Pressing engravements

While gravure printed packaging within Asia-Pacific, for example, is on course to be worth $24.2 billion by 2015 – an incremental rise of 5.1% on current value, and accounting for more than 52% of the total global market – it will not only be almost two-thirds less in volume throughout the entire Western European market, but will generate exactly the same value three years down the road as it does now. As they say: ‘location is everything’.

According to Smithers Pira, the total global market for gravure package printing was worth $40.2 billion last year, and can expect to achieve an overall real growth of 3.5% by 2015. Even so, it continues to lose market share to flexo (its principal competition, accounting for over 40% of all applications) in serving the demands of a booming global flexible packaging market – itself valued at $58.3 billion last year and growing at 4.1% per annum to exceed $71.3 billion by 2016 – over which it once held an unassailable grip.

The bitter-sweet irony for gravure is that while it remains the byword in describing and setting industry standards for quality – and which flexo is investing heavily in front-end prepress solutions such as high definition (HD) plates to match – it no longer automatically qualifies as the preferred process. As those geographical variances so clearly illustrate, one man’s go-to solution is another’s museum piece; but outside developing markets and despite its undoubted attributes, it is in danger of becoming side-lined, with no way back into full-scale contention.

OK, so sales of gravure presses have received something of a fillip over the past couple of years. While there are now an estimated 850 machines of varying capability outputting gravure printed packaging throughout Europe, that continent’s total complement of 350 dedicated gravure plants barely equates to 70% of its counterpart installed base (about 500) in India alone. And while gravure and flexo printed output might be close to parity across Europe, the ratio is 80: 20 in favour of the latter in North America.

None of the leading gravure press manufacturers is wedded to the single process, offering flexo, offset and no doubt, soon enough, digital inkjet as part of their portfolio. With all the corners covered, any reconfiguration of the packaging print manufacturing installed base will be end-user demand rather than supplier driven.

Short and sweet

Regardless of vested interest, however, an increasing number of press manufacturers are keen to dispel the received wisdom that gravure is exclusively geared towards volume runs, with makeready and washdown times on press continuously reducing. “Yes, gravure is less easy to justify in pure cost terms over a short run,” agrees Comexi Converting Solutions MD Gian Vito Schiavi. “It’s a natural limitation of the process – but we do have customers that regularly print within 5,000m in gravure, and in often maintaining more than one machine are using their production capability in a more needs-responsive way. We’ve introduced a number of different features over the past few years; for example, very fast changeover that reduces downtime and facilitates shorter run lengths.”

With a speed of 650m/min, Comexi’s RG Platinum press is typical in incorporating improvements made in gravure changeover technology, viz, a stainless steel trolley that facilitates the handling of the whole inking group and of the printing cylinder, and thereby allows automatic washing without dismantling each single component.

Cerutti is another leading manufacturer to have addressed the demands of an increasingly short run driven flexible packaging print market, says Giampiero Zorigo, sales area manager responsible for Japan. “Big-selling brands used to produce in volume, but can no longer afford to tie up so much cost and resource in inventory; instead they place the order for a lower quantity and have the supplier keep the cylinder for re-use. What’s changed is not necessarily total volume, but the fact that it is staggered over a period of time; so, efficient cylinder changeover is important.

“Sure, if I’m running 200,000 off at one time then automated changeover is less relevant – but if I’m running that volume in several batches, interspersed by printing other orders on a similar basis, then in one shift I may need to change from job to job as many as 10 times. This is now the norm for a gravure printer in Europe,” he says.

“We have two types of equipment for accelerating changeover of cylinders, which takes about 13min, during which time we’re able to wash the inking system in the cylinder before we remove it from the press to have it ready for storage, and thereafter to be returned onto the press as and when required without the need for any further preparation. Previously, that was taking anything between 25 to even 40min.”

Cost competitive

The assumed higher than average cost of installation and operation is another wrong perception that the gravure lobby is keen to correct, says Windmöller & Hölscher’s printing & finishing divisional technical sales manager Udo Neumann: “Quality in flexo is increasing with the introduction of new technologies, but that has had a corresponding upwards impact upon costs.

