How a Ropeless Tail Threading System Improves Paper Machine Runnability

As paper machine speeds continue to increase, conventional rope-based tail threading systems can become more difficult to operate reliably.Threading ropes may wear, slip, break, or lose synchronization with the paper machine. At the same time, manual tail threading becomes more demanding because operators must react quickly and guide the paper tail accurately through different machine sections. For high-speed paper machines, these limitations can increase threading time, increase operator workload, and reduce overall machine runnability. A ropeless automatic tail threading system is designed to transfer the paper tail through the machine without relying on conventional threading ropes. By combining air blowing, vacuum conveying, guiding devices, and automatic control, the system can create a more stable and repeatable threading process. This article explains why tail threading becomes more challenging as paper machine speed increases, how a ropeless tail threading system works, where it can be applied, how to select the right system configuration, and what paper mills should consider when choosing a supplier.

Main Topics：

1.Why conventional tail threading becomes more difficult at higher paper machine speeds

2.What is a ropeless tail threading system?

3.How a ropeless tail threading system works

4.Typical application positions on a paper machine

5.How to select the right ropeless tail threading solution

6.What to consider when selecting a supplier

7.Conclusion

8.FAQ

1. Why Conventional Tail Threading Becomes More Difficult at Higher Paper Machine Speeds

Ropeless automatic tail threading system installed on a paper machine

Tail threading is one of the most important operations during paper machine start-up and after a sheet break. The paper tail must pass through several sections of the paper machine before the full sheet can be spread to operating width. On a conventional system, threading ropes are often used to carry the paper tail through part of this route. However, as machine speed increases, several operating problems may become more noticeable. Rope Wear, Slippage, and Breakage. Threading ropes operate under continuous tension and repeated bending.

During long-term operation, the ropes may experience: surface wear; elongation; loss of tension; slipping from rope sheaves;

contamination; mechanical damage; breakage.

Any of these conditions may reduce threading reliability. If the threading rope slips or breaks during the threading process, the paper tail may drop, wrap around a roll, or need to be threaded again manually. This increases downtime and operator workload. Increased dependence on operator skill. At low machine speeds, operators may have more time to manually guide or correct the paper tail. At higher speeds, the available reaction time becomes much shorter.

The operator must respond quickly to: paper tail position; tail stability; air-blow timing; roll speed; threading direction; sheet break conditions.

This means that the threading result may depend heavily on the operator's experience. A more automated system reduces this dependence and makes the threading process more repeatable. Impact on Paper Machine Runnability. Long or unstable threading cycles can reduce effective production time.

Repeated threading attempts may also cause: additional broke; increased start-up time; higher operator workload; greater risk of paper wrapping around rolls; more production interruptions.

For mills operating high-speed machines or frequent grade changes, reducing threading time can therefore improve overall machine availability.

2. What Is a Ropeless Tail Threading System?

A ropeless tail threading system transfers the paper tail through selected sections of the paper machine without using conventional threading ropes as the main conveying method.

Depending on the machine layout, the system may combine: air blowing devices; tail lifting devices; guiding air blades; vacuum belt conveyors; rotating or movable threading devices; pneumatic actuators; electrical control systems; HMI operator interfaces.

The exact configuration depends on the paper machine section and threading route. A ropeless system is therefore not a single standardized machine that can simply be installed on every paper machine. It normally requires customized engineering according to the paper machine layout.

3. How a Ropeless Tail Threading System Works

Vacuum belt conveyor and air guiding devices used for ropeless tail threading. A typical ropeless threading process can be divided into several stages.

Step 1-Separate or Lift the Paper Tail

The paper tail must first be separated from the roll, dryer cylinder, felt, or fabric surface. Compressed air is commonly used to lift or guide the tail away from the surface.

Depending on the machine section, the system may use: stripping air pipes; transfer air blowers; air nozzles; guide plates; air blowing blades.

The purpose is to create a stable tail trajectory before the paper enters the next threading device.

Step 2-Guide the Tail into the Conveyor

After the paper tail is lifted, air flow and guide plates direct it toward the vacuum belt conveyor or the next transfer point. The geometry of this area is particularly important.

The paper tail must enter the conveyor at the correct: angle; position; speed; tension condition. 

If the approach angle is unstable, the tail may fold, flutter, or miss the conveyor.

Step 3-Vacuum Belt Conveying

The vacuum belt conveyor is one of the key components of the ropeless threading system. Negative pressure holds the paper tail against the moving belt while the belt transfers it toward the next threading position. The conveyor speed must be properly matched with the paper machine operating speed.If the conveyor speed is too low, the tail may buckle or become unstable. If it is too high, excessive tension may be introduced into the tail. Therefore, conveyor speed control is an important part of the system design.

