How to Use Expander Rolls (Install Locations)

Expander rolls are effective in removing wrinkles and slack that occur on the web during transport.
Here, we will explain the basic usage and install locations of expander rolls.
 

When does wrinkles and slack on the web become apparent as defects in sheet products?

At our company, we consider that wrinkles(troughs) and slack at elastic region during the transport process are not particularly problematic. When some operation (processing) is performed, those wrinkles (troughs) and slack develop to creases. In other words, there is no need to install expander rolls at every location where wrinkles occur. This is the basic concept of installing expander roll is “Install in the key points”.

Let’s look at specific installation locations.

Location 1: Just Before Performing an Operation (Processing) 

For example, just before operations would be coating, laminating, slitting and winding. If there are wrinkles when performing these operations, it could not be possible to coat, laminate, cut, or wind properly. Therefore, the idea is to install expander rolls just before these operation process to remove wrinkles and slack. Just before operation process does not exactly meaning of installing the expander roll just before the roll operating. Example in winding process, the diameter of the winding roll changes, the contact angle of the expander roll will also change. We recommend of installing straight roll between expander roll and operation roll.

Remove Wrinkles (Troughs) to Complete the Operation good

Wet Coating Process	Laminating Process	Slitting Process
UV Treatment/Corona Treatment Process	Dry Coating (Vacuum　Deposition/Sputtering)	Winding

Location 2: At or Before the Point Where Creases Develop

If the wrinkles and slack that occur on the base material develop to creases due to drying process or high-tension transport, the location to install expander roll will be “at” or “before” the point where crease occur. If there is a roll that obviously developing the wrinkle to crease, replace that roll to expander roll. If the replacement is not possible, add expander roll before crease developing roll.
Recently, this usage has been particularly common with metal foils for secondary battery electrodes. Base material coming out of high-temperature dryers rapidly cooled and this temperature change leading the development of creases, which are prevented by expander rolls.
High temperature exposed base material come out from dryer will rapidly cooled and this temperature change will cause the crease. Expander roll is also used to prevent this crease.

Prevent the Development of Creases

Dryer	Press Processing	Dyeing, Washing, Chemical Layer

Metal Foil for Secondary Battery Electrodes (Creases Occurring After Dryer Process)

Without Expander Roll	Resolved with Expander Roll

Summary

This time, we explained “How to Use Expander Rolls (Install Locations).” The use of expander rolls is not limited to this, but generally follows these two concepts. Our Variable Bow expander rolls can adjust the optimal wrinkle removal force during transport according to different web types and widths.

We also have wide variety of additional options that can adapt to various environment, and also items to contribute to labor-saving and automation [Wrinkle Detection System, Automatic Wrinkle Removal Device].
For inquiries related to this content or companies looking to solve wrinkle problems, please feel free to contact us through the inquiry form!