Label Slitting Rewinding Machine

The 2023 labelexpo Asia show we participated in in December was a complete success.

I am very happy that many customers from Russia, the Middle East, and Southeast Asia are very interested in our printing machines, slitting machines, and die cutting machines.

There are also customers who place orders directly after discuss with us about machine details in exhibition. Thank you for all the customer trust and support. We will continue to update, bring better machines and services to our customers.

Film slitting rewinding machines are essential in the plastic film processing industry. They slit wide plastic film rolls as per specific demands and rewind them into standard small rolls for various applications.

I. Basic Structure and Components
Unwinding Unit
The unwinding unit, the starting part, holds and releases the wide film roll. It has an adjustable tension control system. For example, magnetic powder brakes or servo motors control the unwinding resistance. The unwinding shaft, like an air expansion shaft, eases roll loading and unloading.
Cutting Unit
The core cutting unit uses tools like round and straight knives. Round knives suit thin, flexible films, cutting fast with smooth edges. Straight knives are for thicker or special films. It has a tool adjustment device to set position, angle, and pressure according to film thickness and material for precise cutting.
Rewinding Unit
The rewinding unit rewinds slit films. It has winding shafts (central or surface types), pressure rollers, and a tension control system. The central shaft is motor-driven for high-tension films; the surface shaft uses friction for thinner films. Pressure rollers ensure tight winding, and the tension system keeps film tension stable for good roll quality.

II. Working Process
Roll Installation and Preparation
First, install the film roll on the unwinding shaft and fix it. Then, check components, set the cutting width, and adjust tension parameters on the operation panel.
Unwinding and Cutting
After starting, the unwinding unit releases the roll. The film moves forward under tension and enters the cutting unit. The tools cut it into narrow strips according to the set width.
Rewinding and Finishing
The slit strips enter the rewinding unit. Pressure rollers press them onto the winding shaft. The tension system monitors and adjusts. As the roll diameter grows, parameters adjust for quality winding. When set, the equipment stops, and the rolls are ready for packaging.

III. Application Fields
Packaging Industry
In packaging, films from these machines are used widely. For food packaging, like wrap films and bags, and industrial product packaging, they provide suitable films for protection and appearance.
Electronics Industry
The electronics industry demands high precision. These machines slit optical, insulating films, etc., into tiny sizes for components. For LCDs, they cut polarizing films precisely, and for circuit boards, they get the right films for insulation.
Agriculture
In agriculture, films from Film Slitting Rewinding  machines cover greenhouse sheds and are used as mulch films. They are slit to fit different greenhouse and crop needs, enhancing production efficiency and crop protection.

Slitting machines play a vital role in the field of material processing. They can precisely cut wide rolls of materials into predetermined widths, lengths or shapes, and are widely used in the processing of various materials such as paper, plastic films, and metal foils. Understanding their working principle is of key significance for optimizing the slitting process, improving production efficiency and ensuring product quality.

I. Principle of the Unwinding System
Installation and Fixation of Rolls
The unwinding system of the slitting machine first needs to correctly install the roll to be slit on the unwinding shaft. Usually, expansion-type or chuck-type installation methods are adopted to ensure that the roll will not become loose or displaced during high-speed rotation. For example, the expansion-type unwinding shaft expands the shaft core through internal air pressure or mechanical structure to tightly clamp the inner core of the roll, providing a stable foundation for the subsequent unwinding process.
Tension Control Mechanism
To ensure that the roll is transported smoothly and evenly during the unwinding process, the unwinding system is equipped with a tension control system. This system uses tension sensors to monitor the tension of the roll in real time and compares it with the set value. If the tension is too high, it will cause the roll to stretch, deform or even break; if the tension is too low, problems such as slack and wrinkles may occur during the unwinding process. For example, when the tension sensor detects that the tension is higher than the set value, the control system will automatically adjust the rotation speed of the unwinding motor to slow it down, thereby reducing the tension of the roll; conversely, if the tension is lower than the set value, the motor speed will be increased to increase the tension.

