Self adhesive label construction
Self adhesive labels (otherwise known as pressure sensitive labels) are made by printing onto a construction of 3 layers
- a release liner (otherwise known as the backing paper , carrier or glassine)
- a layer of adhesive
- the face material.
Self adhesive label release liner
The release liner is commonly made of paper and is silicone coated on 1 side (occasionally 2) to enable the label to be removed cleanly from the liner. Increasingly, especially for some high volume applications where automated applicator machines are used to apply labels at high speed, plastics are used as a release liner as they do not tear and break as easily as paper. Of the major industry suppliers, UPM Raflatac are currently advocating Polypropylene (PP) based liners with their ProLiner product, and Avery Dennison prefer Polyester (PET) liners.
The vast majority of labels we sell is still paper based though as it is the most established and proven product in the marketplace, and moving to a PP or PET liner generally results in an on-cost so you need to have a reason to specify it.
Self adhesive labels adhesives
In contrast the choice of silicone liner, there are many different self adhesive label adhesives to choose from, and making the correct choice is important if you want your label to stick!
One simple breakdown of the various adhesive types are as follows:
The majority of self adhesive labels we manufacture (say 90%) use water based acrylic Permanent or water based acrylic Peelable adhesives. For certain “high tack” applications and for labels that are exposed to moist environments then we may recommend a hot melt adhesive as it generally performs better. There are hundreds of special adhesives to choose from which can be based on water, hotmelt, UV or solvent based formulations for special applications, and if we feel that your application requires it we may recommend such an adhesive.
If you dont know what to specify and you have no imminent need to remove the label then a general purpose permanent adhesive is the best default choice. For other information please see our support page on adhesives.
Self adhesive labels face materials
There are hundreds of face materials to choose from but they broadly fit into one of these main groups. In this diagram, PE is polyethylene, PP is Polypropylene and PET is Polyester.
About 50% of the paper we manufacture are on paper, commonly coated white paper, and the remaining 50% is on synthetics, commonly PP due to its durability, cost and print quality. PEs are used for some flexible applications such as squeezable bottles. PETs are commonly used for higher strength and temperature resistant applications.
Self adhesive labels die cutting
Labels are die cut using blades mounted on a that penetrate through the face paper and the adhesive at high speed, typically 20-100m/min, but do not break the release liner.
Watch self adhesive labels being made
You can see the whole process of manufacturing self adhesive labels on our Youtube video: