Published: 2025-08-21 14:20:29
Choosing drag chain cables in high-temperature environments requires considering multiple factors. Below is a selection manual:
Temperature range
Clarify the operating temperature: First, determine the highest and lowest temperatures in the environment where the cable is located. Ordinary PVC cables can withstand temperatures of only about 70°C, making them unsuitable for high-temperature environments. Generally, silicone rubber-sheathed cables can be chosen for high-temperature environments, with a typical temperature resistance range of -60°C to 200°C, meeting the needs of most high-temperature industrial scenarios.
Consider the rate of temperature change: If the ambient temperature where the cable is located changes drastically, such as a rapid rise or fall in temperature within a short period, it is also necessary to consider the thermal stability and thermal shock resistance of the cable material. Materials like silicone rubber perform well in this regard and can withstand significant temperature changes without affecting performance.
Conductor material
Choose multi-strand fine copper wires: To adapt to the frequent bending of cables in drag chain systems, conductors should preferably be in the form of twisted multi-strand fine copper wires, such as 7 strands or more, with a single wire diameter of ≤0.1mm for movable fine bare copper conductors. This ensures a balance between flexibility and conductivity. Avoid using single-strand hard copper wires or thick copper wires (diameter >0.2mm), as they are prone to breakage due to metal fatigue.
Consider the conductor material: the conductivity of bare copper is higher than that of tinned copper wire, which can reduce resistance, further decrease heat accumulation, and avoid insulation aging caused by high temperatures. However, in humid environments, attention should be paid to the potential oxidation of bare copper wire. Nevertheless, drag chain cables usually use a sheath-sealed design, and the oxide layer on fine copper wires has little impact on conductivity.
Insulation and sheath materials
Insulation materials: High-temperature and voltage-resistant insulation materials should be selected, such as cross-linked polyethylene (XLPE) and silicone rubber. These materials have good electrical insulation properties at high temperatures and can effectively prevent cable short circuits and other faults.
Sheath material: In addition to silicone rubber, for some high-temperature environments with relatively low temperatures but requiring comprehensive properties such as wear resistance and oil resistance, polyurethane (PUR) sheaths can also be considered. They are stable in performance within the range of -40°C to 80°C and have excellent wear resistance and oil resistance.
Mechanical properties
Bending radius: Choose a cable that meets the minimum bending radius requirement, usually 6-10 times the cable's outer diameter. If the cable's bending radius is too small, it can cause damage to the conductors, insulation, and sheath inside the cable, affecting the cable's service life.
Tensile strength: Drag chain cables are subjected to tension during movement, so they need to have sufficient tensile strength. You can choose to add aramid fiber filler cords between the conductor layers or use a high-density braided reinforcing layer (such as Kevlar fiber or galvanized steel wire) in the cable to enhance tensile capacity.
Wear Resistance: In high-temperature environments, the cable's sheath material is prone to wear due to friction, so materials with good wear resistance should be chosen, such as silicone rubber and polyurethane. In addition, the sheath thickness should be ≥1.0mm to prevent mechanical damage caused by being too thin.
Shielding performance
Determine shielding requirements: If the cable is used for signal transmission, such as encoder signals, control signals, etc., the cable's shielding performance needs to be considered to prevent signal interference. For high-frequency signal transmission (>20MHz), impedance matching is also required, and parallel termination resistors are recommended to be 100-120Ω.
Selection of shielding structure: Preferably choose an aluminum foil-braided composite shielding structure, in which the aluminum foil has a high coverage rate, and the braided layer provides flexibility to prevent the shielding layer from breaking due to frequent bending. The coverage rate of the shielding layer should be ≥85% to ensure good shielding performance.
Other factors
Cable fill rate: The fill rate should be ≤50%, leaving space for heat dissipation to prevent cables from pressing and rubbing against each other, which could affect the performance and lifespan of the cables.
Certification standards: Ensure that the cable complies with relevant international and national standards, such as the EN 50396 bending test standard. These standards specify the performance indicators and testing methods of the cable and can serve as an important reference for cable selection.