Shaftless Mill Roll Stand For Corrugated Line FAQ Guide

Welcome to read this article, which is a comprehensive guide on the Shaftless Mill Roll Stand for corrugated cardboard production lines. If you are seeking any
information about the Shaftless Mill Roll Stand for corrugated line, you can find it all in this article. So please continue reading to learn more.

1. What is a Shaftless Mill Roll Stand?

The shaftless mill roll stand is a core auxiliary equipment in corrugated board production lines. Its main function is to carry roll paper through a shaftless support method and realize stable unwinding, providing continuous raw materials for subsequent processes such as corrugation forming and interlayer bonding. As a high-efficiency type of mill roll stand, it further improves the continuity and stability of the production line through mechanical structure optimization.

2. Why does the production line need a shaftless mill roll stand?

The value of the shaftless mill roll stand lies in the triple guarantee of production continuity, operational safety, and product quality.

2.1 Enhancing production continuity

The dual-station shaftless mill roll stand can realize non-stop paper change, and the efficiency varies by scenario: about 90 seconds when there is no residual roll and the operation is skilled, and 150 seconds when residual roll processing is included. With 4-8 paper changes per day, compared with manual paper change (30-60 minutes of shutdown each time), it can reduce a lot of downtime and significantly improve production line utilization.

2.2 Improving operational safety

A single roll of raw paper usually weighs 2-5 tons. The shaftless mill roll stand can avoid extrusion and falling accidents that may occur during manual handling through mechanical fixing (alloy chuck clamping). This not only reduces the risk of work-related injuries but also complies with general mechanical safety specifications in the industry.

2.3 Stabilizing product quality

The precise tension control of the shaftless mill roll stand (steady-state fluctuation ≤±10N, suitable for thick paper under high-speed working conditions) can reduce stretching deformation or wrinkling of raw paper. In actual production, under the same conditions of raw paper quality, corrugating roll precision, etc., the flatness of corrugated board with the shaftless mill roll stand is improved by more than 20% compared with manual paper feeding.

3. What core components constitute a shaftless mill roll stand?

The stable operation of the shaftless mill roll stand relies on the cooperation of various core components, including the main frame, support mechanism, drive system, control components, and auxiliary devices.

3.1 Main Frame

The main frame is generally welded with Q235 (ASTM A36) or Q345 (ASTM A572 Grade 50) steel to provide rigid support for the overall structure.

3.2 Support Mechanism

The support mechanism is shaftless, equipped with an alloy chuck, and has two gears to adapt to the paper core. It can cover the full range without replacing accessories, meeting the needs of different specifications of raw paper.

3.3 Drive System

The drive system is divided into two types according to different types:

• Electric shaftless type: composed of a drive motor (servo motor or asynchronous motor + frequency converter) and a reducer;
• Hydraulic shaftless type: including a hydraulic pump station (controlling the action of the clamping arm) and a drive motor (providing unwinding power).

3.4 Control Components

The control components are the key to ensuring precision, including tension sensors (detection accuracy 0.1N), electromagnetic brakes (response time ≤0.2s), and an operation panel with an emergency stop button. The control accuracy varies for different papers:

• Thick paper: steady-state tension fluctuation ≤±10N (under 300m/min working condition), which is better than the average level of international similar equipment (±15-20N);
• Thin paper (≤120g/㎡): fluctuation is ±10-12N under high-speed working conditions, and the stability is improved by 40% compared with international traditional equipment (±18-25N);
• Medium-thick paper (120-250g/㎡): fluctuation ≤±8N below 200m/min (international similar equipment is mostly ±12-15N), which may increase to ±10N when exceeding this speed, with a dynamic response time ≤200ms.

4. What types of shaftless mill roll stands are there? What are their technical characteristics?

Shaftless mill roll stands are mainly divided into electric and hydraulic types, and their efficiency is significantly better than traditional shaft-type ones.

4.1 Electric Shaftless Mill Roll Stand

• Drive method: mid-to-high-end models are driven by AC servo motors (rotational speed accuracy ±1rpm); economical models use asynchronous motors + frequency converters (rotational speed accuracy ±3-5rpm, affected by load);
• Load-bearing range: 2-3 tons/roll (maximum paper diameter Φ1600mm);
• Adaptable paper width: ≤1.8m, ultra-wide (1.8-2.2m) requires customized reinforced cantilever (load capacity increased to 4 tons);
• Control method: basic type uses knobs + buttons (with digital tension meter); intelligent type can be connected to the production line PLC system;
• Advantages: low energy consumption, noise 65-70dB (1m distance, under load condition, meeting EU noise limit standards), suitable for production lines with a daily output of 50,000-100,000 ㎡ (≤100m/min low-speed lines), especially suitable for raw paper for food and pharmaceutical packaging (≤120g/㎡ thin paper is recommended to be equipped with closed-loop tension control).

4.2 Hydraulic Shaftless Mill Roll Stand

• Hydraulic system function: controlling the lifting of the clamping arm, clamping/opening of the chuck, and lateral movement of the clamping arm;
• Drive method: the hydraulic system is responsible for clamping/lifting, and the servo motor provides unwinding power to ensure synchronization with the production line speed;
• Load-bearing range: 3-5 tons/roll;
• Control method: standard hydraulic reversing valve + electric control buttons; upgraded models can be connected to the production line PLC system;
• Advantages: stable clamping force, adapting to paper core ellipticity ≤3mm deformation. Clamping arm action response: ≤0.5 seconds under normal temperature (25-35℃) no-load condition; under full load (5 tons) or oil temperature ≥50℃, the response time may be extended to 0.8-1.2 seconds (need to control the oil temperature below 40℃ through the oil temperature cooling system to optimize the response). It is suitable for production lines with a daily output of 80,000-150,000 ㎡, adapting to thick paperboards for home appliances and heavy packaging (≥250g/㎡).

4.3 Common Advantages of Shaftless Models

• Paper change efficiency: 90 seconds for single roll replacement (without residual roll) or 150 seconds (with residual roll), significantly better than traditional shaft-type ones;
• Compatibility: adapting to paper cores in different gears without changing accessories;
• Safety: the chuck is equipped with overload protection (hydraulic type automatically unloads when overpressure; electric type is protected by current detection).

5. What is the working principle of the shaftless mill roll stand?

The working process of the shaftless mill roll stand is simpler, and the core is to realize stable unwinding through the cooperation of machinery and electronic control:

① Set parameters (tension, rotational speed) on the operation panel → ② The electric/hydraulic system drives the chuck to automatically center and clamp the paper core → ③ The motor unwinds the raw paper at the set speed → ④ The tension sensor feeds back in real-time, dynamically adjusts the motor output torque to ensure stable unwinding of the raw paper.

6. How to scientifically select a suitable shaftless mill roll stand?

Selection should be based on production capacity and raw paper characteristics to avoid “overkill” or “insufficient capacity”.

6.1 Selection by production capacity scale

• Micro line (daily output ≤10,000 ㎡)
  • Adaptable scenario: experimental lines, sample lines, or small township factories
  • Recommended model: economical electric single-station mill roll stand
  • Core configuration: asynchronous motor + open-loop control, load capacity 1-2 tons/roll, adaptable paper width ≤1.6m
  • Cost advantage: small equipment investment, low energy consumption

• Small line (daily output 10,000-30,000 ㎡)
  • Adaptable scenario: community-type packaging factories, food-grade thin paper dedicated lines
  • Recommended model: electric intelligent single-station or dual-station
  • Technical points: servo motor drive (rotational speed accuracy ±1rpm), standard closed-loop tension control (fluctuation ≤±10N), adaptable to Φ1200mm paper rolls
  • Efficiency improvement: paper change time ≤120 seconds (without residual roll), suitable for continuous production of ≤120g/㎡ thin paper

• Medium line (daily output 30,000-80,000 ㎡)
  • Adaptable scenario: regional packaging enterprises, home appliance parts production lines
  • Grading recommendation:
    • Medium-low speed line (≤200m/min): electric intelligent dual-station
    • Medium-high speed line (200-300m/min): basic hydraulic model
  • Cost balance: electric models have low initial investment, hydraulic models have low long-term maintenance costs

• Large line (daily output 80,000-150,000 ㎡)
  • Adaptable scenario: group packaging bases, heavy paperboard production lines
  • Technical scheme:
    • Standard type: dual-station hydraulic mill roll stand (load capacity 5 tons/roll, adaptable to Φ1800mm large-diameter paper rolls)
    • Upgraded type: integrated pre-drive system (synchronization error with production line speed ≤±0.5%)
  • Efficiency data: paper change time ≤90 seconds (including residual roll processing), adaptable to high-speed operation of 250-400g/㎡ thick paper

6.2 Selection by raw paper parameters

7. How to solve common faults of shaftless mill roll stands?

Most faults encountered in production are related to maintenance or parameter settings. Timely handling can reduce downtime.

