Latest developments in high barrier film technologies

True to its reputation as an innovator focused on creating value to satisfy the different requirements of converters in a constantly evolving industry BOBST addressed the latest trends in new barrier technologies and short run gravure printing at a conference and open house held 28 and 29 October 2014 in S. Giorgio Monferrato, Italy.

Guests heard about the latest developments from a line-up of speakers including BOBST experts and representatives of leading international companies from throughout the flexible packaging value chain. The speakers addressed the challenges and opportunities that the latest materials, systems and production tools represent to the growth strategies of printing and converting companies.

New barrier technologies are developing at a very fast pace and a new generation of clear films and coatings are challenging more traditional barrier packaging structures.  As regards the technicalities of manufacturing and the physical properties of these new materials, the presentations from Bobst Manchester and Reifenhäuser were particularly insightful.

Dr Carolin Struller from Bobst Manchester illustrated the company’s in-depth research on AlOx clear coating from the way it is produced and its performance on various filmic substrates through to its barrier retention with subsequent processes of printing and converting. Bobst Manchester carries out extensive trials on the process and is researching ways that in the future could enhance their printability and prevent barrier loss during converting.

Kurt Freye and Daniele Cerizzi from Reifenhäuser Kiefel Extrusion and Reifenhäuser Cast Sheet Coating presented the latest developments in blown film and cast extrusion for high barrier applications which reflect the trend for lower pack weights yet with increasing pack performance. This makes 9 to 11 layer films an important trend which has generated several ongoing projects for machines which can produce increasingly sophisticated multi-layer structures using less material.

Paolo Serafin for Taghleef Industries presented their EXTENDO film applications offering solutions for better recycling.  He advocated that the day should to be a forum for discussion and cooperation within an industry aiming to find solutions for reducing the environmental impact of packaging.

As regards short run gravure printing Stuart Jones of Janoschka spoke about the innovations the company has been working on in rotogravure sleeve systems and on the retail trends for mass customization.

Professor Armin Weichmann from Stuttgart Media University illustrated the studies that the institute is carrying out on conductive layers, cylinder stability and the feasibility of nickel to replace copper and chromium in engraved cylinders. The professor spoke about how the Rotomec MW 60 gravure press installed in the university press room is a key part of all its projects because it nears productions conditions – something which is essential for the validity of the trials carried out on the behalf of converters.

The gravure technology update was rounded up by Giovanni Caprioglio from Bobst Italia who illustrated the comprehensive range of BOBST gravure presses for flexible materials, focusing on the minimised waste concept of the Rotomec MW 60 Ι 80 press.  Dedicated to very short run printing the Rotomec MW 80 brings together all the essential requisites for profitable operation: minimised waste of material, energy consumption and space requirement.

Of great interest to all participants was the insightful presentation of Philippe Roulet from Nestlé who illustrated all the factors that determine the way packaging needs to evolve in order to better respond to the new and diverse requirements of the consumer. Breaking the rules, generating value for the consumer, streamlining and standardising the structures of materials wherever possible and implementing new technologies into processes were just a few of the key issues presented.

After lunch at the castle, the action moved to the nearby Bobst Italia production plant. A press completely operated from floor level, the 850 mm web-width Rotomec MW 80 awaited the open house guests in Bobst Italia’s Technology Center and was ready to start printing a demo job on a 12 micron PET substrate coated with AlOx.

One highlight of the gravure demonstration was the capability of BOBST technology to handle AlOx coated substrates which in differing from conventional films present challenges to printing and converting equipment. A further highlight was the effectiveness of the MW 80 on-board washing system. The print run showed the validity of the BOBST MW minimised waste concept starting with the TAPS function to set the machine in register. At the completion of the TAPS sequence which lasted a few minutes the screen on the machine registered incomparably low substrate waste.

After an automatic splice carried out on the rewinder at maximum speed a print sample master was collected before changing the color on one print unit from light peach to very dark brown and resuming printing at full production speed. The speed of changeover being very critical in terms of profitability when printing very short runs an operator demonstrated how fast and easy it was on a print unit which was in stand-by during printing. After a few minutes of printing the machine was stopped and the washing sequence of the cylinder and ink pan started on a selected print unit, prior to the ink being changed back from dark brown to the original light peach color.

Guests followed the on-board washing sequence from animations displayed on a screen while being able to check on a separate screen the register accuracy and stability, most particularly during acceleration and deceleration. After another automatic splice at maximum production speed, the machine was stopped and a second sample taken in order to measure the color difference with the print sample master. The Delta E value between the two compared samples was very low, clearly showing the efficiency of the BOBST internal washing system in avoiding contamination from one color to the other, especially considering the great difference of shades in reverting back from a very dark brown intermediate color. Once the demonstration was over, guests were able to get close to the machine to visually see the results of the washing sequences from the ink pan and cylinders which were taken out of the MW 80 press for checking.

A demonstration on the BOBST CL 850D confirmed the laminator’s quality, efficiency and flexibility. The machine featuring the renowned BOBST flexo coating system laminated a 7.0 micron aluminium substrate onto a 12 micron PET film.  The Rotomec system enables a lower coating weight of solvent-based adhesive to be applied directly to the aluminium foil, creating excellent bond strength. The machine produced a flawless, high quality, duplex laminated structure at a speed of 430 m/min.