The customer’s order form sometimes encounters a cable of model WDZ-YJ(F)E. The name of this type of cable should be interpreted as a copper core irradiated cross-linked polyethylene insulated low-smoke halogen-free flame-retardant polyolefin sheathed power cable. The product standard for power cables GB/T 12706.1~3-2008 "Rated voltage 1kV (Um=1.2kV) to 35kV (Um=40.5kV) extruded insulated power cables and accessories", in Appendix D "Supplementary Provisions for Cable Products" Regarding the representation method of the insulation code, the cross-linked polyethylene insulation code is YJ, and there is no distinction between the type of cross-linking (physical or chemical). The radiation cross-linking belongs to the physical cross-linking type, and the type is added "F", this is a commonly used method of radiation cross-linking insulation in the industry. The implementation standard should still be GB/T 12706-2008. The customer chooses this model, intending to use the insulated core of radiation cross-linking to meet the requirements of their special use occasions. So what are the advantages of radiation crosslinking and ordinary silane insulation?
Irradiation cross-linking is the use of high-energy electron beams generated by an electron accelerator to cross-link the cable, so that the insulating layer polyethylene of the cable changes from a linear molecular structure to a three-dimensional network structure, forming a three-dimensional lattice smaller than water molecules , A dense layer is formed on the surface and inside of the polyethylene, which effectively prevents the combination of hydroxide and water molecules. This cross-linking method not only improves the temperature resistance, wear resistance and flame retardancy of the wire and cable, but also Played a water blocking effect. This cross-linking method has no high temperature and no water, which can not only cross-link polyethylene, but also improve the flame retardant and electrical properties of the cable. The cable has the characteristics of low smoke, halogen-free, flame-retardant and high temperature resistance. The specific properties are as follows: high temperature resistance level; long-term allowable working temperature of conductors can reach 135℃ (filling, wrapping, and sheathing materials need to be selected from materials with the same temperature resistance class and insulation, while ordinary silane cross-linked polyethylene insulated cables are resistant to Temperature is 90 degrees); good halogen-free flame retardant performance: no smoke and poisonous gas, light transmittance ≥90%, PH value ≥6.0 (ordinary low-smoke halogen-free cable light transmittance ≥60%, PH value ≥4.3); machinery Excellent performance. The wear-resisting frequency reaches 160,000 times and the service life exceeds 50 years.
However, due to the large investment in irradiation equipment, general cable manufacturers do not have the ability to irradiate. If processing outside of irradiation, transportation and irradiation fees will increase cable costs and prolong the production cycle, which will affect product delivery. Therefore, some cable material manufacturers have developed "silane cross-linked halogen-free low-smoke flame-retardant polyolefin insulation materials" based on the characteristics of radiation cross-linked cables, as their substitutes. Its characteristic is that it can be cross-linked by traditional warm water cooking, and It has the characteristics of halogen-free and abrasion resistance, and the temperature resistance level is also improved. However, because it is cooked in warm water, the hydroxide absorbs water and the insulation resistance decreases, so the electrical performance does not reach the level of the radiation cross-linked cable.
When processing customer orders, if the required model is WDZ-YJ(F)E, it can be understood that there is no special requirement for the temperature resistance of the cable, which is still 90 degrees, but it is proposed in terms of wear resistance and life. High demands. The density of the silane cross-linked halogen-free low-smoke flame-retardant polyolefin insulation material is 1.45 g/cm. The density of the radiation cross-linked insulation material is equivalent to that of water, which is greater than the density of water. If ordinary silane cross-linked insulation is used instead of radiation cross-linked insulation As long as you take a small piece and put it in the water to see the ups and downs, it can be identified. Therefore, it is not feasible to replace the radiation cross-linked material with ordinary silane insulating material, and the performance difference between the two is too large. However, whether it can be replaced by silane cross-linked halogen-free low-smoke flame-retardant polyolefin insulating material, you should fully communicate with the customer first, and understand the customer's application situation before deciding whether to substitute it.
