A tubular stranding machine (also called tubular strander or pipe-type stranding machine) is a high-speed rotating-tube equipment that produces concentric stranded conductors with true 100% back-twist. It delivers uniform lay length, low residual torsional stress, high fill factor and continuous 24/7 operation for copper, aluminum and steel wires used in low-, medium- and high-voltage power cables, ACSR/AAC/AAAC overhead conductors, control cables and steel wire ropes.
Modern models achieve rotor speeds of 400–1,200 rpm and line speeds of 100–230 m/min while maintaining tension variance within ±2% and lay-length accuracy better than ±1%. This performance directly supports IEC 60228 Class 2 conductors and meets the dimensional and electrical requirements of IEC 60502 power cables.
Technological Process For Tubular Stranding Machine
- Pay-off — Single or batch loading from pay-off drums (optional hoist system).
- Wire entry into seamless steel tubular cage — Smooth, low-friction path.
- True 100% back-twist stranding — Rigid rotor rotates at high speed while bobbins remain orientation-fixed.
- Constant tension control — Band-type brakes or optional German hysteresis brakes with electromagnetic compensation.
- Independent servo-driven pulling capstan — Precise synchronization and lay length control.
- Finished stranded conductor — Ready for insulation, compaction, taping or armoring.
The tubular design ensures perfect mechanical/electrical synchronization, low noise and reliable continuous 24/7 production.
How Does a Tubular Stranding Machine Work? Core Process and True 100% Back-Twist Principle
The tubular stranding machine consists of a seamless steel rotating tube (cage), internal bobbin cradles, central pay-off, closing die, dual-wheel or single-wheel capstan, and take-up unit. Individual wire bobbins are loaded inside the tube. As the tube rotates at high speed, the wires are laid helically around a central core or around each other. Because the bobbins remain orientation-fixed relative to the ground (true back-twist), each wire experiences zero net torsion. The result is a stress-free conductor with superior flexibility, fatigue resistance and electrical uniformity.
Typical process sequence:
- Pay-off (stationary or driven, single or batch loading with optional hoist).
- Wire entry through low-friction guides into the seamless steel tube.
- High-speed helical laying with constant tension control (band brake, magnetic particle or hysteresis brake).
- Closing and optional compaction at the die.
- Precise pitch control via independent servo-driven capstan.
- Take-up onto PN1250–PN2000 drums.
Line speeds of 120–200 m/min are routine for 7-wire and 12-wire constructions; higher-bay machines (18–36 bobbins) handle multi-layer ACSR cores and steel strands at lower but still productive speeds.
Core Technical Advantages & Operational Excellence
True 100% Back-Twist Technology
The tubular cage maintains bobbin orientation during high-speed rotation, completely eliminating internal torsional stress in the wires. This results in conductors with superior flexibility, excellent electrical performance, and enhanced long-term fatigue resistance — a significant advantage over non-back-twist or planetary stranders.
High-Speed Rigid Rotating Tube
The seamless steel tube is supported by large heavy-duty precision bearings with an automatic pump lubrication and cooling system. This ensures stable, low-noise, and vibration-free operation even at rotor speeds up to 1200 rpm, supporting high-volume production with minimal maintenance.
Precise & Stable Tension Control
Band-type brakes or optional German hysteresis brakes with electromagnetic compensation maintain constant wire tension from full to empty bobbin. This reduces wire breakage, minimizes scrap, and ensures consistent lay length and conductor quality throughout the production run.
Independent Servo Drive & Intelligent Control
The main rotor, pulling capstan, and take-up unit are driven independently by servo motors. The advanced HMI + PLC control system allows easy pre-setting of stranding pitch, automatic tension compensation, and full-line synchronization with real-time monitoring.
Heavy-Duty Construction & Safety Features
Designed for continuous 24/7 operation, the machine handles copper and aluminum wires from 0.8 mm to 5.0 mm as well as steel wires. Safety features include wire-break detection and door-open stoppage for operator protection.
Compared with planetary or drum-type stranders, the tubular design generally offers higher output, lower scrap rates, better compaction, quieter operation, and reduced maintenance requirements.
Technical Specifications
| Model | Configuration | Pay-Off Drum (mm) | Take-Up Drum (mm) | Copper Wire (mm) | Aluminum Wire (mm) | Rotor Speed (rpm) | Line Speed (m/min) | Main Motor Power (kW) |
|---|
| RLB-50 | 7B / 12B | 500 | 1250 | 0.8–3.2 | 1.2–4.0 | 1200 / 850 | 120 | 75 / 130 |
| RLB-56 | 7B / 12B | 560 | 1600 | 1.0–3.6 | 1.4–4.5 | 1000 | 120 | 75 |
| RLB-63 | 7B / 12B | 630 | 1800 | 1.2–4.0 | 1.6–5.0 | 900 | 120 | 95 |
Custom configurations and higher-capacity models available upon request.
