The process of slitting must be taken seriously and must not be taken lightly. This article combines the extruded composite BOPP/LDPE composite film, the quality problems that occur in the slitting production process and the related problems of the slitting machine to analyze. So that the majority of composite film manufacturers can well solve a series of quality problems in the future slitting production to ensure the stable quality of composite film slitting.
The purpose of slitting
1. Provide accurate specifications according to user requirements.
2. When slitting and unwinding, the large-volume composite film compounded during the extrusion and compounding of the entire previous process can be inspected again to see if there is any quality problem.
3. It can correct the staggered layer of the composite film or cut off part of the printing and composite defects, and improve the grade rate of the product.
4. It can make the finished product get a good winding state.
Precautions in slitting
1. Control the cutting speed
When entering normal production, the speed of the slitting machine should strictly follow the process requirements. Too high will also affect the cutting quality. Therefore, by controlling the slitting speed, the quality required for slitting can be obtained. Because, in the production, some operators artificially increase the cutting speed in order to increase the output and improve their economic benefits. This will make the film prone to longitudinal streaks and split-layer quality problems under high-speed operation.
2. Choose the appropriate slitting process according to the equipment and film performance
In normal production, it is necessary to adopt appropriate slitting technology for production according to the equipment performance, the intrinsic properties of the film and the different types and specifications of the film. Because the process parameters, identification methods, and values of various slit films are different, the process must be carefully adjusted for each product.
3. Pay attention to the correct choice of workstations
In production, the frequency of use of each station of the slitter is different, so the degree of wear is also different. Therefore, there will be a certain difference in performance. For example, there are fewer vertical stripes for slitting products in a better condition. On the contrary, there are more longitudinal stripes. Therefore, each operator must pay attention to the correct choice of workstations, give full play to the best state of the equipment, grasp the on-site usage, constantly sum up experience, and find the use of the best features of the equipment.
4. Ensure the cleanliness of the film
In addition, it should be noted that during the slitting process, each roll of film is reopened and then rewinded, which creates conditions for the entry of foreign objects. Since the film product itself is mainly used for packaging food and medicine, Therefore, the hygiene requirements are very strict, so it is necessary to ensure that each roll of film is clean.
Slitting production control points
1. The cutting material is consistent with the process sheet.
2. The discharge direction of the slit product roll is consistent with the craft sheet.
3. The position of the cutting knife of the slitting product conforms to the requirements of the process sheet or the pattern.
4. The width of the slit product is consistent with the size required by the process.
5. The end surface of the slitting product roll body is flat, without wrinkles and tendons.
6. Printing and composite quality (overprinting, lack of printing, tailing, cutting lines, ink dirty, bubbles (spots, grains), wrinkles, lack of glue lines, and dirt) problems are all eliminated.
7. The roll material of the slitting product is hygienic, free of oil, paper scraps, and diaphragms.
8. The photoelectric detection object is selected correctly, the photoelectric detection head has high sensitivity, and the correction motor moves quickly.
9. The tension of unwinding and rewinding is set properly, and there is no running around, stretching and wrinkling.