Process the wet electrostatic painting of hinges of SAMSUNG washing machine

BASIC PROCESS OF THE WET ELECTROSTATIC PAINTING

1. Manage the gathering of input materials (Ingots) to the production area
2. Mechanical treatment: grinding/polishing
3. Painting process (Oil removal – Water washing x3 – Chemical treatment – Water washing – Drying – Water electrostatic spray painting)
4. Drying
5. QC inspection and packing
6. Delivery

Step 1: Treat the surface of the product before painting

The product surface (metal) before powder coating is treated. Normally, products that are powder coated are Copper, Aluminum, Stainless Steel, Iron, Zinc …

We consider on the surface of Copper, Aluminum, Stainless steel, Iron. The product surface treatment is intended to bring about the following requirements:

• Products clean industrial grease (due to mechanical processing)
• Rust-free product.
• The product does not rust again in the unpainted time.
• Creates a good coating for adhesion between the paint film and the metal.

Due to the above requirements, the metal surface treatment before painting is usually treated by the method of dipping the product into chemical baths.

The system of chemical tanks includes the following tanks:

1. Degreasing chemical storage tank.
2. Clean water washing tank.
3. Acid rust removal tank, usually H2SO4 or HCl.
4. Clean water washing tank.
5. Surface shaping chemical tank.
6. Surface phosphate chemical storage tank.
7. Product passivation tank
8. Clean water washing tank.

These tanks are built and covered with Composite resin.

Painted products are stored in baskets made of 304 stainless steel wire mesh, moved by the chain of tanks in the above order.

Step 2: Dry the surface of the product before painting

Step 3: Paint the product (For paint on Plastic), before painting, a layer of conductive solvent will be applied

Process: Base primer -> Color topcoat -> Gloss 1 -> Gloss 2

The product after chemical treatment and drying is put into the spray chamber and recovered.

Due to electrostatic attraction, the amount of paint will adhere fairly evenly to the entire painted surface. Water-based powder coating uses electrostatic solvents and produces products with very realistic and vivid colors.

Paint spray booths have 2 types:

♦ Type 1 spray gun: Using a spray gun, the paint object is hung, hooked by hand to the spray chamber.

♦ Type 2 spray guns: The paint object moves on the conveyor into the spray chamber, 2 spray guns on opposite sides spray on the 2 sides of the product.

Step 4: Dry shaping and finish the product

After spraying, the product is put into the drying oven. Drying temperature for plastic is from 75oC to 80oC, time is from 60′ to 90′, drying for metal is 140oC to 180oC with time of 25′ to 30′.

Oven with main heat source by Gas.