As far as embedding the thread in the paper is concerned, what challenges do they face today?

Stephan Morgenstern: When it comes to the technical embedding process alone, it has already gotten exciting with the coil: from originally small thread coils with a diameter of 12 centimeters, we now use coils with a diameter of 25 centimeters and a weight of up to eight kilograms. In order not to overstretch the narrow safety threads here, they have to be tension-controlled and thus unwound in a driven manner. The threads are also getting wider and wider, and we mainly use threads with a width of three to five millimeters.

Does this mean that the biggest hurdle, both in terms of handling and processing, is first of all the thread width?

Morgenstern: Yes, because the larger the water-impermeable surface – and that's what a foil is – the more difficult drainage becomes. Very simply explained, we apply fibers in high dilution to a mesh and then dewater until the initial sheet formation. And during this sheet formation process, we then introduce a relatively wide, thick „disturbing factor“ in the form of a plastic film.

Stephan Morgenstern, Head of Paper Production

The thread as the papermaker's „enemy“?

Morgenstern: I wouldn't call it an „enemy“. But in the pure doctrine of the papermaking trade, in which every manufacturer is trimmed to get his paper as pure as possible, everything that is not a paper is a nuisance. Because it can lead to impurities and deposits in the paper machine, and in the worst case, the threads stick to the drying cylinder. Our task now, however, is exactly the contrary: to combine the two opposite worlds, to marry paper and film.

And this wedding calls for foil experts such as Patrick Engelmann?

Morgenstern: Ideally, yes, no marriage works on its own, at least not in the long run (laughs).

Patrick Engelmann: Of course, a blank sheet of paper is easier to print than a paper with four-millimeter-wide security threads. That's why both the foil mill and the paper mill need this close cooperation. Because in this way, new challenges, for example, due to more or greater effects, can be tackled in a targeted manner in close cooperation and also driven forward efficiently.

»As the „depth of effects“ increases, we also need a corresponding „depth of control“«

What new challenges do you face in terms of thread production?

Engelmann: The complexity of the effects and thus the layer structure of a thread is constantly increasing, and at the same time, the threads are becoming wider and wider. For the coating process itself, these two variables are crucial: width and thickness; everything else is „only“ pleasing to the eye.

But the eye ‘reads' too.

Engelmann: Sure, and after all, the purpose of modern security threads is to „carry“ optical effects. This is where both the human eye and our inspection systems play key roles: Because before the owner and user can identify the authenticity of a thread based on its appearance in everyday life, a clear evaluation is required, from the question of whether the thread is embedded on the correct side with regard to the placement of the windows.

Morgenstern: As the „depth of effects“ increases, we also need a corresponding „depth of control“. Our advantage is that we can coordinate more quickly, even with increased demands and complexities, and are not dependent on each opinion. It provides us, but also the product, with maximum security.

Patrick Engelmann

Patrick Engelmann, Project Manager Technologies, Threads & Foils

Alexander Huber, Product Manager Security Thread

In the mixture of effects and properties, how exactly does this "depth of safety" manifest itself?

Alexander Huber: In rapid authentication by the human eye, and this should be completely independent of external circumstances. Whether in bright or faint light surroundings, it must always be ensured that the effects prove: this here, what I am holding in my hand right now, is not a print, is not a copy. It is a clearly defined effect that leaves no unanswered questions.

Engelmann: And not just under laboratory conditions, but also in the evening in a restaurant, in a bar, at sunset or in full sun. There are plenty of counterexamples that look beautiful in a perfectly illuminated meeting room, but in difficult lighting conditions or when folded and creased, nothing at all can be seen.

Morgenstern: And then there's the fact that it's firmly attached to the paper. For me, security also means that I can't tear the thread out. That no one can get the idea of pulling it out, cutting it apart, and applying its parts to a second note.

Engelmann: This is where the close interaction between paper and film comes into play again. We can test and answer quickly and directly questions on-site such as: „What temperatures can the heat-sealing adhesive tolerate? How do we prevent the adhesive from tarnishing the effect? That it does not react with the film, but that it also possesses the highest possible adhesive properties?“

»As a system provider, we want and need to think beyond and beyond«

Does this mean that increasing demands are easier to meet when working as a „couple“?

Huber: Yes, also because by working together we can not only use the technologies faster, but also develop them further. Access to printing technologies that can mimic and beautifully print a banknote is so easy today that we, as a system provider, want and need to think beyond and beyond. But it also means that our technologies have to be qualified and industrialized.

And finally also fully integrated?

Huber: That is correct. We see the thread as an integral part of embedded security, attractively designed and equipped with appropriate machine readability. For us, „Unmatched Security From Within“ does not just mean that the thread is mechanically secure and cannot be detached from the paper. „Unmatched Security From Within“ also occurs in the thread itself, in that we can, for example, individualize the code embedded in the security thread using our MultiCode authentication technology – which makes it virtually impossible for counterfeiters to imitate the complex technology we use. But this also includes our registered thread embedding, which we offer exclusively: here, the thread is already registered during paper production. This ensures that the same effect is always visible in every window – which, in addition to even better authentication, offers an additional plus in security.

„Security by Complexity“, then?

Morgenstern: I would add: security by proximity. Safety needs proximity to reduce logistical barriers. This means that as soon as I have both technologies at one location in one location, I not only become more capable of acting and making statements for each product. Rather, I am in a position to process, assess and adapt the entire package, the complete system.

Engelmann: That may sound theoretical, but in practice it means that we are not 2,000 or 200 kilometers apart, but 200 meters. With the corresponding positive effects on delivery times, on coordination processes, on testing and inspection procedures. Each of our developers can stand next to the machines at short notice.

»We supply complete turnkey products from a single source in which everything is coordinated«

And experience their product for themselves?

Huber: That's right, and as far as I know, this is something that only we can offer. As a system supplier, we supply complete turnkey products in which everything from foil development to embedding – including state-of-the-art security features such as our MultiCode – and more is coordinated and functions from a single source.

Further Reading

RollingStar® i+ Security Thread
With RollingStar® i+ we have taken the visual impact and design possibilities for banknotes to a new level. Simple and fast authentication, outstanding visibility even in unfavourable lighting conditions and cutting-edge dynamics are among the highlights of RollingStar® i+.



Security by Design
Security technology and banknotes, that always means a forward-thinking and acting in advance – in the very best case in a tight interplay with banknote design. Learn more about the triad of design integration, inspiration, and identification.