Extrusion International 5-2017

PREVIEW 46 Extrusion International 5/2017 Gneuss: new at the Fakuma Increased Demand for Filtration Systems At the last „K“ show in 2016, Gneuss presented new genera- tions of their Rotary Melt Filtration Systems. Since then, the demand for the Gneuss process- and pressure- constant Melt Filtration Systems has increased dramatically. The demand has come from all sectors of the industry, from not only recycling industry but also from sheet (including foam sheet) and film producers. The number of Melt Filtration Systems supplied for compounding has also seen a major increase. In the compounding industry, there has been a trend to ever more different colours and material formulations with short- er production runs. This requirement for increased flexibility means that fast material changes become an important eco- nomic factor. The Gneuss Rotary Filtration Systems are espe- cially well- suited to such applications. In addition to process- constant operation, they offer streamlined melt flow paths. A special version of the process- constant, automatic KF screen changer is available, which in addition to having extremely ef- ficient flow paths, is designed to be individually customised for the specific requirements of compounders with short produc- tion runs and drastic material grade changes – and thermally/ residence – time sensitive materials. Permanent pressure- and process-constant melt filtration is important in themanufacture of sheet and foam sheet. Paral- lel to the requirement for every higher quality, manufactur- ers of such sheet are constantly striving to reduce material costs, which usually means higher contamination levels, thus increasing the importance of melt filtration. For such applica- tions, Gneuss has seen a surge in interest for the RSFgenius screen changer, which permits filtration fineness of for ex- ample 56 µmwhilst maintaining constant running conditions and automatically cleaning its filter elements in situ. Constant pressure is an important added bonus for foam sheet man- ufacturers, for whom constant pressure means a constant foam structure. MRS-Extruder with exceptional decontamination performance The MRS Extruder (a single screw extruder with an innova- tive multiple screw devolatilising section) provides excellent devolatilisation of the polymer melt. The multiple satellite screws (which rotate in the opposite direction to the main screw) ensure a rapid surface area exchange of the polymer melt under vacuum, thereby achieving a huge improvement in the diffusion process. The system is therefore ideally suited to the processing of heavily contaminated polymers. The high polymer melt exchange rate by means of the Multi Rotation System is achieved during an extremely short resi- dence time, with low shear and temperature stress for the polymer. At the same time, additives can efficiently and ho- mogeneously be introduced into the melt. As a result, the polymer decontaminated on the Gneuss MRS extruder fulfils the strict requirements of food contact appli- cation standards such as FDA, EFSA and Invima without re- strictions. Odour- Free Products „Decontamination“ refers to harmful volatiles such as oils, solvents etc.. These need not necessarily be harmful but can nevertheless be a problem if the volatiles create an unwanted odour. This is especially often a problemwhen recycling poly- mers. Under temperature, the polymer can absorb residues from the washing process and other contaminants can de- Fig.1: Pressure and process constant Rotary Filtration System RSFgenius Fig.2: Gneuss Processing Unit (GPU) with MRS-Extruder, Rotary Filtration System RSFgenius and Online Viscometer VIS