Why does copper wire inside the wire become black? Today, let's delve into this topic: From a chemical perspective, copper wire is made of copper. Once it comes into contact with oxygen, it turns into copper oxide, which is black in color. Therefore, after a period of use, the copper wire in the wire and cable will turn black, indicating that it has come into contact with oxygen and will definitely undergo changes.

The copper inside the wire turns black, often due to poor copper quality (aluminum mixed in the cable copper core), water intrusion into the sheath, or excessive use time. It could also be because the copper wire diameter is too small. Copper oxidizes to form copper oxide, which is black. This is a common occurrence in normal electrical wires. The wire can still be used as long as it does not overheat during use. However, the resistance will increase, and power consumption will slightly rise. If the blackening is severe but the wire must be used, it can only be used as a secondary conductor, otherwise, it will overheat.

The above introduction covers the issue of电线电缆发黑. Another situation arises due to the widespread use of high-speed drawing, which increases the speed and consequently reduces the relative cooling time, providing space and time for oxidation. Therefore, it is recommended that manufacturers pay close attention to the fat content of the emulsion, the appropriate usage temperature, and the pH value. During the spring moldy rain season, bacteria reproduce rapidly, so it's advisable to use fungicides and anti-mold agents. In summer, antioxidants can be used to address oxidation and blackening issues without any problems.