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[Material] Summary of common problems and solutions for protective film slitting and winding

Issuing time:2022-02-09 11:35

Why should the protective film be slit? Today, I will discuss with you the purpose of slitting the protective film and the common problems of slitting and winding the protective film.

We know that the purpose of protective film slitting is generally four:

①According to user requirements, provide precise specifications;

②When slitting and unwinding, the large roll of composite film compounded during extrusion and compounding in the entire previous process can be re-inspected to see if there is any quality problem;

③It can correct the split layer of the composite film or cut off part of the printing and composite defects, and improve the grade rate of the product;

④The finished product can be in a good winding state.


1. What should I do if the end face of the slitting film roll is poor?

There are about 3 reasons for this problem

Reason 1: Inaccurate photoelectric tracking during slitting


1. If the adjustment method and working state of the photoelectric eye are not selected correctly, they should be re-adjusted according to the requirements of the operating procedures.

2. The chromatic aberration of the tracking line is not obvious, and the chromatic aberration contrast should be increased.

Reason 2: The winding tension is small.

Solution: increase the winding tension, and add an appropriate amount of new magnetic powder to the magnetic powder clutch if necessary.

Reason 3: The film generates electrostatic accumulation, and adhesion or drift occurs between the films.

Solution: Connect the static-conducting device to the slitting device, and touch one of the antennae to the back of the film roll.

2. How are the longitudinal stripes on the surface of the film roll produced?

Longitudinal stripes refer to the formation of annular stripes on the surface of the film roll. Reasons for this phenomenon:

1. During the slitting/rewinding process, a large amount of air entrapment and poor accumulated thickness tolerance are the main reasons for the generation of longitudinal stripes. Once the serious stripes appear, it is difficult to eliminate them. One of the reasons is that the cutting speed is too fast. In general, longitudinal streaks and split-level quality issues are most likely to occur at high speeds.

2. The running accuracy of the equipment. For equipment that requires high running accuracy, after a long period of continuous use, the running accuracy of some parts has decreased. For large slitting machines, it is more difficult to ensure the running accuracy due to the large running parts. And because the plastic film is a polymer product, its thickness is very thin, and it is more likely to be damaged during processing, so once the running accuracy is not enough, it is easy to produce quality problems such as longitudinal stripes. So far, you should be careful when replacing equipment parts and accessories, and you should choose durable and high-precision components, and you must ensure a certain accuracy during installation, otherwise it will be difficult to meet the operating needs of the slitting machine.


3. Why does the bottom wrinkle appear?

Bottom wrinkle only occurs in a length of the film at the beginning of winding, and it is manifested as many and deep wrinkles and streaks, which are caused by many factors.

For example, in terms of process parameters, different types of slitting machines have different setting methods, methods and values of process parameters. The performance of the equipment itself and the intrinsic performance of the film do have a great influence on the quality of the film slitting and winding, but a suitable process can improve the quality problems such as longitudinal stripes and bottom wrinkles. Different equipment and films of different types and specifications 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.

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