This is shaping up to be a bumper year for innovation in decoration on two-piece D&I cans, with the big names in equipment manufacturing launching new products or redesigning existing machines.
While the coronavirus pandemic scuppered plans by manufacturers to showcase their latest offerings at events such as Metpack in Germany and the International Metal Decorating & Packaging Association’s annual gathering in the US, engineers are still pressing ahead with developments.
Insight into how beverage can decorator manufacturers are responding to the latest demands from brand owners for more striking and dynamic label designs was provided during a visit to Unimaq in the UK.
Unimaq has been developing decorators for about 20 years with a global customer base approaching
50 units. Its machines follow a familiar layout based on the industry-standard Rutherford design but with refinements in the eight-colour machine that take speeds up to 2,200 cans per minute.
Decorators were being prepared for delivery at Unimaq’s Wrexham site in North Wales when The Canmaker visited, where sales director Roman Lozano explained how they are being refined to accommodate the application of inks and varnishes that offer properties such as thermochromic, matt, tactile and the like.
“Different varnishes react in different ways,” says Lozano. “So the varnishing unit needs to offer easy film weight adjustability.
“We have been working to make our decorator the most flexible on the market. It’s no longer about producing millions of Coca-Cola cans at a time, but making it easy to change labels. We want ours to have the lowest downtime, with the fastest changeover in the industry.”
With this in mind, Unimaq is working on a special system for even faster changes with a hoped-for launch in a few months, says Lozano.
Unimaq is also diversifying into other aspects of D&I can manufacturing, with the launch of a can trimmer using laser techniques (see item on p31 of this issue), and an enhanced ultraviolet (UV) bottom rim coater for applying mobility-improving coatings on the bottom of cans with less energy and reduced safety risks.
The new rim coater uses LED lamps for the curing of the coating that speeds up canmaking lines and brands’ filling lines.
“We work in an industry with such staggering volumes that what might appear to be a marginal gain adds up to millions of pounds in savings,” says Lozano.
Lozano and director Berty de Jong see the LED-cured coating system as a game changer for canmakers that currently use technology that’s been around for decades, such as ARC and microwave UV lamps. Unimaq will continue to offer these.
Room for improvement
Lozano and de Jong argue that while the newer UV equipment takes curing to a higher level of efficiency, the process still needs improving.
LED technology requires far less energy, produces less heat and substantially cuts maintenance.
“LED doesn’t have the same issues as microwaves – it works at much lower temperatures and saves 75 per cent in energy,” de Jong explains. “There’s also no risk of fire, which has been one of the main concerns to date. There have been other applications for LED drying, but not in bottom-rim coating.”
They are also smaller: Unimaq’s prototype LED unit is at least two metres shorter than UV systems. Additionally, it dispenses with the need for microwave UV lamp heads, ventilators and exhaust systems.
Unimaq, which builds its own bottom-rim coaters, says its innovation is expected to cost about the same as current UV drying systems.
The company has recently built an in-house UV mass rim testing unit offering canmakers and lacquer suppliers off-line testing and qualification.
Lozano said the company hit upon the idea of developing its own complete UV bottom-rim coater in order to provide a turnkey, complete and professional solution to canmakers, adding a UV dryer, conveyance, cooling and controls to their own and existing applicator units.
“Canmakers would need to buy the different components such as the applicator, UV lamps, conveyance, and blowers from different suppliers and integrate these all themselves. To provide a complete solution in which our applicator would be key, we teamed up with a UV curing specialist and packaged that into a turnkey offering,” he says.
With the LED unit now at testing stage, Unimaq is also establishing which coatings would work best with the newly-developed equipment. It is finalising trials with a number of lacquer suppliers and expects to be able to start planning production before the autumn.
“Our system would handle any lacquer but we are working with the suppliers to ensure they have the right initiators to apply this to the can the right way,” Lozano explains.
The process faces the usual challenges presented to any new lacquering process, including the coating’s reaction to pasteurisation and retorting. But de Jong explains these are matters that Unimaq is confident will be easily overcome.
“The technology is there – it’s a question of finding the best performing combination,” he says.
Refining the Reformat
Across the UK at Shipley in Yorkshire, CarnaudMetalbox Engineering (CMbE) has made some key tweaks to the decorator that it has been developing as part of its Reformat equipment range.
First revealed in 2017 and last year shown at Cannex in Denver, the newly redesigned machine’s focus is on enabling efficiencies through quick-change and ‘smart’ technology.
For a start, the decorator spindle disc critical points have been optimised and the angle between infeed and discharge reduced to provide more processing time. Tested at speeds of up to 2,000cpm, the redesign has reduced vibration to as little as one-sixth of that experienced in the product’s previous design.
Efficiencies have also been created by improving access to all eight inking units, reducing the need for tools during changeovers and incorporation of common fittings from the Reformat range.