Step 4-Transfer to the Next Machine Section

At the end of the conveyor, the paper tail may be transferred by: air blowing; guide plates; another vacuum conveyor; a rotating threading device; the existing threading system of the paper machine.

Several devices can be installed in sequence depending on the threading route.

Step 5-Complete Full-width Sheet Spreading

After the paper tail reaches the downstream section and runs stably, the operator or automatic system can gradually spread the sheet to full width. At this point, the threading operation is completed.

4. Typical Application Positions on a Paper Machine

Application positions of ropeless tail threading equipment on a paper machine

The brochure configuration shows several typical application positions.

Press Section

In the press section, the paper tail may need to be separated from the felt or roll and transferred toward the next machine section. Air blowing devices and transfer guide plates can be used to control the paper tail trajectory. For this application, stable tail separation and correct transfer angle are especially important.

Dryer Section

The dryer section is one of the most common areas for ropeless tail threading. The system may be installed between dryer groups or around upper and lower dryer cylinders.

Because dryer-section temperatures are high and the threading route can be complex, the design must consider: available space;dryer-cylinder arrangement; tail path; air flow; heat resistance; access for maintenance.

QCS Area

The paper tail may also need to pass through or around the QCS area. In this position, the available installation space can be limited. A compact vacuum conveyor or rotating threading device can help guide the tail through the section without interfering with the scanner or surrounding equipment.

Entry to Existing Rope Threading System

In some retrofit projects, the entire paper machine does not need to be converted to ropeless threading. Instead, a ropeless device can be used to transfer the paper tail into the existing rope-threading section. This hybrid arrangement can reduce the scope of modification while improving the most difficult part of the threading process.

5. How to Select the Right Ropeless Tail Threading Solution

Customized ropeless tail threading system layout for a paper machine

Paper machine structures vary significantly. A system that works well on one machine cannot necessarily be copied directly to another. In engineering practice, the following parameters should normally be confirmed before finalizing the design.

Paper Machine Speed

Machine speed has a major influence on tail stability.

As speed increases, the paper tail becomes more sensitive to: air turbulence; conveyor speed mismatch; incorrect transfer angle; tail flutter; insufficient vacuum holding force.

The system must therefore be designed according to the actual operating speed, not only the design speed of the paper machine.

Paper Grade and Basis Weight

A lightweight paper tail behaves differently from a heavy board tail.

Important differences include: stiffness; tensile strength; air resistance; moisture content; tail stability.

The air volume, vacuum force, guide angle, and conveyor configuration should therefore be matched to the paper grade.

Tail Width

The required tail width depends on: paper grade; basis weight; machine speed; threading distance; transfer method. 

Threading Route

The complete threading route should be analyzed before the system is designed.

Important questions include:

Where does the paper tail start?

Which rolls or cylinders must it pass?

Where should the paper tail be lifted?

Where should vacuum conveying be used?

Where should air blowing be used?

Which existing paper machine equipment can be retained? 

A 3D layout or detailed CAD drawing is therefore very useful during engineering.

Compressed Air Supply:

Insufficient air supply can reduce the performance of lifting and guiding devices.

Available Installation Space

Retrofit projects often have limited space.

The design must consider: machine frames; walkways; existing pipes; cable trays; safety guards; maintenance access; roll replacement space.

The system should improve threading without creating new maintenance problems.

Key Components of a Ropeless Tail Threading System

The Meixin brochure shows several typical system components.

Vacuum Belt Conveyor

The vacuum belt conveyor holds and transfers the paper tail through the machine.

Key design factors include: conveyor speed; belt material; vacuum capacity; belt tracking; conveyor angle; maintenance access.

The transfer air blowing blade uses compressed air to guide the paper tail from one position to another. Its angle and distance from the paper tail directly affect transfer stability.

Guiding Transfer Air Blowing Blade

This device helps control the direction of the tail and reduces random flutter during transfer. It is particularly useful where the tail must change direction.

Pneumatic Control Cabinet

The pneumatic cabinet controls compressed-air functions such as: air blowing; tail lifting; pneumatic cylinders; switching valves.

Electrical Control Cabinet

The electrical cabinet controls the motors, interlocks, signals, and automatic sequence.

HMI

The HMI allows operators to monitor system status and operate the threading sequence. Depending on the project, the control system can also be integrated with paper machine signals.

Benefits of Ropeless Tail Threading

The main benefits highlighted in the product brochure include shorter threading time, higher threading efficiency, reduced dependence on operator skill, lower manual workload, and more stable threading.

