In a sense, the wire and cable manufacturing industry is an industry of material finishing and assembly. First, the amount of material used is huge, and the material cost in cable products accounts for 80-90 percent of the total manufacturing cost; second, there are many types and varieties of materials used, and the performance requirements are particularly high. For example, copper for conductors requires the purity of copper. At more than 99.95 percent , some products need to use oxygen-free high-purity copper; third, the selection of materials will have a decisive impact on the manufacturing process, product performance and service life. Among them, the selection of copper wires is particularly important. If a little carelessness may cause safety accidents, it is very important to understand some problems related to copper wires in wires and cables.
Yellowing is usually caused by the following reasons
1. The temperature of the tin furnace is too high and the fluidity is large, resulting in too large pinholes in the coating layer and fast penetration of copper and tin.
2. The tin layer is too thin, and the penetration of copper and tin is fast
3. There are too many halogen residues in the flux, and the pickling of the copper surface is not thorough enough
4. The packaging time is too fast, the heat is not dissipated, and there are too many impurities in the tin furnace
5. The quality of the copper material is not good enough, and there are too many impurities
6. The temperature has an impact on the activity of copper atoms, and it turns yellow faster in hot days than in cold days
This problem is handled as follows
1. The diameter of the mold is greater than the diameter of the line plus 0.02mm (the purpose is very simple, and the coating should not be too thin);
2. Put it aside for about 2 hours after production and then pack it (purpose: internal heat dissipation)
3. Buy a good flux and match the concentration of the flux, mainly because the flux affects the quality of tin plating;
4. Choose better oxygen-free copper wire;
