Bobst Group - News - Three BOBST EXPERTCUT 106 for colordruck – but ultimately we buy not machines, but capacity
"At the end of the day, the only thing that counts is how many sheets we can get through the machines in an hour, "says colordruck Managing Director Herbert Klumpp, pointing to the digital counter of the C.U.B.E. control system of the . At this particular moment, the flat-bed die-cutter is processing the six-up sheets of a job for the packaging of an 'air freshener' – and according to the dark-blue numbers on the monitor display, it's doing so at a steady rate of 9,000 sheets per hour. "So, this job's running at maximum speed", says Klumpp.
But to what extent can the packaging printers, headquartered in Baiersbronn in the north of the Black Forest, actually utilise the maximum performance of the three new flat-bed die-cutters from BOBST in their daily work? "That depends on the jobs. We exploit it to the full on simple jobs. When handling complicated designs, the speed depends on the complexity of the packaging designs, the number of blanks and the thickness of the materials to be die-cut", explains Martin Bruttel who, together with Herbert Klumpp and Thomas Pfefferle, manages the business of the company that was originally founded as a lithographic printing house as long ago as 1929. He says the printers, who deliver over a billion cartons per year to their customers, achieve a very high average throughput in die-cutting production, and that's ultimately what matters.
Sophisticated material flow to the last detail
"We keep our stocks as low as possible, because we only have limited storage capacities for semi-finished products. That's why we need dependable technologies in all production segments that guarantee a trouble-free in-house workflow", says Pfefferle, formulating one of the company's fundamental demands on its machines and other equipment. The colordruck advertising slogan is 'Packaging moving you' and the production processes are consistently geared to this philosophy at every level.
For example, driverless transport systems automatically carry the pallets with the printed sheets from the pressroom to a temporary store located directly alongside the company's total of four flat-bed die-cutters. Depending on how long the inks and varnishes need to dry, the sheets are intermediately stored for a maximum of 24 hours. Finally, the warehouse management system gives the driverless transport systems the necessary instructions regarding which pallets are to be delivered to which die-cutter and when. That, too, takes place automatically. It need hardly be mentioned that the printing and die-cutting processes have to be more or less in step. Otherwise, the limited capacities available for intermediate storage of the sheets would be insufficient. The uncompromisingly efficiency-oriented workflow would be disrupted. In an extreme situation, it might even be necessary to stop the printing presses.
That's why the dependability of the flat-bed die-cutters, based on the patented Autoplaten® die-cutter concept devised by BOBST, plays a key role for colordruck. "We set the machines up and start them. After that, the jobs are processed largely without interruption", says machine operator Jens Fahmer, summing up his practical day-to-day experience so far. The first of the new flat-bed die-cutters was already installed in 2010. The second machine followed in early 2011, and the company put the third die-cutter into service in the middle of the year. In addition, a SPRINTERA 106 PER from BOBST is also still in use. As a result, the die-cutting operations at colordruck today have a theoretical capacity of just under 40,000 sheets per hour.
Innovations make for stability
One of the windows in an lets us see how the stripped waste drops into the generously dimensioned waste collector that disposes of the waste from the four flat-bed die-cutters. The stripping tool moves so fast that its up and down movements almost become a blur before our eyes. "9,000 sheets per hour is a pretty impressive speed", is Fahmer's comment on the job in progress.
From the machine operator's point of view, various innovations in the contribute to a hitherto unknown stability and high net performance in the die-cutting process, and also to the sheet feeding system, sheet register, and the waste stripping and blanking sections. Says Fahmer: "The printed sheets are even drawn in correctly from slightly misshapen stacks. All the sheets are accurately aligned both in and transverse to the direction of travel, and the waste is reliably stripped and disposed of. "That generally applies to all the types of carton and corrugated board that colordruck processes, he says. Regardless of the size and weight of the materials, the non-stop Smart Feeder continuously raises the stacks, thereby ensuring a constant transfer height for passing the sheets to the feeding table. Together with the anti-static, stainless-steel honeycomb plate of the feeding table, this guarantees optimum feeding of the sheets. In addition, BOBST designed this feeder in such a way that it also reliably feeds paper and plastics – an important feature for companies that process those kinds of material too.