Reel Size vs Performance Reference
(typical for high-speed tubular configurations; exact values depend on final engineering)
Reel Size Φ200–Φ500 mm — Max rotation speeds decrease progressively with more bays (6B → 36B). Single wire diameter ranges:
- Aluminum: Φ0.8–4.0 mm
- Copper: Φ0.6–4.0 mm
- Steel: Φ0.2–3.0 mm
Higher bay counts (18B–36B) commonly used for steel wire rope or multi-layer ACSR core production. Full data tables available in downloadable PDF.
Optional configurations: 6/12/18/24/30/36 bay, magnetic particle or hysteresis brakes per bobbin, integral core pay-off for zero-twist core presentation, regenerative drive/UPS systems, soundproofing packages.
Tubular vs Planetary vs Rigid Frame Stranding Machines: Technical Comparison
| Parameter | Tubular Strander | Planetary Strander | Rigid Frame Strander |
|---|
| Typical rotor speed | 400–1,200 rpm | 200–600 rpm | 300–800 rpm |
| Line speed | 100–230 m/min | 50–120 m/min | 40–100 m/min |
| Back-twist | True 100% | 100% | Usually 0% |
| Best conductor range | 1.5–400 mm² (Cu/Al), steel rope | Fine to medium, optical, control | Large power, ACSR, 61–91 wire |
| Noise & vibration | Low (heavy bearings + oil cooling) | Medium | Medium-high |
| Compaction & fill factor | Excellent | Very high | High |
| Maintenance intensity | Lower (centralized lubrication) | Higher (planetary gears) | Medium |
| Primary application | High-volume power & control cables | Flexible & precision conductors | Heavy overhead & large cross-section |
Key Technical Parameters and Selection Guide
| Model Example | Bobbin Config | Single Wire Ø (Cu/Al) | Max Stranded Ø | Rotor Speed (rpm) | Line Speed (m/min) | Main Motor (kW) | Pay-off / Take-up |
|---|
| Typical 500 series | 6B / 12B | 1.2–5.0 / 1.5–5.0 mm | 15–21 mm | 500–800 | 150–200 | 45–75 | PN500 / PN1600 |
| Typical 630 series | 7B / 12B / 18B | 1.5–5.0 / 1.8–5.0 mm | 21–35 mm | 400–700 | 100–180 | 75–110 | PN630 / PN1600–2000 |
| High-speed 400–450 | 6B–18B | 0.8–4.0 mm | 12–25 mm | 800–1,300 | 160–230 | 55–95 | PN400–500 / PN1250–1600 |
Primary Applications
- Power Cables: 7/12/19-wire stranded copper or aluminum conductors for low- and medium-voltage cables
- Overhead Conductors: AAC, AAAC, ACSR, and steel-cored aluminum conductors
- Steel Wire Stranding: Galvanized steel strands for ACSR cores and guy wires
- Specialty Conductors: Compressed or sector-shaped conductors for high-current applications
- Optional integration with filling and taping devices for complete multi-layer cable production lines
Why Choose Our Tubular Stranding Machine?
- Superior Conductor Quality — True 100% back-twist delivers stress-free wires with excellent flexibility and electrical performance.
- High Productivity & Low Total Cost of Ownership — Stable high-speed operation up to 1,200 rpm, minimal vibration, reduced maintenance.
- Reliable Tension & Process Control — Advanced braking and servo systems ensure consistent quality from full to empty bobbin.
- Vision 2030 Ready — High-efficiency, low-maintenance technology supporting local cable manufacturing and power infrastructure development in Saudi Arabia and the GCC.
- Full Local Support: Turnkey installation, operator training, remote diagnostics and spare parts availability in the region. Long-term partnership approach with customization and upgrade paths.
Key Takeaways for Cable Manufacturers and Procurement Engineers
Tubular stranding machines remain the most productive solution for high-volume, medium-size concentric conductors when true back-twist, low residual stress and continuous high-speed operation are required. Correct model selection based on wire diameter range, bobbin count, rotor speed and tension-control technology directly determines conductor quality, scrap rate and total cost of ownership. Modern units equipped with servo drives, centralized lubrication and digital pitch control meet current IEC/GB requirements and support long-term production of reliable power and overhead cables.
Tubular Stranding Machine
High-speed Tubular Stranding Machine with 100% back-twist technology for 7/12/19 wire copper, aluminum and steel conductors. Rotor speed up to 1200 rpm, constant tension control, HMI+PLC automation.
Product SKU:
TUBULAR-50 / TUBULAR-63
Product Brand:
Reliable Machinery
Product Currency:
USD
Product Price:
Contact for Quote
Product In-Stock:
InStock
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