Shorter Tail Threading Time

A stable and repeatable automatic sequence can reduce repeated manual threading attempts. This helps shorten the time between a sheet break and the restoration of normal production.

Reduced Operator Workload

Operators do not need to manually guide the paper tail through every machine section. This reduces repetitive manual operations.

Improved Threading Stability

The combination of controlled air flow, vacuum conveying, and mechanical guidance provides a more repeatable threading path.

Improved Paper Machine Availability

Reducing threading time can increase productive machine operating time. The benefit becomes more significant on machines with frequent sheet breaks or grade changes.

Improved Operational Safety

Reducing manual intervention near moving rolls, dryer cylinders, and other rotating equipment can help reduce operator exposure to hazardous areas. The actual safety design should always comply with the paper mill's operating procedures and local machine-safety requirements.

6. What to Consider When Selecting a Ropeless Tail Threading Supplier

Customized Engineering Capability

Ropeless tail threading systems require close integration with the paper machine.

The supplier should be able to provide: site measurement; CAD layout design; 3D interference checking; threading-path analysis; customized equipment design.

Understanding of Paper Machine Operation

The supplier should understand not only mechanical equipment, but also: paper tail behavior; dryer-section operation; press-section operation; machine speed; paper grade characteristics; threading sequence.

This helps avoid a system that is mechanically complete but difficult to operate in real production.

Installation and Commissioning

The final threading performance often depends on site adjustment.

Typical commissioning items include: air pressure; air-blowing direction; conveyor speed; vacuum level; guide angle; transfer position; control timing.

Therefore, experienced commissioning support is important.

Long-term Maintenance

The supplier should also consider: belt replacement; bearing maintenance; nozzle inspection; pneumatic valve maintenance; vacuum-system cleaning; electrical troubleshooting.

Easy maintenance is an important part of long-term equipment reliability.

7. Conclusion

As paper machine speed increases, tail threading becomes more demanding. Traditional rope threading can be affected by rope wear, slippage, breakage, and dependence on operator experience. A properly designed ropeless automatic tail threading system can use compressed air, vacuum conveying, guide devices, and automatic control to create a more stable and repeatable threading process. However, the system must be customized according to the actual paper machine.Paper grade, machine speed, tail width, threading route, available installation space, compressed-air supply, and existing equipment should all be evaluated before the final design is confirmed. Meixin can provide customized ropeless tail threading solutions for different sections of the paper machine, including the press section, dryer section, QCS area, and the transition to an existing rope-threading system. The product brochure also shows multiple installation configurations for these areas. If you are evaluating a ropeless tail threading retrofit, providing a paper machine layout drawing, operating speed, paper grade, basis weight, tail width, and current threading route can help the engineering team prepare a more targeted solution.

8. FAQ

Q: Can a ropeless tail threading system completely replace threading ropes?

A: It depends on the paper machine layout. Some projects can use ropeless threading through a complete section, while other projects use a hybrid arrangement in which the ropeless system transfers the tail into an existing rope-threading system. The final solution should be determined according to the actual threading route and retrofit scope.

Q: Can the system be installed on an existing paper machine?

A: Yes. Ropeless tail threading systems are commonly used for paper machine upgrades and retrofits. However, the available installation space, existing machine frames, roll arrangement, walkways, and maintenance access should be checked before final design.

Q: Is compressed air required?

A: In most configurations, yes. Compressed air is commonly used for tail lifting, blowing, guiding, and pneumatic actuation. The required pressure and flow depend on the system configuration and paper machine conditions.

Q: How is the paper tail held on the conveyor?

A: A vacuum belt conveyor uses negative pressure to hold the paper tail against the moving belt. The belt then transfers the paper tail to the next threading position.

Q: Does conveyor speed need to match paper machine speed?

A: Yes. The conveyor speed should be properly coordinated with the paper machine operating speed. Incorrect speed matching can cause excessive tail tension, slackness, folding, or unstable transfer.

Q: What information is required before designing a system?

A: Typical information includes: paper machine CAD layout; paper grade; basis weight range; operating and design speed; paper width; tail width; existing threading route; compressed-air conditions; available installation space; photos or videos of the current threading process.

Q: Can one system be used for different paper grades?

A: Within the designed operating range, the system can usually be adjusted for different grades by changing parameters such as conveyor speed, air flow, vacuum level, and control timing. However, very large differences in basis weight or machine speed may require different mechanical configurations or additional adjustment.

Q: Where can a ropeless tail threading system be installed?

A: Typical application positions include: press section; dryer section; QCS area; upper and lower dryer-cylinder groups; entry to an existing rope-threading system. The final installation position should be confirmed based on the paper machine layout and threading route.