process · 2014-04-10 · process - Durst news for the science and application of inkjet printing - Issue 10 - April 2014 2 Editorial Laminated decors, as frequently used in the furniture

process - Durst news for the science and application of inkjet printing - Issue 107 - April 2014 1

NewsDurst Industrial Inkjet Application GmbH exhibits at Inprint (Hanover, 8-10 April) with a new product portfolio.

InstallationInvesting in the future

Science & Technology“Multi-pulsing”. Impact on channel acoustics in piezoelectric drop on demand printheads

Media & HandlingModified Heavy Duty 60 roll unit for the Rho 1000 series

ApplicationA fine tribute to Nelson Mandela

processDurst news for the science and application of inkjet printing

107-04-2014

Editorial

Upwards and onwards to new business areas, or strategies for pioneers

In 2014 there should really be little reason for concern. With the Football World Cup in Brazil and its many events and advertising campaigns in the midst of the best summer weather, the printing industry should be expecting a boom. Yet in the light of constant pressure on prices in many areas and the restructuring of advertising and communication budgets in other areas, many suppliers are asking themselves what will come next?

Fespa’s “World Wide Survey” initiative is a worldwide survey of manufacturers and sellers of printing products and provides probably the most comprehensive examination of developments in the printing industry. This has been compiled in collaboration with InfoTrends, as was the last publication in 2010. Ron Gilboa, Director of Functional and Industrial Printing Consulting Service at the consultancy firm, presented some of the results of the current fourth study at the Fespa Global Summit held in Munich in March. He entitled his twenty minute lecture “Existing application as the springboard for future strategies”.

The study considers printing photos and building plans, as well as addresses and barcodes, to be mature markets. According to Gilboa, these should nowadays be regarded as volume business, only remaining lucrative with the highest degree of automation. Yet it is not only there, but in many areas of commercial printing, that the transition from analogue to digital has long since been unable to compensate for the overall loss of printing volume. A strong buyers’ market ensures that rapidity and quality are no longer criteria for awarding contracts, but are regarded as standard. The last purely analogue printing houses are increasingly re-equipping in the face of this development, saturating the market even more and thereby further fuelling the same unhealthy cycle.

This development can be observed right through to the large format and packaging markets. For applications which work in the widest sense on POS, the trends for personalisation and regionalisation suit digital printing. Large companies are distancing themselves from impersonal mass communication and are relying on a direct approach; the much observed Coca Cola campaign “Share a Coke with...” is only one example. Even specialist electronic markets today occasionally use the opportunity to package offers and bundles adapted to special promotions.


Editorial

Laminated decors, as frequently used in the furniture industry, for instance, are a further growth market for digital printers.

For textiles for fashion and home, digital printing has already largely superseded the analogue procedures which used to be the norm in Europe.

The running Coca Cola campaign “Share a coke with ...” addresses consumersdirectly and personally.

Digital printing on glass may have a decorative function, but functional coatings, such as those used in the manufacture of monitor screens, are becoming increasingly important.

Printed communication is still the most broadly effective channel, increasingly segmented across the target groups because to receive it the addressee does not need any expensive equipment. This is why printed products are increasingly becoming the springboard for innovatively interlinked campaigns. Many packages already offer QR codes which are readable by Smartphone or Tablet camera with product information, coupons or games. High performance mobile phones even make technologically advanced campaigns such as “McMission”, launched by McDonald´s in Autumn 2013, possible. Outer packaging and brochures were the trigger for Augmented Reality Experiences, the intention of which was to make the Group’s commitment to the topic of sustainability evident to a technically minded target group. For providers of print services, such complex campaigns mean that they can no longer simply rest on the laurels of their core competencies. They have to engage themselves in processes far removed from what is familiar and also introduce these.

