What Are The Common Problems Of Slitting Machines?

In the process of cutting machine use, various problems often arise due to equipment structure, material properties, operating parameters and environmental factors. These problems not only affect production efficiency, but also lead to poor product quality and even equipment damage. Here's a detailed analysis of common faults, causes and solutions for cutters:
1.Film Deviation
Symptoms: During slicing, the film tilts to one side, causing uneven cut widths or jagged edges.
Reason:
Raw material roll problems: Irregular ends, inconsistent tension, or eccentricity of core.
Improper Tension Control: excessive expansion or redevelopment of tension fluctuations, or tension set that do not conform to the properties of the film.
Guide Roller Installation Deviation: Guide Roller parallelism exceeding tolerance (>0.05mm) or impurities attached to the surface.
Environmental Interference: fluctuations in workshop temperature and humidity can cause film to expand and contract due to heat or static electricity.
Solutions:
Raw material handling: use a winding machine to adjust the end surface, or use a spreader tension buffer to adjust tension.
Tension optimization: The tension fluctuation is monitored and compensated in real time by using closed loop tension control system. Adjust the tension according to the thickness of the film (e.g. PE film, set the tension to 30%-40% of yield strength).
Guide Roller maintenance: Regular cleaning of roller surface, calibration of the guide roller parallelism to ≤0.03mm.
Environmental control: maintain workshop temperature 15-30°C, humidity ≤ 65%, install anti-static devices.
ii. Cutting Burrs
Symptoms: After slicing, Fiber-like burrs appear at the edges of the film, affecting the appearance and subsequent processing of the product.
Reason:
Tool Issuess: Blade dullness, edge wear, or misaligned mounting angle (non-perpendicular cutting).
Improper Cutting Parameters: high speed (>300 m/min) or insufficient tension increases cutting resistance.
Film Characteristics: Films with high hardness materials (such as PET) or additives (such as antistatic agents) are prone to burr.
Solutions:
Tool management:
Replace the blade regularly (it is recommended to check its blade condition every 8 hours).
Adjust the angle of the blade to 15-20° to ensure the cutting surface is perpendicular to the film. Parameter Optimization:
Depending on the thickness of the film, the cutting speed is reduced to 50-150 m/min.
Increase the unfolding tension (for example, for thick PET films, the tension can be increased to 50% of yield strength).
Pre-treatment: Preheat high-hardness films (40-60°C) to soften the material and reduce cutting resistance.
III. Warped edges
Symptoms: After slicing, the edges of the film curl up or down, causing uneven curling and making subsequent processing difficult.
Reason:
Insufficient winding tension: too low inner tension, insufficient outer pressure to flatten edges.
Cutting Heat Accumulation: During high-speed cutting, friction between the blade and the film produces heat, causing local shrinkage.
Internal stress: The stress release after cutting of a a tensile films (such as BOPP) is uneven.
Solutions:
Tension control:
Use conical tension control (tension decreases with roll diameter) to avoid internal collapse.
Increase the initial winding tension (for example, the winding tension of a PE film can be set to between 1.2 and1.5 times the unfolding tension). Cooling Measures:
Install air coolers in cutting areas to reduce blade temperature (recommended cooling wind speed ≥ 2 m/s).
Intermittent cutting of thick films (>50 microns) to reduce heat accumulation.
Stress Relief: Pre-annealing of The the stretched oriented film (maintained for 2 hours at 60-80°C).
IV. INTRODUCTION Product size bias
Phenomenon: After slicing, the film width does not conform to the set values and exceeds the tolerance error range (usually ±0.1 mm).
Reason:
Blade Gap Calibration Error: blade installation position deviation or long-term use of equipment caused by mechanical wear.
Thermal expansion and contraction of films: Changes in ambient temperature cause fluctuations in film size (e.g. linear expansion coefficient of PE films is about 2 × 10-4 °C).
Tension Fluctuation: Unstable tension causes the film to be stretched or compressed during cutting.
Solutions:
Blade Gap Calibration:
Periodically correct blade blade clearance of a laser rangefinder, error ± 0.05 mm.