Fahmer sees the precision of printing/die-cutting registration with the new Power Register II register system as being an enormous step forwards compared to its predecessor. "We now only need to work with register marks". This is because the machines are equipped with highly sensitive cameras that optionally detect the sheet edges, specially printed register marks, or the print itself. The individual sheets are perfectly aligned in relation to the die-cutting tools on the basis of this data. BOBST developed the high-performance Registron cameras used specifically for applications that impose particularly tough demands on precision. The '1 millimetre register mark option' of the Power Register offers additional flexibility as regards the sheet layout. As a result, colordruck can print and read 1 mm register marks instead of the usual 2 mm marks. In other words, better use can be made of the surface of the sheets, depending on the layout. Or the marks can be better integrated in the layouts. "The new register system simply offers more possibilities for specifically achieving the desired production results", says Fahmer, summing up.
In addition, the double-cam gripper bar advance of the Autoplaten die-cutter concept makes for extremely uniform acceleration and deceleration of the sheets. The movements of the gripper bar are continuously controlled, from sheet detection and die-cutting, all the way to stripping and blank separation or the delivery of full sheets. This reduces the stress on the sheets in every phase of the die-cutting process, which is in turn why the number of nicks can be reduced. That likewise contributes to higher quality of the products, while at the same time permitting a higher production speed.
Set-up times are a key factor
"Our customers' target groups are becoming increasingly focused. Accordingly, the run lengths are getting shorter all the time. As a result, the set-up times of the machines are more and more important", says Klumpp, emphasising the need to be able to set up the machines as quickly as possible. In this respect, too, the new die-cutters come up with a number of innovations that are reflected in substantially higher availability. According to Fahmer, that offers potential for savings, especially when handling repeat jobs.
For example, Fahmer reports that the device for full-sheet delivery can be set up much faster. It enables the operators of the machines to switch from blank separation to full-sheet delivery in next to no time, thus further increasing flexibility in the production process. The same applies to the tool lifting platform: at the push of a button, all tools are raised to exactly the level of the stations where they are to be fitted. This makes the job-changing procedure simple, rapid and ergonomic. Also very convenient is the Quick Change concept which, in combination with the patented Centerline® system developed by BOBST, guarantees the high-precision positioning of all tools, and thus the reproducibility of all jobs with exactly identical results. The die-cutting tools, in turn, are automatically blocked when the safety windows are opened and released when closed. "The tools always fit. That's simply made life a lot easier for us", says Fahmer, reporting on the experience of the machine operators.In contrast to printing, where repeat jobs have become a rarity, existing tools and settings can be used for roughly half of the jobs in the die-cutting process. Since all jobs are stored in the intuitive C.U.B.E. control system of the machines, these repeat jobs can be retrieved at the push of a button at any time.
Given several job changes per shift and flat-bed die-cutter, the shorter set-up times add up to more production time at colordruck. "One day, the set-up times will have to approach zero", says Pfefferle, indicating the future target for the machine manufacturers from the point of view of the packaging specialist. "But we're still a long way from that, of course".
Since all the machines deliver exactly identical production results, colordruck can distribute the jobs among them at will. The company also has an interesting philosophy when it comes to investment decisions: "We ultimately buy not machines, but capacity".
In view of the high degree of automation and the sophisticated production processes involved, machine manufacturers like to use colordruck as a reference. Customer visits are also more or less part of the daily routine. "Be they manufacturers of branded goods, private-label producers or industrial companies – we can today offer our customers top-class quality that we are happy to demonstrate to them on site. That particularly applies to the dependability and precision of our new die-cutting equipment", explains Bruttel. Print buyers appreciate the company's openness. After all, in the era of increasing just-in-time production, they need to be able to rely on their packaging suppliers more than ever before.
The after-sales service is just as good
The high availability of the machines and other equipment is backed by the 24/7 technical service offered by BOBST. However, colordruck has not yet needed it for the new die-cutting machines – a fact that is partly attributable to regular preventive maintenance. "But if the worst comes to the worst, we can rely on the speed and skill of the BOBST technicians. We know that from experience", says Klumpp, indicating another aspect that spoke in favour of installing the flat-bed die-cutters, and thus of continuing the cooperation between the two companies that has now lasted for more than 50 years.
"BOBST consistently gears the development of its technologies to the demands of the future, and is open to the individual requirements of its customers in the process. For us, that's another key element of a strategic partnership. "Since 1958, colordruck has purchased a total of 17 die-cutters and 12 folder-gluers from the Swiss machine manufacturer – and the next flat-bed die-cutter is already scheduled to follow in 2012. Bobst SA, Lausanne, Switzerland, February 2012