1600mm Width Adhesive Bopp Tape Slitting Machine
Main factors affecting tension stability：
(1) The change of the speed of the machine will inevitably cause the change of the tension of the whole machine.
(2) During the process of collecting and unwinding, the winding and unwinding diameters of the slitting machine are constantly changing, and the change of the diameter will inevitably cause the change of the material tension. When the unwinding torque is constant, the diameter is reduced and the tension is increased. The winding is reversed. If the winding torque is constant, the tension will decrease as the winding diameter increases. This is the main factor that causes the change in material tension during operation.
(3) The change in the tightness of the raw material roll will also cause a change in the tension of the whole machine.
(4) The unevenness of the material of the raw material is cut. If the material elasticity fluctuates, the material thickness changes along the width and length direction, the mass of the material roll is eccentric, and the temperature and humidity of the production environment change, which also affects the tension fluctuation of the whole machine.
(5) The various transmission mechanisms (such as guide rollers, floating rollers, flattening rollers, etc.) of the slitting machine have factors such as imbalance and unstable air pressure.
Causes, countermeasures and effects on the quality of BOPP film slitting quality ---
One. Winding too loose / too tight
Among the many factors affecting the quality of product use, the tightness of the film roll is critical, and the tightness control is moderate, which not only ensures the quality of the slitting, but also compensates for the quality defects caused by the film making process, but the tightness of the winding. Improper control will inevitably directly affect the quality of the product. As a metaphor, if we compare the film formation to the process of producing rice, the cutting is the cook of the rice. The quality of the rice is important, but the cooking time can not be sloppy, in the various control indicators of the cutting. The grasp of the tightness of the winding is like grasping the amount of rice water used in the cooking process. The lack of water and water must have a direct impact on the quality of the rice.
(1) Several methods for judging the tightness of winding
1. Acupressure test method: the examiner presses the surface or end face of the film roll by hand to judge
Whether the volume tightness is suitable. This is a commonly used test method. The advantages are fast, intuitive, and highly reliable, but it requires some experience, lack of data support, and difficulty in recording. 2. Hardness measurement method: The hardness is measured by using a durometer, and the data is spoken.
The advantages are scientific, quantitative, convenient recording, and less disputes on judgment differences. The disadvantage is that only the surface of the film roll can be detected, and the facts inside the film roll cannot be reflected.
3. Visual analysis method: judging the film roll by visually changing the color change of the end face of the film roll or the shape of the end face
For the same product, the darker the end face, the tighter the winding, especially at the near paper tube. The tightness of the winding is often black; for the end shape, the star is the best. According to the judgment, the appearance of a single star may be the phenomenon of tightness of the film, and the occurrence of double stars should be caused by the tightness of the film. The advantages of visual methods are fast and accurate, but they can only analyze some individual winding problems, which is not comprehensive enough.
4. Process tapping method: tapping the membrane surface with a rigid object during the slitting and winding process, through the feel
And the sound to judge the tightness of the film roll, this method can track the film winding tightness from the inside to the outside, the accuracy and credibility are higher, but it will damage the film surface and have certain operation. Dangerousness, we have forbidden to use this method to test the tightness of film roll since 2000. This method is currently only suitable for non-conventional occasions such as product development, slitting control analysis.
Although the current tapping method is not allowed, we use a combination of acupressure test, hardness measurement and visual analysis in the daily slitting process. There is sufficient means to accurately determine the tightness of the winding. Judge. Since the hardness test method is less used in the film industry, the time for using this method is also short. The test method is introduced below.
Reasons, countermeasures and effects of BOPP film slitting quality ---
Another reason for the burrs is the quality of the parent roll.
First, when the mother roll product is wrinkled, the burr phenomenon is likely to occur when the film is cut to the sipe roll and the film is not effectively flattened;
Second, when the film is thick or thin for a long time, the film is prone to burr phenomenon when the film is not attached to the sipe, especially in the triangular position of the thickness. In addition, since the thinner the film, the lower the stiffness, and the higher the chance of burrs.