Extrusion International 5-2017

47 Extrusion International 5/2017 PET Foam – new at the Fakuma At the Fakuma, Gneuss will present its latest development in PET sheet: the manufacture of PET foam sheet. The sheet lines from Gneuss are characterised by their extremely flexible op- eration with regard to the input material and the sheet manu- factured. These sheet extrusion lines can be quickly and flexibly switched to foam sheet. The MRS foam sheet module enables a weight / density reduction of over 50 %, and this from input materials of up to 100 % post consumer material, regrind, virgin or blends of these materials. With equivalent mechani- cal product properties, a wide range of PET foam products for food packaging can be manufactured cost efficiently. Thanks to the excellent low shear mixing properties of theMRS extruder, both the nucleating and the blowing agent are com- pletely dispersed andhomogenously distributed in the polymer melt. After extrusion and filtration, the polymer melt is condi- tioned so that it has the optimum viscosity and ductility so that material foamswith the requireddensity as it emerges fromthe die. compose and create strong unwanted odours. Additionally, polymers, with simple molecular structures can already have absorbed odours from their first “life” as packaging materi- als. Typical cases are films (e.g. LDPE) which have been used for packaging meat or fish. The high diffusion rate in the MRS extruder reliably removes such odours and enables the production of odour- neutral products. Technology Leader in PET Recycling Gneuss has been at the forefront of polymer recycling tech- nology for over 30 years now and offers a range of innovative solutions for the processing and recycling of polymers. Gneuss´ systems are optimised for the challenges of PET recy- cling. They are perfectly harmonised with one another and can their modular design can be configured flexibly. The Gneuss- Processing-Unit, consistingof the uniqueGneussMRS Extruder, Rotary Filtration Systems and Online Viscometer represent are the heart of the Gneuss recycling systems. With the MRS Multi Rotation System, Gneuss provides a pro- cessing system which can handle a wide range of input ma- terials with different qualities and properties. It can process 100% recycled material without pre-drying or crystallising. In addition to the unmatched devolatilisation performance of this extruder (for example input material with up over 1% re- sidual moisture level) the decontamination performance is so good, that the extruder matches EFSA and FDA requirements without restrictions or compromises. The especially gentle direct processing without pre-drying, crystallisation and above all without the need for frictional heat makes the processing of materials andmixtures of mate- rials with differingmelt temperatures possible and eliminates steps in the processing chain. Polymer purification takes place not only in the MRS extruder but also in the Gneuss Rotary Melt Filtration Systems which ensure a purified polymer melt, without foreign particles or specks. Gneuss has continued to develop the Rotary Filtration Systems and introduced new generations with a host of de- tailed enhancements last year. The Online Viscometer from Gneuss completes the Gneuss- Processing-Unit. With its sophisticated control system, it en- sures that the IV value of the melt matches the setpoint. (The vacuum setting of the extruder is automatically adjusted to compensate for variations in the input material IV). Different IV values can be set for different applications, ensuring excel- lent flexibility. Gneuss GmbH www.gneuss.de Hall A6, booth 6501 Fig.3: Examples of food containers made from foamed PET sheet