What is a liner?
A liner is a paper or plastic film that carries and protects an adhesive as well as prevents it from unwanted early sticking. Liners allow the PSA to be wound into rolls for packaging and dispensing. Liners will often be thrown away after all processing but play a critical role in an application’s success. 3M™ release liners come in a wide range of materials like paper, poly-coated paper, polyester film, and HDPE film substrates and feature silicone release coatings to ensure you have the right product for your project.
Why? The liner is important to the cost and functionality of the application.
The performance of liners can have a major effect on processing materials in the:
- Coating & lamination processes
- Printing & converting
- Label application to end product
- Lay Flat (LF) properties: in applications processed in sheet form (i.e. labels) lay flat is CRUCIAL. If the product doesn’t lay flat, it can lead to curling which can cause costly problems in the printing & converting process.
Liner lay flat is affected by three variables:
- Resistance to humidity
- Dimensional stability when exposed to heat or cold
- Stiffness or thickness of a liner
What types of liners are there?
- Processed in a way to provide good tensile strength so they don’t snap when under strain.
- They often have a silicone coating applied to the top side which prevents the adhesive from adhering to the paper, this way the PSA construction can be separated easily.
- Film liner thickness is more consistent than paper and more tear resistant.
- Film is less receptive to humidity, curling less and better dispensing at high speeds.
- Can offer high clarity.
- The most common types of film liners are polyester & high-density polyethylene (HDPE).
See pages 14 and 15 of the 3M™ Converter Markets Selection Guide for a helpful chart of all the liners 3M offers.
As a 3M Master Converter, Tekra offers a full line of 3M™ materials. To connect with a Tekra contact, click here.