To enhance the performance of their products, control cable manufacturers need to combine the demands of industrial scenarios (such as reliability, environmental resistance, and anti-interference ability), and start from dimensions such as material innovation, structural optimization, process upgrading, and functional customization. The following are the specific strategies:
I. Material Upgrade: The Underlying Support for Core Performance
Optimization of conductor materials
High purity and corrosion resistance:
Upgrading from ordinary annealed copper to oxygen-free copper (OFC, purity ≥99.95%) or tin-plated copper reduces the direct current resistance of the conductor (for example, the resistance of a 1mm² cross-sectional area cable drops from 19.5Ω/km to 17.9Ω/km), reduces power loss, and enhances the stability of conductivity.
In special scenarios (such as Marine and chemical industries), silver-plated copper or nickel-coated copper is adopted to enhance oxidation resistance and corrosion resistance (salt spray test life is increased by 50%).
Flexible conductor structure
By using multi-strand fine-stranded conductors (such as 0.1mm×127 strands) instead of single-strand conductors, the bending flexibility is enhanced (the bending radius is reduced from 10D to 6D), meeting the frequent bending requirements of mobile devices (such as robots and cranes).
2. Iteration of insulating layer materials
Temperature resistance and low loss:
Ordinary PVC insulation is upgraded to cross-linked polyethylene (XLPE, with a temperature resistance of 105℃) or fluoroplastic (PTFE, with a temperature resistance of 260℃), meeting the long-term use requirements in high-temperature environments (such as metallurgy and boilers), while reducing dielectric loss (PTFE's dielectric constant is 2.1, which is better than PVC's 4.5).
Develop nano-composite insulating materials (such as adding graphene-modified PE) to enhance insulation strength (increasing breakdown voltage from 20kV/mm to 30kV/mm) and resistance to corona aging.
Functional design
In oil-resistant scenarios, chlorosulfonated polyethylene (CSPE) insulation is used, and it can withstand 500 hours of mineral oil immersion without cracking. Low-temperature environments (-40℃) use low-temperature flexible PVC to maintain the flexibility of the insulation layer.
3. Reinforcement of shielding and sheath materials
Shielding layer upgrade
The single-layer aluminum foil shielding has been changed to a double-layer shielding of aluminum foil and copper braided (the shielding coverage rate has been increased from 80% to 95%), and the shielding efficiency in the high-frequency band (above 100MHz) has been improved by 30dB, which is suitable for scenarios with strong electromagnetic interference such as frequency converters and servo systems.
Develop high-permeability alloy shielding layers (such as permalloy) to reduce induced voltage noise in response to power frequency (50Hz) magnetic field interference (such as near transformers).
Innovation of sheath materials
The conventional PVC sheath is replaced with a low smoke zero halogen flame retardant sheath (LSZH), which reduces the smoke concentration by 70% during combustion and the halogen release is ≤5mg/g, meeting the high fire safety requirements of scenarios such as subways and tunnels.
The wear-resistant scenarios use polyurethane (PU) sheaths, which have passed 3,000 wear resistance tests (superior to 1,000 tests for PVC), and are suitable for drag chain systems (such as machine tool cables).
Ii. Structural Design: Precise Optimization to adapt to scenarios
Conductor stranding and grouping
Differentiated stranding process
For multi-core control cables (such as 37 cores or more), layer-by-layer stranding (inner layer bundled stranding + outer layer re-stranding) is adopted to reduce the friction between core wires and enhance the overall flexibility (the bending life is increased by 20%).
The power + signal composite cable (such as servo cable) adopts an isolation design between the power core wire and the signal core wire (with a polyester tape isolation layer added in the middle) to avoid the interference of power ripple on the signal (the noise suppression ratio is increased by 40dB).
2. Fine design of the insulation layer
Variable diameter insulation technology
For large cross-sectional area core wires (such as 10mm²), eccentric insulation molds are adopted to ensure uniform insulation layer thickness (the tolerance is reduced from ±0.1mm to ±0.05mm), and to enhance the stability of withstand voltage (the power frequency withstand voltage test is increased from 1500V to 2000V).
High-frequency control signal (such as 4~20mA signal) cables use twisted insulated core wires (twisted pitch 50~100mm) to reduce crosstalk between wires (near-end crosstalk NEXT is increased from 45dB to 55dB).
3. Shielding and filling structure
Optimization of shielding layer grounding
Tin-plated copper drainage wires (with a cross-sectional area of ≥0.5mm²) are added at both ends of the shielding layer to shorten the grounding path, reduce the grounding impedance (from 10mΩ to 5mΩ), and improve the EMC performance.
The filling material uses expanded polypropylene (EPP) instead of traditional hemp rope, reducing the weight of the cable (by 15%) while providing cushioning protection to prevent the shielding layer from deforming under pressure.
