Why Does Thin Paper Start Wrinkling Near the End of the Roll?

When running thin paper, there is a problem that can be particularly frustrating: the paper runs well at the beginning, but things start to change as the roll gets smaller.

Near the end of the roll, the finished small rolls may come out curved, with one side lifting up or large wrinkles appearing across the paper. The finished rolls no longer look flat, and this can also affect conveying, packing and downstream use.

When this happens, the first reaction is often to adjust the knives or web tension.

But the cutting section may not be the real cause.

One area worth checking is the anti-curl frame, especially the aluminum tube and the supporting bearings at both ends.

After long-term operation, bearings naturally wear. Once the support condition at either end of the anti-curl aluminum tube changes, the parallel running condition of the web can also be affected.

Thin paper is particularly sensitive to this.

A small amount of web movement to one side can become more noticeable as the paper passes through the guiding and flattening section. By the time the paper is rewound into small rolls, the result may show up as one-sided curling, wrinkles or a curved finished roll.

Another factor is tension settings that are not properly matched to thin paper.

Thin paper behaves differently from heavier grades. If the same tension settings are used without adjustment, the web may run with too much or too little tension.

So solving a thin-paper problem is not simply a matter of turning the tension up or down.

The tension curve needs to be adjusted for the paper, while the parallel settings of the anti-curl system should also be checked.

When this is confirmed as the cause, there are usually three ways to deal with it.

First, remote adjustment.

If the mechanical components are still in good condition, the thin-paper tension curve can be adjusted remotely, together with the parallel settings of the anti-curl frame.

Second, on-site maintenance.

If the anti-curl aluminum tube or its supporting bearings are already worn, mechanical maintenance is required. The worn aluminum tube and supporting bearings can be replaced.

Third, equipment upgrade.

For customers who run thin paper regularly and in large volumes, an upgraded anti-curl roller sleeve can be considered. A wider and thicker roller sleeve provides better support and helps improve the flattening effect as the paper passes through the anti-curl section.

In thin-paper production, a problem that looks like a “paper quality issue” can sometimes be related to the way the web is running through the machine.

Especially when the problem appears mainly near the end of the roll and shows up as one-sided curling, large wrinkles or curved small rolls, the anti-curl frame, bearings, tension settings and guiding system are all worth checking.

After a machine has been running for years, even a small mechanical change can eventually show up on the paper.

If you are experiencing wrinkles, one-sided curling or curved small rolls when running thin paper, send CHM your paper specifications, roll diameter, running speed and production details, and our technical team can help identify the likely cause and the right solution.