TOMMI plus

Ceramics are densified and strengthened by sintering. This process controls the quality of the final product – and considerably contributes to production costs. The sintering shrinkage is the most telling indicator for the sintering state. Close monitoring of shrinkage and warping during firing can be used to optimize firing conditions.

Our task
ƒƒMonitoring of the sintering shrinkage without mechanical impact of the measuring device on the samples ƒƒ Recording of any warping or adherence of the sample during sintering even if the sample shape is quite irregular ƒƒ Measuring of creep properties under well defined constant or cyclic loads.

Glass is molten and shaped at low viscosities. Numerous thermophysical data are required on the way from the raw material to the melt to ensure the precise design of the thermal processes. The measuring of thermophysical properties of glass around the softening temperature is particularly difficult.

Our task
Determination of the expansion coefficient in the range from low temperature to melting temperature, i. e. around the softening temperature ƒƒ Monitoring of the melting behavior as well as the wetting of refractories and metallic molds by the glass melt at high temperatures

Our solution: TOMMI plus

TOMMI plus is a follow-up model of its successful predecessor TOMMI with improved performance and more flexibility. It combines a high temperature furnace with an optical dilatometer. The crosslight silhouette of the sample is recorded by a CMOS camera. A special optical system provides distortion free imaging – even if the sample slightly shifts during the heat treatment, e. g. due to thermal expansion.

Dimensional changes of the sample are registered by a purpose-made image analysis software; the sample may be of any shape as long as its complete silhouette remains within the dilatometer window. Measurements are taken once every second so that rapid changes can be registered. Furthermore, melting and wetting phenomena can be investigated by examining the wetting angles and infiltration kinetics.

TOMMI plus is controlled by a standard PC and operated via a comfortable graphical user interface. Besides the data on dimensional changes, single images as well as time-lapsed videos of the thermal treatment can be obtained. The resolution of TOMMI plus is about 0.4 μm with very high reproducibility. It is optionally available with several loading stages and a balance for simultaneous gravimetric investigation of the sample.