Challenges and solutions for ultra-thin film slitting: Take optical films as an example
Posted by sebrina
from the Business category at
14 Jul 2025 02:25:15 am.
Share this page: 
First, main Challenges
1. Sensitive material properties
◦ Optical films (such as PET, PMMA, COP, etc.) are usually in the micron range (even < 10μm) thickness, which is susceptible to mechanical stress, and is prone to edge cracks, delamination, or warping during slitting.
◦ Functional layers (e.g., ITO coatings, brightness enhancement film microstructures) may deteriorate due to slitting stress (e.g., reduced conductivity).
2. The slitting accuracy is extremely high
◦ The slitting width tolerance should be controlled within ±5μm, and the edge straightness should be high (e.g., ±1μm/mm), otherwise the alignment of subsequent laminates (such as OLED panels) will be affected.
3. Static electricity and pollution problems
◦ Ultra-thin films are prone to accumulate static electricity, absorb dust, or cause the film layer to stick after slitting.
◦ Debris generated during the slitting process can scratch the surface (especially for surface treatment films such as anti-glare).
4. Tension control is difficult
◦ The thinner the film, the narrower the tension window: too much stretch deformation, too little will cause the transport to shift or wrinkle.
5. Tool wear and thermal influence
◦ Blade passivation or thermal expansion can lead to burrs and melting of the slitting surface (e.g., COP materials have a low melting point).
Second, solution and technology optimization
1. Slitting process optimization
• Tool selection and design
◦ Use a super-hard material tool (e.g., diamond-coated knives, ceramic knives) to reduce wear and optimize the knife edge angle (e.g., below 30°) to reduce the cutting force.
◦ Air Floating Knife: Non-contact slitting to avoid mechanical contact damage, suitable for brittle optical films.
• Closed-loop tension control
◦ Multi-stage magnetic particle brake + high-resolution encoder is used to adjust the unwinding/winding tension in real time (such as controlled in the range of 2~10N).
◦ Pre-tension zone setting (e.g., flattening the film by arc rollers first).
• Improved slitting method
◦ Shear Cutting: The upper and lower knives are overlapped to reduce material deformation and are suitable for films with a thickness of > 20 μm.
◦ Laser cutting: non-contact, small heat-affected zone, suitable for ultra-thin flexible films (wavelength and pulse frequency need to be optimized, such as ultraviolet laser).
2. Environment & Auxiliary Systems
• Static Elimination
◦ Combination of ionic air rod + electrostatic brush, multi-stage power dissipation before and after slitting (target electrostatic voltage<± 50V).
• Cleaning protection
◦ In-line dust removal system (such as dust roller + HEPA filtration), and the slitting area maintains Class 1000 cleanliness.
• Temperature and humidity control
◦ Ambient temperature 23±1°C, humidity 45±5% RH to reduce material expansion and deformation.
3. Detection and intelligence
• On-line monitoring system
◦ High-precision CCD visual inspection of slitting edge quality (resolution up to 1μm), real-time feedback to adjust the tool position.
◦ The thermal imaging camera monitors the temperature of the cutter head to avoid overheating the melt film.
• AI process optimization
◦ Train the model on historical data to dynamically predict tool life and optimize slitting parameters (e.g., speed, tension).
4. Material pretreatment
• Coating-strengthened edges
◦ Apply a temporary protective layer (e.g., water-soluble polymer) to the predetermined cutting line prior to slitting to reduce micro-cracks at the edges.
• Substrate modification
◦ Choose a high-modulus optical film (e.g., modified COP) to improve stretch resistance.
Third, typical Cases
• OLED polarizer slitting: laser slitting + nitrogen purging, edge roughness < 0.5μm, no carbonization.
• PET release film below 50μm: The air suspension knife with tension fluctuation control <± 0.5N, and the yield rate is increased to 99.3%.
Fourth, future trends
• Ultrafast laser technology: femtosecond laser slitting further reduces thermal impact.
• Roll-to-roll (R2R) integration: Slitting is integrated with subsequent processes (e.g., lamination, die-cutting) online to reduce intermediate contamination.
• Adaptive tooling system: automatically adjusts tool pressure and angle based on film thickness/material.
Through comprehensive process optimization, precision equipment and intelligent control, the accuracy and reliability of ultra-thin optical film slitting machine have been significantly improved, but continuous breakthroughs in material limits (such as < 5μm films) still require interdisciplinary collaborative innovation.
Tags: film slitting machine
0 Comments