Causes, countermeasures and effects on the quality of BOPP film slitting quality ---
(3) Causes of loose/overtightening of the film roll
1. The influence of the cutting parameters (winding sheet / pressure curve setting factors, etc.);
2. Effect of film properties (stiffness, thickness, single/double corona surface, smoothness, static electricity, etc.)
Ringing, the slitting parameters must be set according to the film with different characteristics);
3. The effect of the winding speed (when the winding speed is slower, the more time the slitting process is to discharge the air in the film roll, the tighter the film winding is);
4. Product specifications (width, length, collocation, etc.);
5. The influence of the performance of the slitting equipment (adjustability, stability, operability, etc.);
6. The influence of operational factors (professional level, operational skills, job responsibility, etc., generally expressed in the insertion
7. The quality of the work is wrong, such as poor air-suction, rewinding card head position, poor adjustment, and unwinding roller pressure; The influence of environmental factors (temperature, humidity, etc.);
8. Influencing factors of the appraisal system (Operator considers the appraisal of the secondary processing and rewinding indicators in the workshop, and often adopts the coping method of winding up and not loosening, which is one of the factors that cause the film roll to be over-tightened);
Reasons, countermeasures and effects of BOPP film slitting quality ---
twelve. Interface quality problem (poor interface quality, interface identifier does not match)
2. Interface identifier
Due to the large thickness of the film interface, the film roll for some applications must be properly handled at the interface to avoid unnecessary problems, such as slowing down, increasing the gap between the coating blade, and printing the offset plate. The interface products must be identified as necessary to facilitate customer identification and internal management.
1 The color of the adhesive interface is generally beige, special requirements are used according to the regulations. For example, Shanghai Ziquan requires the use of black adhesive tape; the marking method of the joint position is operated according to the regulations, such as Zhuhai Zhongfu Pearl Film, Shenzhen Ruimei The hot film is required to be marked at the ends of the interface with yellow paper dust protruding from the end of the film roll by about 1 cm; other special marks are operated according to the requirements of the production tribe.
2 Require the slitting workshop to mark the length number of the joint product without special requirements after the length of the label in the length column of the package label, and mark the “buter” mark on the note bar of the computer, and mark “+” on the remark column. Marking, pearl film and imitation paper film and exporting pearl film should indicate the length of each product before and after the joint on the length column of the product specification. For special requirements, the relevant marking work should be done according to the regulations (such as Shanghai Ziquan product port). The rate of less than or greater than 25% requires the number of interface products on each board product).
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