Selection of cable materials
(1) Conductor
New energy cable Copper core flexible conductor shall be used, and the conductor shall comply with the provisions of the sixth conductor in GB/T3956-2008 standard.
(2) Insulation
High quality thermoplastic special compound vulcanized rubber tpv material is used for insulation. This material has excellent electrical performance, elasticity and compression deformation resistance, which can make the cable soft, oil and water resistant, high and low temperature resistant, and environmental friendly.
(3) Shielding
The shielding of cable insulation core shall be composed of sub shielding, general shielding and aluminum plastic composite tape.
(4) Cabling
Twist power, control, data signal and safety protection wires into cables.
(5) Outer sheath
The outer sheath shall be extruded with environment-friendly halogen-free low smoke flame-retardant radiation cross-linked sheath material. The extruded sheath layer shall be smooth and round without quality defects such as scorch, scratch and bubble.
3. Problems and solutions in cable design
(1) Existing problems
(a) Separate structure of power, control, data signal and safety protection line;
(b) The low frequency conduction, high frequency conduction and radiation interference functions of the cable are poor;
(c) Poor insulation performance;
(d) The environmental protection performance, high and low temperature resistance and oil resistance of the cable are poor.
(2) The following technical solutions are adopted to solve technical problems:
(a) New structure
The power cable, control cable, data signal cable and safety protection line are integrated in the cable structure. The problem of the original single wire core is solved. (b) The cable core is braided and shielded with copper wire or tinned copper wire after being cabled. The monofilament diameter is 0.15 mm, and the braiding density is not less than 80%. Then wrap aluminum plastic composite tape outside for shielding, and the coverage rate of aluminum plastic composite tape shall not be less than 15%. During the trial production, we followed up to ensure that the braided layer is tight and the coverage rate of aluminum plastic composite belt is high. It effectively avoids low-frequency conduction, high-frequency conduction and radiation interference.
(c) Improvement of cable performance
The conductor of the cable is copper core flexible conductor, which makes the cable have good flexibility.
The insulation of this product adopts thermoplastic special composite vulcanized rubber tpv material, and the sheath material adopts 125 ℃ low smoke halogen-free flame retardant thermoplastic polyurethane elastomer tpu material. The flame retardant performance of the cable can reach the bundle type a combustion test specified in GB/T 18380.35, which ensures the safety of the cable in the presence of combustible gas. The shielding layer of the cable adopts the form of copper wire braid shielding, which ensures the safety of the cable in high temperature and chemical corrosive environment. The auxiliary material filling layer and tape layer of the cable are made of low smoke halogen-free flame retardant materials to ensure the flame retardant performance and environmental protection performance of the cable.
(3) Study on Production Technology of Sheath
During production, the materials are very sensitive to the temperature of the extruder body. High or low temperatures will cause poor surface quality or poor plasticization of the extruded sheath, which will affect the appearance and physical and mechanical properties of the cable. During the production process, because the material contains ether bond in its molecule, it is easy to absorb moisture and has very high water content. It is easy to produce a large number of bubbles during extrusion and cannot be used. So we are New energy cable manufacturer Before extrusion, the materials were properly pre dried. By optimizing the temperature distribution of the extruder, reasonably setting the body temperature, and finally determining the equipment parameters in actual production, the extrusion quality was improved, and the surface of the cable sheath was smooth, round, and fully plasticized, reaching the expected physical characteristics.
