Oldenburg is a manufacturer of PE packaging film such as bubble film, stretch and foam sheet. The company offers a wide range of high-quality films in different formats. The film waste which occurs during start up, shut down, product changes etc. is collected and repelletised on a central recycling extruder.
This central recycling extruder was equipped with a conventional screen changer. With this screen changer, it was practically not possible to filter sufficiently fine, that the material recycled on this line could be used for thinner film gauges on the blown film extrusion lines. If the recycled material was not filtered finely enough, the simple, discontinuous screen changers on the blown film lines would block up quickly.
After running trials at several different potential suppliers of melt filtration systems and evaluating not only the performance of the screen changers but the quality of the recycled material processed during the trials, Oldenburg decided in favour of the Gneuss RSFgenius, with its patented self-cleaning system.
Oldenburg retrofitted a Gneuss RSFgenius 175 to their existing recycling extruder and since then, Oldenburg has been able to filter sufficiently fine (75 µm) that pellets made from their scrap can be put back into their blown film extruders (instead of being sold off as was mostly previously the case). These blown film extruders are equipped with discontinuous screen changers. When using the repelletised material which has been pre-filtered using the Gneuss RSFgenius, the intervals between changing screens on the discontinuous screen changers on the blown film lines is practically the same as when processing virgin material and the quality of the repelletised material is such that it can be used up to 100 % in place of virgin material.
Thanks to the extremely efficient, unique self-cleaning system of the RSFgenius 175 on the central recycling line, the filter elements on the do not need frequent replacement and the quantity of material lost through back-flushing is kept to an absolute minimum. The company director, Mr. Michael Oldenburg confirmed that the Gneuss Melt Filtration System met or exceeded all the performance characteristics which were promised in advance and that in spite of the tight space requirements on the existing recycling line, Gneuss were able to tailor make the installation so that it was possible to install it without needing to move the positions of the existing equipment.