Check the parallelism of the blade shaft and replace worn bearings if necessary. Temperature Compensation:
The workshop is equipped with a A thermostatic system to control temperature fluctuations within + -2°C.
For high precision requirements, such as electronic film, thermal expansion compensation online size correction algorithm.
Tension closed-loop control:
tension sensor and PID controller are configured to adjust tension value ≤ 3% in real time.
V. Rotating "pyramid" or "chrysanthemum" rolls
Symptoms: Curly hair ends in a conical shape with a hollow in the middle and wavy edges.
Reason:
Improper tension taper setting: the taper coefficient is too large or too small, resulting in an imbalance of tension in the inner or outer layers.
Lead roller pressure is not uniform: pressure roller and winding shaft contact pressure is not consistent, resulting in uneven film force.
Thickness of films is not uniform: the thickness of feed rollers varies widely (> + -1 micron).
Solutions:
Tension taper optimization:
Adjust the taper coefficient according to film thickness of the film (e.g., 5%-10% for films and 10%-15% for thick films). Different tension reduction rate is set for different roll diameter range.
Guide Roller Pressure Calibration:
pressure sensor are used to monitor the pressure of the pressure roller to ensure uniform distribution (error ≤ 0.5 N/cm).
Periodically clean the surface of pressure roller surface to prevent impurity caused by pressure fluctuations.
Raw Material Sorting:
For uneven coils, rewind or adjust the sequence of sections (better if thickness is uniform).
VI. INTRODUCTION INTRODUCTION INTRODUCTION Abnormal Equipment Vibration or noise
Symptoms: Periodic vibration or abnormal noise may occur during operation of the slitter, affecting the precision of cutting and the life of the equipment.
Reason:
Mechanical Looseness: Loosen bolts for fixing tool, guide rail, or bearing.
Transmission system malfunction: belt wear, gear meshing or motor imbalance.
Resonance: The speed of the device is close to its natural frequency (for example, resonance due to a mismatch between the speed of the shaft and the number of blades).
Solutions:
Mechanical inspection:
Tighten all bolts regularly, focusing on the connection between the shaft, guide rail and roller. Replace worn belt (tension must meet equipment requirements, usually 5 5% -8% the belt's breaking load).
Transmission Maintenance:
Lubricate and maintain gearbox, check the gear meshing clearance (recommended gap 0.08-0.12mm).
The motor rotor Kinetic energy equalizer inspection shall be 0.5 0.5 g. cm.
Resonance Avoidance:
Adjust the rotor speed of the vane (e.g. from 1200 rpm to 1000 rpm) to avoid resonance.
Install shock absorbers on the blade shaft to reduce vibration amplitude.
VII. Electrical failure (e.g. sensor failure, motor stall)
Symptoms: sudden equipment shutdown, parameter display abnormality, or control failure.
Reason:
Sensor Failure: Contaminated or damaged tension sensor, photoelectric switch or encoder.
Power supply Issuess: Voltage fluctuation, poor contact or aging circuits.
Software error: PLC program crash or parameter setting conflict.
Solutions:
Sensor Maintenance:
Periodically clean sensor surface (e.g. wipe the tensile sensor probe with a dust-free cloth). Replacement of ageing sensors (calibration is recommended every two years with a margin of error greater than 1 per cent).
Electricity Inspections:
Install voltage a voltage stabilizer to control ± 5% voltage fluctuations.
Check wiring connections and replace oxidized or damaged terminals.
Software maintenance:
Reboot PLC and restore default parameters, or contact manufacturer for program updates.
Backup key parameters such as tension setting and cutting speed to avoid data loss.
VIII. Maintenance and Preventive Recommendations
Daily maintenance:
Clean equipment surface and guide roller to prevent dust accumulation and friction changes.
Check lubricant levels (such as gearboxes and bearings) and replace them regularly (it is recommended that they be replaced every 500 hours).
Regular Calibration:
Quarterly calibration of blade spacing, tension sensor and photovoltaic switches to ensure accuracy.
Operational training:
Train operators in tension control, tool replacement and fault diagnosis to reduce human error.
Analyzing the cause of the problem and taking targeted measures can greatly improve the operation stability and product quality of the cutter and reduce maintenance cost and downtime.