Machines take on manpower for materials handling
Monday, January 11, 2016
In the early days of wide-format inkjet printing, the technology was held in check from encroaching on screen and litho markets by limitations in printing itself.
However, subsequent advances, such as flatbed printing, UV inks, ever-faster speeds, and higher image quality, have eroded many of the advantages of those analogue processes. Digital wide-format technology is now at a stage where the biggest challenges are no longer printing, but materials handling and overall process optimisation.
This is leading to developments across the board such as changes in printer configuration, including a dip in the dominance of flatbeds at the very top end of the market in favour of roll-to-roll printing for some applications, and debate about the merits of automated sheet handling.
“The advantage of roll-to-roll is higher productivity than for flatbed machines because the printer can be in continual production rather than having to stop and start for loading and unloading,” says Durst UK managing director Peter Bray.
Simpsongroup opted for roll-to-roll printing investing in a Durst 320R press and a Crest XY cutter. The roll-fed set-up only stops when changing rolls, a requirement that is minimised by ganging jobs by substrate.
“Previously we printed everything as sheets on a pair of HP FB 7600s, but when we reinvested we decided that flexible materials would go onto roll-fed printers and the flatbed would focus on rigid work,” says chairman Mark Simpson.
“As a knock-on benefit we have taken shorter-run work off litho presses and put that onto the Durst. As a result litho utilisation has leapt up from 75% to 90%.”
The company also upgraded its flatbed capabilities, replacing the two HP FB 7600s with one FB 11000. The machine is currently fed manually, but automation will be the next step as part of the move to “cut out touch points” and enable the digital operation to run with minimal operator intervention.
Choosing whether or not to automate media handling on a flatbed depends on a number of factors and can be tricky as market trends are pulling in different directions.
According to Mark Turner, production director at SMP in south London, some form of automation is a benefit. “But it will depend on quantity and material variation. Full automation would be desirable if you ran the same substrate a lot. We constantly change substrates, so we have semi-auto equipment.”
For some firms, just as it makes sense to split work between roll-fed and flatbeds, it also makes sense to split work between automated and manual handling. One example is Ossett, West Yorkshire-based Kolorcraft.
“We have two flatbed machines – the Durst 1030 and the Inca S40 as we need the flexibility of both automated and manual handling,” says commercial director Michael Atkinson. “We don’t live in a world where it will be one or the other. What job goes where depends on the application, the substrate and the run length.”
Durst’s Bray outlines the parameter thus: “Print runs of 50 up to 500 benefit from three-quarter automation, and those of 500 to 1000 from full automation.”
Another consideration when choosing the level of automation is the range of materials handled. Feeders can require a lot of adjustment when changing materials, which may negate the benefits. As there is a trend towards using a wider range of materials this needs to be considered when weighing up the best option.
The vendors are looking at ways around this issue; for example at Fespa in May 2015, Durst showed a feeder on rails that selects from pallets of different substrates.
Another trend is for ever-faster printers, which increases the need for automation.
“With faster machines such as the Onset X2 and X3 the physical demands on an operator are significant and can impact throughput over the course of a shift if they tire,” says Fujifilm marketing manager for Corrugated Display & Packaging Steve Wood.
While there are clear benefits of splitting sheet work into rigid sheets and flexible rolls there is a divide on how to produce that work.
For big operations such as Simpsongroup with the volumes to justify it, dedicated production lines offer the most efficiency.
“In future we may end up with machines dedicated to specific job types with the right ink and material – it’s all about running lean with less changeovers,” says Simpson.
For firms that don’t have the volumes or the budget it’s about having a machine flexible enough to handle both types of work.
“A lot of clients demand three-quarter automation and roll-to-roll on same machine,” notes Bray.
This hybrid approach offers an opportunity to maximise return and productivity. Rather than running both rigid and flexible sheets interchangeably, you can print rigids with an operator during the day and then switch to running flexibles on a roll unattended overnight.
Similar discussions about the automation, or not, of handling are also taking place in wide-format finishing too, albeit at a less advanced stage.
