Characteristics and causes of different quality problems of color steel plate

1. Manufacturer of color coated plate with poor hardness

Features: Use a drawing pencil to force a scratch on the coating surface, leaving a scratch on the surface after wiping

Cause:

① The furnace temperature is low and the coating is not fully solidified.

② . Improper heating conditions

③ The coating thickness is thicker than the specified thickness

2. Pitting

Features: The foreign matter or dust mixed from the outside has rice grain protrusion on part or all of the surface after coating

reason:

① . Paint mixed with other kinds or other companies' paint.

② . It is caused by the mixing of foreign matters in the paint.

③ . Poor washing during pretreatment.

3. Poor bending

Features: When the steel is bent 180 degrees, the coating on the processing part cracks and peels off

reason:

① The amount of pre-processing is too much.

② The coating thickness is too thick.

③ Excessive baking.

④ The lower coating is different from the coating manufacturer, or the thinner is improperly used.

4. Bump

Features: due to the external impact on the steel strip, the plate surface appears prominent or concave, some have a certain spacing, and some do not occur

reason:

① Foreign matters are mixed on the roller during painting.

② The binding marks of sheet products during binding.

③ . External impact during rewinding.

5. Edge bubble

Features: There is paint on both sides, and bubbles occur after drying

Cause: burr on raw material, coating and cracks on both sides

6. Orange peel

Features: The dried surface coating is as rough and uneven as orange peel

Cause:

① The wet film is too thick.

② When the viscosity of the coating is high.

7. Poor solvent resistance

Features: paint peeling occurs when wiping with butanone

reason:

① The baking temperature does not meet the requirements

② There is a problem with the curing of the coating

③ The pretreatment is not clean