Extrusion International 5-2021

24 Extrusion International 5/2021 PROCESSING Polymer melt from recycling pro- cesses usually contain a high degree of contamination, which makes it impossible to reuse the polymer for the food sector. ECON offers the solution for this problem – the ESD (discontinuous screen changer) is a single-piston screen changer that provides high-quality melt fi ltration for low-contaminated raw materials such as polyole fi ns, standard plas- screens during the pelletizing pro- cess and thus extends their service life considerably. Another concern for this process is melt pressure and how it can fl uctu- ate while being fi ltered, which can affect pelletizing. To ensure a con- stant pressure for fi ltration and the pelletizing process, ECON offers melt pumps with a throughput range of up to 12,000 kg/h. tics, engineering plastics and high- temperature plastics. In case of highly contaminated polymers, especially from recycling, ECON recommends the ESK (con- tinuous screen changer) which is equipped with two pistons and allows the screen to be changed during production. ECON also of- fers back fl ush equipment (ESK-B) for this product, which cleans the Example of use – ECON PET-Edition: EUP 600 – EWT 350 – ECS 1500 In a world in which circular economy and sustainability are getting more and more important, the reuse of PET is essential. Especially to produce packaging, recycled PET is becoming increasingly important. After all, most PET bottles put into circulation now consist of a high percentage of recycled material – and the amount is rising. In the so-called bottle- to-bottle process, the bottles are puri fi ed for use. The loop starts with the sorting and cleaning of the PET bottles which are then shred into PET fl akes - that become the base material for the recycling process. In the next step, the pre-sorted material pass through a multi-stage fi ltering process in which contaminants like metal, foreign colors and other polymers are removed. After this step, the fl akes are melted in an extruder, puri fi ed if necessary and cut into pellets by means of an underwater pelletizer We PET the Future