Developments in inkjet printing technology are expected to make a significant impact in the package printing industry in the next five years. From secondary packaging applications, such as case-coding, to full-color imaging directly onto primary packaging, inkjet printing is poised to be accepted alongside established printing methods, and, for some applications, may even offer a replacement.
“Analysts project that in five years a growing percentage of the packaging market will use piezo inkjet technology.”
Hugh Baker-Smith group sales director Xaar plc
Recently we have seen new package printing product introductions that incorporate the latest generation of inkjet printheads and new inks, and we expect more in 2001. This activity will put inkjet technology firmly in the packaging industry spotlight and will certainly change the perception of what can be achieved using inkjet printing technology.
Inkjet Printing Technologies
There are essentially two categories of inkjet printing technology — continuous inkjet and drop-on-demand inkjet printing.
The first, continuous inkjet printing, will be well known to readers. A highly successful technology, continuous inkjet is very well established in packaging applications and rightly commands a dominant position in product coding and marking applications.
Drop-on-demand inkjet falls into two categories — thermal/bubble jet and piezo. Thermal inkjet printing technology, led by Hewlett-Packard, Canon and Lexmark, uses water-based inks and is primarily used in home, office and wide-format printing applications where it has been extremely successful.
However, piezo drop-on-demand technology is the inkjet technology generating the news in the packaging industry today. There are many companies with piezo technology, each with their own way of firing ink from the nozzles, but the print capabilities vary considerably.
Already successful in the office and wide-format arenas, piezo inkjet technology has also found wide support in packaging applications because it supports a variety of ink formulas, both liquid and solid inks, which enable printing onto a range of substrates. In particular, inks for most piezo head constructions support the addition of polymers, binders, acrylics, etc. to bind with and adhere to different substrates.
Inkjet Printing in Secondary Packaging
Inkjet printing is a non-contact printing technology. This means that unlike electrophotograhic (laser/toner-based) printing processes, there is no contact with the substrate. Thus, inkjet printing can be used to print onto uneven surfaces such as ribbed corrugated board and raised surfaces — any material with some sort of relief surface.
In secondary packaging where the objective is to print barcodes on the outer carton package, there is a growing trend towards higher resolution, higher quality and higher throughput printing. The latest piezo inkjet printhead technologies offer higher resolution and definition than has heretofore been available. This means that inkjet printing will become more attractive for barcode applications that require a higher quality image to ensure reliable readability.
New outer carton devices are incorporating multiple print heads or single, but wider, printheads for higher productivity in support of the trend towards printing more information such as logos and graphics, including marketing messages, in a single pass.
Spot colors are also used in multi-head systems for added effect. For example, the latest wide printheads enable 2.8-in. of information to be printed in a single swath and at speeds of 22-in. per second. In case-coding, where piezo inkjet printing already dominates, the trend at the higher end of the market toward printing more data, better graphics and using more color is driving demand for wider printheads that can also deliver higher resolution without any loss of productivity.
One such device is available from U.S.-based Weber Marking Systems. Weber is one of the first companies to incorporate the XaarJet 500 printhead, in a case coding device called the LegiJet Model ML500. Weber has already introduced the machine and showed it last November at Pack Expo 2000 in Chicago. The unit is able to produce the tallest bar codes and text in the industry, up to 2.8-in. high, at a print resolution of 180-dpi. This fully addressable unit outputs any combination of large and small character codes, ranging in font size from 5-points (.06-in. high) to 280-points (2.8-in. high).
Another leading industry name, Domino, launched the G-7000 case coder, using the XaarJet500 printhead, also at Pack Expo in November 2000. The Domino unit incorporates an innovative ink delivery system and supports all major graphic file types and barcode symbologies.
A different system is offered by AssiDomän Packaging. The AD+Print system prints onto the case while it is still in flat sheet form, allowing print to be applied to every side of the pack, including the flaps. The machine can print a variety of fonts, logos, graphics and barcodes in any color and in a variety of sizes.
