In April, Koenig & Bauer Durst invited two groups of carton printers from across Europe and North America to Radebeul in Germany, home of the sheetfed production centre. About 100 interested prospects attended, keen to see the solution on offer. Ralf Sammeck (CEO Koenig & Bauer Sheetfed, CDO & Member of Koenig & Bauer AG) opened the event, welcoming visitors and reiterating the commitment of K&B’s senior management to provide a robust inkjet workhorse press, designed to slot into existing offset workflows. The VariJET 106will print at an initial 5,500 sheets per hour (this works out at 230 feet per minute) on a press designed to run 24 hours per day for ten years. The modular press features standard components found on K&B Rapida sheetfed machines at infeed, priming station, coating towers and delivery. The seven-color (CMYK plus OGV to match 95% of the pantone Library of colors) inkjet unit sits after the priming station, with a high resolution camera system, drier and sheet conditioner.

The sheet transfer mechanism passes a gripper held sheet to a vacuum feed to pass under the Fujifilm Samba inkjet bars, then back for top coating and into the delivery. There is no margin for failure and K&B Durst has been testing and refining the machine before shipping the first Beta machine to a European customer where it is being installed now. The second machine was about to be packed up and installed into the second beta site where it will start printing in summer, while the third press will be delivered in Q3 of 2023.

[caption id="attachment_6412" align="aligncenter" width="682"] Figure 1 Koenig and Bauer Durst VariJET106 in the press assembly hall undergoing final tests prior to customer delivery[/caption]

That will be part of next batch of machines that are being built now. Robert Stabler, the CEO of K&B Durst is bullish, saying: “We have tested the reliability and quality thoroughly here in Redebeul and are sure our first customers will be successful. By drupa [in May 2024] we hope to have the first tranche of machines proven and we are considering the future roadmap to add modules that customers need to meet their customer demands of quality, cost, fast turnaround with a more sustainable production machine. We are confident the VariJET will deliver.”

They ran a demonstration featuring five carton jobs in a little over 15 minutes which ran seamlessly on both days when I was there. Three were on the same stock, simply changing the designs and ink coverages without stopping – the delivery can put in a tab, offset the stack or the continuous delivery can swap the delivery pallets which will be useful for pharma print applications.

The final two jobs featured, then onto a spot varnished job on a different board with a changeover of varnish plate and a final job with board size change and another spot varnish. Here it was a couple of minutes to swap the priming and varnish plates, if that is too long customers can specify a second coating unit and set up the coating plate while the previous job is running, this is an option selected for the next installation.

The printers in attendance were carefully examining the print quality which was fine, and I couldn’t see any defects. The press features a high-resolution camera that monitors every inkjet nozzle, when it detects a missing line it will compensate by activating neighbouring nozzles to compensate.

The four-metre high smoked glass inkjet print tower is designed for easy access in the event of maintenance, and the print bars are raised to clean rather than moving sideways, helping reduce the press width. This automated routine takes about three minutes and can be scheduled during a job changeover to minimise non-productive time.

The press comes with a Durst Workflow, proven in many inkjet machines for other applications. There is highly automated file submission, approval and delivery to the press. It offers automated unique coding and numbering applications for track and trace applications. An optional Smart Shop module that provides a full e-Commerce front end, including design and job submission tools with all the bells and whistles. The final piece of the jigsaw is a comprehensive Analytics tool set, providing detailed performance data and KPIs that will aid managers optimise the press performance.

I am looking forward to seeing the machine in operation at customer sites and I think there will be a lot of these. K&B Durst has really thought this machine through, with reliability the key performance metric. “We have to do this,” says Ralf Sammeck. “After all, it has the Koenig & Bauer Durst logo on it, and it what our customers expect and need.”