If nothing is allowed to show through the label material, label printers have usually had to make compromises: Either the selection of appropriately colored label materials is very small, or you have to use a material with a colored adhesive. However, due to the carbon black particles usually used, this has different properties to a conventional adhesive - and is certainly not suitable for direct food contact. These compromises are now a thing of the past.
With the innovative HERMA multilayer technology, most label materials can be made opaque very flexibly - without affecting the adhesion properties of the adhesive, but with the greatest possible migration security.
HERMAperfectOpaque range of pressure-sensitive adhesives is able to cover even critical applications where, for example, extremely high initial tack is required or damp and/or cool substrate surfaces occur. The opacity achieved with the multilayer technology corresponds to the opacity that can also be achieved with previous methods, without the need for lengthy and complex adhesion and processing tests.
This is accompanied by a very high degree of flexibility, as label materials and pressure-sensitive adhesives can be optimally combined again and again for the respective opaque application.
Advantages
- Migration-proof due to innovative colour pigments
- Only the intermediate layer is colored and therefore has no effect on the adhesion properties
- HERMAperfectOpaque can even reliably cover critical applications (cool/humid).
- Label materials and adhesives can now be combined flexibly and optimally for the respective opaque application
- For the first time, opaque thermal eco labelstock can also be produced without a barrier layer
- Better opacity for lasers, e.g. scanners
No new adhesion and processing tests required
The principle of coloring the adhesive is nothing new. However, the usual use of carbon black inevitably changed the adhesion properties of conventional, single-layer pressure-sensitive adhesives.
Until now, it was also unthinkable that a pressure-sensitive adhesive colored in this way would receive a certificate for direct food contact. With multilayer technology, only the intermediate layer is colored with a new type of colour pigment that is approved for direct food contact. The adhesive layer, which acts directly on the substrate, remains unchanged. As only proven standard adhesives are used for this "adhesion-effective" layer, HERMAperfectOpaque can be used without any problems and without the need for lengthy and costly adhesion and processing tests. This is accompanied by a very high degree of flexibility. In this way, label materials and pressure-sensitive adhesives can always be optimally combined for the respective opaque application.
Opaque Thermo-Eco adhesive materials
With HERMAperfectOpaque, it is possible for the first time to produce opaque Thermo-Eco Self-adhesive materials. This is because the new colour pigments - in contrast to the carbon black used previously - have no influence on the thermal reaction. As it has not been possible to colour Thermo-Eco papers until now, HERMAperfectOpaque is a completely new product.
Dark blue colour preserves the whiteness of the labels
The intermediate layer is dyed with dark blue colour pigments. Tests in our development laboratory have shown that it is not possible to increase the opacity any further with black, but that the whiteness of the label material is impaired as a result. In our opinion, dark blue is the better choice because it preserves the whiteness.
Opaque labels are often used, for example, to cover misprints and to localize imported or re-imported products. As the range of products and packaging is very wide, the gain in flexibility for label printers is an important advantage. This applies both in terms of the label materials that can be used and in terms of application security.