Impact on Primary Packaging
Inkjet printing is expected to have a dramatic effect on primary package printing applications where the need for digital printing is even more compelling. Producers of primary packaging are increasingly looking to reduce consumption and waste, handle shorter, more customized print runs, shorten turnaround times, lower capital costs, improve logistics and reduce packaging inventories. A tall order.
But digital printing addresses many of these requirements. Because it is available instantly, digital printing facilitates shorter print runs and offers the flexibility to accommodate customized, localized print runs, special promotions and text marketing. It also supports just-in-time production, enabling reduced inventories.
However, the key issues of printing high quality for text and graphics, combined with production speed and the ability to print on multiple substrates have restricted the adoption of digital printing. Until now. The latest advances in piezo inkjet printing technology begins to address these requirements with higher quality printing than previously seen and with the ability to handle a variety of inks that can print on a wide variety of media — in particular, UV curable inks.
Printing industry analysts project that in five years a growing percentage of the packaging market will use piezo inkjet technology, accounting for billions of dollars worldwide.
The concept and promise of piezo inkjet are now becoming a reality with new printers being introduced. For example, Barco made an impact at Drupa with its launch of the Dot Factory, a digital press designed for variable-data industrial printing applications. Incorporating both binary and/or grayscale printheads, depending on the application, from Xaar and using UV curable inks to print onto non-porous substrates, the Dot Factory can achieve an apparent resolution of 1080-dpi. It can print at widths from 5.5-in. (140-mm.) to 24-in. (630-mm.), with a linear speed of up to 8,600-sq.-ft./hr. for full color printing.
The high quality printing that machines like this can provide at acceptable production speeds is critical for success in primary packaging. The Dot Factory can also be integrated on line with a flexo press to create a hybrid production device such as the one in development by Mark Andy. The integration of digital and analog printing illustrates how inkjet and flexo can complement each other and play to the strengths of both technologies. The Argio 75 from Chromas, shown at LabelExpo USA last year, fitted onto a conventional press, also illustrates this trend towards hybrid technology devices.
Another new trend which is expected to impact package printing is the introduction of flatbed devices as seen at Drupa and SGIA last year. Flatbed devices can print directly onto a broad range of materials in varying degrees of thickness, from foamboard to metal, using UV curable inks. These products are targeted directly at screen printers and open up opportunities for directly printing on point-of-purchase materials, by printing on cardboard containers in full color.
SGIA saw the U.S. debut of the Sias Digit from Italian company SIASprint, distributed by M&R, and the VUTEk PressVu. In addition, Belcom recently launched the Bel2000 at SuperCorr — a flatbed device with inkjet technology from Aprion. Other flatbed printing devices with Xaar inkjet printing technology include printers from Perfecta, Inca Digital Printers, Tampoprint and Durst. All of these machines are capable of high quality printing at production speeds of 861 to 1076-sq.-ft./hr., and although the machines will be used for many different applications, packaging will be one of them.
Several companies are exploring solutions such as stitching multiple printheads together to be able to print the entire side of a flat, unpacked box in a single pass in full color. Also in the works, from a number of large packaging companies and their chosen system integrators, are custom inkjet solutions for printing spot and full color on primary product labels. Piezo inkjet systems, using UV curable inks, will ultimately enable printing directly onto non-porous substrates, eliminating the need for a label. Companies that produce personal care products, cosmetics, household cleaning products and the like, especially those that need to label products in multiple languages, are increasingly interested in using inkjet to print directly on bottles or containers.
Perhaps the strongest impetus towards digital printing in the primary packaging segment comes from primary product labeling applications where pre-printed label runs of under 2,000 account for one-fifth of total orders. In this area, there is currently a high level of waste — over 15% — and an increasing requirement for legal reasons to include more information, ingredients, etc. in multiple languages.
The inkjet printing processes mentioned above are already migrating through the breadth of packaging applications. Beyond text and barcode variations on secondary packaging and primary package labeling, the immediacy of digital printing, and the capabilities of inkjet in particular, are expected ultimately to allow access to new applications, such as the ability to print promotional flashes (e.g., percent off) directly on packages, foster competitions and collectables and enable just-in-time production of packaging linked to sellers' inventory levels.