This applies all the more in the areas identified in the “World Wide Survey” as strong growth sectors. “Decorative” printing covers a broad field of applications in which prints are embedded in industrial production. For textiles and tiles, digital printing has, to a large extent, already superseded the analogue procedures which used to be the norm in Europe and is now spreading worldwide. Digitally printed glass, whether a decorative architectural element or a functional coating in the automotive or electronic sectors, is also a strong growth area. However in many areas, especially for functional applications, we are still at the early pioneering stage. This also applies to 3D printing, which Gilboa includes in the “Functional Printing” segment. Half a dozen technologies are currently vying for for supremacy in the market, many of them only suitable for narrowly defined applications. What a difference from the graphics industry, where versatile procedures such as UV, Latex and eco-solvent printing have long since gained the upper hand!

This advancing technology offers a broad field of brand new possibilities in related markets to service providers for whom well-developed digital printing areas promise too few opportunities for profit, development opportunities and perhaps also personal challenge. From the springboard of traditional applications, they can move into exciting and profitable areas. But one printing services provider could hardly handle such complex tasks all by himself, he has to be a proactive team-player who not only accepts the client as a strategic partner on his route into the new world of printing, but also appreciates and supports him.


News

Graphic Communication Packaging Decorative Functional

Graphics Arts Functional & Industrial

Ink & Toner Materials

Paper ObjectsPaper/Board/Plastic Industrial Substrates

AddressingCADPhotoPromotionalPublishingSign & DisplayTransactional

Image printing on substrate Decorative and functional surface traetment

Brand protectionCoding/BarcodesConsumer LabelsCorrugatedDirect-to-shapeFlexible PackagingFolding carton

CeramicsGlass Architectural Automotive Consumer electronics Consumer goodsLaminates Wall/Floor covering WoodTextiles

3D Prototypes Tooling ManufacturingPrinted Electronics Semiconductors Displays Solar panelsBiomedical Pharmaceuticals Organs

Industrial Inkjet Printing vs. Large Format Printing

Durst Industrial Inkjet Application GmbH exhibits at Inprint (Hanover, 8-10 April) with a new product portfolio.

Durst Industrial Inkjet Application GmbH, a 100% subsidiary of Durst in Lienz, was founded to create new industrial markets for inkjet printing technology and to provide customer-specific system solutions. The aim was to cover those markets outside graphic printing which promise the highest growth rates for inkjet printing technology in the future. Inprint, which is held in Hanover from the 8th to the 10th of April in co-operation with the Hanover Trade Fair, will provide the first opportunity to present the new product range. DIIA, as the new company is called for short, will present the Rho IP 507 at the trade fair, which is designed to address the “printed electronics” markets. The printer, with its moveable vacuum table and new generation of printheads, is designed for printing membrane keyboards, switches, soldering paste and legends on printed circuit boards and will in future be used for printing sensors, as well as conductive inks. The inks used at present are UV inks with a high degree of bonding to plastics, and high plasticity, which are suitable for injection moulding procedures. UV hybrid inks, silver inks and functional inks will be added to these in the near future.In addition to 2 models (203 and 507) of the Rho IP printer series, DIIA will also produce the glass XY printer with inorganic ink (Glasstec this autumn) which will serve the furnishings and timber markets, as well as metal packaging (Metpack). Using samples, the whole range of printed materials will be on display at Inprint.


Installation

Investing in the future

Octink. The Exchange

Mike Freely, Managing Director and Brad Candy, Operations Director

Looking ahead to anticipated growth, Octink, a leading producer of signage, graphics and decorated interiors for clients in retail, events and construction, has expanded its capacity with an investment in two new Durst large format inkjet printers.

Mike Freely, Managing Director of Octink, which is based in Brentford, Middlesex, said: “The business environment is changing rapidly and investing in new equipment will increase our capacity. We’ve emerged from the recession stronger than ever, and now is the perfect time to invest in the next phase of our growth plan as we look to diversify and increase our client list.”

“We needed to expand our capacity to match our ambition, and while our existing equipment had served us well, we were eager to invest in print solutions that deliver even higher quality and productivity. This together with our need for colour consistency, which is vital for our work, led to our decision to invest in new equipment.”

