Extrusion International 3-2021

25 Extrusion International 3/2021 RECYCLING – CASE STUDY The Gneuss Rotary Filtration Technology ensures an unin- terrupted production process under constant conditions – even when post-consumer recycled material is processed. Gneuss Melt Filtration Systems are especially well suited for retro fi tting to existing extrusion lines. RSFgenius Back Flushing Filters as Optimum Retro fi t Solution for PET Bottle Flake Recycling The processing of PET Bottle Flakes presents particular challenges for Melt Filtration Systems. On the one hand, the post-consumer material source typically has a relatively high contamination level, on the other hand, the quality re- quirements ( fi ne fi ltration) are very high – especially when the material is to be put back into transparent bottles for beverages. Inorder that the fi lter elements donot need tobe constant- ly changed by hand, the ideal Melt Filtration System should be self-cleaning. Typically, the principle of back fl ushing is used. A proportion of the melt fl ow is diverted so that it fl ows in the reverse direction across fi lter elements which are not in use in order to wash the contamination out. The cleaning ef fi ciency of the back- fl ushing and the quantity of material needed for back fl ushing vary greatly between the different systems available on the market. With the Gneuss RSFgenius Melt Filtration System, the high pressure sequential cleaning system ensures that the fi lter elements are completely cleaned with the absolute mini- mum of polymer. Nosoplas in Spain decided in favour of the RSFgenius Rota- ry Filtration System due to the high ef fi ciency and the fast return on investment which it offers. Nosoplas manufac- tures bottle grade pellets (chip) from PET bottle fl ake. The pellets (chip) are supplied to other companies, where they are injection moulded to pre-forms which are later blown into high quality bottles for beverages. Nosoplas decided to replace their existing, conventional fi ltration system due to problems with back fl ushing and high polymer losses. They replaced this conventional sys- tem with a Gneuss RSFgenius 175 for a throughput of 1.500 kg/h and a fi ltration fi neness of 56 μ m. In fact, the customer is even able to operate with 30 μ m for special products. And this all with a constant, steady melt pres- sure, minimal losses due to back fl ushing and without any production variations, even during replacement of the fi l- ter elements. The expectations that Nosoplas placed on the retro fi t with a Gneuss Rotary Filter have been completely ful fi lled. Im- mediately after commissioning the units, a drastic reduc- tion in in material loss due to back fl ushing was observed and, at the same time, the quality of the rPET granulate produced was noticeably improved. Gneuss Kunststofftechnik GmbH Mönichhusen 42, 32549 Bad Oeynhausen, Germany www.gneuss.com PET Bottle to Bottle Recycling – Major Efficiency Improvements by Retrofitting Melt Filtration System Against a background of government rules prescribing the proportion of recycled polymer, the plastics strategy of the EU and the commitment of many market leaders to responsible use of polymers, the conversion or modi fi cation of extrusion lines represents an important trend. The Germanmanufacturer of Filtration Systems, Gneuss, has seen a surge of interest among customers looking to retro fi t their extrusion lines Fully-automatic, process and pressure constant RSFgenius Back Flushing Filtration System