Extrusion International 5-2021

35 Extrusion International 5/2021 and moisture resistance, as well as a light weight and material strength. PP is excellently recyclable, with a great potential for future high value products. It can be sorted and mixed with the existing PP recycle stream – and there is a large market for PP recycling material: For example in in- jection moulding, as a substitute for engineering thermoplastics such as ABS and PA, as a housing material for small electrical appliances and in moulded parts for household appli- ances. The automotive sector needs PP for body parts such as bumpers or in the interior of cars. In the con- struction sector, PP is used for fl oors, pipes, containers and garden furni- ture. Several developments for PP mono- material packaging have been suc- cessfully launched recently: E.g. fl exible pouches, where complex laminates are now substituted by all-polypropylene versions based on BOPP and CPP. The switch to PP mono-material structures is giving a good combination in terms of prod- uct protection (barrier to humidity, aromas or gases), promotion (matte or glossy, high stiffness, good aes- thetics and haptics) and performance (printing, lamination, packaging and fi lling operations) – even for retort- able applications. BOPET fi lms for an upcoming circular economy All over the world, BOPET fi lms are a highly esteemed material for vari- ous applications – with every right to be. In technical applications such as solar panel back sheets, optical fi lm grades, insulations, printed circuits or sequin fi lms their excellent mechani- cal characteristics, brilliantly clear nature or high temperature stability are unbeaten. For a wide range of packaging solutions, more properties come on top: high barrier features, a good surface treatment suitability or an excellent stiffness, to name only a few. To make BOPET fi lms also fi t for the upcoming circular economy, raw ma- terial suppliers, Brückner Maschinen- bau, fi lm producers, converters and brand owners are actively following the idea of PET mono-structures. Trials on the Brückner laboratory line clearly showed that post-consumer waste recylate PET can be added to the virgin material in a proportion of above 50% without any losses in quality: optics, mechanics and the dimensional stability are absolutely comparable to 100% virgin BOPET. Using certi fi ed bottle fl akes which are fully food contact approved, the manufactured fi lm is ready for a cir- cular economy and furthermore re- duces the carbon footprint. PET in general is not known for good sealing properties. Members of the www.sml.at each detail matters for unrivalled performance Extrusion lines. Engineered to perform. Only a company who has a constant focus on the productivity of its customers thinks ahead and creates extrusion solutions that leave the rest standing. SML specialises in the development of extrusion lines for film, sheet, coating and lamination as well as multifilament spinning lines.