At the 31 August-1 September 2023 Elite Conference on Speciality films in Mumbai, Dr Sascha Witt of W&H presented recyclable flexible packaging solutions that comprise innovations in film production using its Varex blown film line with an MDO unit and the subsequent creation of an oxygen barrier in the structure using a special varnish on the first printing station of its updated Heliostar rotogravure press. He illustrated the concept by showing a structure that had the 25-micron MDO-PE film on top, coated with a 6 grams per square meter oxygen barrier varnish on its Heliostar gravure press, which is then overprint printed on the ink stations of the press. The rest of the structure is then laminated using a solvent-free adhesive to an inner 145-micron PE sealing layer. The resulting laminate apparently receives 19 out of 20 points for recyclability from Intersearch.
Actually, the first part of the W&H presentation on film production is key to bringing down the cost of more sustainable flexible packaging. The doubling of the width of the blown film lines with MDO from 1.6 meters to 3.2 meters has brought substantial efficiency in that step. Additionally, the innovative dies used in the company’s cast film lines have decreased the changeover time and material wastage for a significant saving of up to 70%.
Dr Witt then went on to speak about W&H CI Flexo and gravure presses that are both equipped for printing with water-based inks and for the Extended Gamut Solutions (ECG) that are bound to add sustainability and efficiency to the process with their increased use. ECG generally used a standard set of inks, including CMYK and two or three special colors to produce both photorealistic images and most brand colors.
While W&H’s CI flexo press has already been proven in ECG use by South Asian printers such as ALFT in Sri Lanka, Dr Witt added that the new Heliostar gravure press is now ‘ECG ready’ – as well as having the capability to print at high speeds on recyclable and thin MDO-PE films. This is made possible by the Heliocontrol registration system, which has a new Sensor tracking system and the company’s new Supergrip idler rollers that together provide stability and overall production control even at top speeds. The Supergrip idler roller is a completely new technology with a special surface treatment, which guides the material through the machine in a much more stable manner. Apart from the intuitive automation and job control on the revised press, all production parameters are recorded for use in downstream processes via W&H’s own Ruby IoT system linked to the cloud.
