Bobst has launched three technologies to reduce changeover times and improve colour consistency on its inline flexo presses.
Ink-on-Demand (IoD) is a digital inking unit; Highly Accurate Liquids (HAL), an ink mixing factory; and DigiColor, a system for controlling ink density without changing ink film thickness, enabling closed-loop colour control.
The three technologies, all designed to improve flexo’s time to market and cost effectiveness for lower volumes, were unveiled at a Labels & Packaging Innovations event at Bobst's factory in Florence, Italy, this week.
By improving the consistency of the flexo process they also make it easier to swap jobs between flexo and digital production, improving a supplier’s flexibility.
Bobst also announced two new presses: a version of its M6 optimised for folding carton work and a hybrid line that will integrate subsidiary Mouvent’s inkjet printing and which will be shown at LabelExpo 2019 in Brussels this September.
Also present at the event were Bobst’s partners in the Revo extended colour gamut/fixed palette printing project, including AVT, Esko and X-Rite, which showed a closed-loop colour system that automates colour setup, control and reporting.
This system combines Esko’s Automation Engine workflow, X-Rite’s ColorCert colour server and AVT’s Spectralab on-press measuring system.
IoD replaces the ink tray used in a standafrd flexo unit with a digital ink dispensing system that travels across the inking cylinder and incoroprates automatic wash-up.
“The consequences of the new flexo inking system are bigger than you can imagine,” said Bobst hybrid printing programme manager Federico d’Annunzio.
HAL is a compact and precise ink mixing system that enables the production of 30g batches of ink for press tests of special colours when used with the IoD.
Finally, DigiColor is an inking system for extended gamut printing that enables the control of ink density on press. Each of the seven units of the press are fed by two ink tanks which are the same hue but have different brightnesses.
By varying the proportion of the lighter and darker inks and mixing them before they are applied to the inking cylinder, the press can alter the density of the ink applied. This makes colour adjustment possible without impacting the ink film thickness laid down.
When this is combined with an on-press spectrophotometer it enables on press adjustment of the colour to correct for fluctuations from the desired colours, eliminating the need to remake plates or stop the press to reformulate the ink.