“Only a few of the systems we sell are intended to operate unattended (fully automated), but interest is increasing,” says Zünd product manager Lars Bendixen. “Even people who don’t want it now feel it is important that systems can accommodate it in the future.”
Printers may be looking in the wrong places for improved throughput in their finishing though.
The speed of cutting tables isn’t increasing at the same pace as that of printers, and is unlikely to due to mechanical limitations, assuming there is no fundamental shift in technology. Something like Moore’s law applies to printheads, which means more nozzles and faster throughput for the same cost every couple of years, which is not the case for cutting, creasing and routing tools. This makes demands for physically faster machines difficult to deliver. Instead, the way to get more throughput is smarter handling.
“Manual handling can cause delays whereas automation ensures there is no idle time,” says Bendixen. “Even our cutters continue to get faster. There is a huge potential in better utilisation or reducing idle time. In the past, when customers asked for faster cutters we had no way of countering that the problem was not cutting but handling, now we can show that. Our ZCC software can analyse how much time was cutting and how much handling and show it’s not a productivity problem but one of utilisation.”
Firms such as Simpsongroup, which has the levels of throughput to justify it and who have used their MIS to identify the bottlenecks, are already implementing more automated post-press.
In April 2015 the firm invested in an Elitron table with twin heads and pallet feeding and delivery. This tripled throughput and reduced manual handling in digital finishing, increasing the run lengths possible from tens to hundreds, therefore reducing the time and expense of making cutting forms for its die-cutters.
“If you’re in corrugated POS the Elitron is a must-have,” says Allan Ashman, managing director of UK Elitron dealer Atech. “The £200,000 price tag is expensive but the whole concept is geared around productivity. It’s not just the faster cutting, it’s the way it cuts waste to make stripping take a fraction of the time.”
Similarly Zünd’s Board Handling System also moves finished work in a way that eliminates the need to leave bridges in the cut path, speeding up stripping.
Now the problems have been addressed in printing and cutting, automation is also beginning to make inroads further down the chain.
Kolorcraft put in Bickers Tapejet and Gluejet machines for assembling POS units earlier this year.
“The machines take 15 minutes to set up but beyond 50 units that time is negligible,” says Atkinson. “There’s also a health & safety benefit as operators no longer have to handle hot-melt glue.”
It’s a similar situation at Simpsongroup, which recently installed a taping machine that’s 10 times faster than hand working. The firm is also looking at collating and packing.
“Collating is a bottleneck and automating that is the Holy Grail,” says Simpson. “I never thought we’d be able to do it but from what we’ve seen it’s possible.”
Some firms have already taken the plunge with Delta Group recently installing a Col-Tec Smart Collator. Higher-tech options are emerging that may take away a tedious task that is also error-prone at a stage in the process when mistakes are at their most expensive.
“At Fespa we introduced a robot, which has made people think about how they do things,” says Zünd’s Bendixen. “Besides better utilisation, most of the conversations have been around using it to eliminate mistakes in kitting where some parts can look almost identical.
“The challenge is merging robots safely with people, ours is designed to work side by side as man and machine.”
Case study: Magenta Print & Display
Taunton-based Magenta is the in-house print operation of department store Debenhams. It recently refreshed its large-format print operation with a pair of Durst Rho P10 250 machines. Both feature three-quarter automation for handling boards and roll-to-roll units for flexibles. They joined a pair of Durst 320 roll-to-roll machines and replaced an Inca flatbed.
“We were looking for something better suited to our poster production, which has big peaks in demand,” says Debenhams print operation director Chris Tester. “The Inca was only really efficient on boards and they don’t recommend running the machines unattended, whereas the Dursts can, so now one operator can run three machines.”
While unattended throughput was important for reels, for the board work Tester feels a more hands-on approach is better.
“For our mix of work I don’t think robotics would be flexible enough. The average run is six and the trend is towards shorter runs, which makes it less viable. If you have automation but then have to work around it to get the job done it’s a much bigger compromise than just accepting some manual handling.”
For finishing it has two Kongsberg tables and two Fotoba X-Y cutters.
“The Kongsbergs are so quick that I consider them a production device. In the run-up to Christmas we produced a 1,000-off gift tag shaped job.”