A Package Printing Supporting Cast

It’s become almost a reflex to think of a printing press as the sum of its inking units and not much else. That’s why descriptions of presses nearly always begin with references to the number of colors they can reproduce: six-color-plus-coater this, eight-color-perfecting that, and so on.

The problem with this ingrained mental habit isn’t that it’s inaccurate; it’s that the assumption behind it is simplistic.

It’s simplistic because it doesn’t give due weight to auxiliary press equipment: supporting systems, either built into the press at the factory or added later on, that extend its useful life by making it more productive and consistent in everyday operation.

Some are essential to the basic functioning of the machine. Others help it to do a better job of handling the short runs and strict quality requirements that increasingly define both packaging and commercial presswork.

Like so many other things in printing, choosing press systems often happens in response to market forces.

Take it Seriously

“If your sales rep tells you that you need to adopt something in order to get a job, that means your competition is already doing it,” says Bruce Leigh Myers, associate professor and director of Rochester Institute of Technology’s School of Media Sciences. Printers, he says, can’t afford not to invest in supporting systems that can make them leaders in the markets they serve – especially when the technologies have a track record of quickly paying for themselves.

“Smart” systems for color management and quality control bring competitive advantage in the form of standardized production, according to Isaam Lutfiyya, director of global sales and marketing for the Vision Systems unit of Baldwin Technology Co., Inc.

TRESU’s F10 iCon ink pumping system controls the flow, viscosity and pressure of ink from bucket to substrate in flexographic printing; it also filters and recirculates. Image courtesy of TRESU.

Printing, he explains, is manufacturing, and operating at peak efficiency in non-automated manufacturing is a sporadic occurrence at best. This is why many printers find they can’t build a business around selling their “best” runs: there aren’t enough of them.

“Printers are only as good as their ability to standardize” with the help of press systems that raise the quality of their everyday output and keep it consistently high, Lutfiyya says. That way, “you can sell your standard” instead of an elusive “best” with data from smart systems acting as the “digital insurance policy” for staying at that optimized level of performance.

As a manufacturer of ancillary press systems, IST Metz is tightly focused on UV curing solutions for inks and coatings. Bill Bonallo, president and CEO of IST America, notes that installing a traditional or an LED-UV curing unit on a press is the easy part — the challenge is assuring that rollers, blankets, press chemistry, and even inks and coatings are correctly matched to work with it.

In preparing a press for UV printing, says Bonallo, “there’s always something that has to be done:” a task made no easier by the fact that each press manufacturer tends to have its own definition of what UV preparation should consist of.

There’s a divide between package printers and commercial printers in terms of what they expect from UV technology, according to Bonallo. Commercial shops see its fast curing primarily as a way to increase throughput from the pressroom to the finishing department; hence their interest in the instant-on, low-heat, reduced-energy LED-UV systems that have come to market from IST and others in recent years.

Package printers, on the other hand, emphasize UV curing’s high-end special effects and tend to see traditional UV as the best “no risk” way of achieving them, Bonallo says.

He adds that it’s crucial for newcomers to packaging — particularly commercial printers just breaking in — to understand the merits of both types of UV curing. LED-UV, according to Bonallo, can be thought of as a supplement to traditional UV, with its own set of best-use applications. He says LED-UV has become “the king of digital,” for example, because it has proven to be as well suited to digital presswork as traditional UV is to flexo and offset production.

From Bucket to Paper

Before the ink in a flexo press can be dried or cured, it has to be dispensed correctly to the anilox rollers in the printing units: the function of ancillary technologies from TRESU, whose product line includes systems for regulating the circulation of inks and coatings in flexo equipment.

“Efficient management of the ink supply is crucial to the profitability, not to mention the reputation, of a printing business,” says Søren Maarssø, CEO of the TRESU Group. “Calibration of ink recipes requires the precision balancing of a tightrope act.” He explains that achieving uniform, accurate, high-gloss and uncontaminated print results depends on tightly regulating the ink or coating medium’s flow, viscosity and pressure from the bucket all the way to the point at which it is applied to the substrate.