“Our clients trust us with their brand identities, so colour consistency is vital,” continued Freely. “We provide a broad range of different products to big brands across Europe, therefore it is vital to their brand teams that we match corporate colours every time, on every graphic, regardless of where in Europe it will appear. A great example in the UK is the RHS Chelsea Flower Show, for which we produce thousands of signs of similar design for use all around the show. As one of the most prestigious shows on the event calendar, the RHS insist on the highest possible quality and colour consistency.”

The Durst P10 250 provides perfect consistency and is supported by Caldera software, which helps to ensure excellent colour management across different media and sizes of print.

Brad Candy, Operations Director of Octink, said: “The purchase of the new Durst large format inkjet printers was initiated because we wanted to increase both our capacity and the turnaround speed of printed work. We are handling increasing numbers of volume-based events, and expanding our capacity will help us to cope with growing demand.”

“We looked at several manufacturers’ products and finally narrowed the choice down to just two. We asked several people within the industry, including our suppliers, and they all recommended the Durst.”

“Having contacted Durst, I visited the factory in Lienz and I have been there now on three different occasions. Not only was I very impressed by the quality of manufacture, but also by the helpfulness of the Durst staff. They really cared that we only bought a machine that was the best for our business, and they all seemed like people we would be able to work closely with,” said Candy.

“I chose the Rho P10 250 because I was so impressed by the quality of print that was possible whilst still being providing a high level of productivity. Also the P10 250 is a true hybrid. It is capable of printing both roll and rigid media equally well, whilst maintaining amazing colour consistency and reliability.”

“We have also ordered another Durst large format printer - a Rho P10 160, and when this is installed later this year, it will fit in well with our mix of print requirements. The quality is, once again, superb and we believe the two machines will work well in tandem. The 250, with its ability to print 2.5 m wide, is a great advantage to our business, but it is not necessarily always the most efficient size for some work. The P10 160 at 1.6 m wide will fill that gap perfectly.” “Investing in the two machines will enable us to rationalise our large format inkjet printers. Before this, we were using between eight and ten different printers, so consistency of quality and colour could vary and had the potential to cause us problems. Ultimately, we intend to reduce that to the two Durst machines.”


Installation

Octink is committed to reducing its impact on the environment through day-to-day business practices that encourage sustainability. The company’s environmental credentials comprise both ISO 14001 and ISO 9001 compliance, and this, together with the complete recycling scheme that the company offers clients, has led to Octink being featured on The Sunday Times Best Green Companies list three times.

“Our ‘green credentials’ are as important to many of our clients as they are to us,” said Candy. “Naturally, the fact that the Durst printers will help to support this goal with their VOC-free inks was an important factor in our decision.”

“Having now seen the P10 250 installed and running for that past 3 weeks, we are very impressed by how quickly it has settled down,” added Candy. “Durst also trained all our operators, who are as excited as we are about the new machines.”

“We’re looking forward to a bright future in all areas of our business, and our investment in these Durst machines is an important step that will enable us to grow further,” concluded Freely.

About OctinkOctink is a leading producer of signage, graphics and decorated interiors for clients in the retail, live event and commercial and residential property sectors. The award-winning company’s 100-strong team is experienced at managing every aspect of clients’ projects, from concept and technical design, through to installation.

For more information on Octink visit: www.octink.com

Chelsea Flower Show and the Mercedes Poster at „The festival of speed „ – „Type of work that the Rho P10 will produce in the future“


Science & Technology

“Multi-pulsing”. Impact on channel acoustics in piezoelectric drop on demand printheads

