What are the specific process flows of the paint spraying line for mobile phone casings?

he following is an introduction to the coating process of mobile phone casings in English:

Degreasing: The first step is to remove any grease, oil, or dirt from the surface of the mobile phone casing. This is usually done using a degreasing agent to ensure that the paint can adhere properly.
Surface Abrasion: After degreasing, the surface of the casing may be abraded slightly. This can be achieved through methods like sandblasting or using abrasive papers. The purpose is to increase the surface roughness, which helps the paint to stick better.

Primer Application: A primer is then applied to the pretreated surface. The primer serves as a base layer that improves the adhesion of the topcoat and provides additional protection against corrosion and other environmental factors. It is usually sprayed evenly onto the casing using specialized spraying equipment.
Drying and Curing: After the primer is applied, it needs to be dried and cured. This can be done at room temperature for some primers, while others may require heat treatment in an oven. The drying and curing time varies depending on the type of primer used.

Base Color Spraying: Once the primer is fully cured, the base color paint is sprayed onto the casing. Mobile phone casings come in a wide variety of colors, and the paint is carefully formulated to achieve the desired hue and finish. Multiple layers of paint may be applied to ensure even coverage and vibrant color.
Special Effects Coating (if applicable): Some mobile phone casings may require special effects such as metallic finishes, pearlescent effects, or matte textures. Specialized paints and coating techniques are used to create these effects. For example, metallic paints contain small metal particles that give a shiny, reflective appearance.

Clear Coat Spraying: A clear coat is applied over the color layer to provide additional protection and a glossy or matte finish, depending on the desired look. The clear coat helps to prevent scratches, UV damage, and fading of the color. It is sprayed on in a similar manner to the base color paint.
Final Drying and Curing: The coated casing is then dried and cured again to ensure that the clear coat hardens properly. This final curing process is crucial for the durability and quality of the coating.

Visual Inspection: After the coating process is complete, the mobile phone casings undergo a thorough visual inspection. Inspectors look for any defects such as paint bubbles, scratches, uneven coating, or color discrepancies.
Adhesion and Durability Tests: Various tests are conducted to ensure the quality of the coating. Adhesion tests are performed to check if the paint adheres firmly to the casing surface. Durability tests may include scratch resistance tests, impact tests, and chemical resistance tests to ensure that the coating can withstand normal use and environmental conditions.