On Print | Digital Print at Labelexpo

Published: October 25, 2012, By Dene H. Taylor

I have been telling all label manufacturers for the past couple of years that they need access to digital printing, even before being ready to purchase, so they can provide their primary client base full service. That still applies, although the incentive to invest is greater: the value of short-run label production is appreciated by the market and selling is easier. And there are more choices; they come with more in-line finishing options; and all the important substrates are proven with multiple suppliers. Plus the operating systems are more complete with better end-to-end control capability. The risk is lower than ever, but selling remains key.

More than 35 digital printer manufacturers were on the floor at Labelexpo, with many offering several models. The majority had standalone machines, but several integrators showed how they could retrofit existing label presses. The accompanying table represents the list I prepared of roll-to-roll machines being demonstrated or actively promoted. (I also was able to collect representative samples from most, so if any of you have an interest in comparisons, please contact me directly.)

2012 Web Color Digital Printers at Labelexpo 2012

Electrophotography represents the greatest installed base, with HP Indigo having the lion’s share. Xeikon and Indigo were introduced at the same time and set high image quality standards early. They deserve the credit for developing the premium digital label market. Recently both have focused on increasing press output and effective up time. Xeikon introduced the 20-in. wide 3050 last year; HP Indigo soon will be at beta stage with the 30-in. 20000.

Xeikon continues its focus on productivity with new software suites for different applications, for example, heat transfer label capability so that printers of plastic tubes, tubs, and pails now have an efficient digital option. Both companies are facing speed limitations from their print engines. Indigo’s is more apparent, as the colors are introduced with separate rotations of the primary drum. But as we know, print quality often can be satisfactory with just the three primaries (CMY).

HP offers this with the enhanced production mode (EPM). It reduces job time about 25% from four-color mode and about 40% from five-color. Both Xeikon and Indigo offer integration into finishing lines in conjunction with a number of partners. Indigo also is offering an in-line pre-coater option on most machines, so that many more of the standard flexo stocks on hand in a large label factory can be used.

Ultraviolet (UV)-cure inkjet is very durable, but the first generation of label printers did not impress me for image quality—the droplets were too large and the resolution too coarse for print that we frequently read about 12 in. from our eyes. But that is no longer the case. All OEMs can use high-resolution printheads with smaller primary drop volumes, which can print each pixel at several gray scales. This gives smooth solids and half tones and crisp text—even the fine print is legible. The Heidelberg/Gallus CSAT press was doing an outstanding job—others equal or are close to that standard. These aesthetic and practical improvements extend the applications available, e.g., for pharmaceutical where a lot of information is required by regulation in a small area.

Food contact is always a concern with UV-cure inks. Low migration inks, which can be demonstrated as compliant for indirect food contact, are becoming more broadly available for conventional presses. From drupa I reported that the Agfa inkjet ink team has LMI solutions available. Now Sunjet has announced it too has an LMI family. This is of interest for packaging as well as labels. It’s worth remembering that compliance is based upon full cure, so anyone contemplating that should have a quality management system that will prevent under-cured ink from being shipped. Remember that you have full responsibility for that—the ink vendors are at arm’s length.

Durst had a first with metallic UV-cure ink at the show. UV cure is difficult for this because the metallic platelets are total light reflectors and therefore excellent light barriers. The sample prints from the factory are pleasing. Release is expected early in 2013.

The big appeal of UV cure is that satisfactory performance can be obtained with common substrates that have little or no pretreatment. Some label stocks are heat sensitive and so less than ideal for UV cure with conventional mercury lamps that emit a great deal of heat. The new generation of lamps use light emitting diodes (LED) that emit only UV and therefore run cool. The early challenge was obtaining individual diodes with suitable intensity. Now it is packing them tightly so the power can be concentrated sufficiently to get fast cure. But that is happening, so with the improvements in formulation, useful performance is being obtained, and heat-sensitive substrates, such as 1 mil OPP and ½ mil PET, can be printed. We see this trend continuing.

