Things are moving at the KTI: New equipment for processing and refining plastics

How does plastic become antibacterial? How can the material be recycled and reprocessed in line with the circular economy? And how are the properties of biobased plastics modified? This is what scientists of the Plastics Technology Group (KTI) at TU Ilmenau are researching. To make this even more successful in future, space is now being created in the KTI's project hall: A new twin-screw extrusion line is to be put into operation at the beginning of next year where until recently there was an outdated and largely non-functional line.

Unlike simple extruders, the new system, which works in a similar way to a meat grinder, has two so-called screws that move side by side in a cylinder in the same direction of rotation. The granulate is fed through a hopper to the screws, which melt the granulate using friction, shear and high temperatures and convey the resulting viscous mass to the end of the system. There they are pressed through an opening under pressure. By adding additives such as antibacterial additives to the viscous plastic mass, plastics with new properties are created.

The special feature of the new extruder is that additional components such as plastic additives, fillers and reinforcing materials such as natural fibers as well as reactive, i.e. chemical, components can be added, kneaded and mixed using dosing devices and side feeders. Thanks to its improved adjustability, the new system saves material: plastics that have already been used can be easily reprocessed. In addition, liquid components can also be added in future - this was previously not possible at KTI.

As the length of the screws can also be adjusted for different applications, temperature-sensitive plastics, such as plastics based on renewable raw materials, which require gentle processing, can also be processed in addition to reactive extrusion. This will enable scientists to conduct even more precise and reproducible research in the future and advance the recycling and upcycling of plastics.

The acquisition of the new equipment is funded within the framework of the funding program FTI Thüringen 2021-2027 by the Thuringian Ministry of Economics, Science and Digital Society, co-funded by the European Union under the funding code 2022 FGI 0014.