1, surface treatment function
Principle: Both sand blasting and shot blasting use high pressure air or compressed air as the power to blow the spray out to impact the surface of the workpiece to achieve the cleaning effect. However, different media are selected, and the blasting medium has a cutting effect on the surface; after blasting, the surface of the workpiece is removed, the surface of the workpiece is slightly damaged, and the surface area is greatly increased, thereby increasing the bonding strength with the workpiece and the coating/plating layer.
Sandblasting surface treatment application range:
(1) Workpiece coating, pre-bond bonding
(2) Cleaning and polishing of the rough surface of the casting and the workpiece after heat treatment: descaling, oil stain and other residues; polishing the surface of the workpiece to improve the smoothness and make the workpiece uniform and uniform
(3) Machining workpiece burr cleaning: sand blasting can clean the tiny burrs on the surface of the workpiece; and can make small rounded corners at the junction of the workpiece surface
(4) Improve the mechanical properties of the parts: After sand blasting, a uniform and fine uneven surface is generated on the surface of the parts to store the lubricating oil, thereby improving the lubrication conditions.
(5) Lighting effect: sand blasting can achieve different reflective or matt surface of the workpiece, such as stainless steel workpiece, plastic, jade polishing
2. The surface compressive stress formed by sandblasting is much smaller than that of shot peening and shot blasting.
3. Sandblasting type commonly used for surface treatment of paint metal: cold cast iron sand, crushed slag
4, surface cleaning quality
The surface of the workpiece after sandblasting is metallic, but since the surface is rough, the light is refracted, so there is no metallic luster and it is a dark surface.
Sandblasting effect:
5, sandblasting process
(1) Pre-treatment process before sand blasting: solvent cleaning, pickling, hand tools, power tools
(2) Sandblasting process
6, sandblasting process notes:
(1) Gas storage tanks, pressure gauges and safety valves should be checked regularly. The gas storage tank discharges dust once every two weeks, and the filter in the sand tank is inspected once a month;
(2) Check if the ventilation pipe and the sand blasting machine door are sealed. Five minutes before the work, the ventilation and dust removal equipment shall be activated. When the ventilation and dust removal equipment fails, the blasting machine is prohibited from working;
(3) The compressed air valve should be slowly opened, and the air pressure is not allowed to exceed 0.8 MPa, generally 0.2 to 0.6 MPa;
(4) The blasting particle size should be compatible with the work requirements, generally between 10 and 20, and the sand should be kept dry;
(5) After the work is finished, the ventilation and dust removal equipment should continue to operate for five minutes and then shut down to discharge the indoor dust and keep the site clean.
