Gneuss Engineering, a machinery company known for unique Rotary Filtration Systems, is enjoying increased recognition for its additions to PET extrusion lines.
Gneuss, based in Bad Oeyenhausen, Germany, introduced its revolutionary MRS Multi Rotation System extruder 10 years ago which immediately became a success. The MRS extruder offers dryerless processing or PET and offers unparalleled devolatilisation and decontamination performance. The MRS extruder is complemented by a low maintenance vacuum system, a rugged and accurate Online Viscometer and of course the Gneuss Rotary Filtration System. These units combined form the core of the Gneuss Processing Unit (GPU).
With a worldwide supply to PET extrusion lines, users have a better degree of flexibility on lines with the GPU, which can operate on both virgin and recycled material (post-consumer bottle flake, edge trim and skeletal waste regrind). Practically all types of PET input material can be used without the need for drying or crystallising and the sheet manufactured on these lines is suitable for food contact.

Gneuss
Foam roller, Gneuss
PET sheet extrusion lines with the Gneuss Processing Unit can be quickly and flexibly switched to producing physically foamed PET sheet. Thanks to the extremely good mixing properties of the MRS extruder, the nucleating and foaming agents are distributed completely and homogeneously in the melt. The Online Viscometer ensures that the viscosity is maintained at the required level. After extrusion and filtration, the melt is conditioned so that it has the optimum viscosity and strength. This ensures that as the polymer emerges from the die, it foams with the required density reduction.
Thanks to the MRS foam module, foam sheet with half the weight can be manufactured, with a consistent foam structure and mechanical properties, completely derived from post-consumer material, edge trim and skeletal waste regrind and combinations of these. Foam PET sheet is an ideal material for economically manufacturing thermoformed containers for the food industry such as meat trays, egg boxes, cups and pots.
The effect of foaming sheet is to reduce the weight and therefore the raw material costs compared with rigid sheet. Depending on the requirements, this weight reduction can also permit an increase in the linear sheet output rate or can permit a thicker sheet to be made from the same amount of material.