II. Principle of the Cutting System
Types and Selection of Cutters
The cutting system of the slitting machine uses various types of cutters, with round knives and straight knives being common. Round knives are suitable for cutting thinner materials with certain flexibility, such as plastic films and paper. They can generate continuous cutting force through high-speed rotation, and the cutting edges are relatively smooth. Straight knives are more suitable for cutting thicker and harder materials, such as metal foils. The material of the cutters is also crucial. High-quality cutter materials have high hardness, wear resistance and good toughness. For example, cutters made of cemented carbide can maintain sharpness during long-term cutting, reducing the frequency of cutter replacement and improving production efficiency.
Cutting Actions and Adjustments
During the cutting process, the cutters operate according to the set parameters. For round knives, their rotation speed, the contact angle with the roll, and the clearance between the upper and lower round knives need to be precisely adjusted. For example, when cutting thin plastic films, appropriately reducing the rotation speed and contact pressure of the round knives can prevent the films from being stretched or having burrs during the cutting process. Meanwhile, the clearance between the upper and lower round knives needs to be adjusted according to the thickness of the films. If the clearance is too large, the cutting cannot be completed; if it is too small, it will increase cutter wear and cutting resistance. For straight knives, the stroke and speed of their up and down movements as well as their relative position to the roll also need to be precisely controlled to ensure the accuracy and stability of the cutting.

III. Principle of the Rewinding System
Rewinding Methods and Structures
The materials after slitting are collected and organized by the rewinding system. There are central rewinding and surface rewinding methods. Central rewinding involves winding the slit materials around the core shaft of the rewinding roll. The core shaft is driven to rotate by a motor. This method is suitable for situations where higher rewinding tension is required and the materials are relatively thick. Surface rewinding relies on the friction between the rewinding roll and the materials to drive the materials to be rewound. It is suitable for thinner materials with relatively low tension requirements. The rewinding system also includes auxiliary structures such as pressure rollers. The role of the pressure rollers is to closely attach the slit materials to the rewinding roll to prevent problems such as loose winding or air entrainment.
Rewinding Tension and Speed Control
The rewinding system also needs to precisely control the tension and speed. The rewinding tension should match the unwinding tension and remain stable during the rewinding process. If the rewinding tension is too large, the rewound materials will be wound too tightly, resulting in internal stress and affecting the quality of the materials; if the tension is too small, the materials will be wound loosely, which is not conducive to subsequent storage and transportation. For example, at the beginning of the rewinding process, since the diameter of the material roll is small, the rewinding tension can be set appropriately low; as the rewinding process progresses and the diameter of the material roll gradually increases, the rewinding tension needs to be adjusted accordingly to ensure the winding quality of the materials throughout the rewinding process. The rewinding speed also needs to be reasonably controlled according to the overall production efficiency of the slitting machine and the characteristics of the materials. Excessive rewinding speed may cause problems such as material offset and wrinkles during the rewinding process.
 

The label rotary die cutting machine plays a crucial role in the label printing and processing industry. Its cutting effect is directly related to the quality of labels and production efficiency. Numerous factors can have an impact on its cutting process. A deep understanding of these factors is of great significance for optimizing the die cutting process, improving product quality, and reducing production costs.

Blade-related Factors
Blade Material and Hardness
The material of the blade determines its key properties such as wear resistance, toughness, and sharpness. For example, blades made of high-quality high-speed steel have high hardness and good wear resistance, enabling them to maintain a sharp cutting edge during the long die cutting process, thus ensuring the neatness and smoothness of the cutting edges. Blades with insufficient hardness are prone to edge wear and dulling when cutting relatively hard label materials, resulting in rough cutting surfaces and even the inability to complete the cutting task smoothly.
Blade Edge Shape and Angle
Different edge shapes and angles are suitable for different types of label materials and die cutting requirements. For thin paper labels, a sharp edge with a small angle can achieve precise and rapid cutting and reduce the pulling of paper fibers. For some plastic labels with a certain thickness or toughness, special-shaped edges, such as wavy edges, may be required to distribute the cutting pressure and prevent the materials from deforming or tearing during the cutting process. Incorrect selection of the edge shape or angle will lead to uneven distribution of cutting force and cause problems with the quality of label cutting.

