A generation ago, in the years before digital printing became the industry’s future, there was serious speculation that flexography might become the technology of the future, the process that eventually superseded litho. Various reports stressed the simplicity of the process compared to the complexity of litho; the consistency that was possible compared to continually refining litho to achieve any kind of repeatability; and the simplicity of the flexo presses that would follow. At the time flexo was denigrated as rubber stamp printing, suitable only for corrugated box printing and for printing frozen pea packets, which no other process could reasonably manage. Every year there were awards which showed flexo creeping towards litho quality, but never quite close enough. And with the advent of digital printing, any thoughts that flexo might win out were pushed aside
That was then. Today flexo is capable of high quality on not only frozen pea packs and other plastic materials, but also on labels, on sacks and pouches and also on carton board as well as corrugated. For while printers could be dazzled by the staggering progress of toner and inkjet technologies, developments in flexo continued almost unremarked except by those closely involved. Plates, inks, anilox systems have all taken strides in the last generation and with commercial print seemingly in decline, packaging where flexo has staked its place, is growing. Flexo stands on the cusp of the future promised for it.
It has already gained the crown in label printing, in printing on flexible films and on corrugated. Now flexo can challenge litho in cartons. Already flexo can claim to print 15% of the world’s carton packaging, frequently the lowest value work where traditional processes struggle to be cost effective. Its market share can only increase.
Certainly Heidelberg hopes so. The epitome of all things litho announced the development of the Boardmaster during the Interpack exhibition. This is a full flexo press intended to print the high volumes of cartons that the company can no longer challenge for with litho printing having withdrawn from the VLF sheetfed market.
The Boardmaster, it announced, is “the next big thing in high volume packaging”, a game changer for carton printers that are being squeezed on margins.
The new ground up press design was under development before the VLF decision was taken so one machine is not the consequence of the other. “It was not the main intention when we started development of this press. When we started the VLF sheetfed press was in place,” says Heidelberg Web Carton Converting managing director Matthias Boog. “We started by asking customers what they wanted from a new press. It was less waste, greater production efficiency, removing job changeover time and especially in the US, where safety is very important, we didn’t want people to have to climb ladders to change the ink. We tried to cover all these aspects when we developed the press.”
It is a press that comes in four web widths: 850mm, 1,000mm, 1,400mm and 1,650mm, at either 350m/min or 600m/min and with options on inline finishing and whether the job is rereeled before finishing, sheeted, die cut on a rotary or flatbed unit. The company already has a flatbed die cutter running at 350m/min. Running at top speed will require rereeling.
At speed, the Boardmaster will print the equivalent of 38,000 VLF sheets an hour. The argument is that for every one of the flexo machines sold, there would have to be almost three VLF presses in action and with all the cost of operators, let alone the challenge of finding qualified press operators capable of running a press of this size and complexity.
The Boardmaster print decks each have a pair of print units, either to print two colours at the same time, or as a single colour but with on the fly job changeover. The plates are mounted on sleeves which slide and lock into place on air shafts. The plates are themselves scanned on an Intellimatch scanner which uses multi cameras to capture the precise profile of a plate so that when it is on press, the automation adjusts the press settings not just for lateral and circumferential register, but also for pressure to ensure that solids come out as intended while small type is also correctly rendered.
This takes place in around one second, says Boog, enabling a job change to generate 10-50 metres of waste material. The settings are logged in a database and accessed via a 2D matrix or QR code. This also ensures the the correct plate is loaded in the correct position.
With the two-unit deck, the next job can be loaded and queued while one is running ready for the switch point. One cylinder bounces out of impression with the second unit comes into play, perhaps with the same process colour, perhaps with a different spot colour. This is similar to technology used by Bobst on its M6 label press and by Timson on its ZMR litho press for book printing. The ink system will become a closed chamber system, at the moment a semi closed design is used.
Despite the instant changeover, the Boardmaster is really intended for longer run packaging for retail and food customers for example where cost per unit is crucial, the far end of the spectrum from digitally printed short run and personalised and highly embellished print. Items like pizza boxes, cereal boxes, beverage containers and tops, print for the hospitality industry, sleeves for French fries, for example, general purpose food cartons have all been printed by flexo presses already. And in many instances by the same companies that run large format litho presses. “We reckon that 50-60% of our customers use both technologies as well as gravure and digital,” says Boog. “Every technology has its place.”
Those customers span the major international packaging groups, but the Boardmaster is not only for those businesses, says Boog. An independent printer might consider an 850mm wide web version or a 1,000mm version. Even these, he says, can be more productive than a sheetfed VLF litho press depending on the size of the carton blank being printed.
“We have to work very closely with customers to understand the product mix and to come up with the right solution and press configuration for them,” he explains.
To date the business has done this with a first installation in the US now in place and a second at the acceptance trials stage. Other orders are in the bag, even before the Boardmaster was announced. That sparked even more attention. “Most inquiries wanted to know about the cost and there was a strong wish to see it in the flesh.” That is likely to happen first at the Wieden plant that has been home of flexo printing carton technology since 1974. It became part of Gallus and subsequently Heidelberg.
The press is not going to make it to Drupa for the simple reason that installation takes too long for a trade show appearance. A print deck to show the options is possible, so too will be a video link to Hall 11 among the packaging equipment that Heidelberg has on show. That is for next year.
Boog’s immediate concern is meeting the demand. Here Heidelberg can offer its capacity and skills to produce new machines should orders exceed what the business can cope with. He reckons that demand could reach ten, 15 or 20 machines a year. “The feedback makes me positive this will be a success,” Boog adds.
In this country Heidelberg UK will handle sales, and there are companies showing interest for planned projects according to UK managing director Ryan Miles. This is driven by sustainability, helping to generate interest. He says: “There is the move away from plastic towards fibre based packaging, the need to reduce complexity in packaging and to make packaging easier to recycle, to reduce the amount of material in packaging. And the Boardmaster also meets the challenges of deskilling, productivity and efficiency for these companies.”
If orders are taken for that rate of sale, it will not be long before flexo eats away at the other technologies for printing cartons.
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