Extrusion International 5-2021

36 Extrusion International 5/2021 FILM EXTRUSION PET value chain, as well as Brückner Maschinenbau, are currently devel- oping measures to change exactly this. An exemplary application for such sealable mono (BO)PET fi lms could be lidding fi lm for a wide va- riety of thermoformed PET trays and containers or several overwraps in food packaging: a perfect match for easy sorting and recycling. Addition- ally, BOPET white opaque fi lms with a density below 1 g/cm³ are soon be- coming reality. BOPE – a promise for the future BOPE fi lms offer completely new pos- sibilities for a sustainable packaging industry. Due to the available, in mul- tiple countries already established PE fl exibles recycling stream – the product live circle can be immediately closed. Two different fi lm qualities are avail- able to the market: • Sealable BOPE-LLD • Stiff base fi lm BOPE-HD Improved by biaxial stretching, BOPE-LLD allows down-gauging in comparison to PE blown fi lm. The sealing performance and seal integ- rity is superior to BOPP, also puncture resistance and a linear tear behavior for easy opening functionality are bene fi cial. BOPE-HD is a stiff printable web and enables in combination with BOPE- LLD or PE blown fi lms real PE mono- material packaging, providing even high oxygen barrier in combination with coating or metallizing (Al, AlOx, SiOx) technology. This was recently proven by manufacturing a 100% BOPE pouch made of a 3 ply struc- ture: 20 μ m BOPE-HD transparent printing fi lm // 20 μ m BOPE-HD trans- parent barrier fi lm // 35 μ m BOPE-LLD sealable fi lm. Some highlights of the all-BOPE pouch are: • PE Mono-material with high stiff- ness • Outstanding opening behavior and linear tear • High, transparent barrier against oxygen and water vapor Besides the all-BOPE pouch, more and more packaging structures are being introduced into the market in real applications. From bilateral teamwork with raw material suppliers, masterbatch spe- cialists, fi lmproducers and converters tomore complex co-operations along the value chain: Brückner is involved at many levels. Thus, the best pos- sible PE raw material for the biaxial stretching process with optimal fi lm properties has been developed. The results have been transferred from the laboratory scale to production lines by upscaling and fi nalized in the BOPE/BOPP hybrid line layout. Bulgarian Plastchim-T as well as Po- livouga from Portugal, one of Eu- rope’s top manufacturers of high- quality fi lms and fl exible packaging, soon will go on stream with 6.6 m / 8.7 m wide, ultra- fl exible BOPP/BOPE hybrid lines for an extended range of biaxially stretched fi lms. As the demand for innovative BOPE fi lms is only now starting to develop, hybrid lines allow to react swiftly and fl ex- ible to market trends by also pro- ducing BOPP specialties such as UHB fi lms and coated fi lms alongside con- ventional packaging fi lm. Full output for BOPP, BOPE-LLD as well as BOPE- HD fi lm types is guaranteed, a mate- rial change can be handled within a few hours. The 5-layer machine is additionally equipped with the new Brückner in- line coater, making the production of extremely thin functional layers with- in the nano-range possible. Thus, the layers don’t disrupt the sorting and recycling, but cater, for example, for an improved adherence during met- allising and excellent barriers in com- bination with the equally thin but ef- fective aluminum oxide coating. Brückner Group www.brueckner.com