The production process of the protective film is generally assembled in the steps of material selection, blown film→printing→coating→quality inspection→rewinding→cutting. Generally, the rewinding and cutting are arranged at the end. For many protective film manufacturers, the complex the focus of the slitting is not enough. In fact, the process of rewinding and cutting the protective film should be taken seriously and must not be taken lightly. This paper summarizes the purpose of the slitting, the process flow, etc., to ensure the stable quality of the slitting of the composite membrane.
First, the purpose of the protective film slitting
1. Provide accurate specifications according to user requirements.
2. In the case of slitting and unwinding, the composite large-volume composite film can be re-inspected during the extrusion process of the entire previous process to see if there is any quality problem.
3. It can correct the fault layer of the composite film or cut off some defects of printing and compounding, and improve the grade rate of the product.
4, It can keep the finished product to get a good winding state.
Second, the protective film slitting process
When readying to start, first check the appearance of the large film roll of the previous process, printing, and compounding, and test the hardness and appearance flatness of the large film roll to see if it can meet the requirements of cutting. Then, fully understand the performance of the slitting equipment that is about to run, and check the main operating parts and electrical control parts of the equipment. At this time, a large film roll is made, the blade is adjusted according to the specifications required by the user, and the production is started according to the normal production process.
The normal operation of the slitter is the basis for ensuring the quality of production. Because each slitting machine often runs at high speed for a long time, the running accuracy of some important key components will be reduced. This is difficult to ensure the running accuracy of cutting small-sized film rolls. Because the composite film is a polymer product, its thickness is relatively thin, and it is easily damaged during processing. Therefore, when the running precision at the time of slitting is insufficient, quality problems such as vertical streaks are likely to occur on the film. To this end, after years of observation and research, we have confirmed that the vertical stripes generated in the slitting are the main quality problems in the slitting and must be solved.
When entering normal production, the speed of the slitter should be strictly in accordance with the process requirements. Too high will also affect the quality of the cut. Therefore, by controlling the slitting speed, the quality required for slitting can be obtained. Because, in the production, some operators in order to increase production, improve their own economic benefits, artificially increase the slitting speed, which will make the film at high speed, prone to vertical streaking and staggered quality problems. Therefore, in normal production, we must use the appropriate slitting process to produce according to the performance of the equipment and the intrinsic properties of the film and the different 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. In the production, the frequency of each station of the slitting machine is different, so the degree of wear is also different. Therefore, there will be some differences in performance. For example, for a station with a better condition, the longitudinal stripes are less. On the contrary, there are more vertical stripes. Therefore, each operator must pay attention to the correct choice of the station, play the best state of the equipment, grasp the use of the scene, constantly sum up the experience, find the best use of the equipment.