Gneuss at Interplastica 2013

At Interplastica 2013 Gneuss (Hall FC 50) will be back to show its MRS extruder for the devolatilization of polymer melts, its online viscometer VIS, the range of Rotary Filtration Systems and screen changers as well as its environmentally-friendly melt temperature sensors and pressure transducers.

Today, the Multi Rotation System extruder from Gneuss is operating in a number of different PET applications worldwide, including sheet, fiber and pelletizing applications.
The MRS offers new possibilities to PET converters because it permits the processing of PET without pre-drying or crystallizing. By providing a very large surface area and using a simple water ring vacuum system it is possible to process the material directly into a high quality product. This is achieved with a unique and patented processing section. Based on a conventional single screw extruder, the Multi Rotation Section (MRS) is a drum containing eight satellite single screws, driven by a ring gear and pinion transmission. The “barrels” cut into the drum are approximately 30 % open and provide optimum exposure of the melt.

Thanks to this design, the devolatilizing performance is fifty times greater than that of a conventional single screw extruder – and this at a vacuum of only 25 to 40 mbar. By avoiding the need for a high vacuum system and pre-drying, the MRS is an extremely economically efficient alternative to conventional technologies. Further arguments in its favour are the simple and rugged design, small footprint and flexibility.

In addition to the excellent devolatilizing performance, the MRS also offers excellent decontamination performance. The US American Food and Drug Administration (FDA) issued a total of 4 LNOs (letter of non objection) for the MRS extruder for reprocessing material for the food industry. The MRS extruder not only efficiently extracts water but also decontaminates the material so that up to 100 % PET bottle flakes can be processed to food containers. This is achieved without the need for any treatment of the material before or after it is processed on the extruder (no restrictions on the washing process, no drying, no crystallizing etc.).

Gneuss’ Online Viscometer VIS has been equipped with an improved and more robust drive with an encoderless speed control. The viscometer offers precise measurements of the melt viscosity and thanks to its very compact design can be added to almost any extrusion line.
The advantages of the MRS extruder are underlined by the fact that a European company has recently ordered a high capacity complete line for 3 layer PET sheet for thermoforming for delivery during 2013.

Gneuss’ Filtration Technology division will present its Rotary Melt Filtration Systems with further design enhancements. Several new safety features and the option for an automatic ejector for the backflush material of the RSFgenius have been added.

The Rotary Filtration Technology is based on a filter disk on which 10-13 screen cavities are located in a ring pattern. The filter disk rotates between two filter blocks and only part of the filter disk is active in the melt channel. When a pressure increase upstream of the filter disk is registered, the filter disk is indexed in small steps by means of a pneumatic or hydraulic drive. The active screen area is always kept constant, which guarantees a process and pressure constant mode of operation. Screens can be changed on the other side by opening a small hatch door giving access to the cavities. The production process is not disturbed by the screen change at all.
With regard to the achievable product quality, economic efficiency and in terms of operator and maintenance friendliness, the fully-automatic and backflushing RSFgenius model offers unrivalled possibilities.

Source: Gneuss