pre painted steel coil quality analysis (3)
1)Color difference
characteristics:
The color of the standard steel coil is different.
Cause:
1. The coating thickness is too thick or too thin.
2. Not a batch of paint.
3. Uneven stirring when the viscosity is diluted.
2)Poor gloss
characteristics:
The range of gloss is abnormal.
Cause:
1. The coating thickness is not appropriate.
2. Improper curing conditions.
3. Insufficient stirring.
3)Collapse
features:
The inner diameter of the coil is deformed during storage in the warehouse after coiling.
Cause:
1. The coil is affected by an external force after coiling.
2. The winding tension is incorrect.
3. Uneven load.
4)Anti-stick
features:
There is slight peeling during unwinding; the primer will appear grainy particles similar to millet, and the surface will be uneven after top coating.
cause
1. Insufficient cooling before coiling.
2. Insufficient baking.
3. Part of the load is too large.
5)Crushing
Features:
The crater after coating.
Cause:
1. The raw material roll is crushed.
2. Crushing through various rollers before coating.
3. Pressure injury with the paint after coating.