Currently Funded Project

Drying the green bodies is the first crucial temperature step in ceramic production and reduces the water content of the components to around 1 to 2% before firing. Controlled and optimized drying is important to prevent cracks and component defects.

The drying process accounts for up to 50% of the total energy used in ceramic production. In view of climate targets, it is therefore necessary to optimize the drying process. Since drying kilns have very long operating times, energy savings can be achieved both through technical and process-related changes and through optimized material and process approaches. 

This project focuses on optimizing the drying of technical ceramics with the aim of significantly increasing efficiency and saving energy. The work is being carried out on extruded tubes and rods made from the most important technical oxide ceramics: Al₂O₃, MgO, and ZrO₂, as well as composite plates made from Al₂O₃ with a ZrO₂ coating.

The process-related characterization and optimization of the drying behavior is carried out using in-situ analyses with the TOM_dry measuring system, which is to be adapted, and the use of the measurement data in novel drying simulations.

In the case of Al₂O₃-ZrO₂ composite plates, a further objective is to sinter them in a co-firing cycle, which is achieved by thermo-optical in-situ recording and adjustment of the respective sintering kinetics.

The project pursues two main approaches to optimizing the drying of technical ceramics:

Firstly, inorganic raw materials and drying additives are varied. The morphology and grain size distribution of the raw materials influence the packing density and capillary tension and thus the drying behavior. The influence of organic additives such as binders and plasticizers is also analyzed in order to increase drying efficiency without compromising construction quality.

On the other hand, improved drying parameters are being developed. In defined drying programs with varied process parameters of temperature, relative humidity, and flow velocity, mass loss, shrinkage behavior, and surface temperature are recorded in situ in TOM_dry and then integrated into novel FE models for drying simulation in parameterized form. The optimized drying curves are then verified in laboratory dryers and transferred to the production dryers.