21
Sep
The role of cable sheath
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Wire and cable is the transmission of electrical energy and electrical signals of wire products, mainly by the transmission of electricity or electrical signals of the cable core and play a protective role and insulation role of the sheath of two major components. The core is generally made of copper or aluminum metal with good electrical conductivity, and the sheath is generally made of plastic, rubber, nylon and other materials.
High-quality sheath with resistant tensile, resistant bending, resistant vibration, resistant torsion and other good physical and mechanical properties, can go to adapt to different use of the environment.
At the same time, it can protect the inner layer from mechanical damage and chemical corrosion, do not contact water vapor moisture, prevent contact conductor electric shock, fire retardant, enhance the mechanical strength and extend the service life of the role to ensure that the cable in the harsh environment can operate normally and reliably.
Cable sheath is the outermost layer of the cable, the main role is to protect the cable, such as YJV - PVC insulation PVC sheath CU/AL conductor power cable, the type of cable sheath is PVC material, to protect the role of the core.
If the sheath material used is not qualified or process technology does not meet the standard may cause the following hazards.
1 Increase the risk of electric shock cable
If the cable is in those directly buried, immersed in water, exposed to the open air or prone to corrosion, because of prolonged corrosion by external media, the sheath will lose the protective role of the cable, resulting in the inner conductor is exposed, not only easy to oxidation, if you accidentally touch the conductor and the risk of electric shock.
2 Reduce the service life of the cable
The cable itself will generate a lot of heat in long-term use, the sheath material is not qualified or the thickness does not meet the standard, the insulation level and mechanical level will be reduced, greatly affecting its service life.
As the most important barrier of the cable, cable sheath of various materials play a different protection, the following is an introduction to several common high-quality sheathing materials:
1 PVC (polyvinyl chloride)
PVC plastic material
Has a stable physical and chemical properties, the most important feature is flame retardant (flame retardant value of 40 or more), and is therefore widely used in fire applications.
PVC was the world's largest production of general-purpose plastics, the application is very wide. It is widely used in construction materials, industrial products, daily necessities, floor leather, floor tiles, artificial leather, pipes, wires and cables, packaging films, bottles, foaming materials, sealing materials, fibers, etc.
2PE (polyethylene)
Odorless, non-toxic, feel like wax, has excellent low temperature resistance (the lowest use temperature can reach -100 ~ -70 ° C), good chemical stability, can resist the erosion of most acids and bases (not resistant to acids with oxidizing properties). Because polyethylene is non-polar, it has excellent electrical properties of low dielectric loss and high dielectric strength, and can be used as FM insulating material, corona resistant plastic, and high voltage insulating material.
3Armored
Armored cable mechanical protection layer can be added to any structure of the cable to increase the mechanical strength of the cable and improve the erosion resistance, and it is a wire and cable designed for the area which is vulnerable to mechanical damage and highly susceptible to erosion. It can be laid in any way, and is more suitable for direct burial in rocky areas.
The purpose of cable plus armored layer is not only above, but also can enhance the tensile strength, compressive strength and other mechanical protection to prolong the service life, have certain performance of resistance to external force, also can prevent the rat from tearing, not to cause power transmission problem through the armored, the bending radius of the armored should be large, the armored layer can be grounded to protect the cable.
4Nylon braid
The above are the most widely used sheathing materials, there are also PUR, TPE/TPR, TPU and other materials as sheathing.
In summary, the sheath has a particularly important role for the cable, is an important guarantee of long-term safe and reliable operation of cable products. Choose the right material to play the role of flame isolation, waterproof, insulation, corrosion resistance, high temperature resistance, etc., to maintain the integrity of the line, the smooth flow of power communications.
High-quality sheath with resistant tensile, resistant bending, resistant vibration, resistant torsion and other good physical and mechanical properties, can go to adapt to different use of the environment.At the same time, it can protect the inner layer from mechanical damage and chemical corrosion, do not contact water vapor moisture, prevent contact conductor electric shock, fire retardant, enhance the mechanical strength and extend the service life of the role to ensure that the cable in the harsh environment can operate normally and reliably.
Cable sheath is the outermost layer of the cable, the main role is to protect the cable, such as YJV - PVC insulation PVC sheath CU/AL conductor power cable, the type of cable sheath is PVC material, to protect the role of the core.
If the sheath material used is not qualified or process technology does not meet the standard may cause the following hazards.1 Increase the risk of electric shock cable
If the cable is in those directly buried, immersed in water, exposed to the open air or prone to corrosion, because of prolonged corrosion by external media, the sheath will lose the protective role of the cable, resulting in the inner conductor is exposed, not only easy to oxidation, if you accidentally touch the conductor and the risk of electric shock.
2 Reduce the service life of the cable
The cable itself will generate a lot of heat in long-term use, the sheath material is not qualified or the thickness does not meet the standard, the insulation level and mechanical level will be reduced, greatly affecting its service life.
As the most important barrier of the cable, cable sheath of various materials play a different protection, the following is an introduction to several common high-quality sheathing materials:1 PVC (polyvinyl chloride)
PVC plastic material
Has a stable physical and chemical properties, the most important feature is flame retardant (flame retardant value of 40 or more), and is therefore widely used in fire applications.
PVC was the world's largest production of general-purpose plastics, the application is very wide. It is widely used in construction materials, industrial products, daily necessities, floor leather, floor tiles, artificial leather, pipes, wires and cables, packaging films, bottles, foaming materials, sealing materials, fibers, etc.
2PE (polyethylene)
Odorless, non-toxic, feel like wax, has excellent low temperature resistance (the lowest use temperature can reach -100 ~ -70 ° C), good chemical stability, can resist the erosion of most acids and bases (not resistant to acids with oxidizing properties). Because polyethylene is non-polar, it has excellent electrical properties of low dielectric loss and high dielectric strength, and can be used as FM insulating material, corona resistant plastic, and high voltage insulating material.
3Armored
Armored cable mechanical protection layer can be added to any structure of the cable to increase the mechanical strength of the cable and improve the erosion resistance, and it is a wire and cable designed for the area which is vulnerable to mechanical damage and highly susceptible to erosion. It can be laid in any way, and is more suitable for direct burial in rocky areas.
The purpose of cable plus armored layer is not only above, but also can enhance the tensile strength, compressive strength and other mechanical protection to prolong the service life, have certain performance of resistance to external force, also can prevent the rat from tearing, not to cause power transmission problem through the armored, the bending radius of the armored should be large, the armored layer can be grounded to protect the cable.
4Nylon braid
The above are the most widely used sheathing materials, there are also PUR, TPE/TPR, TPU and other materials as sheathing.
In summary, the sheath has a particularly important role for the cable, is an important guarantee of long-term safe and reliable operation of cable products. Choose the right material to play the role of flame isolation, waterproof, insulation, corrosion resistance, high temperature resistance, etc., to maintain the integrity of the line, the smooth flow of power communications.
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