HERMA: More safety for transparent (tamper evident) labels

With the innovative HERMA 62L luminophore adhesive, the presence monitoring of transparent labels becomes more reliable. This results in clearly improved safety – for the product manufacturer as well as the product user. Security features, for example for protection against product piracy, are in great demand in many industries. They have even been legally prescribed for numerous pharmaceutical products across the EU since February 2019. To make manipulation attempts visible, corresponding closure labels are often used, for example on folding boxes. They can be applied particularly economically without having to change existing packaging. Because these and other labels on pharmaceutical packaging are often transparent for optical reasons, their seamless and reliable presence monitoring using optical sensors is a challenge. That is why in the past labels were equipped with luminophores that become visible and detectable as soon as they are exposed to UV light. Generally, this was achieved with a special varnish that was applied to the labels. With the new HERMA 62L adhesive, the luminophores are already integrated during the coating of the adhesive bond. "The coating of the adhesive takes place with a precision and uniformity that is clearly superior to typical commissioned varnish work," says HERMA's head of development, Dr. Ulli Nägele. "This allows us to achieve a better and complete distribution of the luminophores. We also no longer have to monitor whether the varnish was actually applied everywhere and whether there may have been any glitches." In the 13-stage Laetus scale, which is used to measure the intensity of luminescence and which is used as a virtual industry standard, the 62L reaches a value of at least 7. This is the value that is usually required for pharmaceutical applications.

Adhesive ideal for no-label-look

The 62L adhesive used here is distinguished by additional advantages. Due to its high transparency and an extremely high whitening resistance, the 62L is on the one hand predestined for use in no-label-look labels, including for subsequent printing in multi-coloured UV-printing. On the other hand, it is distinguished by its high tack with very high cohesion in conjunction with very good final adhesion. This high cohesion helps to avoid adhesive leaking. In addition, the UV stability of 62L is extremely high. 62L also has especially good resistance against light, heat, water and ageing. It will also be low-migration.