PETpla.net Insider 10 / 2016

TRADE SHOW PREVIEW 81 PET planet Insider Vol. 17 No. 10/16 www.petpla.net Reprocessing of PET industrial and post-consumer waste Purified polymer The Gneuss Processing Unit (GPU) has been available for several years now and has proved itself on the reprocessing of bulky PET waste such as post-consumer bottle flake and industrial waste from fibre and film manufacture. This GPU consists of the Gneuss MRS extruder with its devolatilisation and decontamination performance together with the Gneuss Rotary Disc melt filtration systems and the Gneuss Online Viscometer for intelligent dynamic viscosity control, monitor- ing and logging. Since the last “K“, Gneuss has continued with its intensive development programme, so that the MRS extruder is claimed to represent a robust, rugged and reliable system especially tailored for recycling applications. Gneuß Hall 9 Booth A38 Subsequently, the purified and homogenised polymer is fed by means of a melt pump into the Jump, where the second important stage of the pro- cess takes place. Here, too, a large surface area of the polymer melt and optimum residence time of the poly- mer under vacuum are decisive fac- tors. The polymer melt is kept under vacuum as it passes over slowly rotat- ing elements. Through control of the residence time and the speed of the rotating elements, controlled poly- condensation takes place, whereby controlled IV boosting of typically 0.02 to maximum 0.3dl/g is achieved. The design of the Jump system avoids the ingress of oxygen, so that the yellowing effect encountered during the recycling of PET is reduced to an absolute minimum. After the PET melt has passed through a stilling cham- ber in the Jump system, the polymer is pumped directly into the production process (for example direct extrusion spinning, strapping) or to a pelletising (chip cutting) system. The Jump system is available for different capacities of between 100 and 2,000kg/h. At the “K”, Gneuss will show an MRS 90i for a throughput rate of 400kg/h, for industrial waste recy- cling with intermediate material buffer, auger and crammer/feeder. The extruder is coupled to the new Jump system, model V600. www.gneuss.com A further development is the extension of the venting system with several openings in the barrel. Depending on the application, these additional openings can be in the form of several openings in the MRS section of the barrel or venting ports in the barrel of the plasticising sec- tion. Additionally, the company has developed the Jump system. This is installed directly downstream of the Processing Unit and is intended to ensure an accurate and controllable IV boost of the PET by up to 0.3 in the melt phase. The Jump system is claimed to be a compact, quick and efficient alternative to conven- tional SSP (solid state) systems and enables direct reintroduction of the polymer into the production process without the need to remelt the PET. Depending on its properties, industrial waste is first fed through a shredder or a knife mill until the size is reduced so that it can be fed into the extruder. This can mean either compaction of the size reduced waste or a crammer feeder fitted directly to the extruder. The first important process- ing stage: melt decontamination takes place in the extruder. With its devolatilisation capacity, the MRS extruder can process PET waste with high residual moisture levels and/or contamination (such as spin finish oils) without the need for any pre-treatment of the waste. In the Multi Rotation section (MRS) of the extruder a huge polymer surface area and rapid surface exchange rate under vacuum ensure that all these volatile contaminants are reli- ably extracted. Solid contamination is extracted with the fully-automatic and process-constant Rotary Melt Filtration System. With filtration fine- nesses of down to 20μm and below, a pure and particle-free polymer melt is guaranteed. Industrial waste recycling line as to be shown at the „K“: MRS 90i extruder equipped with dosing feeder and crammer – feeder system, Rotary Filtration System RSFgenius, Online Viscometer VIS and Jump system. IV boosting system Jump