to the finishing requirements of different materials and parts with different accuracy;
4. During the working process, the abrasive is recycled and the consumption is small;
5. The main parts have a long service life and are easy to maintain.
Common blasting process parameters
Three factors for obtaining superficial results:
Accelerating effect of compressed air on jet flow (adjustment of blast pressure) P
Type of abrasive (S)
Spray gun distance (H), angle (θ)
1.The effect of pressure adjustment on surface results
After setting S, H, θ, the larger the value of P, the higher the speed of the jet flow, the higher the blasting efficiency, and the rougher the surface of the workpiece, otherwise, the surface is relatively smooth.
2.Effect of changes in spray gun distance and angle on surface results
After the P and S values are set, this is the key to manual blasting technology. The spray gun is generally 50 to 150 mm away from the workpiece. The farther the spray gun is from the workpiece, the lower the efficiency of the jet flow and the smoother the surface of the workpiece. The smaller the angle between the spray gun and the workpiece, the lower the efficiency of the jet flow and the smoother the surface of the workpiece.
3.The effect of abrasive type on surface results
Abrasives are divided into spherical and rhombic types according to the state of the particles. Diamond abrasives (white steel and brown corundum) usually used for blasting are diamond-shaped abrasives. Glass beads are spherical abrasives. After the three values of P, H and θ are set, the surface obtained by blasting the spherical abrasive is smoother, and the surface obtained by the rhombic abrasive is relatively rough, and the same abrasive is divided into thicknesses. The abrasive is divided by the number of screens in China The thickness is generally called the number. The higher the number, the smaller the particle size. After the P, H, and θ values are set, the higher the number of the same abrasive blasting number, the smoother the surface result.