Independent servo motors that drive eight elements of the decorator, including the spindle disc, blanket drum and overvarnish unit, also allow for easier operation. They can all be overseen by one operator with the addition of Servo Registration innovation, which is also said to improve plate registration accuracy.
Automated inking systems
At Stolle Machinery in the US, the Inkjector is seen as the first significant step towards fully-automated ink control and label inspection on beverage can lines.
An ink fountain for use on Stolle’s Concord and Rutherford decorators, the Inkjector features fountain keys that are remotely servo-adjustable, enabling the operator to control the ink application across the fountain on each inking station.
Testing in production has shown reduced ink usage and improved label change times, says Stolle. When changing labels, set-up time is shortened using the system’s memory for settings by returning to a previous label, or similar.
Stolle’s objective is to reduce set-up time in label changes while reducing ‘hold for inspections’ (HFIs), which are a major cause of lost production. Inkjector is the first of three phases in Stolle’s decorator automation initiative, and “has passed all field tests with flying colours”.
In Germany, three years ago Koenig & Bauer MetalPrint, revealed its first D&I can decorator, a ten-colour machine with highly-automated plate changing, since when field trials have been carried out with customers.
Development continues, according to marketing and communications chief Ursula Bauer. “We are still working on the machine and continue to push the development,” she says. “However, we are working within non-disclosure agreements and therefore cannot release any information at this time. We are excited about the print quality of the machine and have implemented additional features.”
In Lynchburg, Virginia, Belvac has been upgrading the decorator technology acquired from Rosario by speeding up the changeover for its inker sleeves, with what it claims to be “game changing” results.
The latest development in this process is its Tiger Sleeve System, which Belvac says can reduce change times to just 30 seconds, or four minutes for an entire eight-inker decorator.
“The key features of this decorator sleeve system are the quick label change times, DLE high image quality, immediate accurate registration, high circulation performance with less ink usage, and that they can be used on multiple-make decorators,” Belvac says.
The Tiger Sleeve achieves its registration accuracy thanks to the use of a pin and slotted hole system. This enables the register of all colours by sliding the sleeve over the cylinder onto the pin. Sleeves are engraved on a similar cylinder and the image always starts at a fixed zero point.
“Millions of cans have been printed with one set of sleeves,” the company says, adding that its engravable material is resistant to high temperatures and has good ink transfer properties.
Intercan, a UK company which is owned by China-based Suzhou SLAC, is working on the development of its D&I can proofing machine to provide more capacity and refinement.
The ten-colour machine, called the IMP400 (Intercan Mini Printer), will have a 400cpm capability and is being promoted as an alternative to SLAC’s 200cpm digital printer on its Mini-Line.
This setup is a low-capacity D&I production process, which requires much less capital investment, and is being aimed at canmakers that need short production runs. The decorator will also be well-matched for use on monobloc aerosol can lines, which run at up to 250cpm.
The IMP400 features servo-controlled drives for the web cylinder and print heads, enabling registration while it is operating.
“The speed of the IMP400 prototype is currently about 200cpm,” says Intercan’s managing director Pete Strode, “but the target is 400cpm”.
While the high printing speeds achievable on litho decorating machines mean they continue to dominate canmaking lines, increasing demand from customers for shorter-run batches and speciality cans have increased demand for digital printing technology from canmakers.
Last year in the UK, Tonejet unveiled its Cyclone Digital Printing System, which prints directly onto blank necked cans before filling, resulting in what Tonejet describes as true late-stage customisation.
The company’s facility in Hertfordshire has a full end-to-end digital printing line at which customers can carry out direct-to-pack demonstrations and trials, and even full production runs. Among brands that have recently utilised the system are BrewBoard, a local craft beer producer.
In Canada, Solucan is using the first commercial installation to produce hundreds of thousands of cans in batches ranging from 48 up to 165,000, the company adds.
Last year, Hinterkopf in Germany delivered the first of its nine-colour digital printers to a canmaker in China. The D240.2 is equipped with white, seven-colour separation CMYK OGV plus varnish.
Alexander Hinterkopf says the seven-colour separation allows for the first time a full digital workflow from artwork, image processing and calibrated printer.
“It is now possible to match the target colour tone to a very, very fair extent without any manual correction,” Hinterkopf tells The Canmaker.
“This speeds up the process of pre-press enormously, reduces the start-up scrap, doesn’t require highly skilled operators to run and can match the customer’s target colours in a very short time.”
The D240.2 is not as power hungry and requires less ink, meaning energy and resource costs are reduced, he says.
“If one wanted to reproduce this in a conventional way, a very qualified printer with a top offset printing press would be needed and still some hundreds or even thousands of misprinted containers would be needed to match all the target colours,” Hinterkopf adds.