Four Shafts Bopp Slitting Machine Causes, countermeasures and effects on the quality of BOPP film slitting quality —2
Wrinkles (wrinkles, vertical wrinkles, cross wrinkles, wrinkles)
(2) Causes and countermeasures of longitudinal wrinkles
Longitudinal wrinkles mean that the surface of the film roll forms a circumferential rib line. In the process of slitting, a large amount of air entrapment or cumulative thickness unevenness is the main cause of longitudinal streaks, and it is difficult to eliminate the occurrence of a relatively serious stripe. When the longitudinal wrinkles appear in the slitting process, the tension is reduced and the pressure is applied to discharge the air in the film roll to improve the longitudinal wrinkle problem. However, the adjustment range should consider the impact on wrinkles and other aspects (according to relevant professional information, longitudinal wrinkles One of the reasons is that the slitting speed is too fast, and the film roll is most prone to the quality problem of the longitudinal stripe at high speed, but there is no obvious influence in actual production, which remains to be studied). Another reason for the vertical wrinkles is the influence of the running accuracy of the equipment. For equipment with high requirements for running accuracy, after a long period of continuous use, the running accuracy of some components has decreased. For large slitting machines, it is more difficult to ensure the running accuracy due to the large number of running parts. Moreover, since the plastic film is a polymer product, its thickness is very thin, and it is more susceptible to damage during processing. Therefore, once the running accuracy is insufficient, quality problems such as vertical streaks are likely to occur. For this reason, it should be cautious when replacing equipment parts and accessories. It is advisable to use durable and high-precision parts, and it must also ensure a certain precision during installation. Otherwise, it is difficult to meet the operation requirements of the slitting machine.
The flattening roller flattens the film and eliminates some of the longitudinal wrinkles produced by the film under tensile stress.
(3) Causes and countermeasures of cross wrinkles
In addition to the influence of the parent-rolling factor, the transverse wrinkles of the film are mainly caused by the sag-like transverse wrinkles produced by the loosening of the slit film roll. Generally, the slitting process is effective in reducing the wrinkles and reducing the pressure, and should be effective for different types of products. Adjusting the slitting and pressure can effectively eliminate the occurrence of cross wrinkles.