“Also, the equipment is becoming more complicated to use and so requires a more skilled level of operator,” he says. “While we habitually sell four flexo presses to every one of gravure, those are factors that are making gravure a more attractive option. We’re seeing a rise in demand worldwide with new systems going to Indonesia, Pakistan and South America.

“While a new gravure system can be expensive when fitted with additional capability such as coldseal, as just the printing machine itself the price level can be very close compared with an increasingly sophisticated flexo press.”

Gravure and flexo inks are also price comparable, with the gravure inking system easier to manage. And innovative software has gone a long way towards reducing unnecessary waste, says Costanza Cerutti. “Whereas five years ago a new job might expect to result in 400m of scrap at start-up, today that’s below 150m: a 60% improvement,” she says.

Bobst is significantly reducing waste at start-up and during changeovers via a number of features. TAPS technology (totally automatic pre-register setting) is incorporated within its Rotomec MW80 (minimum waste) RS4003 high speed gravure press for shaftless cylinders, capable of printing a high barrier biodegradable film with certified inks for compostable packaging at 350m/min.

Early detection of production errors is another area in which attendant technology has made considerable progress towards eliminating unnecessary waste.

Eltromat’s ‘twin check’ workflow facilitates a 100% inspection process at full-out machine speed in both narrow and wide web gravure printing, and will detect process-related as well as design or substrate faults (including reflective and transparent materials).

Eltromat has also recently introduced its Inco_check spectral colour measurement technology, which can be fully integrated within the press itself. Capable of operating at up to 600m/min, the system provides a regular series of spectral measuring results drawn from 12 designated points located as appropriate along the production process.

Meanwhile, reduced substrate usage is further realised via fully integrated tension and temperature control systems that enable the press to handle extremely thin film grades of below 10 micron.

Next stage developments

While cylinder costs have been reducing for some time, laser engraving of zinc could represent an even less expensive and faster to produce alternative to the longer-established electro-mechanical engraving process that currently accounts for 95% of the total cylinder sector, says Peter Watson of Daetwyler Graphics (part of the Heliograph Group, whose member companies Hell and Schepers are applying the same technology to copper).

“It’s already widely used in the tobacco market, and will definitely grow with the galvanic process, bringing zinc more up to speed with copper in terms of time and efficiency,” says Watson. “And the cost of the laser engraving itself and the cost of the equipment are coming down every day.

The process allows you to engrave at very fi ne screens, says Watson. “Although that’s possible via the electro-mechanical alternative, laser runs at a far faster speed: 70,000 cells/sec, compared with the latest developments in electro-mechanical being shown at Drupa at 12,000 cells/sec.

Taking everything into account, laser probably operates at least four times faster, he says: “And as these cylinders are all chrome plated after they’ve been engraved, they last the same length of time irrespective of construction or process.

“The laser engraving process is all fully automatic now," Watson stresses. "You can produce an initial cylinder from a steel base fully engraved and chromed in two to three hours; thereafter, it is 30min to repeat it, and probably even quicker and no more expensive than than an HD flexo plate.”

Another future possibility for gravure is as part of a hybrid press alongside other processes, says Uteco’s marketing & sales vice-president Leonardo Gobbi. "Because of flexo’s increasing ability to print very good quality on a wide variety of substrates, plus taking up less space on the production floor and consuming less power, it’s more and more difficult for rotogravure to compete – except in certain geographical areas, of course, such as Asia, where it has always been the dominant printing technology.

“There is a lot of interest in hybrid machines, however,” says Gobbi, “and we’ve custom-built many such systems – in the main comprising an 8 to 10-colour CI flexo gearless system to which we add, via an electric shaft, one or more gravure units for specialist inline technologies such as coldseal, coating and laminating.”

Comexi’s Gian Vito Schiavi agrees. “It’s not unusual to build a flexo machine with gravure capability, because customers are most likely to deal with pure printing technology in order to be more effi cient and more flexible,” he says. “We have supplied any number of combination machines including 8-colour stations in offset plus two specialist gravure down-streams.

“Indeed, well over 90% of our total production is purpose-built – designing solutions to meet job requirements is what we are best known for.”