Extrusion International 5-2024

36 Extrusion International 5/2024 FAKUMA 2024 waste for the production of di- rect food contact products such as HDPE bottle caps, coffee caps and for odour reduction and degassing of PA, SAN or other polymers. In addition to its compact design, which takes up very little space and can therefore usually be easily inte- grated into existing premises, the OMNI scores highly in terms of flex - ibility. The fully automatic control of vacuum, extruder, dosing, degas - sing time and filter change ensures a consistently high quality of the end product while allowing the opera - tor to use lower cost raw materials. In today's tight and fluctuating ma - terials market, it is becoming increas - ingly important to be able to pro - duce regardless of the properties of the input materials, especially in the future when the quality of the input materials will vary and be uncertain. The compact design also results in very low energy consumption. Any energy used in the extrusion process is designed to be used in the next process step. This not only has a no- ticeable effect on electricity and gas consumption, but also significantly reduces the CO 2 footprint of the re- cycling process. Multiple Screw Extruder MRS The MRS extruder is based on conventional single screw technol - ogy but is equipped with a multiple screw section for devolatilization. It enables very efficient and gentle decontamination of the polymer melt, whilst achieving the require - ments for direct food contact standards. In addition, the MRS extruder permits the processing of R-PET directly into high quality end products such as packaging sheet, strapping tape or filaments with - out pre-drying by using a simple and rugged vacuum system. All this is achieved by means of its unique and patented processing section. The Multi Rotation Section is a drum containing multiple satellite single screws, driven by a ring gear and pinion transmission. The satellite screws rotate in the opposite direction to the main screw. This disproportionately in- creases the surface exchange of the polymer melt. A large opening for venting, exposing the full length of the satellite screws, is completely under vacuum. This provides excel- lent and unrestricted access to the polymer melt, the surface of which is constantly replaced at an extremely high rate by the action of the satel - lite screws in the multiple screw sec- tion. The surface area – and the sur- face area exchange rate – available for devolatilization are far greater than in other extrusion systems. As the thermal and mechanical stress on the polymer melt is minimized, re - claimprocessed on theMRS extruder has excellent optical and mechanical properties. In a single, simple extrusion step, harmful contaminants can be removed so thorough - ly that the resulting recycled pellets are safe for use in food contact applications. Vacuum System Gneuss has developed its own vacuum systems for the extraction of volatile impu- rities, some of which have patented separation systems. Due to the large melt surface in the MRS extruder, the suc - tion capacity is considerably higher than in conventional systems, so that large quan - tities of volatile impurities can be extracted from the polymer and separated from the vacuum flow by means of automated separator systems. In addition to a water ring pump vacuum system, Gneuss also offers deep vacuum systems with appropriate separators. The vacuum system on display is a water ring pump system designed for vacuums of 25-40 mbar and offers high au - tomation and process control with low maintenance, even in recycling applications. Gneuss Filtration Technology Gneuss’ topmodel, the RSFgenius, operates with an integrated back- flushing system offering self-clean - ing for very demanding applications and highest quality requirements. Screens can be automatically re- used up to 400 times and filtration finenesses below 10 microns/1200 mesh are available. Retrofitting a fully-automatic RSFgenius to an existing extrusion line, whether in a pelletizing, sheet, fiber or pipe application, permits the use of more contaminated (and often cheaper) material and/or the use of finer screens. Every retrofit is tailor-made and usually without the need to move any existing equip - ment. Gneuss Kunststofftechnik GmbH www.gneuss.com Fakuma: Booth A6-6501 Patented Rotary Filtration System RSFgenius