Iii. Process and Manufacturing: Assurance of Precision and Consistency
Upgrade of precision manufacturing equipment
Conductor drawing and twisting:
The fully automatic CNC wire drawing machine (with an accuracy of ±0.001mm) is adopted to ensure the uniformity of the conductor diameter (roundness error < 1%) and reduce the skin effect loss.
The high-speed stranding machine is equipped with a dynamic tension control system (tension fluctuation ≤5%), which prevents the conductor from breaking or loosening during the stranding process and enhances the stability of the cable core structure.
2. Insulation extrusion and vulcanization
Multi-layer co-extrusion technology
The insulating layer + semiconductive shielding layer (such as cable) is completed in one extrusion process, reducing inter-process errors and ensuring a tight interface (interface resistance < 10Ω · cm).
Cross-linked cables are vulcanized in ultra-high pressure steam vulcanizing tanks (with a pressure of 10bar and a temperature of 135℃), which shortens the vulcanization time by 30%, and simultaneously increases the cross-linking degree of the insulation layer (from 85% to 92%), enhancing the temperature resistance and service life.
3. The quality inspection system is complete
Full-process detection coverage:
Conductor: DC resistance test (accuracy 0.1%), elongation test (error ±2%).
Insulation layer: Breakdown voltage test by Shenhua Electric Group (Anhui) Co., LTD. (voltage rise rate of 500V per minute), thermal elongation test (elongation under load ≤150%, no deformation ≤25%).
Whole cable: Bending test (radius 5D, 1000 times without cracking), low-temperature impact test (-40℃, impact with a 1kg hammer from a height of 1m without damage).
Intelligent detection
The machine vision system was introduced to detect surface defects of the insulation layer (with a resolution of 0.05mm), and combined with the AI algorithm to automatically eliminate defective products, the missed detection rate decreased from 0.5% to 0.05%.
Iv. Function Customization: In-depth Adaptation for Specific Scenarios
Industry-specific product development
Special cables for high-end equipment
Wind power industry: Design torsion-resistant cables (capable of withstanding 360° torsion per meter and adapting to tower swing), and add UV-resistant additives to the sheath (outdoor lifespan ≥20 years).
Photovoltaic industry: Develop weather-resistant control cables (passing the 5000-hour UV aging test), with insulation layer PID (electropotential-induced attenuation) design, suitable for outdoor high-humidity environments.
Special environment cables
Explosion-proof scenarios: It adopts metal armor + flameproof sheath. The control cable manufacturer has passed the Ex d IIC T6 certification and is suitable for hazardous environments such as hydrogen and dust.
Medical equipment: Develop halogen-free and low-noise control cables, with shielding layers to suppress electromagnetic interference from medical equipment (MRI, CT) (attenuation ≥60dB in the 10 MHZ to 1GHz frequency band).
2. Intelligent and modular design
Integration of status monitoring function
Temperature sensors (with an accuracy of ±0.5℃) or strain sensors are embedded in the cable sheath, and the status data is transmitted in real time through the built-in data cable to achieve predictive maintenance.
Quick connection modularization
Develop prefabricated plug cables (such as prefabricated M12 and M23 connectors) to reduce on-site wiring errors and improve the installation efficiency of industrial automation equipment (reducing wiring time by 70%).
V. Green and Compliance: Sustainable Development and Market Access
1. Environmentally friendly materials and processes
Lead-free and recyclable
Completely phase out lead-containing stabilizers and adopt organotin or calcium-zinc stabilizers to meet the RoHS 3.0 directive (with A new restriction on tetrabromobisphenol A).
Develop recyclable cable structures (such as single-material sheaths/insulation layers, with a separation recovery rate of ≥90%) to meet the environmental protection requirements of the EU CEC certification.
2. International standard certification
Pass strict certification:
To enter the European market, it is necessary to pass the CE (LVD/EMC) and **EN 60227 (low-voltage cable) certifications; The North American market requires UL AWM 2919 (Industrial Control Cable) certification to enhance the global competitiveness of the products.
Summary: Systematic improvement path
The performance improvement of control cables needs to follow the logic of "scene demand-driven → collaborative optimization of materials - structure - process → detection - customization - compliance closed loop" :
Core performance: Through the upgrade of conductor/insulation/shielding materials, basic issues such as conductivity, temperature resistance and anti-interference are solved.
Structural innovation: In response to the mechanical stress and signal quality requirements of industrial environments, optimize the stranding, shielding, and sheath structures.
Manufacturing capacity: Relying on precision equipment and intelligent detection, ensure product consistency and reliability.
Differentiated competition: Deeply cultivate niche industries (wind power, photovoltaic, high-end equipment), and provide customized solutions.
Long-term compliance: Balancing environmental protection and international standards, building technological barriers and market access advantages.
Through the above strategies, manufacturers can transform from "general-purpose suppliers" to "industrial connection solution service providers", achieve import substitution in high-end control cable manufacturers (such as servo cables and robot cables), and increase product added value (unit price can be increased by 30% to 50%).