Die Cutting Pressure Factors
Precise Setting of Pressure Magnitude
Appropriate die cutting pressure is one of the core factors to ensure a good cutting effect. If the pressure is too low, the blade cannot completely cut through the label materials, resulting in phenomena such as incomplete cutting and continuous cutting, which will affect the separation and use of the labels. For example, when cutting multi-layer composite label materials, if the pressure is insufficient, the layers of materials may not be completely separated. On the contrary, excessive pressure will cause excessive wear on the blades and equipment and may also lead to the crushing and deformation of the label materials. Especially for some labels with soft textures or special coatings on the surface, such as thermal labels, excessive pressure will damage their thermal coatings and affect the functional characteristics of the labels.
Uniformity of Pressure
The uniform distribution of die cutting pressure across the entire die cutting area is also of vital importance. If the pressure is uneven, the edges of the labels after cutting will show different degrees of quality differences, such as some edges being smooth and some having burrs or serrations. This may be caused by factors such as poor surface flatness of the die cutting rollers, failure of the pressure adjustment device, or uneven thickness of the label materials. For example, when the die cutting rollers have local wear after long-term use, the pressure in this area will be inconsistent with that in other areas, thus affecting the cutting effect.

Label Material Property Factors
Material Thickness and Hardness
The thickness and hardness of label materials have a significant impact on the die cutting process. Thicker or harder materials require greater die cutting force to complete the cutting. For example, thick cardboard labels require higher pressure and sharper blades compared to thin paper labels. Moreover, the uneven hardness of materials, such as some label materials containing fiber impurities or local hardening, will increase the difficulty of die cutting, easily lead to increased blade wear, or unstable cutting quality, and may result in local incomplete cutting or uneven cutting surfaces.
Material Flexibility and Elasticity
Label materials with high flexibility and elasticity, such as some rubber or stretchable plastic labels, are prone to rebound during die cutting. This requires that the blade and pressure settings of the  Label Rotary die cutting machine can adapt to this characteristic. Otherwise, the edges of the cut labels may not remain flat and may curl or deform. For example, when cutting elastic rubber labels, if the cutting speed and pressure cannot be reasonably controlled, the labels will rebound quickly after the blade leaves, resulting in uneven cutting edges and affecting the appearance and pasting effect of the labels.

Equipment Mechanical Precision Factors
Concentricity and Cylindricity of Die Cutting Rollers
The concentricity and cylindricity of die cutting rollers are directly related to the uniformity and stability of die cutting pressure. If the concentricity of the die cutting rollers is poor, radial runout will occur during the rotation process, causing the die cutting pressure to change periodically, resulting in regularly uneven cutting edges of the labels. The cylindricity error will make the contact area between the die cutting rollers and the label materials uneven, causing local excessive or insufficient pressure and affecting the cutting quality. For example, when the die cutting rollers have a large concentricity deviation due to manufacturing or installation precision problems, the edges of the cut labels will have obvious wavy undulations.
Precision and Stability of the Transmission System
The precision and stability of the equipment's transmission system also have an important impact on the die cutting effect. The transmission system includes components such as motors, gears, and chains. If the transmission precision is insufficient, such as excessive gear meshing clearance and chain slack, it will lead to unstable rotation speed of the die cutting rollers or instantaneous pauses, making the relative movement between the blades and the label materials discontinuous, thus producing scratches, faults, and other defects on the cutting surfaces of the labels. Moreover, unstable transmission will also exacerbate the wear of blades and other components of the equipment, reducing the service life and reliability of the equipment.

Label die cutting machines play a vital role in the label printing industry. They can precisely cut the printed label materials into specific shapes and sizes to meet the diverse needs of different products for labels. Whether in traditional industries such as daily chemicals and food and beverages or in emerging fields like anti-counterfeiting and electronic labels, they have extensive and crucial applications. The following will introduce in detail their application cases in various fields.

