February 23, 2019
Computer cable It is suitable for indoor, cable trench, pipeline and other occasions requiring non electrostatic shielding. High pressure polyethylene with small dielectric constant is used as insulation for computer shielded cable. It adopts such structural forms as twisted pair, screen pair and collective screen (or three wire combination, group screen and collective screen group). It has the characteristics of small dielectric loss, strong signal transmission capability, good anti-interference performance, and can reliably transmit weak analog signals. It can be widely used in computer systems or automation devices for detection and control in power generation, metallurgy, petroleum, chemical industry, light textile and other departments, And general industrial computers.
Computer cable belongs to Cables for electrical equipment This cable is applicable to electronic computers and automatic instruments with rated voltage of 500V and below, which have high requirements for anti-interference. According to the use requirements of different environments and equipment, the cable insulation can be made of polyethylene, polyvinyl chloride, cross-linked polyethylene, fluoroplastic, silicone rubber and other materials.
Computer cable is usually a rope like cable twisted by several groups of conductors (at least two in each group). Each group of conductors is insulated from each other and often twisted around a center to form a cable core. Some groups of conductors are covered with shielding layers, some are covered with shielding layers throughout the cable core, and some are covered with shielding layers for each group and cable core. According to different laying conditions, in order to protect the cable, some computer cables are covered with an armored layer, and the outermost layer is covered with an outer sheath. Computer cables are widely used in power generation, metallurgy, mining, petrochemical industry, transportation, science and technology, national defense and other fields, as cables for computer network (DCS system), automatic control system detection devices and instrument connections.
The common plastics for computer cables are polyethylene, cross-linked polyethylene, PVC, polypropylene, polyolefin, fluoroplastic, nylon, etc. Polyethylene is a widely used plastic with large consumption at present. With low meson loss, high resistivity, high breakdown field strength, good weather resistance and processability, polyethylene is a good electrical insulation material at present. However, due to its low operating temperature, it is mainly used as the insulation of communication cables. Cross linked polyethylene (XLPE) is an excellent thermosetting insulating material formed by adding cross-linking agent to low-density polyethylene (LDPE). On the basis of inheriting many excellent properties of polyethylene, it has improved mechanical properties, weather resistance and allowable working temperature, thus becoming the current power cable Good insulating material.
PVC has good physical and mechanical properties and excellent processing properties. Fluoroplastics are widely used in computer cables due to its high working temperature, small medium, insulation, weather resistance, acid and alkali resistance, oil resistance, flame retardancy and many other advantages. Among them, perfluoroethylene propylene is especially popular because of its good processability. But it is expensive. Low smoke halogen-free polyolefin is a new cable sheath material that was not developed in the 20th century. This computer cable material has the advantage of flame retardancy, small smoke and no toxic gas when burning. It is increasingly widely used in important public buildings.
