Paper Roll Slitter Rewinder Machine

Firstly, the operating environment requirements for the slitting machine: The machine should be installed in a place with appropriate temperature, dryness, ventilation, good lighting, and convenient operation. In addition, in daily use, the usage environment should be kept clean, and the machine should be cleaned regularly to keep it clean.

Secondly, the operating requirements for using a slitting machine are to use high-quality longitudinal and transverse cutting knives; the machine needs to cut and process the entire roll or sheet of raw materials into fixed lengths; the fixed length slitting control of machines needs to be divided into two types: Static and dynamic slitting; the important performance indicators of machine fixed length slitting are slitting accuracy and good consistency of finished product length; the cutting length of the machine can be continuously set. If there is an error in the actual cutting length, it needs to be calibrated by setting parameters.

Thirdly, precautions when using a slitting machine: Ensure that the voltage, current, and hydraulic equivalents are correct and stable before starting the machine; before the machine is ready for operation, all personnel must be notified to leave to ensure personal safety before starting up and running; when the machine is running, do not touch the running film roll or roller core with your hands to avoid getting your hands rolled up and causing personal injury; during operation, do not use knives or hard objects to scratch or cut the various roller cores of the machine.

There are three general functions that a slitter rewinder performs in fixed order. To begin the process, the already rolled paper (or other material) must be unwound to pass through the slitter rewinder in a single layer. As it passes through the machine, it is slit by one of a number of different cutting methods into strips of the desired thickness. Once the material has been slit to the finished, market-ready dimensions, it is rewound into sellable rolls.

The actual cutting of the material can be done in a number of different ways, depending mostly on the material being cut. The oldest form of cutting, called score cutting, involved slicing the material between a relatively dull blade and a hard surface. This method is beneficial for cutting adhesives (like various forms of tape), especially those with one sticky and one dry side. Although this method is quick and easy to set up, it is risky to use on many materials. It can potentially cause an excessive amount of dust when used with paper, stretching and warping with used with films, and cracking when used with hard plastics.

The second easiest cutting method to set up is razor blade cutting. It is also the most economical method. It uses a positioned blade often suspended over the area through which the sheet is feed. As the material is pulled across a drum or series of drums, it is drawn against the blade, which extends downward into either an empty space or a groove in one of the drums. This method cannot be used to cut heavy, abrasive, or rigid materials. Additionally, when used at high speeds, the friction between the blade and the material can heat the blade, which can cause beading along the edges of some materials like films.

Shear cutting is the most accurate slitting method, and it can be used against heavier, thicker, more rigid materials such as thicker films, foils, papers, and laminates. The defining characteristic of shearing cutting is that it uses two blades, usually rotating. The material is pulled between these two blades which cut the materials from above and below, similar to the way a pair of open scissors could be guided through paper.

The cutting technique in plastic film slitting and rewinding machines is usually longitudinal, hence the use of rotary knives or industrial razor blades. Slitter machines use different types of rotary and razor blades depending on the material being cut, and here are some common types of blades used in slitting machines.

Industrial Razor Blades for Film Slitting
These are the most straightforward type of knives used in slitter rewinders. They are essentially fixed blades that the material is pulled over. Razor blades are especially effective for very thin materials, offering a clean cut due to their sharpness. However, they tend to dull quickly and need frequent replacement. They are best suited for applications where precision is critical and the material is not too thick. Razor blades are sharp, thin blades commonly used for slitting thin materials such as paper, plastic films, and foils. They provide clean and precise cuts and are suitable for high-speed slitting operations. Read more about razor slitting here.

Circular Knives for Plastic Film Slitting
Circular knives, also known as rotary knives or disc knives, are circular-shaped blades mounted on a rotating shaft. They are versatile and can be used for slitting a wide range of materials, including paper, films, textiles, and non-woven materials.

Shear Blades for Plastic Film Slitting
Shear cut blades, also known as top and bottom circular knives, consist of two opposing blades that move in a scissoring motion to cut the material. They are typically used for slitting thick or rigid materials that require extra cutting force, such as laminates, multilayers, foils. Shear slitting is preferred for materials that require a cleaner edge and can include everything from thin films to thicker papers and laminates. The shear blades can be adjusted for different materials, making them highly versatile. Read more about shear cutting here.

Crush Cut Blades for Plastic Film Slitting
Crush cut blades consist of a circular blade mounted against an anvil roll. They operate by crushing and cutting the material against the anvil roll, making them suitable for slitting delicate or stretchy materials that may deform under pressure. This method is often used for materials where the precision of the cut edge is not as critical, such as some types of tape, paper and board. The score slitting technique is robust and can handle materials that are difficult to cut with other methods.
The selection of the appropriate type of knife depends on factors such as the material's thickness, elasticity, surface characteristics, and desired slit quality.