Multi-Stage Haul-Off System (Low-Speed & High-Speed Units) for Precise Tension Control
Product Introduction
Tension control is a critical factor affecting product thickness uniformity, stretching orientation effectiveness, and final winding quality in PP strapping production. This production line utilizes a multi-stage haul-off system consisting of a low-speed three-roller haul-off unit (0-40 m/min), a high-speed five-roller haul-off unit (0-250 m/min), and multiple high-speed three-roller haul-off units, forming a stepped speed and tension control network. The low-speed unit stabilizes the nascent tape after extrusion, while the high-speed units provide precise tension adjustment after stretching and setting. Multi-stage haul-off combined with closed-loop speed control ensures constant, fluctuation-free tension across all sections, providing a solid foundation for high-precision, high-speed production.
Main Specifications
- Low-speed three-roller haul-off: φ268mm, face width 450mm, chrome-plated & polished, hardness HRC58-60, speed 0-40 m/min, motor 5.5KW
- High-speed five-roller haul-off: φ268mm, face width 450mm, chrome-plated & polished, hardness HRC58-60, speed 0-250 m/min, motor 15KW
- High-speed three-roller haul-off (multiple units): same specs, speed 0-250 m/min, motor 5.5KW
- Speed adjustment accuracy: ±1 m/min
- Control method: Inverter speed control, full-line closed-loop linkage
Technical Parameters
| Item |
Low-speed 3-roller |
High-speed 5-roller |
High-speed 3-roller |
| Roller Diameter |
φ268mm |
φ268mm |
φ268mm |
| Face Width |
450mm |
450mm |
450mm |
| Surface Treatment |
Chrome-polished |
Chrome-polished |
Chrome-polished |
| Hardness |
HRC58-60 |
HRC58-60 |
HRC58-60 |
| Speed Range |
0-40 m/min |
0-250 m/min |
0-250 m/min |
| Motor Power |
5.5 KW |
15 KW |
5.5 KW |
| Adjustment Accuracy |
±1 m/min |
±1 m/min |
±1 m/min |
Customer Questions & Answers
Why are both low-speed and high-speed haul-off units needed?
The low-speed unit stabilizes the nascent tape after extrusion and before stretching, preventing accidental deformation of not-fully-cooled tape. The high-speed units transport the stretched and set finished tape, meeting high line speed requirements. Stage-specific control optimizes tension matching at each section, improving overall stability.
What are the advantages of a five-roller haul-off over a three-roller one?
The five-roller structure provides a larger wrap angle and more uniform pressure distribution, offering stronger gripping force. This is especially beneficial for high-speed operation or smooth-surfaced PP tape, effectively preventing line speed fluctuations and tension spikes caused by slippage.
How is speed synchronization ensured among multiple haul-off units?
The entire line uses PLC closed-loop coordinated control. The operator sets the main line speed on the touch screen, and the system automatically calculates the speed ratios for each haul-off unit, precisely executed via inverters. Individual units can be fine-tuned independently to suit different draw ratios and process requirements.