Developments in PET sheet
Fakuma, Gneuss, Hall A6, Booth 6501 Gneuss systems are optimised for the challenges of PET recycling. The Gneuss-Processing-Unit, consisting of the Gneuss MRS extruder, rotary filtration systems and online viscometer represent the heart of the Gneuss recycling systems.
With the MRS Multi Rotation System, Gneuss provides a processing system which can handle a wide range of input materials 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 (e.g. input material with up over 1% residual moisture level) the decontamination performance is claimed to be so good, that the extruder matches EFSA and FDA requirements without restrictions or compromises.
The gentle direct processing without pre-drying, crystallisation and above all without the need for frictional heat makes the processing of materials and mixtures of materials with differing melt 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 detailed enhancements last year.
The online viscometer from Gneuss completes the Gneuss-Processing-Unit. With its sophisticated control system, it ensures 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 flexibility.
PET foam – 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 flexible operation with regard to the input material and the sheet manufactured. These sheet extrusion lines can be quickly and flexibly switched to foam sheet. The MRS foam sheet module enables a weight / density reduction of 50%, and this from input materials of up to 100% post consumer material, regrind, virgin or blends of these materials. With equivalent mechanical product properties, a wide range of PET foam products for food packaging can be manufactured cost efficiently.
Thanks to the low shear mixing properties of the MRS extruder, both the nucleating and the blowing agent are completely dispersed and homogenously distributed in the polymer melt. After extrusion and filtration, the polymer melt is conditioned so that it has the optimum viscosity and ductility so that material foams with the required density as it emerges from the die.
