What are the common quality problems in the production process of color steel coil?

1. Bumps and pits: When the steel strip is subjected to external impacts, the surface of the plate may appear to be protruding or concave. These phenomena may be caused by the mixing of foreign materials on the rolls during painting, tie marks on thin products during bundling, external impacts during rewinding, etc.

2. Edge bubbles: the two sides are stained with paint and bubbles appear after drying. This may be caused by burrs in the original material with a lot of paint, and gaps on both sides.

3. Spots: The paint is mixed with other kinds of paints or paints of other companies, caused by foreign matter in the paint, or caused by poor washing in the pre-treatment process, etc., resulting in the foreign matter or dust mixed from the outside appearing as rice-like protruding on part or all of the surface after painting.

4. Bad bending (T-bend): When steel is bent 180 degrees, the coating on the processed part is cracked and peeled off, which may be caused by too much mastering in pretreatment, too thick coating thickness, excessive baking, or different manufacturers of the lower coating and the upper coating, or improper use of thinning materials.

5. Poor hardness (pencil hardness): use a drawing pencil to scratch the surface of the coating with force, and leave a scratch on the surface after erasing, which may be due to insufficient curing of the coating due to low oven temperature, inappropriate heating conditions, and the thickness of the coating is thicker than that specified.

6. Holes and Leakage Coatings: Leakage coatings may occur due to substrate quality defects such as severe edge damage and gaps, or holes in the substrate that may cause painters to skip coatings in accordance with industry code of practice requirements.

7. Tile marking paint flaking: this is mainly due to the sharpness of the pressing wheel, the new press equipment is prone to cause dry film scratches in the color steel paint.

The above quality problems are more common in the production process of color steel coil, for these quality problems, the manufacturer needs to strictly control the quality of each link and take timely measures to solve the problems when they occur.