Production is a very complex process that requires strict control of every process. A slight negligence during the production process will cause product defects. This article summarizes the analysis of common defects and causes of several aluminum coils and sheets for your reference.
1. Surface bubbles,
Irregular circular or strip-shaped cavities bulge on the surface of aluminum coils and sheets, becoming surface bubbles. The raised edges are smooth, asymmetrical up and down, and irregularly distributed.
cause:
1. The surface of the raw material is uneven, with dents or scratches.
2. The raw materials are not clean.
3. The heating temperature of raw materials is too high or the time is too long.
2. Burr:
Burrs are thin short wires or sharp and thin metal thorns of varying sizes on the edges of aluminum coils and sheets after shearing them.
cause:
1. The cutting blade is not sharp enough.
2. Poor lubrication of cutting blade
3. The cutting blade clearance and overlap amount are improperly adjusted.
3. Water marks:
Light white or light black irregular waterline marks on the surface of aluminum coils and sheets become water marks.
cause:
1. The surface moisture has not been cleaned after quenching, leaving traces after calendering.
2. After washing, the drying is not good, leaving residual moisture.
3. There is residual moisture on the surface due to rain and other reasons, which is not treated in time.
4. Imprints
There are single or periodic depressions or ridges on the surface of aluminum coils and sheets, which become impressions. Generally, the surface is relatively smooth.
cause:
1. There are metal shavings or other dirt on the surface of the pressure roller or plate.
2. There are defects or foreign objects on the surface of other equipments.
3. The surface of the sleeve is not clean and smooth.
4. When curling, the aluminum coils adheres to foreign matter