I. In the Field of Daily Chemical Product Labels
Diversified Shape Cutting
For various daily chemical products, such as labels for cosmetic bottles and packaging boxes of skin care products, label die cutting machines can achieve a rich variety of shape cutting. From common rectangular and circular shapes to unique irregular designs like petal-shaped and wavy shapes, they can all be cut precisely. For example, the bottle label of a high-end cosmetic brand adopts an exquisite butterfly-shaped label. Through the high-precision die cutting of the label die cutting machine, the edges are smooth and delicate, greatly enhancing the visual appeal and brand recognition of the product.
Special Material Handling
Some daily chemical product labels use special materials, such as shiny holographic paper and texture paper with unique textures. Label die cutting machines can adjust the die cutting parameters according to the characteristics of these materials to ensure that the surface of the materials is not damaged during the cutting process and that the original luster and texture effects are maintained. For example, the label of a perfume brand uses special paper with a metallic texture. When the label die cutting machine cuts the die, it precisely controls the pressure and the angle of the cutting tool, so that the cut label not only meets the design shape requirements but also retains the metallic luster of the paper intact, adding a sense of luxury to the product.

II. In the Field of Food and Beverage Labels
Meeting Packaging Requirements
In the food and beverage industry, labels need to fit closely to the shapes of various packaging containers. Label die cutting machines can perform customized die cutting for different packaging bottle shapes, such as cylindrical, conical, and square ones. For example, for the label of a cylindrical beverage bottle, the die cutting machine can accurately cut out a label that perfectly matches the curvature of the bottle body, so that the label is flat and wrinkle-free after pasting and looks beautiful. Moreover, for some labels with special design requirements, such as those with tear-off openings or easy-peel lines, the label die cutting machine can also produce them precisely. For example, the label of a yogurt cup has an easy-peel line for consumers to open. The die cutting machine uses special cutting tools and processes to ensure that the depth and continuity of the easy-peel line are just right.
Ensuring Hygiene and Safety
The die cutting process of food and beverage labels must meet strict hygiene standards. Label die cutting machines use food-grade cutting tool materials and clean die cutting processes to avoid generating impurities or contaminating the labels during the die cutting process. For example, when producing labels for infant food, the working environment and equipment components of the die cutting machine are strictly cleaned and disinfected to ensure the hygiene and safety of the labels and prevent any potential threats to the health of infants.

III. In the Field of Anti-counterfeiting Labels
Cutting Complex Anti-counterfeiting Patterns
Anti-counterfeiting labels often contain complex anti-counterfeiting patterns and structures, such as laser holographic patterns, micro-text, and QR codes. Label die cutting machines can accurately cut out the label shapes containing these anti-counterfeiting elements. For example, the anti-counterfeiting label of a well-known liquor brand combines a laser holographic pattern with a QR code. When the label die cutting machine cuts, it keeps the laser holographic pattern intact on the label and ensures that the QR code is clear and readable, so that consumers can easily verify the authenticity of the product by scanning with their mobile phones, effectively combating counterfeit and shoddy products.
Producing Tamper-evident Anti-counterfeiting Labels
Tamper-evident anti-counterfeiting labels are a common anti-counterfeiting means. When producing such labels, label die cutting machines precisely control the die cutting depth and pressure to make the labels remain intact under normal pasting conditions, but once they are attempted to be peeled off or tampered with, they will break into small pieces and cannot be restored. For example, the tamper-evident anti-counterfeiting label on drug packaging. After the label die cutting machine cuts it into a specific shape, it provides reliable anti-counterfeiting protection for the circulation and sale of drugs, ensuring that consumers can buy genuine drugs.

IV. In the Field of Electronic Labels
Cutting Antenna for RFID Labels
In the production of RFID labels, label die cutting machines are responsible for cutting the materials of the antenna part. They can cut conductive materials (such as copper foil and aluminum foil) into specific shapes and sizes according to the design requirements of RFID labels to form an effective antenna structure. For example, for RFID labels widely used in the logistics industry, label die cutting machines can cut the antenna into rectangular, circular or other suitable shapes and ensure that the electrical performance of the antenna meets the communication standards of the RFID system, realizing accurate identification and tracking management of goods.
Processing Flexible Electronic Labels
With the development of flexible electronics technology, flexible electronic labels are increasingly widely used. Label die cutting machines can adapt to the characteristics of flexible electronic label materials (such as flexible plastics and thin metal foils) and perform high-precision die cutting processing. For example, in the production of flexible electronic labels for wearable devices, label die cutting machines can cut the labels into shapes that conform to the curves of the human body, while ensuring that the electronic circuits and components on the labels are not damaged, so that the flexible electronic labels can be stably attached to the surface of wearable devices to achieve functions such as health monitoring and identity identification.