The quality analysis for PPGI steel coil
1) Orange peel features:
The dried surface coating is rough and uneven, like an orange peel.
Cause:
1. The wet film is too thick.
2. When the viscosity of the coating is high. Orange peel features:
The dried surface coating is rough and uneven, like an orange peel.
Cause:
1. The wet film is too thick.
2. When the viscosity of the coating is high.
2)Shock unqualified features:
After the paint film is impacted, part or all of the paint will peel off after taping.
Cause:
1. Poor pretreatment.
2. Check whether the curing temperature of the topcoat is reasonable.
3) Poor solvent resistance (MEK)
Features
Butanone wipes a little paint off.
Cause:
1. The baking temperature does not meet the requirements.
2. There is a problem with the curing of the coating.
3. The pretreatment cleaning is not clean.
4) Shrinkage features:
The paint film is uneven and partially exposed.
Cause:
1. The surface of the steel belt is not clean.
2. The primer cooling water is not clean.
3. The viscosity of the coating does not meet the requirements of the machine.
5) Missing paint
Features
Topcoat not applied.
Cause:
1. The edge topcoat is not applied, the substrate shape is not good, or the pressure between the coating roller and the large back roller is insufficient.
2. The middle topcoat on the board surface is not painted, and there is water or other foreign matter on the board surface after the primer is cooled.