In the last couple of years, we have witnessed a strong growth of industrial inkjet printing in the interior decoration markets, such as ceramics, flooring, walls and panels, among others. In the meanwhile, inkjet is also a firm stakeholder in the label industry, in flexible packaging and folding cartons. More and more new implementations of inkjet technology take inkjet straight where it belongs: right into the production line.
Innovative inkjet solutions in the packaging world
Innovation is a process starting from a creative idea over evaluation, development and finally implementation. This innovation process applies to products, processes, structures, relationships, strategies and maybe also to you.
Today’s inkjet technologies have gone through a number of significant changes with regards to reliability (e.g. through flow TF architecture), quality and performance. These changes nicely combine with advances in new jet-able fluids and inks, with improved material handling, transport and finishing systems all leading to a new generation of cost effective printing solutions.
The scalability and non-contact capabilities of full colour inkjet systems have the potential of filling roles in package printing that cannot effectively be serviced conventionally. Over the next decade, more and more inkjet based printing solutions will find their way in the packaging world to enable product decoration, impacting how packaging is created, printed, distributed and managed. Inkjet could truly be a disruptive technology; you may not see it coming, and you notice it only when it’s too late, by which time your market position could be totally undermined.
Digital label printing leading the way
Label printers are familiar with the digital printing process for labels. It all started with the toner based HP Indigo and Xeikon systems, but during the last five years, a couple of new inkjet based label print solutions have joined them. Thanks to the success of the digital label print solutions and with an honest belief in the potential of digital alternatives, label printers started introducing digital print to help with product versioning, ever decreasing batches and customisation.
Brand owners also support that evolution and demand increased efficiency and flexibility. They have a holistic view, looking for solutions with smaller lot numbers, more personalised products, print-on-demand and just-in-time deliveries while eco trends drive material reduction, sustainability and carbon footprint.
Industrial inkjet solutions, jetting labels in the production line
Today, printing and converting are separate processes. Labeling is a labor-intensive process: labels are printed on rolls, often pre-cut, just to finally glue/transfer/attach/pull them on a box, container, bottle, tube or whatever needs to be labeled. Labels are expensive too, even though the costs don't stem from the printing as such, but rather from the substrate and the transfer materials, which are thrown away afterwards anyway.
No wonder that the industry thinks about taking product decoration and production into a single integrated process. Inkjet technology is key to that. Already today there are solutions available, to either work without transfer materials or to use inkjet technology and directly print on the bottle, container or tube. We will soon witness a marriage between printing and industrial production. That will not only reduce costs and simplify logistics, but it will also be more environmentally friendly by reducing waste. That is why more and more companies will think about reengineering, about simplifying processes while increasing flexibility.
First inkjet based direct product decoration for PET bottles
A first version of a direct print solution for printing on PET beverage bottles has been installed at Martens Brouwerij in Belgium for the printing of special campaigns. The system merges a variety of new and existing technologies into one brand-new production line, ready to take on new challenges from their customers.
Before entering into the specific benefits of the Martens Brouwerij print-to-PET-bottle case, let’s discuss the challenges to engineer and build such integrated inkjet based direct print solution.
Developing and integrating an inkjet based solution in a manufacturing line
The true virtues of the inkjet technology are scalability and non-contact; no more compromises, no image carrier, no step-and-repeat to fit short runs of labels of different formats and no limitations in material and widths. Robust inkjet heads with a choice of resolution, speed, and inks are available now and are highly reliable. However, inkjet technology is only part of the equation. Integrating a single pass inkjet system in a production line adds a different level of complexity: mastering the filling, handling, positioning and registration for printing on the bottles in a production-speed bottling system.
It sounds obvious that a leader in industrial automation systems (like KHS is known in the beverage industry) are the preferred partners to define the specifications for such a system, because they have access to the market, know the product requirements and speak the 'language' of their customers. They have the mechanical engineering expertise to guarantee high precision bottle handling, positioning and accurate motion control, and are thereby ready to find answers to the challenges of the development and integration of the inkjet building blocks to print directly on the bottle.
That is where industry experts meet
KHS has not disclosed too many details of the Direct Print system. They have been working on the solution for many years, and it is encouraging that KHS had worked on the development of the solution with industrial partners specialised in inkjet, for example Xaar and Agfa Graphics.
The Direct Print by KHS is commercialized by a wholly-owned KHS subsidiary, NMP Systems. It is configured with Xaar print heads optimised for single pass printing and it uses low-migration inks from Agfa. It will print with an optical resolution of 1080 x 1080 dpi at a speed of up to 36.000 PET bottles per hour.
The cornerstones for a successful direct product decoration solution are reliability, quality and overall performance.
As mentioned, inkjet printing is all about finding the ideal interaction between an inkjet print head, ink and surface. Good understanding of the inks, material surface tension issues, UV curing/pinning and finishing elements are important factors.
Setting up the right configuration, the vertical jetting station, jet straightness, firing and throwing distance control for variable drop volumes, perfect colour-to-colour registration (including white), dynamic fluid system and electronics and maintenance system, are all crucial to the system.
Not to forget about the digital image path. The availability of a digital front end and workflow system are new to this industry. It is required to initiate jobs, handle data, ripping, screening, color management and print engine operation control and will be a key element to drive productivity and ease the operation.
