Color Printed Warning Tape Cutting Machine

Color Printed Warning Tape Cutting Machine

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.

Color Printed Warning Tape Cutting Machine

Reasons, countermeasures and effects of BOPP film slitting quality ---

eleven. Width deviation is too large
     The width of the film roll is limited by the gap of the sipe roll. The actual slit width will deviate from the width required for the order, but the deviation should be controlled within the tolerance range of ±2mm required by the national standard. The so-called width deviation Large, that is, the actual width of the film roll exceeds the requirements of internal control standards or customer standards.
     Not all products have a tolerance of ±2mm, and some customers can only take deviations from the film width, such as the Pd film of Kunshan Zhangpu, the LL film of Shanghai Zhicheng, the PL film of Beijing Amcor, etc. It is required to adjust the film width.

Color Printed Warning Tape Cutting Machine

Slitting machine parts ---


2. Attenuation and tension compensation of the tension of the rewinding and unwinding: It is generally believed that maintaining the constant tension of the aluminum foil during the rewinding and unwinding of the aluminum foil is beneficial to the apparent quality of the finished aluminum foil, but it is not. The best method is to increase the tension of the aluminum foil according to a certain rule as the diameter of the coil increases, and the smaller the diameter, the lower the tension value. There are automatic tension control and manual tension control during the slitting operation. The automatic tension control system is the leading set tension attenuation value, which is maintained throughout the winding process. The manual tension control requires the operator to continuously adjust the diameter of the master roll to meet the tension required for the aluminum foil during operation. When setting the automatic tension operation, set the initial tension before setting the tension attenuation value. Taking the setting of the slitting and unwinding attenuation value as an example, the setting principle is that the aluminum foil tension attenuation value (%) is equal to the tension at the end of winding of the aluminum foil minus the initial tension and then divided by the initial tension. Multiply by 100%. When setting the automatic tension value of the unwinding, it should not be too large, otherwise the aluminum foil winding surface has a large hardness and is prone to warping. But the tension should not be too small, too small and easy to cause the rewinding body to be too loose, and the winding is not neatly running. Therefore, the quality of the rewinding and unwinding during the aluminum foil slitting operation is mainly affected by the change of the tension of the aluminum foil. It can be seen that the mastery of the retracting and unwinding control system is the key to affecting the quality.

3. The change of speed during slitting affects the change of tension: When the speed is increased or decelerated, the speed of the main motor changes. Firstly, it causes the instantaneous change of the tension of the unwinding traction to the winding section of the aluminum foil, and it is necessary to slightly vibrate the aluminum foil after a period of time to gradually stabilize the tension. The instability of this tension is manifested in the fact that the finished roll is not well-wound, and the end face has unevenness, which affects the quality of the product.


Zhengzhou EAST IMPORT AND EXPORT co., ltd . ( a goulian group of company) a manufacturer and exporter for all kind of packaging machinery , like bopp tape coating machines, bopp tape slitting machines. Bopp tape core cutter, bopp tape core loader etc

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