Sat, Sep

Travels in time

Richard Stuart-Turner looks at the latest developments in large-format printer transport systems and asks what's new and what's next?

For some time now we’ve been told that robots will eventually possess the intelligence and capabilities to make our lives easier and, perhaps more worryingly, even replace some of our jobs. But, while 'The Future of Employment: How susceptible are jobs to automation' - last year's study by researchers at Oxford University and Deloitte - suggests there is an 83% likelihood that printing machine minders will at some point be replaced by automated systems, it’s hardly an immediate consideration. Is it?

Many inkjet printer manufacturers share the outlook of Epson, which recently stated its ultimate goal is “to create a world in which its robots support people by handling day-to-day repetitive tasks within the service sector”. Rather than replacing humans altogether, then, robots would theoretically become an extension to existing workflows and increase a PSP's productivity by freeing up operators to get on with other jobs.

One area of large-format print production where automation is already becoming noticeably prevalent is in printer transport systems. While most roll-to-roll devices are already quite automated, with many able to reliably run unattended, flatbed users are starting to benefit from improved robotic technology.

Of course, the level of flatbed automation required depends a lot on both a PSP's run lengths and the variety of materials being used. For companies printing short runs on a wide range of media, automation is perhaps not as essential, but it can be hugely beneficial for those printing longer runs on only one or two substrates, particularly if a lot of similar jobs are ganged together.

(Mention of PIC B here Tan) Inca Digital says it is currently putting a lot of focus on automating substrate handling. Last year the manufacturer launched its Onset X series of flatbed UV inkjet printers, which are compatible with a number of different types of automated media handling systems.

The Onset X series printers feature a 25-zone vacuum table and UV control system, which eliminates masking. The top model in the range - the Onset X3 - can print up to 900m2/hr and 180beds/hr. Vacuum zones can be independently controlled and managed by the operator using the auto zone function.

Inca Digital head of product strategy, Colin Mills, says there is always going to be some operator intervention required, even when using the automated features of the machine to separate and load substrates and then move them to a stack.

“Even if you've got full automation, you still need people to bring in palettes of material and put them in the machine and then take them again. But we're looking at moving automation forwards now. With the X series, we've increased print speeds to near the limit in terms of what we can do with flatbeds so we're now looking at the end-to-end process to try to consider how to save time and improve the productivity all-round.”

Mills says Inca Digital is expecting to have its first robotic automation systems operating in the market early 2017. He notes that one of the main challenges on the POP side is for the robots to be able to pick up all of the different sizes and ranges of media. This problem is further exacerbated if stacks are used.

“Although a robot can identify where the top of a stack or the corner of a palette is, it just adds a bit more complexity, whereas if you're picking off the table you know where the substrate is.”

At the moment Inca Digital is seeing more interest in robotics in the industrial space, Mills says. “Here you're looking at handling wood, metal sheets or things that are more bulky and weighty and more difficult for people to handle. We are doing work in both areas but that's where we're seeing a bit more of a pull for robotics.”

(Mention of PIC C here Tan) Inca Digital's parent company, Screen, is also seeing increasing demand for more automated transport systems. In March this year Screen showed the latest version of its Truepress Jet W3200UV flatbed printer at Fespa Digital in Amsterdam. The machine, originally launched in 2013, has received a number of upgrades since, including the addition last year of an optional 3.2m-wide roll-to-roll system that integrates with the original flatbed. With each upgrade has come a number of media handling enhancements.

Screen's European product manager for wide-format systems, Martijn van den Broek, says the machine is near enough fully-automated when using the roll-to-roll option. “When you can combine roll-to-roll and flatbed capabilities on one machine there are a lot of advantages and the only disadvantage is that you cannot run both at the same time. The roll-to-roll can print unattended, so when you batch your production and do your flatbed printing first, you can then run 250 square metre rolls continuously.

“But flatbeds make it easier to position things; you've got a better vacuum and double-sided printing is more accurate.”

Some Screen customers, van den Broek reports, have already started using robots developed by third parties to load and unload media onto the W3200UV flatbed.

“It depends on whether the company needs it because it is an investment and, also, what you lose with a robot is quality control, so if a missing nozzle comes up the robot will just continue printing. The risk of losing some media is something that needs to be taken into account so many customers still prefer to do it manually.”

Quality control, then, may be one thing holding back robot-automated transport systems for now, but this is something that will change over time as the cost of the technology comes down and the reliability improves.

“Our continuous presses that print on paper at speeds of up to 220m/min have high-speed cameras mounted on them that make a picture of every A4 that flies by and collates these with the Rip file. Once those cameras get cheaper and can be linked up to the workflow I'm sure this will become possible for wide-format machines and they will be first linked up to high-speed machines running 500 to 900 square metres per hour.”