In the last few decades, inkjet has developed into a dominant printing technology for many applications, with unrivalled flexibility being one of its greatest advantages. The term ‚inkjet‘ refers to two groups of very different technologies, which have the same goal in the final analysis, namely the precise generation of freely moving liquid drops. Precision is required in terms of the generated drop volume, the timing of the drop formation and the speed at which the drop moves. The two different types of technology are known as “continuous inkjet” and “drop on demand inkjet”. The scientific basis for describing the processes involved in both technologies was established by the Belgian physicist Joseph Plateau and the English physicist Lord Rayleigh in the mid 19th century. Plateau was the first to recognise and write about the relationship between the diameter of a jet of liquid and the size of the resulting drops when it breaks up. Lord Rayleigh published a series of scientific papers starting with “The Instability of Jets” in 1878. He was the first to realise that the surface tension of a liquid is the driving force behind the breakup of liquid jets and the formation of drops. It was several decades later, in 1951, when Siemens patented the first “continuous inkjet” printer based on Lord Rayleigh‘s instabilities. The first “drop on demand” inkjet applications were patented in the 1970s, initially using the piezoelectric inkjet system. The first bubble jet printers appeared soon after that in the early 1980s and were very popular, so that inkjet printing started to follow a modified version of Moore‘s Law. But since bubble jet technology has clear disadvantages compared with piezoelectric inkjet technology, such as restriction of the fluid being printed and service life, piezoelectric drop on demand printheads are installed on many modern, large format inkjet printing machines. With piezoelectric drop on demand printheads, the inverse piezoelectric effect is used to generate the drops. In a piezoelectric ceramic material, electrical energy is converted into mechanical energy. As acoustic energy in the ink channels, it imparts kinetic energy to the ink droplet. The most basic form of a single ink channel in a piezoelectric drop on demand printhead, with a simple representation of the acoustics, is shown in Figure 1.

Figure 1: Schematic representation of an ink channel with nozzle opening and description of the acoustics in the ink channels1

As shown in Figure 1, when an electrical voltage is applied to the piezoelectric actuator, it undergoes mechanical deformation, there-by inducing a pressure wave in the ink channel. The pressure wave moves in the direction of the channel and is reflected if the acoustic impedance of the ink channel changes. The acoustic impedance of the ink channel depends on the cross sectional area “A” and the effective speed of sound ceff and is given by:

ρceffZ = A

1 Illustration from Herman Wijshoff, “Free surface flow and acousto-elastic interaction in piezo inkjet”, Nanotec 2004, 2

where “ρ” is the density of the fluid. The ink channels in real piezoelectric drop on demand printheads used for industrial applications usually have a relatively complex geometry, and a variety of different materials are used in the printheads, resulting in frequent changes of impedance. This leads to complex pressure distributions in the ink channels resulting from a voltage pulse applied to the piezoelectric actuator. Consequently, at high printing frequencies and thus with voltage pulses that are temporarily close together, the attenuation in the channels is no longer sufficient to fully dampen the pressure waves originating from the previous voltage pulse, leading to interference. If drop velocity is measured at different printing frequencies, we observe the characteristic dependence shown in Figure 2.



Figure 2 shows pronounced maximum and minimum drop velocity values using a single trapezoidal voltage pulse, as a result of constructive and destructive interference of pressure waves with incompletely damped pressure waves of the previous pulse in the ink channel. Typical ways of improving the behaviour illustrated in Figure 2 include shortening the ink channels to increase the resonant frequency which increases the flow resistance of the channels to improve damping and variation of the acoustic impedances of individual passages in the ink channels. In addition, the frequency dependence shown in Figure 2 can be influenced with the help of a carefully optimised “multi-pulse” voltage waveform consisting of two or more voltage pulses following each other in quick succession. This multi-pulse waveform can be used either (a) to influence the frequency behaviour alone or (b) to vary the drop size as well. If we first consider the rather less complex case (a), the frequency behaviour can be influenced by adding a second, smaller voltage pulse. Figure 3 shows drop velocity as a function of printing frequency for a single and double pulse voltage waveform.

