PETpla.net Insider 09 / 2021

EVENT REVIEW 50 Vol. 22 No. 09/21 www.petpla.net The Online Viscometer (VIS) is used in a by-path, as a closed loop. By using a small amount of the material from the main flow conveyed by a gee-pump into a slip capillary, which is a defined meas- ure capillary, the differential pres- sure and the temperature are meas- ured. With the capillary, one can calculate the viscosity during the process. It is possible to monitor and to control the viscosity anytime in the process. Gneuss tray-to-tray recycling solution Dr Carl-Jürgen Wefelmeier stated that for the tray-to-tray recy- cling a different concept is needed. The question is how to keep or to increase the input IV? Gneuss offers the new MRSjump system, that combins decontamination per- formance of the established MRS devolatilising extruder with viscos- ity boost in one processing step. The MRSjump extrusion system can be used in pellet processing, direct recycling (e.g. fibre or strapping tape production) or in a tray-to-tray closed loop recycling system. The extruder is an advance on a simple single screw extruder, equipped with a multi screw sec- tion for optimum devolatilisation. The MRS technology enables effi- cient and gentle decontamination of PET, without the need for pre- drying whilst achieving the required decontamination for food contact standards. What is new about the MRSjump is the longer, modified version of the multi-rotation sec- tion which ensures both a longer residence time of the material and surface area exchange under vacuum. At the same time, material shearing has been reduced. As the thermal and mechanical stress on the polymer melt is minimised, PET processed on the MRSjump extruder has very good optical and mechani- cal properties. Dr Axel Hannemann further explain, that the longer Multi Rota- tion Section, coupled with a powerful vacuum system with 1 mbar can be used to boost the viscosity of rPET and to hold it at a stable level in spite of variations in the input mate- rial. In this way, there is no need for any liquid phase (LSP) or solid-state polymerisation (SSP) for many appli- cations. With the stabilisation and/or increase of the intrinsic viscosity in the extrusion process, the MRSjump is well suited to recycling for exam- ple reground PET film waste or fibre recycling – cases in which direct recycling with an extruder was previ- ously impossible due to the too low intrinsic viscosity or variable input viscosities. Sukano masterbatches for processing rPET application Ms Alessandra Funcia, Head of Sales and Marketing at Sukano spoke about the use of Sukano mas- terbatches to ensure a high quality and productivity in the final rPET application. She started by taking a look at the European rPET market. Alessandra explained that in 2019 there was un uplift in the collection rate in Europe. This was an organic growth because the consumption growth level was little bit lower than the collection rate. The growth of the collection rate was about 5%. She pointed out that there is a great room for improvement in the collec- tion of PET and that there is a big lack of harmonisation in collection systema and this leads to a varied rate across Europe. This throws up the problem of waste quality and variety. An un-har- monised collection system leads to a significant variety of waste quality of anything between 20 to 99%. The food contact bottles are one of the most important applica- tions when it comes to rPET output (32%), and they are also the most significant growth area. Sheets, or more specifically PET trays are the major outlet for rPET (38%). Recy- cling PET thermoforms has become a business opportunity. Out of one million tons of PET sheet consumed in Europe, just 15% is collected. The major country for the collection of PET waste is the UK. At the moment there are very little data from other countries. By 2025 and 2030 when the industry has organised itself cor- rectly we will be up at 550 kgt PET from trays in less than 10 years. As an example for upcycling PET trays, a project by Gneuss, Illig, Veolia and Sukano was started. The aim was to convert out of mixed APET flakes thermally stable rCPET- food trays that can go back to a closed loop. As material source, the wide variety of PET collected in the yellow bin by German households was used. To crystallise the PET polymer a masterbatch is needed. Sukano PET Nucleating Combi- masterbatch for rPET increases the crystallisation capacity of the rPET film and ensures faster and uniform crystallisation. This results in a higher processing window and leads to a temperature resistance of up to 200 °C for the end application. Additionally, a temperature-resistant colour pigment improves aesthetics. In the example the following result was recorded: “Veolia supplied the rPET collected from the yellow bin from Germany. We mixed it with a combimasterbatch of Sukano which contains a colour and additive pack- age that leads to nucleation and some other functionality. We put it together in the MRS extruder from Ms Alessandra Funcia, Global Head of Marketing & Head of Sales EMEA at Sukano