Linerless labels have been taking over more and more of the market for some time. They have proven their benefits extend far beyond their use in the fruit and vegetable aisles of supermarkets. What should manufacturers and customers know?
Similar to regular household tape, the adhesive layer on linerless labels sits directly on the bottom layer of paper or film without a release liner. This brings a series of benefits: in addition to simplified production, the most noteworthy is the saving of material, since around 50% of standard labels are usually wasted.
In most cases, the label release liner used as a backing before use cannot be recycled. Work is underway to address this issue, but recyclable technology for liner sheets is still in the early stages of development. In general, liner sheets still need to be stored, transported and disposed of as waste. If this cost can be avoided, there will of course be an impact on the carbon footprint. Other space and cost savings can also be achieved; for example in shipping, since the linerless label only contains the product itself. It is also possible to produce more label material for the same roll size without using a liner.
Linerless labels have three layers. Essentially, it’s a piece of thermal paper or film with a layer of silicone on the front and an adhesive on the back. The information is printed immediately before using the thermal printer. In order to be successful, some details in all three components must be attended to.
Why use the right paper?
The key criteria for paper used for linerless labels is that it has a closed surface so that silicone cannot penetrate the paper, or that there is a surface coating underneath the thermal paper. If the silicone penetrates the paper, it can damage the adhesive hold on the reverse side. Rather, it is important that no part of the adhesive penetrates the paper into the heat-sensitive layer, as this would make the printed information illegible. Finally, paper quality will affect the die-cutting effect and cause more or less residue on the die-cutting blade.
Silicone coating
Choosing the right silicone is also important. Linerless label manufacturers purchase existing linerless self-adhesive materials or purchase their own paper and materials for coating. There are a few details to consider: If using UV-cured silicone—which is the norm—viscosity matters. If the viscosity of the silicone oil is too low, there is a risk of insufficient cross-linking when the silicone penetrates the paper. Instead, the surface of the paper must allow good anchoring of the silicone. The glue layer and silicone layer must be in direct contact on the roller. Here, too, the silicone must not be transferred to the adhesive, otherwise its adhesive properties will be impaired. Finally, the thermal head on the printer is also at risk of being contaminated by silicone.
Therefore, choosing the right paper and silicone combination is crucial. The best options may be slightly more expensive, but will help save you money in the long run.
Why choose the right glue?
The same applies to choosing the right adhesive; a key component of linerless labels. The ideal choice is a hot melt adhesive. The right hot melt adhesive will easily silicone peel from the resin layer, will not contaminate the printing press cylinder or die-cutting equipment, and ensure a strong bond of the label.
Hot melt adhesives are also characterized by high initial adhesion. This enables high-speed application of linerless labels. At the same time, hot melt adhesives are moisture-proof and low-temperature resistant. Modern hot melt adhesives also contain no harmful chemicals and are suitable for use in direct or indirect contact with food.
Here too, it pays to use high-quality equipment, as contamination of printer components such as rollers, cutting blades or printer heads can lead to downtime and significant expenses for professional cleaning and repairs. With the right hot melt solution, approximately 1 million labels can be printed and cut without serious printer failure.
In addition to hot melt adhesives, water-emulsion adhesives and solvent-based adhesives are also available for linerless labels. If one of these types is chosen, it is important to consider the moisture sensitivity of the paper. However, no matter which type you choose, the right combination of adhesive and paper is a key factor.
Application
The classic application area for linerless labels is the sales counter; for example, in supermarkets, fruits and vegetables are weighed by customers and then labeled. Hot melt adhesives also bond well to frozen products. Another typical use is at the fresh food counter of cheese, meat or fish, where the supermarket tallyman packs the purchased item in a bag and seals it with a label with all the necessary information. Especially driven by the rapid growth of terminal applications such as grocery stores, logistics and fast food restaurants, the latter two are developing rapidly, with an annual growth rate of approximately 15%.
Generally speaking, linerless labels are suitable for all application scenarios where variable information must be displayed quickly. This is why they are rapidly occupying markets beyond supermarkets: for example, as shipping labels on logistics cartons, in medical applications where personalized test samples must be accurately labeled, in field work for maintenance results on heating systems, on incoming and outgoing goods Label, and anywhere labels are typically required in mobile use. Flexibility won the day.
Siga provides permanent adhesive and removable adhesive linerless label solutions. Please talk to our linerless experts about your application.