8. How to maintain the shaftless mill roll stand?

Scientific maintenance can extend the service life. It is recommended to operate in three cycles: daily, regular, and annual.

8.1 Daily Maintenance (Daily)

• Clean paper scraps on the chuck jaws, then apply grease;
• Check brake pad wear (replace when the remaining thickness < 2mm);
• Observe the oil level of the hydraulic system (hydraulic type, keep it at 1/2-2/3 of the liquid level gauge).

8.2 Regular Maintenance (Monthly)

• Electric type: check the carbon brushes of the wound asynchronous motor (replace when the remaining length ≤5mm); check the encoder connection of the servo motor; squirrel-cage type does not need to check carbon brushes;
• Hydraulic type: replace the return oil filter element, check for pipeline leakage;
• Clean the tension sensor (to avoid dust affecting accuracy);
• Laser calibrate the equipment level (±0.5mm/m).

8.3 Annual Overhaul

• Check for cracks at the frame welds (conduct dye penetrant testing if necessary);
• Calibrate the tension control system (error ≤±5%);
• Replace hydraulic oil for hydraulic types.

9. What are the precautions for operation and storage of shaftless mill roll stands?

9.1 Safety Operation Taboos

• Do not reach into the working area when the chuck is rotating;
• It is strictly forbidden to start the hydraulic type without oil (which will burn the pump body);
• Do not overload: due to the cantilever structure of the shaftless type, it is recommended that the actual load ≤80% of the rated value (to avoid chuck deformation).

9.2 Long-term Storage Requirements

• If idle for more than 3 months, release the chuck pressure (to prevent seal deformation);
• For electric types, power on for 30 minutes monthly (to prevent motor dampness);
• For hydraulic types, release the oil pressure to 0MPa (to avoid long-term pressure on the pipeline).

Through reasonable selection, standardized operation, and regular maintenance, the service life of the shaftless mill roll stand can reach 8-10 years, and the failure shutdown rate can be controlled within 0.5%, providing stable support for the corrugated board production line.

JEYTOP Corrugated Carton Machinery is rooted in China’s core industrial cluster of corrugated carton machinery. Relying on the whole industrial chain resources from core steel, precision components to assembly technology, it realizes efficient local collaboration from raw material procurement to complete machine production. This industrial depth advantage enables us to shorten the production cycle by 15%-20% compared with the industry average while maintaining strict quality control (full-process traceability of core components). The optimization of supply chain costs brings higher cost performance, providing solid support for customers to balance performance and investment.

JEYTOP shaftless mill roll stands have multiple series of models, covering all scenario needs from economical to high-performance. Whether it is cost optimization for small and medium-capacity lines, or efficiency improvement for complex working conditions such as high-speed thick paper and precision thin paper, they can help customers reduce 20%-30% of shutdown losses.

All models have reliable operation stability, and some models support practical functions such as dual-station paper change and intelligent monitoring, with optional precision components and diagnostic modules. For special production scenarios, customized solutions can be provided according to customers’ specific needs (such as width, load capacity, local voltage standards, or safety protection upgrades). Relying on the rapid response capability of the whole industrial chain, the customization cycle is further shortened to ensure rapid adaptation to local production lines.

As a national high-tech enterprise with 15 years of industry experience, JEYTOP has provided customized solutions for packaging enterprises around the world (covering home appliances, food and other fields), serving thousands of carton factories, covering all types of customers from small and medium-scale production to large-scale intensive production lines. The shaftless mill roll stand series has passed CE and ISO9001 certifications, providing one-stop full-process services from equipment selection evaluation, installation and commissioning to operator training to ensure stable and efficient operation of the production line.

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