Rissland Kunststoffe GmbH, located in Katzhütte, Germany was able to drastically increase the throughput rate of their extruder when reprocessing PP whilst at the same time increasing the screen pack life from a matter of days to several weeks. This was made possible by the Process and Pressure–Constant Rotary Filtration System RSFgenius 175 from Gneuss (Bad Oeynhausen, Germany).
The reprocessing of thermoplastic waste from industrial and post consumer sources to high quality repelletised material and compounds is Rissland´s speciality. The company reprocesses 15.000 metric tonnes annually on 5 extrusion lines, 2 single screw and 3 twin screw machines. In addition, the factory in Katzhütte is equipped with grinding equipment for the processing of 1.800 metric tonnes of regrind and an agglomerator for 1.200 tonnes of agglomerate.
| The fully automatic and process constant RSFgenius 175 screen changer with integrated self-cleaning has been in operation now for roughly 9 months. It is in operation on a 95 mm twin screw extruder, mostly on PP. “In spite of the fact that we are processing contaminated polymer waste, we have been able to increase our throughput rate by 33% and extend the intervals between screen changes to up to several weeks. This is a clear cost advantage and the investment was recovered quickly” explained the Director, Ms. Corinna Rissland. “With this case example, we can once more prove that with a high performance filtration system, the reprocessing of polyolefins can be an attractive business” added Dr. Stephan Gneuss. |
All the Polymer Melt Filtration Systems from Bad Oeynhausen operate using the proven Rotary Disc Technology. The Rotary Disc is sandwiched between two steel blocks and rotates through the polymer melt. The contaminated filter area is continuously removed from the melt flow and replaced with clean area. In this ways, the active filtration area remains constant and reliable filtration is always guaranteed. This is extremely advantageous when processing material with a high level of contamination as is usually the case when recycling. The cleaning of the contaminated filter elements takes place continuously in situ and without disturbing the process. Using a unique, high pressure self-cleaning system, a segment of roughly 1 % of the active area at a time is “shot” clean and discharged in controlled slugs of material from the inlet side of the screen changer.
Thanks to its patented technology, the RSFgenius operates absolutely pressure and process-constant, permitting production without variations and / or strand breaks. This ensures a high quality product. The fully automatic operation guarantees optimum filtration performance and a minimum of operator attention. This is explained by the long filter element life (the screen packs can be re-used up to 400 times). Filter element changes are carried out without any influence on the production process. The material loss through self-cleaning is in recycling cases typically a factor of 10 lower than for alternative technologies. The completely enclosed design with the Rotary Disc completely encapsulated between the two blocks ensures that the polymer can not become damaged due to contact with oxygen or airborne moisture, which could lead to quality deficiencies in the product.
Rissland Kunststoffe GmbH in Katzhütte
| Mrs Andrea Koßmann Marketing Tel: 05731 / 5307 -10 Fax: 05731 / 5307- 77 gneuss@gneuss.com |
