“There is currently a lot of interest in stretched barrier films in the film market,” explains Bernd Bayer, Head of R & D of the Film Extrusion Division at Hosokawa Alpine. Since print substrate films for full PE packaging made from 5-layer MDO films are now available on the market, yet another step in the development process is complete. “This means we have combined sustainability and resource conservation,” says Bayer. But the possibilities by no means stop there. “We are continuing with our research of a variety of film composites that are of interest in the production of flexible packaging,” Bayer adds. Each film layer has clearly defined tasks. “Each of these individual layers should be as thin as possible. That is why stretched films are particularly suitable for this purpose,” adds Bayer.
To ensure a brilliant presentation of the packaged products, the films are finished with surface or reverse printing. Since surface coatings with Al, AlOx or SiOx or special lacquers are created in the high-barrier area, predefined film properties are necessary for all of these processes. “With our systems and their proven, extremely flexible 7-layer and 9-layer die heads, we meet the high requirements here,” emphasises Bayer. “This is because the right MDO technology makes every layer the right thickness with the required physical properties.” In addition to MDO films, these system types can also produce standard barrier films such as: EVOH barrier films or lidding films with resealing properties. “This is how we are able to develop the right MDO system technology for individual customer requirements,” concludes Bayer. The MDO stretching system from Hosokawa Alpine combined with the TRIO technology, for example, meets the highest quality demands in film production while also enabling lamination and printing of full PE material composites.
The new machine and control technology “TRIO 2.0” from Hosokawa Alpine includes a single layer measurement of the stretched film after separating and before the winding points. “This more precise film layer detection enables the thin sections to be even better positioned for the stretching process,” explains Bayer. Using the measured values obtained, a smart control algorithm calculates an improved presentation of the factors influencing the MDO on the entire control circuit. The optimised recording and calculation of the target values for the thin sections makes the control in the inline MDO process more precise, thereby increasing the quality of the further processing.