Causes, countermeasures and effects on the quality of BOPP film slitting quality ---
(iv) Effect of film roll tightness on product quality
1. The winding is too tight:
1 fluttering/starting bone: As BOPP film, it is normal for the thickness of the product to fluctuate within a reasonable range. If the reeling tightness is appropriate, this thickness fluctuation will not affect the quality of use, but when the slitting is too tight The thicker layers of the film are stacked together to cause edge thickness or bone swelling, which affects the quality of use. The fluttering or bone formation that is formed by over-tightening is often difficult to find during the slitting process, but after the product has been stored for a period of time, the problem will be highlighted. In addition, there are several types of products with uneven thickness defects that can be easily revealed, such as ultra-transparent tape film, crystal film, heat sealing film, etc., while fluttering and bone-starting phenomenon will cause different quality of all film products. The degree of influence, especially for products that require printing and processing, is particularly prominent.
2 Adhesion: over-tightening of double-sided corona products, anti-corona products and products with less anti-adhesive content will cause adhesion quality problems, and the problem can only be found in the customer's use, the impact is great, and appears Products with adhesion problems can only be disposed of as scrapping, causing large losses to the company.
3 Face wrinkles: Due to the tight winding, the film cushioning performance is degraded. The wrinkles formed by the extrusion of the film on the end face of the product during handling and loading and unloading are difficult to eliminate, forming the end wrinkles and affecting the quality of the product.
4 Pitting: Due to the tightness of the winding, the film near the paper tube is affected by the rough surface of the paper tube, which causes pitting, which affects the quality of the product. The use of the polished paper tube will eliminate the surface of the film and improve it. Start wrinkles).
Slitting machine operation guide ---
Standardize operations, ensure product quality, improve work efficiency, and ensure safe production.
2 Scope of application
Suitable for aluminum foil slitting machine, cardboard slitting machine, tipping paper slitting 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