Comparison of oxygen-free copper network cable and full copper network cable

Ethernet cable, according to different prices and applications, the internal cable material will also change. Generally, we call the network cable oxygen-free copper network cable, but there are also other network cable names, such as copper-clad copper, copper-clad silver, copper-clad steel, etc. In this issue, we will analyze the materials of these network cables.

First, the type of network cable

1. Copper-clad steel: the center is steel, and the surface is plated with a layer of copper, which has high electrical resistance, strong rigidity, and is relatively hard and not easy to bend and deform. The melting point of steel is higher than that of copper (the melting point of copper is about 1000 °C, and the melting point of steel is about 1500 °C), so burning copper with a lighter will melt the steel first and then melt, resulting in sparks and darkening of the color of the steel (the steel is easily oxidized and the color changes black). Furthermore, the copper clad steel will be adsorbed on the magnet when it is sucked by a magnet.

2. Copper-clad aluminum: the center is aluminum, and the surface is plated with a layer of copper. When it is burned with a lighter, it hangs down immediately, and the color turns gray. multi-section. Moreover, the specific gravity of copper-clad aluminum is light, only 1/3 of that of copper (the specific gravity of copper-clad aluminum is about 3.0g/cm, and the specific gravity of pure copper is 8.9g/cm).

3. Copper clad copper: the center is brass, the surface is plated with a layer of pure copper, brass is an alloy composed of copper and zinc, the surface color is dim, not very bright, look at the cut end face and cut the end face of the wire, the outside of the end face is red, The yellow one in the center is copper-clad copper, and the copper wire is scraped with a knife to a certain extent. The reddish one is pure copper, and the yellow one inside is brass.

4. Pure copper (Oxygen-free copper OFC 4N): OFC 4N is pure copper with a purity of 99.99% without oxygen and without any deoxidizer residue, and has excellent electrical conductivity, thermal conductivity, ductility and corrosion resistance. The method to distinguish pure copper (oxygen-free copper OFC 4N) is: the surface color is bright and reddish red. When burning with a lighter, it slowly melts into a small point, and the unburned red and black color becomes the primary color after cooling. , It should be noted that if the surface has changed color because it has been oxidized with fire, if the surface is scraped off, the inside is still red.

2. Why is the wire core in the conductor of the network cable plated with a layer of oxygen-free copper?

Because oxygen-free copper is pure copper that does not contain oxygen or any deoxidizer residue (but actually contains a very small amount of oxygen and some impurities), according to the standard, the content of oxygen is not more than 0.003%, and the total amount of impurities The content is not more than 0.05%, and the purity of copper is more than 99.95%.

Oxygen-free copper has high purity, excellent electrical conductivity, thermal conductivity, hot and cold processing performance, good welding performance, corrosion resistance and is suitable as a high-quality network cable material, and now there are oxygen-free copper network cables on the market. Network cable, also known as all-copper network cable, copper-clad copper network cable.

In general, small and long-life projects will choose bronze network cables, while larger projects will choose oxygen-free copper network cables as the medium for transmitting network signals. When network signals are transmitted, the transmission effect and distance are related to the material of the network cable. , The better the material of the conductor, the smaller the resistance of the network cable, the better the transmission effect, and the longer the transmission distance.

Since oxygen-free copper is higher in purity than bronze, the resistance of oxygen-free copper wire is much lower than that of bronze wire. Within 300 meters, the resistance of bronze wire is about 110 ohms, while the resistance of oxygen-free copper wire is only about 30 ohms.

The effective transmission distance of the network cable is also related to the size of the resistance. The oxygen-free copper network cable can transmit about 120 meters to 150 meters under normal circumstances, while the bronze network cable is only about 70 meters. The physical properties of oxygen-free copper wire and bronze wire are relatively stable, with high oxidation resistance, and their colors are basically the same. The copper wire conductor will be coated with an oxygen-free copper layer, which is indistinguishable from the surface. , When the oxygen-free copper and bronze wire conductors cannot be distinguished, the surface or cross-section can be scraped with a knife.