Reasons, countermeasures and effects of BOPP film slitting quality ---
three. Irregular end faces
The end face irregularity refers to the unevenness of the end face which occurs when the film width is constant. The end face is generally in two forms: one is that the end faces are irregularly jagged, and the other is a regular wave-shaped irregularity.
1. Causes and countermeasures for uneven end faces:
1 The cutting parameters are not well adjusted. For example, if the cutting speed and the sheet/pressure are poorly matched, the sheet/pressure curve should be set according to the slitting speed;
2 abnormal vibration of the cutting device, overhaul;
3 divided and unwinding rolls are unbalanced and adjusted;
4 The parameters of the winding arms at both ends are inconsistent, and the force distribution of the winding process affects the flatness of the end face, usually the wavy end faces are not aligned and overhauled;
5 The influence of film properties, such as smoothness, etc., Ts, Pm and other models are more prominent, and the cutting parameters should be set according to different film characteristics;
6 film thickness is uneven;
7 Wrinkling during the slitting process will also cause unevenness of the end face and adjust the flattening film;
8 If the film is too static, improve the electrostatic properties of the film or check if the static eliminator of the slitter is invalid.
Slitting machine operation guide ---
7 Equipment maintenance
7.1 Daily Insurance Project:
A The main part (including safety protection) should be inspected before work (shift or interruption).
B Press the lubrication diagram of the machine and refuel before working.
C A cleaning job should be performed and the tools should be placed in place before the end of each shift.
7.2 The contents of the weekly insurance shall be implemented in accordance with the relevant provisions of the “Device Two Guarantee Record”.
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