Three Leistritz extruder for new laboratory


The Thuringian Institute for Textile and Plastics Research Rudolstadt (TITK) put its new technical center into operation in the presence of Wolfgang Tiefensee, Minister of Economic Affairs. Three Leistritz twin-screw extruders are the heart of the plants The investment amounts to around 1.5 million euros. In particular, the systems are to be used to develop high-performance plastics for medical technology as well as biodegradable adhesives and foams. Another important goal is the production and processing of polyurethanes without the harmful isocyanate.

New approaches
 "The production of these non-isocyanate polyurethanes - the so-called NIPUs - has so far only been possible under laboratory conditions," explains TITK Director Benjamin Redlingshöfer. The institute now wants to make progress in the development and production on a larger scale in order to contribute to the abandonment of isocyanates. These volatile, highly reactive and toxic compounds are frequently used in industrial manufacturing processes. "We are now pushing ahead with research into sustainable and safe polyurethanes," says Redlingshöfer. The TITK is currently working on lightweight foams and coating solutions for this purpose. Thanks to the new plastics laboratory, the institut's new Caremelt® bio hotmelt adhesive developed in-house can now also be scaled up to industrial scale.

New possibilities
This is made possible by two special extruders with auxiliary equipment, such as vacuum degassing and melt recirculation. In one of the machines, the polymer mass can be circulated. "This makes it possible to thermally and mechanically process the polyurethanes over a longer period of time. This is necessary to build up high molecular masses," says Dr. Frank Meister, head of the Department of Native Polymers and Chemical Research at TITK. With the second extruder, gases can be added to the molten polymer mass. In this way, biodegradable foams based on starch can be produced. "They can be used for so-called packaging chips, pourable cushioning materials and much more," says Meister.

His colleague Dr. Stefan Reinemann is also impressed by the new possibilities. His plastics research department benefits above all from the third, even more powerful extruder. "It is equipped with a particularly long process section and can achieve very high temperatures," says Reinemann. This also allows chemical reactions. "With the integrated Leistritz Inline Elongational Rheometer, we can also measure the viscosity of the material during the extrusion process and readjust it if necessary. This allows us to produce high-performance plastics that are used in medical technology as implants or as high-strength surgical nails, among other things," says Reinemann. The material for this: Polyetheretherketone (PEEK), to which carbon fibers are added at temperatures of over 400 degrees Celsius.

Lively cooperation
Anton Fürst, Managing Director of Leistritz Extrusionstechnik GmbH Nuremberg, emphasized during the commissioning ceremony that the company is aiming for a very lively cooperation with the TITK. "Our extrusion lines are installed in numerous institutes and research facilities worldwide. It is important for us to be a part of the process of developing and working on the materials of the future," said Fürst. "For recipe developments, basic research and small-scale production, the extruders used here offer an excellent machine base and scalable operating conditions. One major advantage that we see in this cooperation is above all the fact that we can use the TITK as a kind of outsourced pilot plant. We will be coming to Rudolstadt with important industrial customers to solve their problems together with the TITK."