Technological innovation and application expansion of slitting machines under the challenges of new materials and new processes

As the core equipment in the field of material processing, slitting machines are widely used in the back-end processes of films, foils, paper, fiber composites, battery electrodes and other industries. Its core mission is to slice the wide master coil into several narrow small coils under the condition of high speed and high precision, and to ensure the quality of slitting. With the rapid development of strategic emerging industries such as new energy, electronic information, and flexible displays, the requirements for material performance are becoming increasingly stringent, and the emergence of a series of new materials and processes is posing an unprecedented challenge to traditional slitting technology, and also driving the profound innovation and wide application expansion of slitting machine technology.

1. The core challenges brought by new materials and processes

Traditional slitting techniques primarily target homogeneous materials such as paper and plain plastic film, but the emergence of new materials has revolutionized the game.

1. Extreme thinning and high brittleness materials:

◦ Challenges: For example, copper and aluminum foils for lithium batteries are as thin as 4-6μm, or even thinner. This type of material is extremely thin, easy to stretch, easy to wrinkle, easy to break, and requires extremely high tension control accuracy and stability, and small fluctuations will lead to broken bands or folds.

◦ New process requirements: The slitting after electrode coating must be free of burrs and dust, otherwise it will cause a short circuit inside the battery.

2. Multilayer laminated and functionalized films:

◦ Challenges: such as multi-layer optical film in OLED screens, high-barrier packaging films, etc. These materials are composed of different materials (PET/PA/AL/CPP, etc.), and the friction coefficient, tensile rate, and hardness between each layer vary greatly. During slitting, it is easy to cause delamination, serpentine (crimping) or internal stress due to uneven stress, which affects the subsequent processing and use performance.

◦ New process requirements: It is necessary to avoid damage to functional layers (such as optical glue and barrier layer) by slitting thermal stress.

3. High adhesion adhesive materials:

◦ Challenges: such as various high-viscosity protective films, double-sided tapes, OCA optical adhesives, etc. During slitting, adhesive transfer (sticky knives) can easily occur, contaminating the edges and blades of the material, resulting in poor slitting quality or even inability to produce continuously. Cleaning downtime is long and inefficient.

◦ New process requirements: It is necessary to solve the problems of anti-sticking and precise cutting to fixed length.

4. High-Strength Fiber Composites:

◦ Challenges: such as carbon fiber, fiberglass prepreg, aramid paper, etc. The material has high hardness and wear resistance, and the wear of the blade is extremely severe. At the same time, the control of fiber chips and dust is key, otherwise it will affect the cleanliness and performance of the product.

◦ New process requirements: require slitting equipment to have extremely high rigidity and wear resistance, as well as an efficient dust removal system.

5. Process integration requirements:

◦ Challenge: The new process pursues high efficiency and high consistency, hoping to seamlessly connect slitting with online inspection, winding, packaging and other processes to form an intelligent production line. This puts forward higher requirements for the automation, informatization and collaborative control capabilities of the slitting machine.

2. Systematic innovation of slitting machine technology

In order to meet the above challenges, modern slitting machine technology is undergoing comprehensive innovations, mainly reflected in the following aspects:

1. Ultra-High Precision Tension Control System:

◦ Innovation: Adopt full servo motor drive to replace the traditional magnetic powder clutch. Real-time feedback of the coil diameter change through a high-resolution encoder, and use adaptive algorithms (such as fuzzy PID control) to achieve full-process tension taper control from unwinding, traction to rewinding. The tension control accuracy can reach ±0.5% or even higher, ensuring the stability of ultra-thin materials under high-speed slitting.

2. Smart Blade Technology and Cutting Solutions:

◦ Innovation:

▪ Tool Material: Ultra-hard coating (e.g., diamond DLC, titanium nitride TiN), ceramic insert, or polycrystalline diamond (PCD) insert to handle cutting composites and high-wear materials, greatly extending tool life.

▪ Knife design: Develop special blades for different materials, such as anti-stick coated blades for adhesive materials, round knives with low friction angles.

▪ Drive mode: Servo cutter axis control has become standard, which can achieve "flying shear" (synchronized cutting of the tool during material operation), precise bite depth control and vibration suppression to ensure smooth and burr-free cuts.

▪ Air support knife (air cushion knife): used for slitting extremely sensitive materials, through the air film to make the material and blade non-contact "slitting", completely avoid scratches and dust.

3. Intelligent operation and condition monitoring system:

◦ Innovation:

▪ Machine Vision (AOI): Integrated online surface defect detection system to monitor burrs, streaks, stains, folds and other defects in the slitting process in real time, and can automatically mark or link the sorting system.

▪ Intelligent winding (IRC/IBC): Adopts full servo winding, with advanced winding curve algorithm, automatically calculates and adjusts pressure, torque and speed, perfectly controls the hardness of the coil, and avoids collapsed core, chrysanthemum pattern and other drawbacks.

▪ Predictive maintenance: Sensors monitor parameters such as blade wear, bearing vibration, and motor load, and use big data analysis to predict the time of failure, provide early warning, and reduce unplanned downtime.

4. Modular and Specialized Design:

◦ Innovation: Slitting machines are no longer general-purpose equipment, but specialized and modular design based on material characteristics. For example:

▪ Lithium battery pole slitting machine: emphasizes dust-free, metal-free, explosion-proof, equipped with high-frequency vacuuming system and anti-static measures.

▪ Optical film slitting machine: emphasizes cleanroom environment, ultra-low tension control, and anti-static winding.

▪ Tape slitting machine: equipped with special anti-stick guide rollers, silicone rollers and cold knife systems.

3. Expansion of application fields

Technological innovations are directly driving the boundaries of slitting machine applications:

1. New energy field: This is the biggest growth point at present. The slitting of lithium battery electrode pieces (anode/cathode) is the core of manufacturing, and the precision, cleanliness and reliability of the slitting machine are the highest. In addition, hydrogen fuel cell proton exchange membranes, photovoltaic backsheet membranes, etc. also require high-performance slitting equipment.

2. Flexible electronics and display fields: OLED flexible display substrates (PI film), touch screen sensors (ITO film), transparent conductive films, etc., require slitting in a 100th/1000th level dust-free environment to ensure no dust, no scratches, and no static damage.

3. High-end packaging fields: high-barrier food packaging, pharmaceutical packaging, anti-static shielding packaging for electronic products, etc., need to cut multi-layer composite films without compromising their structural integrity.

4. New semiconductor materials field: precision slitting of semiconductor auxiliary materials such as wafer grinding film, dicing tape (wafer cutting tape), CMP polishing pads, etc.

5. Cutting-edge material fields: The preparation and processing of emerging materials such as carbon nanotube films, graphene films, and aerogel materials have also begun to require customized precision slitting solutions.

Conclusions and prospects

New materials and processes are both challenges and core drivers of slitting machine technology evolution. The future slitting machine will no longer be a single mechanical product, but a highly intelligent system integrating precision machinery, intelligent control, sensing technology, big data and artificial intelligence.

Its development trends will focus on:

• Extreme: Challenge for higher speeds, narrower widths, and higher precision.

• Intelligent: Realize self-perception, self-decision-making, self-execution, and adaptive "unmanned" intelligent production.

• Integration: Deeply integrated with upstream and downstream processes, becoming an indispensable digital node for intelligent factories.

Only continuous technological innovation can meet the increasingly demanding needs of material processing and thus support the vigorous development of strategic emerging industries. The innovation of slitting machine technology is a microscopic and profound microcosm of China's transition from a "manufacturing power" to an "intelligent manufacturing power".