Bobst used its open house in Italy this week to premiere a new ink on demand (IoD) system and closed-loop, inline colour matching for narrow web flexo presses, which it says ‘will establish a new benchmark in the market, reduce costs and environmental burdens.’ It was also revealed that the company plans to launch a hybrid label press.
Shown at the event on an M5 narrow web machine, the inking system significantly reduces the amount of ink circulating in each print station and features a faster cleaning process that minimises manual handling of the dirty ink roller.
By reversing the direction of the metering roller, which in traditional print stations transfers the ink from the ink tray to the anilox, so that it instead rotates in unison with the anilox, an ink gap is created between the two. This in turn eliminates the need for an ink tray and just 30g of ink will be present in the station at any one time. The ink reservoir is replaced by a rubber hose connected to a bucket, which delivers the ink directly to the meter roller on demand.
The automated cleaning cycle is implemented simultaneously on every ink station during changeovers, as needed, taking a maximum of four minutes depending on the colour change.
To complement the IoD system, a new ink mixing station has also been developed. The Highly Automated Liquids ink dispensing system, or HAL, uses 14 inks to create the colours needed and contains only one pump performing a pipette-style action to measure out the very small amounts of colour needed.
The introductions are part of Bobst’s new DigiColor system, which also features colour sensors on each of the seven print stations for automatic colour management in real time, using Extended Color Gamut (ECG) inks, which are split into a darker and a lighter shade mixed to match the targeted Delta E.
Program manager of joint Bobst-Mouvent hybrid label presses Federico d’Annunzio, who demonstrated the innovations at the event, also unveiled that these are paving the way for a new hybrid flexo+digital label press, due for launch at Labelexpo in September.
