Extrusion International 5-2023

53 Extrusion International 5/2023 FILM EXTRUSION – CASE STUDY The New Generation of Recyclable Plastic Films The Polish packaging manufacturer ERG S.A., headquartered in Dąbrowa Górnicza, has invested in a modern 7-layer blown film line with inline MDO (Machine Direction Orientation) from Hosokawa Alpine for the first time. The line has been in operation since August 2022 and supports the traditional company in its vision to produce only fully recyclable plastic films. In addition to the positive environmental effects, the plant has increased production capacity by 30 percent. H osokawa Alpine’s MDO technology is a key compo- nent in the production of high-performance mono- material films made of polyethylene. In the past, to create certain product properties, composites had to be pro - duced from different materials that cannot be fully re- cycled. A more sustainable concept is packaging solutions made from pure polyethylene composites. These are in line with the principle of the circular economy, as they can be fully recycled after their original use and reused for end products without material loss. "Our vision and mission is the sustainable development and production of inno- vative packaging that meets the needs of our customers while minimising the negative impact on the environ- ment," emphasises Tomasz Gwizda, commercial director of ERG. In doing so, the company can draw on 120 years of experience. Today it produces various types of films, including films made of PE composites or EVOH, fully re - cyclable films or full PE films. For full PE films, ERG uses the new 7-layer line with inline MDO fromHosokawa Alpine. Precisely fitting line design and high film quality. "More than 100 MDOs made by us are now in use all over the world," says Richard Hausner, Sales Manager Poland in the Film Extrusion Division of Hosokawa Al- pine. Together with the customers, Hosokawa Alpine designs the respective MDO blown film line precisely for the desired film production, tailored exactly to the cus - tomers’ needs. "This was also the case with ERG and this is one secret of our success. The other is the quality of the MDO films," says Hausner. It is characterised by ex - cellent processability, optimised flatness and no hang - ing edges. To achieve this, Alpine’s MDOs are equipped with three unique features: TRIO technology (Trim Re- duction for Inline Orientation) for best flatness and roll cylindricity, the flexible adjustment of the stretch gap to reduce neck-in, and the unique vacuum technology for best flatness and excellent process stability. The Hosokawa Alpine MDO technology is based on monoaxial stretching of blown film. The film is pulled between two rollers that rotate at different speeds. De- pending on the application, the film runs over eight to twelve rollers, two of which are stretching rollers. After heating to the optimum temperature, the film is brought to the desired ratio in the stretching phase. The stretch- ing process reduces the film thickness while improving the optical and mechanical properties. These include, for example, barrier properties, transparency or processabil - ity. "The raw material requirement can be reduced with this technology in a resource-saving way and efficiency can be increased," Hausner explains. The stresses created during stretching are reduced in the subsequent anneal- ing phase. Finally, the film cools down and compensates for the thermal shrinkage. "Our composite films based on MDO-Full-PE films and a sealing layer made of LDPE - also in a high-barrier version for gases - meet all the re- quirements of a modern circular economy and are 100 per cent mechanically recyclable," says Gwizda happily. PE-MDO film replaces BOPET and BOPP films One of ERG’s products manufactured with the MDO system is the PE-MDO film Premium. Depending on the version, it is a seven- or fourteen-layer film for printing and laminating. As a mono-material packaging and an The new 7-layer line with inline MDO (Machine Direction Orientation) from Hosokawa Alpine at ERG in Poland