Maarssø points out that when ink pumping takes place in a closed-loop process that includes controlling these factors, it’s much easier to achieve consistent, high-quality color output. He says that TRESU’s F10 iCon ink pumping system provides precisely this kind of bucket-to-paper control with features that counteract problems such as ink foaming caused by unwanted air in the chamber doctor blade enclosure; and the failure to return ink to the bucket at the end of a production run.

The system also eliminates the need to top up ink trays with ink or extenders to make up for evaporation — a routine that poses health and fire hazards.

Click to enlarge.

Maarssø adds that the TRESU F10 iCon, which can be supplied as original press equipment or retrofitted to existing presses, filters and recirculates flexo ink so thoroughly that the press may lose only about half a liter of ink per flush cycle. That’s much less than the 10 to 15 liters of contaminated ink that may have to be discarded from presses running older, less capable ink pumping systems.

Additional benefits of controlled ink circulation with systems like the TRESU F10 iCon include uniform density and improved coverage as well as faster job setups and changeovers, according to Maarssø. TRESU drying systems that set ink without excessive heat — thus minimizing paper shrinkage — make flexo production that much more efficient, he says.

On newer machines, systems for key supporting functions are integral to the press as designed by the manufacturer and installed by the user. Myers says, for example, that closed-loop color control systems with scanning spectrophotometers have been standard equipment on many sheetfed offset presses built in the last decade.

Lutfiyya says that on presses eligible for retrofitting, the No. 1 demand “hands down” is for defect detection and color control systems that automate the reproduction process and take unpredictability out of it.

Expendable Expertise

Lutfiyya says that in some packaging environments, too much still depends on the individual skills of “that special artist, that special ink kitchen expert”: a breed of craftsperson the industry is seeing steadily disappear. What Baldwin systems aim to do, Lutfiyya says, is to help printers manage their customers, processes and people by automating their production routines in ways that make them as uniform and defect-free as possible.

There appear to be no deal-breaking differences in performance between factory-installed press support systems and those acquired later as add-ons. As Myers points out, they typically come from the same suppliers, and while built-in components may be more tightly integrated with the press platform than add-ons, they eventually obsolesce and will have to be replaced with retrofits when the time comes.

Lutfiyya says one advantage of add-ons is that they tend to be open-platform in design and thus aren’t tied to specific makes and models of press equipment. This permits Baldwin to respond to printers’ retrofitting requirements with “a much greater cadence of market updates” in both hardware and software. In this way, Lutfiyya says, printers can enhance their production capabilities without having to make major new capital investments.

But, retrofitting a legacy press isn’t simply a matter of pulling old components out and snapping new ones in. Bonallo says that because of cylinder configurations and space limitations, some presses are less accommodating to add-on UV units than others. Installing them on long perfectors, for example, can sometimes be challenging.

“One thing is for sure,” Bonallo observes, “the one-size-fits-all, universal approach is a dangerous one.”

He adds that IST usually advises customers to spend one to two weeks getting to know the new technology of the curing system before bringing the press up to full production. IST technicians remain on site during the first phase to head off potential issues and to help the customer grow comfortable with the UV workflow.

Better, Not Faster

As Maarssø notes, retrofitting a press with an ink supply system won’t make the press run faster. It will, however, increase utilization, ensure control of ink recipe setups, accelerate job changeovers, and reduce waste and maintenance — all keys to making the press more profitable to operate. TRESU’s focus is on developing systems that help to minimize environmental impact while optimizing production flow and press function. “We want to be sure we are taking care of our environment with systems that focus on green technology,” Maarssø says.

According to Lutfiyya, the most worthwhile retrofits are those done with “smart” components that bring print production closer to the norms of Industry 4.0: highly automated manufacturing based on machine-to-machine data exchange. Representing a step in this direction from Baldwin are systems that can compare the performance of a press to that of thousands of other similarly equipped machines in the network. Packaging will undergo “a pretty predictable evolution” toward this kind of data-driven standardization, Lutfiyya believes.

To select an auxiliary press system, advises Myers, first build a business case for it based on customer requirements. Then look for a solution that is easy to use, integrates readily with the plant’s MIS, and supports the types of customer compliance reports that the plant may be called upon to provide.

Above all, recognize that these technologies are investments that can’t be deferred indefinitely if the business is to remain competitive. As Myers puts it, “you can drive your car without a radio” — but no package printer should risk operating a press without the performance-boosting accessories that make it truly roadworthy.