Figure 2: Normalised drop velocity as a function of printing frequency using a single trapezoidal pulse

Figure 3: Normalised drop velocity as a function of printing frequency for two different voltage waveforms

Figure 4: Voltage-equivalent signal as a function of the time between two pulse packets for a double pulse

To illustrate the differences in Figure 3 more clearly and get a better understanding of the reaction of the drop velocity to the change in waveform, it is useful to subject both the waveform and the dependencies shown in Figure 3 to a frequency analysis. This has been described in detail by Hasenbein et al. in US Patent 2008/0074451 A1. In piezoelectric drop on demand printheads there is usually a linear relationship between pressure response in the channels and the voltage applied to the piezoelectric actuator voltage. This is not usually true of the drop velocity, therefore the dependencies shown in Figure 3 must be converted into a voltage equivalent signal and thereby linearised. Figure 4 shows the corresponding voltage equivalent signal as a function of the time intervals between two successive voltage pulse packets.



Both the voltage equivalent signal and the voltage pulse can be converted to a discrete frequency spectrum with a discrete Fourier transform. This is illustrated in Figure 5 for the voltage equivalent signals using a single and a double pulse and in Figure 6 for both voltage pulses.

Figure 5: FFT of voltage equivalent signal using a single pulse and a double pulse

Figure 6: FFT of a single trapezoidal voltage pulse and of a double pulse

In Figure 5, a pronounced maximum is recognisable at approximately 50kHz using a single voltage pulse. This corresponds to the fundamental frequency of the ink channels of the printhead used. This is already deducible from Figure 2. When a double pulse is used, this feature disappears almost entirely, but a new one appears at around 100kHz. The reason for this is apparent from Figure 6. The frequency spectrum of the double pulse shows a sharp decline in the area of 50 kHz and has larger amplitudes in the area of 100kHz. Naturally the system can be made more complex and the methodology described here can be applied to any multi-pulse voltage waveforms, which also have other attributes such as drop size modulation or influencing the tails of the drops. However, as demonstrated above, multi-pulse waveforms have a large impact on acoustic processes in ink channels, even if only a small amplitude voltage pulse is added to a main pulse. The fine tuning of a voltage waveform for applications suchas greyscale therefore requires appropriate measuring equipment and experience.


Media & Handling

Modified Heavy Duty 60 roll unit for the Rho 1000 series

The Heavy Duty 60 roll unit has been mechanically modified to ensure secure transport of heavy rolls weighing up to 600kg. Such rolls are subject to generating problematic stresses in the material, for example, in Dynajet textiles for digital printing (http://www.dynajet.fr/).

These new developments prevent the formation of folds in the material during transport, such folds would affect the quality of the printed image.

In detail, the modifications consist of:

1.Adjustment units at the two docking points, so that the roll unit can be aligned absolutely parallel to the printer.

Heavy Duty 60 adjustment unit

2. Adjustable roll supports under the 3 transport rollers. Their purpose is to counterbalance the forces within the material, thereby ensuring an even distribution of stress within the material to be printed.

Heavy Duty 60 - roll support


Media & Handling

Heavy Duty 60 - modifications 1 and 2

3. A free-running axle which ensures that the material is unwrapped evenly from the roll, to ensure that no folds occur during guidance.

Heavy Duty 60 - free-running axle

These modifications support printing without the need for constant supervision. The free-running axle also ensures smooth unwrapping of the Dynajet digital printing material, which tends to be somewhat sticky.


Application

A fine tribute to Nelson Mandela

Towards the end of last year, Grosvenor Branding Solutions (BBS), based in Cape Town, produced this stunning display as a tribute to Nelson Mandela. The display was then presented by Grosvenor to a very good client as a gift.

Barrows in Durban, which is part of the WPP Group, has the display in pride of place in its reception area. The connection between Grosvenor and Barrows is that Grosvenor supplies a range of semi-permanent FSU displays and promotional stands using ReBoard.

“ReBoard is an ideal media for us to be associated with and to use,” said Graham Hawthorn, C.E.O. of GBS. “It is extremely versatile and it fits perfectly with our environmental ethos. It is the most eco-friendly board of its type and ideal for creating semi-permanent eco-displays. Also, it can be recycled as paper.”

