Pressure sensitive labels are plastic or paper labels with adhesive pre-coated on the back to adhere securely to the packaging surface. “Pressure sensitive” logo surface labels adhere to the container when pressed against the container surface. This type of label is a common labeling solution for many rigid plastic, glass and paperboard round containers and many flexible packaging bags.
Pressure sensitive labels are available in two forms, one is a single label suitable for manual application, and the other is a roll label suitable for mechanical application on high-speed production lines. To avoid premature activation of the adhesive, a protective plastic-coated release paper is used to cover the adhesive surface area. This paper is peeled off and discarded before the labeler applies the label.
If the pressure sensitive label is marked with production or required regulatory codes, it can be coded after labeling using CIJ (continuous inkjet printer) or laser systems
In early packaging operations, the brand and other required information were often printed directly on the packaging surface. This method of marking is slow and costly, and requires the container surface to be very smooth and ink-friendly. The subsequent development of hand-applied labeling has improved productivity to a certain extent and made packaging more cost-effective. By using a variety of labels, packagers are able to use the same container format for multiple flavors or recipes and only need to change the label to identify them. The introduction of pre-applied pressure-sensitive adhesives and automatic labelers have made labeling solutions efficient in packaging operations.
Early pressure-sensitive adhesives allowed labels to be permanently fixed in place. Recycling rigid glass and plastic packaging requires the removal of labels. As recycling became more widespread, adhesive manufacturers developed water-soluble pressure-sensitive adhesives that allow labels to be easily peeled from packaging before recycling. This feature also allows packagers to reuse unused labeled packaging to remove the label and replace it with a new one.
Until now, pressure-sensitive labels have been commonly found in rigid plastic and glass containers for food packaging, and are increasingly being used on flexible packaging.