Packaging has been a prime driver in the development of printed electronics, from RFID to QR codes and other digitally ‘readable’ data. The printing expertise, specialist materials, and conductive inks required to reliably create these ‘intelligent’ functions have long been a specialty of the label production chain – an extended value chain which is supported by a single umbrella organisation in Europe, FINAT, the international association for the self-adhesive label industry. Proactive participation in educating and supporting its member companies as well as the industry in general in newly-developing territories such as the printed electronics arena is an ongoing focus for FINAT, as innovation continues apace. A recent members-only expert webinar on printed electronics provided a valuable update on existing applications and potential opportunities for printers in the narrow-web flexo market – not just in packaging or labels.
New directions for label printers
Presented by Chris Jones of Novalia, a conductive print and capacitive touch specialists based in the UK, the webinar encouraged label industry delegates to think ‘out of the box’. “By combining extant mainstream equipment, consumables, and expertise, they can create state-of-the-art printed electronics that, in addition to scannability, bring the dimensions of touch, sound and vision into play to add real additional functionality or even ‘must have’ desirability to a product or its packaging,” explains Mr. Jones. “Today, as well as printed circuit boards and transistors, print can deliver a variety of other mainstream applications – including lighting, LEDs, photovoltaics, and even skincare patches, and features strongly in automotive, aviation, architectural and military applications and in pharmaceuticals and healthcare, toys, music, and of course brand protection and anti-counterfeiting.”
The world of the smartphone
In a world where the majority of the population has a smartphone, the opportunities to link up such instruments to interact, via printed electronics, with what would appear to be simple printed posters or other items is now attracting more and more interest internationally. Outdoor advertising and displays are good examples. As part of the launch for their new Flavour Shots herbs and spices range, Schwartz used a ‘sonic poster’ featuring Novalia’s capacitive touch technology. The paper poster, when touched, plays music wirelessly through a Bluetooth-enabled smartphone or tablet. Touching the artwork on different spots triggers musical chords that are meant to add an extra level of engagement with the new Schwartz products. It is conductive inks that turn the surface area of the paper into an interactive interface. Adding new dimensions such as sound or movement to display print is certainly an innovative way to enhance a consumer’s perception of, and interest in, a product.
There are also creative examples from the extended world of packaging Mr. Jones illustrates: “For example, a box of tissues that featured a playable piano keyboard on the side of the packaging, and multiple-pack secondary packaging for beers and cigarettes that also carried special printed ‘touch’ and ‘connectivity’ features. What consumer could resist the added value of such packaging?”
On a more serious note, pharmaceutical and healthcare applications add user-friendliness to alert a patient to the need to take his blister-packed medication – and enable the pharmacist/dispenser to check, thanks to a microprocessor in the pack, that the drugs were in fact taken at the right time in the right quantities.
The winning features of flexo print
For volume production of printed electronics, narrow-web label printers are particularly well positioned as providers. “While screen and gravure have their place in certain application areas,” Mr. Jones explains, “flexo has proved itself the most attractive print process for the job. Its combination of good print speeds and ease of repeatability; the high, consistent application weight of wet ink that flexo achieves; and the good range of available flexible, inexpensive substrates (paper, PP, PET), constitute an ideal combination. The conductive pigments themselves represent an additional consideration for the flexo printer – both in practical and cost terms – and, additionally, drying the ink is a key factor. Currently, evaporative solvent and water-based drying provide the desired characteristics. UV ink curing remains a challenge, because at this time it does not pack the ink particles together sufficiently. The process of printing conductive inks embraces, in summation, anilox specification, production speed, drying, and press consumables – all of which can affect the ‘sheet resistance’ of the conductive inks – the characteristic which is at the heart of a good result.”
Innovation beckons the brand owner!
“There is certainly a considerable and growing interest from narrow-web label printers in extending the range of specialist capabilities they can offer to brand owners. Their skills base and pressroom equipment can enable them to deliver printed items incorporating printed electronics in a variety of creative forms that go well beyond traditional functional/industrial applications and conventional label print,” Mr. Jones concludes.