A separate factor that will impact printer transport system development over the coming years is the continued rise of single-pass inkjet technology.

Many of the recent single-pass launches have focused on the corrugated market and feature a range of media handling options to help manage the high print speeds. EFI's Drupa-launched Nozomi C18000, for example, features top and bottom feeding options and automated material stacking.

As the technology starts to filter further through the wide-format sector to focus on other applications, things could start to get more complicated.

Inca Digital's Mills says: “We're doing developments in single-pass and learning about the specific issues in terms of inkjet. Where there will be some development is if you're printing aqueous inks with inkjet because then the challenge is more in controlling the substrate as you've got a lot of water going onto the paper that needs to be dried off in the process.

“We'll have to find ways around controlling the media in terms of alignment between the print colours. If you're putting a colour down and there's a lot of water going onto the material then it's going to grow and stretch if you're on a web system and it will change the size of the paper. You've got to make sure the media is in the right place before it goes under the next colour.”

Another area of large-format printing that requires very precise media handling, due to the more delicate nature of the substrates used, is the fast-growing digital textile industry.

Textile printing for home and interiors is the market that the highest proportion of UK PSPs that responded to Image Reports’ Widthwise 2016 survey said they are hoping to move into over the next two years, with textile printing for banners and flags not far behind.

Responding to increasing market demand, the likes of Durst and Mimaki are now focusing more of their efforts on developing machines aimed at these applications. Back at Fespa Digital in March, Durst launched its first 5m dye-sub printer, the Rhotex 500.

This machine, which can handle coated and uncoated polyester blend textile rolls up to 350kg and 5.05m-wide, required a new type of transport system to enable it to accommodate the wider textiles.

Durst product manager for roll-to-roll printing Fabian Sottsas explains: “The unique thing about the transport is the combination of mechatronics and software allowing to transport textile dimensionally stable over 5m width through a printing system. This is necessary to provide perfect quality over the entire width in terms of sharpness, colour stability and step and the least stress for the textiles structure.

“Precisely controlled motors are linked to the media axles - seamlessly, no matter which width and media type is being used - and this combined with data of media load and sensor systems calculates the right tensioning. Additional highly precise rollers with minimal tolerances linked to the dancer roll systems makes the transport really unique.”

Sottsas, who says the media transport for the Rhotex 500 is “the most important piece of the puzzle” next to correct drop placement, believes that in the future printer transport systems will further have to adapt to the customer's workflow and work more closely with peripheral devices outside the printer.

(Mention of PIC D here Tan) Mimaki has also increased its textile transport focus with its new Tx500P-3200DS direct sublimation printer for soft signage, which is expected to be available from January 2017, and the Tx300P-1800, which was released last year. These machines use Mimaki's AMF (Automatic Media Feeder) to apply appropriate levels of tension to the textile to ensure stable transportation.

Stephen Woodall, national sales manager for textile and apparel at Mimaki's UK and Irish distributor Hybrid Services, says: “The AMF system is a bulked up, higher-precision motor for controlling the take-up and the feed of the materials. Mimaki has always taken the handling of substrates very seriously.

“What we're seeing with the Tx300P-1800 in particular is a whole host of features that have appeared on various machines throughout the ages of Mimaki that have all been incorporated into this design to try to stabilise and fix the fabric while it's printed.”

Woodall says accurate media handling is crucial with certain materials, such as silks and cottons or fabrics with a level of stretch and instability, to ensure that they are kept stable enough to print sharp images onto while going through the machine at high speeds.

“As technology moves on, and the things that can be controlled with sensors and automation improves, I think we're only going to see more in the printer designs to control the actual stability of the fabrics and prevent printhead crashes and strikes.”

Earlier this year MTEX launched Blue K, a new addition to its Blue range that features a special transport system that enables printing on knitted and stretch fabrics. Instead of using belts like other MTEX machines, this system uses rollers to ensure fabrics are not overstretched.

MTEX Technologies business support manager Rick Kwiecien says: “With Blue everything is as automated as we can make it but with fabrics there are so many variables involved with temperatures and humidity that it becomes quite tricky. You have to be very au fait with how to run the process and know how your machine reacts and how your fabrics react to water, moisture, humidity and temperatures.”

Automation may not always be easy to achieve, but it's a key R&D focus. And while robots are yet to reach the stage where they are taking over numerous jobs, it looks as if they are going to have a major impact on large-format transport system developments - and could hold the biggest key to unlocking productivity gains.

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