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Paint reasons

1. Refers to the poor material extraction performance of the paint itself
2. Reason for formation: When the line speed increases, the radiation speed ratio remains unchanged, and the adhesive roller speed increases accordingly. The paint in the material tray is prone to faults, and when the fault reaches between the adhesive and coating layers, it is easy to cause the board surface to flower.
3. Shape: watery or elongated
4. Regularity: No specific position, no regularity, observe the status of the adhesive roller from the paint curtain inside the material tray or during reverse coating
5. Feature: Uneven film thickness
6. Solution:
Reduce the speed of the adhesive roller
Increase viscosity
Reduce speed
Note: Improper proportion of paint wax content, watermarked pattern (flake like) on the surface of the glossy board

2、 Floating color (glossy line)
1. The pigment carried by the paint itself floats on the surface of the paint due to prolonged agitation
2. Reason for formation: Due to insufficient flow of paint in the material tray, colors with lower density inside the paint surface appear
3. Shape: spotted or color difference bar
4. Rule: Near the feeding port
5. Feature: No significant change in film thickness
6. Solution:
Irregular mixing tray
Add a baffle
Increase the painting speed to ensure that the paint in the material tray returns as soon as possible
Change the position of the feeding port or overflow port, and change the overflow method
3、 Coating roller
1. Marks or drum marks appear during the use or grinding process of coating and rolling
2. Reason for formation:
Appearing during use
Improper operation by grinder workers
Injury during transportation
3. Shape: point shaped, linear
4. Rule: There is no specific position, but the position remains unchanged, and the interval is the circumference of the coating roller
5. Characteristics: Poor film thickness and regular spacing distribution
6. Solution
Determine the flatness of the coating roller before starting the machine
Strictly control the grinding machine
4、 Board surface
1. There is water, oil, and passivation liquid on the board surface
2. Reason for formation: There is oil and passivation liquid on the substrate, and when passing through the coating machine, the paint cannot be applied to the substrate normally, causing the surface of the board to be scratched or missed
3. Shape: Dotted or banded
4. Regularity: Irregular
5. Feature: Uneven film thickness
6. Solution
5、 Low viscosity
1. The board surface has a zinc leakage pattern
2. Reason for formation: viscosity too low
3. Rule: The feeding port is lighter, while the choke port is heavier
4. Feature: The film thickness cannot be increased, and the speed ratio of the adhesive roller cannot be increased
6、 Speckled pigmentation
1. There are<shaped color spots on the board surface (facing the light)
2. Reason for formation:
Short mixing time for paint
Expiration of paint and precipitation
Paint contains incompatible colloidal substances
3. Shape:<shape
4. Regularity: Irregular
5. Features: Only visible under bright light
6. Solution: Increase the mixing time
Primer board has low temperature and is not fully cured
1. After applying the topcoat, there are spots or stripes on the surface of the light
2. Rule: The board has patterns when coated with topcoat
3. Feature: Equivalent to roller pattern
4. Solution: Increase the temperature of the primer board
8、 Horizontal stripe
1. Improper setting of roller speed ratio or damage to roller coating and sticking bearings
2. Rule: Roll patterns appear continuously with equal intervals
3. Characteristics: The paint film changes significantly (alternating light and dark)
4. Confirmation method: For the former, the roller pattern is relatively uniform and there is no significant difference on both sides of the board. The latter has significant differences on both sides of the board

9、 Watermarked pattern
1. When the substrate undergoes precision coating, the board temperature is too high
2. Rule: The entire board surface is evenly distributed
3. Feature: Similar to watermark but cannot be erased