Types of Common Faults of Fringe Mill and Troubleshooting Methods for Edge Folding and Rolling Machines them
As a necessary equipment in textile, packaging and printing industries, the folding machine has the characteristics of high automation and fast operating speeds, so it is necessary to eliminate faults in time. In this paper, the typical faults of three key modules ofmechanical transmission, pneumatic control and electrical system are summarized,and a standardized solution is put forward.
I. Mechanical Transmission System Faults
1.1 Folding Accuracy Deviation
Typical Manifestations: dislocation of the hem, size inconsistency, wrinkle accumulation.
Root causes:
Insufficient suction cup pressure: When air supply pressure is less than 0.4 MPa, vacuum suction cups does not grip the fabric reliably, causing material to slide. A case of a face-mask line showed that a air compressor failure reduced pressure to 0.3 MPa leading to 30% of product rejection per day.
Fold template wear: Long-term use can result in displacement of positioning reference points on the template. In the case of linen folding machines, a 0.5mm template wear can produce a 5mm hinge error.
drive belts loosening: servo motors synchronously relaxes with folding mechanism, causing speed fluctuations. A rolling case showed a 2% increase in hinge speed variation with 15 mm belt overhang.
Solutions:
Install digital pressure gauges for real-time monitoring of air supply with 0.4-0.6 MPa alarm thresholds
Use of laser positioning systems calibration templates every 500 working hours
Dynamic Belt Tension adjustment mechanisms Based on silicone grease Treatment on Pulley Surface
1.2 Abnormal Material Jamming
Typical Manifestations: Material accumulation and equipment overload protection activation
Root causes:
Static adhesion: Synthetic fibers such as polyester can generate static electricity during high-speed conveyance. The mask line line measured 8 kV of static electricity, resulting in 40% material adhesion.
Guide plate misalignment: when guide plate clearance is less than 1.2× material thickness, the frequency of interference of packaging machine box increases twice.
Photoelectric sensor contamination: dust accumulation reduces signal strength. A linen folder case demonstrated a 25% false activation rates when sensor sensitivity dropped to 70%%.
Solutions:
Install ionizing air blowers to eliminate static electricity and maintain 45-65% RH environmental humidity
Use adjustable guide plate mechanism with 0.1 mm precision tuning
Implementation oflevel 3 sensor cleaning protocols: daily briefing, weekly rubbing alcohol and monthly accuracy calibration
ii. Pneumatic Control System Faults
2.1 Pressure Fluctuations
Typical Manifestations: Sluggish folding actions incomplete cylinder strokes
Root causes:
Air compressor pressure instability: The activation frequency of safety valve increases fivefold in a rolling mill box with total pressure exceeding 0.6 MPa, causing ±0.15 MPa fluctuations.
Leakage: The main leakage points is the failure of pipe joint seal. Equipment tests revealed that a hole with a diameter of 1mm would result in a loss of compressed air of 0.3 cubic metres per hour.
Solenoid valve failures: Statistical analysis of linen folder shows that 38% of pneumatic faults are due to coil burnouts and 27% to valve core failure.
Solutions:
Implementation of phased pressure control: 1 fold 0.35 MPa, 3 fold 0.55 MPa, 5 fold 0.6 MPa.
ultrasonic detectors detectors Locate leaks points and replace metal seal joints
Establishment of preventive maintenance: replacement of coil every 2,000 hours and monthly cleaning of valve body
2.2 Blowing System Failure
Typical Manifestations: uneven folding, fabric wrinkling
Root causes:
Blowout stick blockage: According to one face-mask line, 30% of products can become wrinkled due to clogged air holes.
synchronization errors solenoid valve: When the timing difference of dual blowout valve is greater than0.1 seconds, the linen jacket shows a material deviations of 8 mm.
Moisture contamination: Unfiltered compressed air caused 40% of steel cylinders in mill boxes to rust.
Solutions:
Installation of 0.01 μm filters with automatic drainage pipe
Using PLC synchronization module, ± 0.05 second timing tolerance
Daily blow bar cleaning using 0.6 MPa reverse air pulses
III. Electrical Control System Faults
3.1 Communication Interruptions
Typical Manifestations: Touchscreen display abnormalities and program stops
Root causes:
Inverter phase loss: A linen folder case shows that due to phase loss operation, the motor temperatures reached 95°C, triggering thermal protection.
Limit switch Failure: When the left limit switch pressure plate breaks, the device recorded a fold rate of 100%.
Grounding interference: When grounding resistance of a mill exceeds 4 omega, the communication error triples.
Solutions:
Install phase sequence protectors with 0.5 second phase 0.5-second phase-loss cutoff
Replacement of mechanical limit switches with magnetic limiter switches to improve reliability
Implementation of a dedicated grounding system ≤ 1 omega resistance
3.2 Sensor Failures
Typical Manifestations: false activation and false counting
Root causes:
Photovoltaic pollution: A mask line showed 15% of counting errors come from sensor pollution.
Encoder misalignment: When a counter encoder connection shaft breaks, a linen folder recorded a 100% fold layer error.
Tachometer wheel slippage: A rolling chassis has a rotational error of 25% when material rotational speed exceeded the rotational tachometer design capacity capacity by 120%.
Solutions:
Use of IP67-rated sensors with automatic cleaning systems
Implement redundant encoder design Based on Real-Time Master Conformity Comparison
Install tension control systems to maintain ±5% material tension tolerance
IV. INTRODUCTION Typical Fault Handling
Take the Five Replication Board Inaction:
Preliminary inspection: 0.6 MPa air pressure, solenoid valve energization and copying plate bracket verified
Depth Diagnosis: Measurement of elastic band tension (standard 12±1 N) and cylinder stroke (standard 50±0.5 mm)
Problem identification: detection and seizure of copying plate bearing with dried grease
Correction: replacement of bearings, application of high temperature lithium resin, adjustment cylinder position
Validation: 20 tamper-free drying cycles and ±0.5 mm folding accuracy were confirmed during material testing
V. Preventive Maintenance system
Daily checks:
Clean all photoelectric sensors (lint-free cloth + alcohol)
Verify air supply pressure (digital gauge recording)
Testing emergency shutdown features
Weekly checks:
Measurement of drive belt tension (tension gauge)
Lubricating moving components (high-temperature lithium grease)
Calibration folding template (laser positioning verification)
Monthly checks:
Integrated wire inspection (megohmmeter insulation testing)
Replacement air compressor filters (differential pressure monitoring)
Update PLC program backup (prevent data loss)
A large textile enterprise has adopted the system fault management approach, increasing the lead time from 800 MTBF to 1,500 hours, while increasing overall efficiency of the equipment by 22%. Practice shows that standardized fault handling and preventive maintenance greatly reduce unplanned downtime and ensure continuous stability of the production line.
