How to judge the quality of color steel plate?

Color steel plate is particularly significant for the steel structure construction. And it has played an increasingly important role in today's building materials system. Under such circumstances, how do we judge the quality when we purchase color steel plates? Below we list some common quality problems of color steel plates and recommend four methods to judge the color steel plates quality.

Picture-color steel plate

1. Common Quality Problems of Color Steel Plates

• uneven edges

The substrate panel is made by hand rolling, and the uneven edges phenomenon is mostly caused by the non-uniform thickness. Generally, it is caused by the fact that the hot-dip galvanized sheet is not properly straightened, or the straightening roller is broken, or the roller is uneven during the production of the color steel panel.

• unpainted line

The color steel plate products finished painted with paint leakage on face coating or back coating, which is called unpainted line in the industry. Generally, it is an unavoidable problem for every manufacturer and caused by the impurities in the paint, the equipment problems, and the substrate panel itself.

• wrinkle

If there is no problem with the equipment, it's likely that the substrate is already wrinkled. The wrinkles of the hot-dip galvanized steel sheet mainly come from the process technology of the galvanizing production line and the malfunction of the equipment.

• hole & paint omission

Defects due to substrate quality. If the substrate has severe edge damage, gaps, or holes, then the painter will open the paint equipment according to the requirements of the industry specifications and let it skip, which will inevitably cause the paint omission.

• paint flaked off after tiles pressing

The production team should check the pressure level and make sure the equipment operation system is normal and good. Ensure the bearing works well and consistent pressing action of the tile press machine’s steel rollers in every group. The new press equipment can cause the scratches on dry film of the color steel plate paint easily due to the sharpness of the pressing wheel.

• color difference

The quality of paint, the production process, and the type of substrate will all affect the color difference to a certain extent. The color difference will occur even the process and raw material of color steel plate is all the same, which largely related to the substrate type.

• zinc granule

The original problem caused by the quality defects of the color steel plate substrate. Generally, such a substrate is not suitable for production. The quality inspector has the right to decide whether to produce or not.

2. How to Judge The Color Steel Plates Quality

• Investigate substrate thickness and film thickness

The color steel plate is composed of the substrate and colorful peritoneum or plating. The thickness of the substrate and the peritoneum coating must be considered firstly. The better color steel plate substrate thickness is 0.02~0.05mm, and the thickness of the film or the coating is generally 0.15mm or less. The thickness of the substrate is very important for affecting the use time of color steel plates. Some manufacturers often play a trick on the substrate and coating or film. They reduce the thickness of the substrate but increase the thickness of the peritoneum to reduce the production cost, which greatly reduced the service life of color steel plates.

• Investigate the outer leakage edge of color steel plates

Firstly investigate whether the steel is finely crystallized, whether it is gray or dark, and if there are impurities on exposed sections such as the cross-section. The quality is better if the surface is finely crystallized.

• Judge by the sound

Use a finger or a hard object to hit the color steel plate. If the raw material of the color steel plate is poor, then sound is dull, and the metal sound is not obvious. The metal sound of the color steel plate with better raw materials is relatively loud and crisp.

• Check the quality certificate

If possible, go to visit the manufacturer. Look at the company's environment and whether it is formal. Ask about the reputation of this company in the market.