Differences and Applications of Shot Blasting and Sand Blasting in Coating Lines

In the coating industry, shot blasting and sand blasting, as two important surface treatment technologies, play a vital role. They clean and pre-treat the surface of the workpiece through different physical principles and working methods, laying a solid foundation for the subsequent coating process. Here I will introduce the differences, application advantages and how they jointly promote the development of coating technology between shot blasting and sand blasting in coating lines.

1. Overview of Shot Blasting Process

Shot blasting, also known as shot peening technology, is a physical processing method that uses a high-speed rotating shot blaster to spray metal or non-metallic particles onto the surface of the workpiece at a certain speed and angle. These hard granular materials (such as steel shot, sand, etc.) can remove impurities such as oxide scale, rust, burrs, etc. on the surface of the workpiece under high-speed impact, while improving the surface finish, enhancing surface adhesion and corrosion resistance.

Shot blasting is widely used in metal surface treatment and coating processes in the fields of aviation, trains, automobiles, shipbuilding, machinery, and construction. Before painting, shot blasting can effectively remove impurities and dirt on the metal surface, while increasing the surface roughness, so that the paint can be more firmly attached to the metal surface, prevent the coating from peeling or falling off, and extend the service life of the coating. In addition, shot blasting can also improve the corrosion resistance of the metal surface, reduce surface defects and cracks, improve the finish of the metal surface, and make the product appearance more beautiful.

2. Overview of Sandblasting Process

Sandblasting process is to spray sand or other abrasives onto the surface of the workpiece through compressed air to achieve the purpose of rust removal, grinding or increasing surface roughness. Sandblasting not only removes rust quickly, but also prepares the surface for painting, spraying, electroplating and other processes. The surface treated by sandblasting can meet the requirements of cleanliness and a certain degree of roughness, thereby improving the bonding force between the coating and the parts.

The sandblasting process has the characteristics of thorough cleaning, strong versatility, rapidity and efficiency. It can be arbitrarily selected between different roughness, which is difficult to achieve with other processes. It is usually used in the aluminum and stainless steel cookware industry. We Guangdong Chuangzhi have independently developed a fixture-free automatic sandblasting machine, which is one of our latest patented products. This sandblasting machine has been upgraded from the original 1,300 pieces per hour to 2,600 pieces per hour, and can realize the internal sandblasting process of the inner pot of the rice cooker, which can be customized according to customer needs.

3. The Difference between Shot Blasting and Sandblasting Process

Although shot blasting and sandblasting both play an important role in the coating line, they have certain differences in working principles, application scope and effects.

1. Working principle: The shot blasting process mainly uses a high-speed rotating shot blaster to spray hard granular materials onto the surface of the workpiece; while the sandblasting process uses compressed air to spray sand or other abrasives onto the surface of the workpiece.

2. Application scope: The shot blasting process is suitable for the treatment of large steel, castings, aluminum alloys and other basic workpieces; while the sandblasting process is widely used in workpieces of different materials, including metals, plastics, ceramics, etc., for rust removal, grinding, surface treatment before spraying, etc.

3. Treatment effect: The surface of the workpiece after shot blasting is smoother and brighter, and can enhance surface adhesion and corrosion resistance; while sandblasting focuses more on rust removal and increasing surface roughness, providing better bonding for the coating.

4. Application of Shot Blasting and Sand Blasting in Coating Lines

In coating lines, shot blasting and sand blasting each play a unique role. Shot blasting is mainly used for pretreatment of metal surfaces to remove impurities such as scale and rust, and improve surface finish and adhesion; while sand blasting is more used for rust removal and increasing surface roughness to provide better bonding and adhesion for coatings. The two complement each other and jointly promote the development of coating technology.

In addition, with the continuous advancement and innovation of technology, shot blasting and sand blasting processes are also being continuously optimized and improved. For example, the emergence of wet sand blasting technology not only improves cleaning efficiency, but also reduces costs and environmental impact.

In summary, shot blasting and sand blasting, as two important surface treatment technologies, play an indispensable role in coating lines. They provide comprehensive surface pretreatment services for workpieces through different working principles and application ranges. In the future, Guangdong Chuangzhi will continue to explore and optimize the application methods of these two processes and contribute more to the development of the coating industry.