Extrusion International 5-2021

17 Extrusion International 5/2021 ELEKTROWÄRMETECHNIK FRANZ MESSER GMBH ERGE Elektrowärmetechnik - Franz Messer GmbH 91220 Schnaittach - Hersbrucker Straße 29-31 Tel. +49/9153/921-0 Fax +49/9153/921-117 www.erge-elektrowaermetechnik.de mail: verkauf@erge-elektrowaermetechnik.de HEIZEN TROCKNEN REGELN CONTROLLING HEATING DRYING Visit us: Hall A6, Stand 6301 „ The blow molding specialist W. MÜLLER has developed a new generation of screen changers for its extruders in extru- sion blowmolding. It is designed to be particularly space-sav- ing. It is also suitable for installation in vertically oriented ex- truders, can easily be retro fi tted and operated safely. When using PCR, a screen changer is recommended. Filtering the melt is an essential element of controlled ex- trusion – especially when using Post-Consumer-Recyclates (PCR). The fi ltering screen consists of a fi xed perforated car- rier plate, which is covered by several interchangeable grids with different mesh sizes. If the differential pressure on this grid exceeds a certain value, the screen must be changed. Johannes Schwarz, sales manager at W. MÜLLER explains: “The screen changer ensures, that impurities are kept away from the extrusion head. In addition to the use of PCR, which can be contaminated with other plastics or particles, it is, for example, abrasion from the mill, degraded plastic material or today often sections of cable ties, which are to be absorbed by the screen changer from the material fl ow. Such impuri- ties interfere with the process and may lead to interruptions in production. It would be even more problematic if a leak- ing container would be produced and ended up in the fi lling station.” Managing Director Christian Müller speci fi es: “Of course, we are also talking about the usage of recyclates. In the process- ing of recycled material, in particular PCR materials, the risk of contamination increases, which does not enter the pro- duction process from the outside but from the used material itself. These can be, for example, snippets of aluminum lids New Screen Changer Enables Sustainable Use of Recyclate W. MÜLLER GmbH www.mueller-ebm.de or sleeves of bottles. In operation, the screen is slowly get- ting clogged and must be changed regularly. How often, de- pends on the quality of the processed material. W. MÜLLER has designed its own system for this change.” The screen changer can be retro fi tted and does not require any special safety precautions, as it does not have its own drive. It can be operated manually or e.g., by using a cordless screwdriver without effort. For PCR processing, W. MÜLLER offers the ReCo3system for its extrusion units, consisting of three independent extrud- ers. The PCR layer is enclosed in the middle by two layers of virgin material. The extruders are mounted vertically for this process. Jens Schlueter, President of W. MÜLLER USA, Inc. explains: “We are also receiving more and more inquiries from North, South and Central America about systems for safe recyclate- processing. I expect a further signi fi cant increase here, also because of the changing raw material situation. The produc- tion of gasoline and diesel is declining. Accordingly, less eth- ylene and propylene is present for polymerization. This will further drive the demand for alternative materials.” The screen changer is safe to operate manually. To simplify the process, for example, a cordless screwdriver can be used (Photo: W. MÜLLER)