While much consideration goes into the selection of face films and adhesives, the release liners are often an after-thought as the disposable part of a pressure sensitive solution. However, release liners are responsible for carrying and protecting the adhesive until the end-product is ready for its intended application.
The wrong adhesive release film could compromise your entire pressure sensitive product. The Ameri-Cal team will ensure the right liner is used for your application so problems like tunneling, tight release, and adhesive lock-up aren’t an issue.
How are liners judged?
Most release liner coatings are silicone based. Other kinds of liners exist, but silicone tends to dominate the market because of its excellent anti-stick properties, like low surface energy.
Release liners and their level of release are measured on a scale of 1-10 by most suppliers. This rating system measures how tightly the adhesive is expected to adhere before it releases as the liner is removed.
This rating is determined with a control release additive that is put into the silicone formula when manufacturing the liner product. Many applications will require specific levels of release. In the case of transfer films, multiple release liners are needed to meet needs.
Tunneling is a common release liner issue that is caused by a dimensional change.
For example, a small tunnel can form when the vinyl face stock is shrinking, and the liner can’t shrink with it.
Tunneling can also occur when the liner, often roll paper without a waterproof polyethylene coating, goes through the baking process and cools to room temperature. The collection of moisture can cause the liner to swell, and its increase in size can begin to create a tunneling issue.
Depending on the application, the level of release might need to be loose or very tight. This determination is often made based on the aggressiveness of the adhesive.
The more aggressive the adhesive, the more subtle the level of release liner to ensure the success of a product. If the wrong level of liner is selected, there is a potential for tight release or the inability for the liner and the adhesive to be easily separated. The contrast can also occur, and the wrong liner can lead to premature release.
A catastrophic error, adhesive lock up, is when the adhesive and liner system are completely incompatible.
This happens when the wrong adhesive and liner are matched, and the adhesive’s strength and the liner’s release are both too significant for the paper to be removed without total product failure.
We understand the importance of interactions between adhesives and release liners as they apply to trouble-free processing and ease of end application. If you are experiencing one of these common problems, contact us for the right solution.