The shielding was opened back in 1836 by the famous scientist Michael Faradya, who became famous for the invention of his own cell. If you explain the technology in simple words, it turns out that when you get into the electric field, the closed shell sets free electrons of fields. In the electric and magnetic field, many interference in the area of high frequencies occurs, therefore, a technology of shielding is needed, which reduces the amount of interference and losses, which improves the electrical characteristics of shielded cables. But this technology is necessary only at very high frequencies, the usual network wire used in the installation of electrical wiring does not need to be shielding.
During the existence and manufacture of wires, a large number of shielding technologies were developed, each of which had both advantages and disadvantages. One of the most effective is the technology that uses a sandwich, a polyester film and foil, which is applied to it. This type of shielding has many advantages such as excellent flexibility, high wear resistance and excellent quality. All this provides a long service life of cables, shielded using this technology.
This type of screen is used only on cables with copper tinned conductors, which are perfectly in contact with foil along the entire length of the cable. This makes it possible to quickly and simply perform grounding, remove any noise and aims.
But, like any other, this technology has some disadvantages, one of which is a small insignificant gap, which makes shielding worse, especially at very high frequencies. But there is also a solution to this problem, which consists in the use of a special fold, which is used in cable wraps. In general, today there are a lot of different technologies and types of cables used according to various purposes, such as the connecting, installation, cable cords and much more.
Screening for a long time was performed on only one twisted pair, but in the modern world it is necessary to use shielding at once on several twisted pairs. To improve technical parameters, not one layer of foil can be used, but two, which significantly increases the reliability of protection and the durability of the cable, especially relative to the number of bends.