What are the reasons for the color difference on the surface of stainless steel color coating? How to buy?

Paint, film thickness, viscosity, plate temperature, cooling water, curing oven, uneven or non-stirring of paint will cause color difference on the surface of stainless steel color coating.

Paint

1. Refers to the color difference (light color) of paint in different batches or barrels.

2. The paint pigments and fillers are different.

3. When a new batch number or new paint is replaced, it starts to extend from the feed port to the return port, resulting in color difference.

4. Features: It extends from the side of the feed port to the direction of the return port, and is distributed in a strip shape and gradually widens.

5. Solution: Find the reason from the paint itself.

6. Confirmation: Compare the laboratory scraper with two batch numbers on one board.

Film thickness

1. It refers to the color difference caused by the different thickness of the paint film.

2. The viscosity of the coating and the pressure change between the coating rolls.

3. Refers to different stainless steel color coating rollers or both sides of the same stainless steel color coating roller.

4. There are no noticeable changes, but the volumes vary widely.

5. Solution: strictly control the amount of paint.

6. Confirm: Pay attention to the change of paint dosage.

Stickiness

1. Refers to the color difference caused by low or high viscosity on the computer.

2. The viscosity in the barrel is very different from the viscosity of the barrel paint.

3. After changing the paint for a few minutes, there is a color ribbon on one side of the feed port.

4. This example is the same as the previous film thickness change. In essence, a high or low viscosity will eventually cause a change in film thickness.

5. Solution: After changing the paint for a few minutes, there is a color ribbon on the side of the feed port.

6. Pay attention to paint consumption.

Fourth, plate temperature

1. Color difference caused by too high or too low fingerboard temperature.

2. The furnace temperature setting is unreasonable and the feeding is wrong.

3. Phenomenon: The gloss of the layout is not high, and the MEK is unqualified.

4. There is no problem with the same panel, but the different volumes are very different.

5. Solution: Test the temperature of the stainless steel color-coated coil from time to time, and replace the specification (large difference) to measure the coil temperature.

6. Determination: MEK scratch gloss

Cooling water

1. Color difference caused by water quality.

2. The water quality is not good, and the effect of pressing and rolling is not good.

3. Phenomenon: The board surface is black and the gloss is not high.

4. Features: Surface dirt can be wiped off with cotton yarn.

5. Solution: replace the cooling water in time to enhance the pressing effect of the pressing roller.

6. Confirm: The surface gloss of the stainless steel color-coated roller is not high, but the surface dirt can be wiped off with cotton yarn to restore the original luster.

Curing oven

1. Refers to the color of both sides of the board.

2. The temperature of the driving side and the operating side of the curing oven is uneven.

3. Features: There is no obvious color difference in the longitudinal direction, and the horizontal color difference is large (similar to the film thickness difference on both sides).

Seven, the paint is not evenly mixed or not stirred well.

1. It is distributed on the board surface in a strip shape.

2. The paint is layered, causing viscosity differences.

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