Miyakoshi has been a leader in this area with the MJP20W, a true digital press like those used for publication printing. It is more than 21 in. wide and capable of 450 fpm. Interestingly, Miyakoshi has adopted aqueous ink for its new label press, the MJP13LX-2000, perhaps for use with food. It will be featured at an open house in Japan next month.

Aqueous ink is also, of course, in wide use for label printing. It is not restricted in the same manner that UV cure is, and with the right substrate, there is sufficient durability and water resistance for a great many jobs. High speed is provided by machines from OEMs that first focused on the publications market. But there are also printers produced from desktop engines, so digital label printing is available to those with very limited budgets and a willingness to work with precut label stocks.

Most OEMs assemble their own print engines, although they are outsourcing components more and more. Memjet, however, has taken a different approach. It provides a choice of print engines based on its 5-channel 8.5-in. wide thermal head. Native resolution is 1600 dpi, and drop volume is about 1 pl, which gives very good innate resolution. The two engines in the label market support either one head, with five colors (commonly CMYKK), or multiple heads in-line for the primaries and an optional spot color. The heads provide feedback on the firing state of each nozzle. If a nozzle is out, there is compensation in the graphic to mask the effect so that the machine can continue to run.

At previous shows, nozzle-outs were an issue, but from the performance at LabelExpo, this issue has been dealt with. Memjet’s vendors also are experienced with web handling, (e.g., Super Web) or have partnered with others who are (e.g., Colordyne with Aztech), so there is inherently proven engineering in their devices. Printers from five companies were on the floor. Several of these were also shown by finishing equipment vendors in fully integrated configurations. Again, integration with finishing is more efficient for anyone who runs multiple label sizes.

A few wide format printers and printer cutters were shown. They were developed for the sign industry—the printer cutter is a very efficient machine for decals and self-adhesive vinyl. Obviously it also can be used for labels. Wide format printers have reciprocating printheads, so they are comparatively slow, certainly compared to fixed head printers. Those using solvent or aqueous inks are economical and well suited for very short runs or for proofing, demonstrating, or making prototypes in plants with high-volume traditional presses.

Landa Digital was the talk of drupa (see On Print, May 2012) and drew a near-capacity audience at the conference. Those who have signed letters of intent to purchase soon will have substrates printed for them at the demonstration facility in Israel, so they can begin to understand the capability and give Landa direct feedback even before the first beta machines are placed later next year. My sense is that it could transform the flexible packaging industry. The conventional inkjet industry is stepping up its activity to secure its position. Digital printing for packaging is getting more and more interesting and, indeed, is actually becoming entertaining.

Inkjet is not just for printing graphics. Digiflex demonstrated an industrial application—printing the mask on standard flexographic plates. The mask must have a black optical density two or three orders of magnitude greater than standard black ink. Digiflex achieves this with a simple two-step two-part reactive ink technology. First, a thin reactive layer, provided as a coated film, is cold-laminated onto a standard flexo plate. This is then placed on a vacuum platen in an inkjet printer with a modified Epson print engine. The ink containing the second react is printed, and it develops the intense black where it meets the first reactant, forming the mask. The plate is then exposed by UV light and washed to complete the process—it is simple, elegant, and fast, and eliminates a process step.

Digital is not just printing, of course. Nowadays it also encompasses the full job control and finishing. There was plenty of that on display, and I wish the show had an extra day just so I could have gathered the material to report on it, too. Even so, LabelExpo was a terrific showcase of digital technology, and a reflection of the development of the industry and the market. Pack Expo is the next event, and we are looking forward to being back in Chicago for it.

Printing expert Dene Taylor, PhD, founded Specialty Papers & Films Inc. (SPF-Inc.), New Hope, PA, in 2000 for clients seeking consultation for technical management, new product design, development, commercialization, and distribution, as well as locating/managing outsourced manufacturing. Contact him at 215-862-9434; This email address is being protected from spambots. You need JavaScript enabled to view it.; www.spf-inc.com.