Latest improvements in process productivity impress at Bobst Italia’s open house

The gravure printing and lamination open house held at Bobst Italia in S. Giorgio Monferrato 15-17 October 2012, rounded up in style the impressive showcase of web-fed printing and converting technologies displayed by BOBST during three open houses held for the first time in close succession in the UK, Germany and Italy. The 150 visitors to the Bobst Italia open house were treated to a dazzling display of both new and well-established gravure printing and laminating solutions in demonstration in Bobst Italia’s Technology Center.

Lamination was the first technology on show starting with the BOBST SL 1000 duplex laminator dedicated to solventless applications. The job run on the machine showed coating of 20 ? metallised BOPP film laminated to 20 ? BOPP which had been pre-printed on a BOBST F&K flexo press.  

Visitors followed the production data unfold on a screen which showed the rewound material length and the machine speed increasing from the 50 m/min starting speed to the production speed of 400 m/min. 
A flexible production line providing the possibility of line customisation in terms of web width, shafted or shaftless winders and reel diameter, the SL 1000 provides for a range of configurations and the machine in demonstration featured the lamination nip after the machine bridge just before the rewinder.

After seeing the performance of equipment dedicated to solventless lamination and assessing the high quality of the laminated product, visitors entered the Technology Center to see the demonstration of BOBST CL 850D trolley-type multi-technology machine confirm the quality and reliability of its performance, most particularly of the renowned flexo trolley the CL 850D was equipped with.

As the quality BOBST flexo trolley is acknowledged especially for the performance in coating solvent-based adhesives directly on thin aluminium foil, the demonstration showed the efficiency and output quality with a job coating solvent-based adhesive on 6.35 ? aluminium foil which was then laminated to a 12 ? PET film. The BOBST flexo system provides the possibility of a better coating of the adhesive on thin aluminium and an excellent optical quality of the final product.  

The CL 850D laminator achieved a production speed of 430 m/min, producing a high quality, duplex laminated structure without any defects. Then gravure printing technology came under the spotlight, starting with the BOBST Rotomec 4003HS high speed press which presented a number of innovations.
The BOBST Rotomec 4003 platform of gravure printing presses is very successful as it provides different solutions, each addressing specific printing requirements and applications; 120 Rotomec 4003 machines sold and in operation worldwide speak for the efficiency and quality of the solutions which BOBST continues to innovate and improve in line with its corporate philosophy.

The Rotomec 4003HS gravure press on show featured a new configuration with shaftless cylinders. The demonstration showed printing of a 6-colour food-packaging type job on 12 ? PET film, printing repeat 625 mm.

First the press was set in register using the TAPS system, BOBST patented function that works at the touch of a button. One operator of the two-man crew went to the main console to press the dedicated TAPS button which started the machine, moved all cylinders in register position, switched the register control and auto mode ready to start production.

The sequence was completed automatically in less than five minutes, generating approx 100 m waste. The press then reached top production speed of 500 m/min. Visitors could follow all the stages of TAPS setting and accuracy of the register system during the acceleration ramps and during production on a screen placed on the machine catwalk.

After the printing demonstration BOBST presented Twin Trolley a new concept in terms of trolley design and machine make-ready at changeovers. It allows the offline separation between the printing cylinder and the colour which enables to move both or either of them to storage or to a different printing unit, thus enabling to keep the CMYK process colours always on the machine independently from where in the press they should be positioned.

The Twin Trolley system confers to printing an unprecedented flexibility in job preparation and ink logistics. This was quickly and clearly explained by showing the visitors all the possible options, namely changing only the gravure cylinder, changing only the colour, and complete trolley changeover
Further important features aimed at decreasing consumption of consumables and increasing the speed of job changeovers are the possibility to use 50 litres commercial ink tanks on board the trolley, a 3-way valve and a pre-washing cylinder device.

The 50 l commercial ink tank has a suitable capacity for high speed processing of long run production, it does away with the need to transfer the ink to a dedicated tank, thus no time wasted in cleaning it. The 3-way valve enables to discharge separately the dirty solvent during pre-washing while the pre-washing cylinder device enables easy cleaning of the printing cylinder on board the machine. The efficiency of the Twin Trolley system enables up to 50% reduction of ink and solvent waste as well as considerable time savings. 

The second gravure printing machine demonstrated addressed different market needs and showed the quality and uniqueness of BOBST solutions in handling profitably very short production by printing a 6-colour cosmetic sachet-type job on a 20 ? BOPP substrate on a Rotomec MW 80 press. The MW (Minimized Waste) press is dedicated to printing medium web, very short run production and the demonstration highlighted its efficiency.

To show how easy and fast the job preparation on the printing units of this no-trolley/catwalk machine is the operator performed the complete operation on one print unit, including cylinder change, without using any tools. The press was equipped with lightweight cylinders, however, the machine is able to use all kinds of different printing cylinders: regular hollow printing cylinders with cones, lightweight printing cylinders with cones and thin sleeves printing cylinders. 

The TAPS function is integrated on all Rotomec MW presses and the sequence was completed again very quickly with even lower levels of waste – approx 60 m – due to the machine compactness.  The press accelerated very quickly and in only 30 seconds achieved its maximum production speed of 250 m/min, also performing an automatic splice on the rewinder at full speed at the end of the demonstration.
The quality of the demonstrations provided the open house visitors with a comprehensive overview of the industry state-of-the-art and the opportunity to see and quantify the remarkable savings in time and waste afforded by the latest BOBST developments and technologies in gravure printing and laminating.