Sand blasting is used to clean and roughen the surface of the matrix by the impact of high speed sand flow. It is powered by compressed air to form a high-speed jet beam to spray the spraying materials (copper ore, quartz sand, emery sand, iron sand, hainan sand) at high speed to the surface of the workpiece to be processed, so that the appearance or shape of the surface of the workpiece surface changes. Due to the impact and cutting action of abrasive on the workpiece surface, the workpiece surface is clean and with different roughness. The mechanical properties of the workpiece surface are improved, thus improving the workpiece's fatigue resistance, increasing the adhesion between the workpiece and the coating, prolonging the durability of the coating, and facilitating the flow and decoration of the coating.
Range of application
(1)Sandblasting before workpiece coating and workpiece bonding can remove all dirt on the workpiece surface, etc., and establish a very important basic pattern on the workpiece surface (commonly known as the rough surface). Workers can exchange different sizes of abrasive, to greatly improve the workpiece with coating, plating, making the adhesive joint stronger and of better quality.
(2)The cleaning and polishing of the workpiece after heat treatment can clean up all the dirt on the workpiece surface (such as the residues of oxide or oil, etc.). The workpiece surface polishing can make the workpiece show uniform and consistent metal color, which is better-looking
(3)The burr cleaning can clean the tiny burr on the workpiece surface, and make the workpiece surface more even. It can eliminate the harm of burr and improve the workpiece class. What’s more, sandblasting can hit a small corner at the junction of the workpiece surface, so that the workpiece appears more precise.
(4)Sandblasting can improve the mechanical properties of the parts. After sandblasting, mechanical parts can produce uniform and slight concavoconvex on the surface of the parts. The lubricating oil can be stored, which can improve the lubrication condition and reduce noise to improve the mechanical service life.
(5)For some special purpose workpieces, sandblasting can achieve different reflection or matte at will. For example, the polishing of stainless steel workpiece and plastic, the polishing of jade, the matting of wooden furniture surface, the pattern of ground glass surface, and the wool processing of cloth surface.
Pretreatment
The pretreatment stage refers to the treatment of the workpiece surface before the coating.
The quality of pre-treatment affects the adhesion, appearance, moisture and corrosion resistance of the coating. Poor pretreatment, rust will continue to spread under the coating, making the coating chip off. Compared with the workpiece coating with simple cleaning, the coating life with good pretreatment is 4-5 times longer. There are many methods of surface cleaning, the most commonly accepted methods are: solvent cleaning, pickling, manual tools, power tools.