MRS Extruder Easily Handles Wide Range of PET Reclaim
A major Eastern European synthetic fibre manufacturer carried out extensive tests to convince themselves of the excellent devolatilisation performance and the ability to set and hold a specific IV regardless of the input viscosity of the material. Subsequently, Mogilev Khimvolokno in Belarus decided in favour of the reprocessing concept from Gneuss Kunststofftechnik GmbH, Bad Oeynhausen, Germany.
This line has now been successfully commissioned and consists of a Multi Rotation Extruder type MRS, an Online Viscometer and an RSFgenius Melt Filtration System.
The decision in favour of the Multi Rotation System extruder was largely influenced by the ability of this system to handle the wastes generated in this synthetic fibre factory, regardless of their type and form and provide a consistent, high quality glycolysed PET melt.
Mogilev Khimvolokno is one of the largest European manufacturers of all kinds of Pet synthetic fibres. The fibres manufactured there range from bicomponent fibres with a low melting point and an IV of 0,63 to industrial yarns with IV values of around 0,9. Waste is generated in the various stages of the production of all these fibre types and occurs as start up lumps, tangled fibres, tow etc. before and after the application of spin finish oils.
For economic and environmental reasons, the customer placed great importance on recycling the internal waste. This waste is processed on the MRS extruder which efficiently extracts the spin finish oils efficiently. Thanks to the multiple satellite screws, a huge polymer surface area exchange takes place, providing unparalleled devolatilisation performance, even at low vacuum levels before automatically adjusting varying levels of ethylene glycol (depending on the input viscosity of the material) and glycolysing the material to a constant, low viscosity. The excellent, gentle homogenising performance of the MRS extruder ensures efficient and constant glycolysation of the material. The Gneuss Online Viscometer provides the control loop for the glycol injection in response to the different viscosities of the input material. Subsequently, the glycolysed material with a consistent and reproducible, low IV is fed in a side stream where it mixes with virgin material in the finisher.
Under normal conditions, the IV value of the glycolysed material is constantly regulated automatically and remains stable within +/- 0,001. Finally, the Rotary Melt Filtration System RSFgenius provides efficient and reliable filtration even at such low viscosities and even with sometimes very high contamination levels.
With this extrusion line from Gneuss, Mogilev Khimvolokno is able to put production waste back into the process without any penalty in terms of product quality, thereby making considerable savings with regard to raw material costs (not to mention disposal costs).