Reasons, countermeasures and effects of BOPP film slitting quality ---
Deviation refers to the phenomenon that part of the film on the end face of the film roll is misaligned, which is caused by the sliding of the film during the winding process.
2. Causes and countermeasures of deviation:
(1) The problem of the quality of the slitting in the same category as the deviation of the end face is, in terms of degree, the degree of misalignment is more serious than the misalignment of the end face; in terms of nature, the general end face is not a continuous problem. However, the deviation is mostly an accidental problem; from the analysis of the reasons, the cause of the unevenness of the end face may cause the occurrence of the deviation problem.
(2) Since the deviation of the deviation from the end face is more prominent, the eye point should be placed in the fine point when the end face is not aligned. When analyzing the deviation problem, the eye point should be widened, especially the factor of the cutting speed. The effect is that the acceleration and deceleration are too rapid. For a film with good smoothness, it is easy to cause slippage and cause a split layer, and the slitting speed should be slowed down.
(3) For products with narrow slitting, too tight winding of the film roll will cause the film to slip laterally. If the film roll is too loose, air will be trapped, which will cause the film roll end to be staggered. Roll tension.
The basic knowledge of the slitting machine and its development process --
Basic knowledge and development of slitting machine
In the modern packaging industry, the slitting machine is a relatively important equipment that is often used before and after printing. The raw materials are mainly cut before printing, such as paper, plastic film and so on. This is a process that raw material manufacturers must complete in order to meet the width requirements of packaging manufacturers such as customers. The slitting machine is used to divide the printing and composite film of a plurality of sets of patterns of a fixed width into a finished film roll to adapt to the subsequent automatic packaging and bag making process.
With the improvement of flexible packaging automation and consumer goods manufacturers focusing on reducing the inefficiency and pollution of intermediate links, some manufacturers have gradually changed the process and replaced manual packaging with more automated automatic packaging lines. As the demand for coils continues to increase, the position of the slitter is becoming more and more important, and higher requirements are placed on the efficiency of the slitter.
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