To control the quality of the slitting, on the one hand, it is necessary to control the stability of the large shaft film roll as much as possible, and the quality of the raw and auxiliary materials; on the other hand, it is necessary to adjust the slitting process in time according to the actual situation, so as to improve the cutting quality as much as possible. The properties of plastic films are different, and there are some differences in the slitting method.
Vertical stripes
Longitudinal stripe means that the surface of the film roll forms a circumferential rib-like stripe. A large amount of air entrapment and cumulative thickness tolerance during the slitting/rewinding process are the main causes of longitudinal streaks, and the more severe strips appear. It is difficult to eliminate. One of the reasons is that the slitting speed is too fast. Generally speaking, the quality problems such as vertical streaks and staggered layers are most likely to occur at high speed.
Split layer
There is a phenomenon that some of the film is staggered on the end face of the film roll, which is caused by the sliding of the film during the winding process or the change of the film width. The wrong layer is firstly related to the slitting speed, acceleration, deceleration is too fast, and smoothness is good. The film is prone to slippage resulting in a staggered layer, which should be slowed down. The film roll too tight will also cause the film to slip laterally. If the film roll is loose, air will be trapped, which will cause the film roll end to be staggered. , should adjust the take-up tension.
Bottom wrinkle
The bottom wrinkles only occur in a length of the film winding start, which is characterized by wrinkles and streaks and deep, which is caused by many factors. For example, in the process parameters, different types of slitting machines, process parameters The way, the method, the value are different.
For example: The old-fashioned slitter controls the winding tension by manually adjusting the winding motor voltage and uses the mechanical friction resistance to obtain the unwinding tension, while the new slitter uses the computer to control the winding and unwinding motors according to the input process parameters. The appropriate setting, unwinding tension, the parameter setting between the two is fundamentally different.
The performance of the equipment itself and the intrinsic properties of the film have a great influence on the quality of the film slitting and winding, but the suitable process can improve the quality problems such as vertical stripe and bottom wrinkles. Different equipment and different types of film should adopt appropriate slitting process. When the equipment condition changes, it can also be compensated by process adjustment, but the process adjustment must be cautious.
In addition, the most important raw and auxiliary materials for the slitting process are the paper core and the large shaft film roll. The quality of the paper core and the large shaft film roll not only affect the slitting speed, but also closely related to the longitudinal stripe and the bottom wrinkle. It requires process control, purchase inspection and The final inspection combined method to strengthen monitoring, stabilize the large shaft film roll and the quality of raw and auxiliary materials.
Sharp edge
The curling occurs at the edge of the film winding, and the edge of the thick film is wound up to make the edge portion lift up. The common reason is that the cutter is too blunt, and the stretching phenomenon occurs at the slit when slitting, resulting in rewinding. The edge of the film roll is turned outwards to cause the edge to be curled. In this case, the cutter should be replaced in time to avoid the problem of curling. The tool is not installed correctly, the take-up speed is too fast, and the curling is easy to occur when the take-up is too tight.
Ribbed
The gluten is a prominent protrusion formed on the surface of the film roll due to the thick thickness tolerance of the film. This is mainly caused by the quality of the film itself. The quality of the film itself refers to the already-formed large-volume roll that is slit or re-cut. The quality of the finished product, for example: the thickness tolerance of the film, the winding state of the film, etc., all have an important influence on the apparent quality of the film roll after slitting. The film of inferior quality cannot be satisfactorily even after slitting/rewinding. Apparent quality.
Slitting is only to improve local problems and not to change all the problems. To obtain good product appearance and winding quality, on the one hand, make appropriate adjustments when cutting, on the other hand, it is necessary to improve the quality of the previous film forming process.
Insufficient length, excessive width deviation
This is caused by incorrect winding count or insufficient length of the slitted film, and incorrect positioning of the device. In order to meet the user's need to obtain a certain length of film roll, in general, the operator can obtain the data from the winder. Winding length.
However, in production, it is often encountered in the case of rupture of the membrane and the removal of part of the film on the surface of the large-diameter film roll. If the calculation and cutting are performed according to the length of the mark, it is not until the slitting is found that the length is insufficient and the splicing is impossible. Products can not be genuine, especially the slitting machine with a width of more than 1 meter, the economic loss is even greater.
In order to avoid this, the length of the large shaft roll should be corresponding to the diameter of the film roll according to the model, specification and process. As long as the measured diameter data is compared with the winding length after the machine is on, Know if the roll length of the film roll meets the requirements. If the difference between the two is large, pay attention to the stitching length when cutting. Avoid the phenomenon of insufficient length.
There are dust, even small flying insects and other foreign objects in the film roll.
During the slitting process, the film needs to be reopened and then re-rolled, which creates conditions for the entry of foreign matter. Since many film products themselves need to be in direct contact with foods, medicines, etc., the hygiene requirements are very strict, purification The production workshop is very important to ensure that the product is clean.