Burrs on the edges of stretch film slitting and rewinding machines during the slitting process directly affect the product's appearance and performance, and can even lead to serious consequences such as film breakage. Avoiding burrs requires comprehensive optimization from multiple dimensions, including equipment condition, process parameters, material characteristics, and operating procedures. The core of this approach lies in ensuring blade sharpness, controlling tension stability, matching material properties, and standardizing operating procedures.
The condition of the blades in a stretch film slitting and rewinding machine is a key factor affecting burrs. Dull blades or incorrect installation angles can cause the material to be stretched rather than cut during slitting, resulting in jagged edges. Therefore, it is necessary to regularly check blade wear, replace dull blades promptly, and ensure that the blade installation angle matches the material characteristics. For example, high-toughness stretch films require blades with a larger backslope angle to reduce plastic deformation through "slicing" cuts; for thin films, ceramic-coated blades with higher sharpness are needed to reduce cutting resistance. Furthermore, the radial runout of the blades must be controlled within a minimal range to avoid uneven cutting due to blade vibration.
Tension control is the core aspect of avoiding burrs. During the slitting process, the tension in the unwinding, slitting, and rewinding stages must be coordinated and matched: excessive unwinding tension will cause material stretching and deformation, affecting porosity; insufficient slitting tension will cause material vibration, making the blade prone to "pulling" burrs; excessive rewinding tension may press upper burrs into the lower layer, forming indentations. A tapered tension control method is typically used, that is, gradually reducing tension as the roll diameter increases, ensuring a tighter inner layer and a looser outer layer. For example, when slitting lithium battery separators, parameters need to be adjusted in real time through a closed-loop tension control system to ensure the material is in a stable and taut state at the cutting point, avoiding burrs caused by tension fluctuations.
Matching material characteristics with process parameters is crucial. Stretch films of different thicknesses and toughness require targeted adjustments to slitting speed, cutting depth, and blade speed ratio. Thick films require a reduced slitting speed to decrease cutting resistance, while increasing the cutting depth to ensure a complete cut; thin films require a higher blade speed ratio to avoid wear caused by relative sliding. For example, when slitting 0.02mm thick PE film, if the cut depth is too shallow, the material is only surface-cut without being completely removed, easily resulting in long burrs; if the cut depth is too deep, excessive heat may cause the film surface to melt, forming hard burrs. Therefore, it is necessary to determine the "minimum effective cutting depth" through experiments, that is, the state where the material is just cut off without excess chips.
Equipment precision and maintenance are fundamental guarantees. Long-term operation of equipment may lead to problems such as guide roller eccentricity and loose blade holders, causing cutting path deviation or blade vibration. Regular checks of the guide roller surface flatness, blade holder coaxiality, and wear of transmission components are necessary, with timely replacement of aging parts. For example, after the slitting machine has run for more than 5000 hours, the hydraulic system oil may deteriorate, causing pressure fluctuations. The hydraulic oil needs to be changed quarterly, and the backup battery tested; during the annual major maintenance, worn bearings need to be replaced, and the control system precision calibrated to ensure the equipment is always in optimal condition.
Operating procedures and environmental control are equally important. Before slitting, the guide rollers, blade holder, and bottom roller must be cleaned to prevent dust or foreign objects from scratching the film surface. Operators must wear cut-resistant gloves and use specialized tools to replace blades to prevent human-caused damage. Furthermore, stretch film is sensitive to static electricity, so ion fans must be installed to eliminate static electricity and prevent film adhesion. Temperature and humidity should also be controlled to prevent the material from becoming damp or generating static electricity that attracts dust, indirectly reducing the risk of burrs.
To avoid burrs on the slitting edges of stretch film slitting and rewinding machines, a systematic management approach is needed: regularly replacing sharp blades, optimizing tension control parameters, adjusting processes to match material characteristics, maintaining equipment precision, standardizing operating procedures, and controlling environmental factors can significantly reduce the burr incidence rate. Companies should establish equipment health records, documenting each malfunction and its handling, creating a knowledge base. Simultaneously, introducing condition monitoring technology, such as vibration analysis and infrared thermal imaging, can proactively identify potential faults, shifting from reactive maintenance to preventative maintenance, thereby ensuring stable slitting quality and enhancing product competitiveness.
