PETpla.net Insider 03 / 2012

MATERIAL / RECYCLING 12 PET planet insider Vol. 13 No. 03/12 www.petpla.net Extricom offers recycling plants with capacities of up to 36,000t/a PET recycling at large The goal for every recycling company is to implement an economical system and deliver high product quality for the final application. Since 1998, the RingExtruder RE devel- oped by German company Extricom has been used for the bottle-to-bottle recycling of PET. The post-consumer waste is transformed into high quality raw materials approved for food contact. Capacities of up to 4,500kg/h rPET (36.000 t/a) can be achieved with the RingExtruder RE7 XPV. The requirements of an economi- cal extrusion concept are varied and must be analysed on an individual basis. One focus is on energy con- sumption, disposal costs (e.g. vacuum slurry, screen cake, start-up mate- rial), plant availability and mainte- nance costs. These running costs are evaluated on a continuous basis and incorporated in the plant concept and design. Technology The process section of the RingExtruder RE mainly consists of 12 co-rotating and tightly intermeshing screws orientated in a fixed ring. The adjacent screws constantly wipe each other’s surfaces as well as the outer barrel and the stationary centre core. Stagnant areas are there- fore eliminated inside the process section and deposits on surfaces are efficiently prevented. This arrange- ment results in a distribution of the depending on customer requirements and the final application for the pro- duced material . Bottle-to-bottle application Both of these features lead to the high degassing efficiency of the RingExtruder RE. Thus, PET bottle flakes can be extensively decon- taminated without pre-drying at high throughputs. In addition, the gentle treatment of the melt and the high ratio of heat transfer surfaces to volume allow for an accurate control of the material temperature. Plant availability Plant availability is a key factor in the design of the Extrusion System. For example, maintenance or clean- ing work can be carried out without interrupting the extrusion process, since there is a dual filter/separator system, incorporating parallel cir- cuits in the vacuum unit. According to Extricom, more than 260,000t/a of bottle-grade PET regranulate are produced with the RingExtruder RE. The increase in PET collection rates in various countries make high-duty plants over 20,000t/a very attractive. Extricom’s PET recycling plants cover a throughput range between 2,800 and 36,000t/a. www.extricom.de Extricom’s RingExtruder RE7 XPV melt flow into multiple small portions providing an effective surface to volume ratio. Furthermore, the twelve intermeshing areas create a unique flow pattern with a high rate of melt surface renewal. Setup of extrusion system Extricom is continuously develop- ing the RingExtruder RE to create a complete turnkey concept. The focus of the development was always on a high level of flexibility, productiv- ity and profitability and this has also resulted in the ecological efficiency of the system. The complete Extrusion System is based on the careful selection of every single component. Every module, e.g. gravimetric feeding, vacuum system, melt pump and filtra- tion, pelletiser and crystallisation is tailor-made and optimised for PET recycling. Different kinds of pelletising and SSP systems can be integrated