The Nelson Mandela tribute display was printed on Grosvenor’s Rho P10 200 which was installed almost a year ago. “Since then,” continued Graham Hawthorn, “it has proven to be the ideal hybrid printer for us. It is very versatile and prints onto the widest range of substrates including roll media and direct to boards. It also complements our ReBoard and other product ranges, both for the quality of print and also because Durst UV inks are environmentally friendly, containing no harmful VOCs and they are also GREENGUARD certified.”

Grosvenor is also involved in a national ecological project using ReBoard. “We are proud to be associated with the “Save the Rhino” campaign. This is part of the Kingsley Holgate Foundation’s “saving and improving lives through adventure” initiative. GBS has created box seats made out of ReBoard which travel all over the country and a giant 4m high Rhino horn display which children use to present their writings and drawings.”

Charity projects are not the only use GBS has for reboard. In addition to commissions placed by Barrows, the company works directly with many major brands and retailers in South Africa including many different brands for the liquor trade. In addition GBS works with large exhibition, event and promotional companies, advertising agencies and also provides stadium signage and graphics for sporting and other outdoor events, including the FIFA 2010 world cup.

Although Re-Board products represent a large part of GBS’s output, the company offers a range of materials and printing methods. The company was founded 1990 as a silk screen company which printed onto vinyl and plastic as well as other media. After 5 years, it added its signage division and moved to a larger factory. In fact, during its steady growth over the 20+ years it has been in business, GBS is now in its fourth factory, moving each time to increase capacity.

Mandela tribute display

Mandela tribute display reverse with quotes


Application

The screenprint and signage division run in tandem with the wide format digital division but the emphasis is firmly with environmentally friendly products. “Nowadays, there are many more eco-friendly products available to customers,” said Graham Hawthorn. “They are now much more competitively priced and longer lasting, and can be used outdoors more effectively. More customers now specify environmentally friendly products and often companies will have sustainability policies to ensure this.

Since its installation about a year ago GBS has been delighted with the performance of its Rho P10 200: “The quality of the Rho P10 is exceptional and the white ink option is fantastic, it is perfect for printing onto transparent film, backlit media as well as coloured media. In addition to ReBoard, it also prints perfectly onto Perspex, Forex and Corex etc.”

“The Rho P10 200 has given us a substantial commercial advantage. It provides consistent high quality print without sacrificing productivity and it has also brought down our print cost per m². The printer ticks all the boxes as far as speed, quality and size are concerned.”

About Grosvenor Branding Solutions GBS is a technology driven branding solution company, it employs 20 people who provide a very effective and efficient production workflow. Starting with concept design, innovation and creativity, GBS’s art department feeds the production workflow through its printing divisions to distribution and installation. Winning at retail and positive exposure is our priority for our clients.

For more information on Grosvenor Branding Solutions, visit: www.grovprint.co.za

Save the Rhino desks made out of ReBoard

Rhino Horn Display


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and illustrations.

Durst® is a Registered Trade Mark

Events

Durst PhototechnikAGLarge Format PrintingJulius-Durst-Strasse 439042 Brixen/Bressanone, ItalyP.: +39 0472 81 01 11F.: +39 0472 83 09 [email protected]

08/04/2014 - 10/04/2014InprintHannover, GermanyDurst Industrial Inkjet Application GmbHHall: 21Booth: B04www.inprintshow.de

24/04/2014 - 26/04/2014ISA International Sign Expo 2014Orlando, USADurst Image Technology U.S.Booth: 1859Products: Rho P10 250, Rho P10 320Rwww.signexpo.org

17/04/2014 - 20/04/2014Keramika 2014Jakarta, IndonesiaDurst Phototechnik AGBooth: KA13www.keramika.co.id

Documents

process · 2014-04-10 · process - Durst news for the science and application of inkjet printing - Issue 10 - April 2014 2 Editorial Laminated decors, as frequently used in the furniture