Decoration for PET bottles as an example, inkjet technology
The Direct Print equipment at Martens uses the Xaar print heads to jet text and images in five colors (CMYK+W), using low-migration LED-cured inks from Agfa directly onto PET bottles at the production rate of 12000 bottles per hour. The print heads use the TF Technology™; this ink recirculation architecture is key for any single pass inkjet system, as this will determine the reliability and productivity of the system solution. At head level the waveform-, voltage- and temperature-control are a must when combined with this through flow ink circulation.
Maximum reliability is achieved with these continuous flow heads; the right reflow rates for the inkjet heads for recovery of failing nozzles and a sufficient slight under-pressure to control meniscus. The jet straightness, the throwing distance (the distance from the nozzle to the bottle substrate) and drop formation all influence the image quality. Techniques like variable dot printing and appropriate software algorithms allow for smoothening distance tolerances and can assist to generate distorted imaging. Addressing these variable throw distances and controlling the drop formation is the combined result of jet dynamics and the fluid properties. Firing conditions such as pulse amplitude, pulse width, and pulse frequency will also affect drop formation. Finally, the UV ink’s viscosity, wetting performance, surface energy and careful control of drop spreading behaviour contribute to the control of dot gain, which is vital for a consistent image quality.
Some secret is definitely in the ink
Inkjet systems can only perform well if the inkjet head and the ink meet the criteria for heavy-duty production. A successful printing result can only be achieved if the correct jetting properties (particle size, latency, viscosity and surface tension) have been set for a specific inkjet head. If this is not the case, the ink may not jet at all, nozzles may fail or the nozzle jet direction might be slightly angled. As much as material compatibility between ink and the ink-supply system (tubing, manifolds, pumps and level sensing) is crucial, also conditioning the ink for optimal production performance, the jetting properties of ink and the interaction between the ink and the object surface requires specific development from the ink manufacturer. Typical properties of the inkjet ink are colour gamut, ink density, adhesion, light stability and scratch resistance.
In 2014, Agfa was awarded with the essenscia Innovation Award for these innovative UV-curable low-migration inks for use on the bottles. Without disclosing the specifics of the ink formulation, they explained the basics of their ink technology in many conferences and in articles published in specialist magazines (e.g. article in UV+EB Technology, Issue 3, 2015).
The concept behind a low-migration ink for printing directly on the PET beverage bottles is to limit migration through the substrate as much as possible, even for a thin wall PET bottle, which is the trend in the industry today.
For direct printing on a PET beverage bottle, many more requirements are demanded on the ink formulations to meet the customer expectations of adhesion, scratch resistance, flexibility etc.
Also impressive is that the digitally printed bottles fully support the existing recycling processes to be used again. Last but not least, it must have been a big challenge to design the inks towards the industrial reliability of constant jetting performance.
Martens Brouwerij: first direct print solution for PET bottles
Back to the original story now: the world’s first ‘Direct Print Powered by KHS™’ system in industrial-scale production and printing directly onto PET beer bottles was installed at Martens Brouwerij in Bocholt, Belgium and is operational since mid June this year.
The company uses this new direct product decoration system for a new application called the Talking Bottles Kampioenenbier. A new marketing campaign to promote the upcoming release of a movie 'Jubilee Generale' by a popular group of local TV actors 'F.C. Kampioenen' was the reason for the new beer and related printed images. The direct colour decoration on the bottles is combined with digitally printed QR codes and augmented reality. A special app brings the images of the actors printed on the bottle to life. They bring a small performance to your smartphone. When two bottles are scanned together, the app even starts a dialogue between them, very innovative and engaging talking bottles.
The entire set-up is a great example of creativity and innovation. The design and direct print solution for this late stage and customised packaging illustrate the capabilities of a truly complete digital world. The 'no label look' image on the PET beer bottles does not only inform, but communicates the message over a relatively small surface on the bottle. The QR code and augmented reality are instrumental to bridge the off-line and on-line communication, which fits perfectly with upcoming digital technologies, social media, online shopping, globalisation and the like.
Message on a bottle, the future
It is interesting to see how this new direct product decoration solution for PET beer bottles already deals with trends in the industry: short run printing, print-on-demand and customisation straight in the manufacturing environment. Digitally printed alternatives are the only way to tackle these challenges. Thanks to the non-contact inkjet printing technologies that are available today, it is possible to print on a wide range of industrial surfaces. The single pass printing concept is ideally suited to take inkjet into the industrial packaging-converting-production lines.
Technology drives business innovation and customer requirements drive technology development. Beyond the technology, there are many drivers in favor of integrating print at multiple stages in the product supply chain: just-In-time procurement and logistics systems of major retailers, environmental initiatives aimed at reducing packaging, and the demand for customised and regionalised labeling within global distribution models.
These are powerful arguments for consumer producer groups to integrate print activity in the in-line packaging process, aiming at serving customers better and potentially saving costs by integrating production with customer consumption, reducing lead times, 'versioning' products and most certainly offering sustainable products. Everybody in the 'value chain' will benefit from better-planned production, reduced levels of stock and a tight connection to the order process.
Will ‘packaging’ converters rigorously re-engineer their business processes? Many of them have been working for decades with their existing equipment and print technologies and may not see the new possibilities today. But the message on a bottle is clear: doing things like we used to is not an option; packaging converters will eventually embrace these new digital technologies and admit the need for change. As a believer in single-pass inkjet, we know the challenges and we are convinced that direct print will take bottle printing (as an example), whether in-line or near-line, into the manufacturing process as an integrated part of a production-speed system.
Is there any beer left in the bottle?