Method and device for determining the sticky point of powder samples

A method for using a rheometer, the method comprising:

• introducing a sample to be tested into a first measuring part receiving the sample;
• placing a second measuring part above the first measuring part and using the first and second measuring parts to delimit a sample chamber therebetween for the sample to be tested;
• using at least one rotary motor to drive the first and second measuring parts in rotation or in a rotating-oscillating manner relative to one another at a predefined or predefined and constant, rotation speed;
• using a force application unit to exert a constant normal force acting in a direction normal to a plane of rotation of the measuring parts on the sample being disposed between the first and second measuring parts;
• using a measuring unit or a torque measuring unit to record a torque or a shear stress of the sample to be tested being disposed between the first and the second measuring parts;
• using a temperature-control unit or an oven to apply a temperature change over time to the sample while measuring the torque or the shear stress;
• supplying the measured values of the torque or the shear stress recorded by the measuring unit and the respective temperature of the sample present at individual points in time to an evaluation unit;
• and
• using the evaluation unit to determine the sticky point based on the measured values of the torque or the shear stress and the respective temperature present in the measured values, by determining a characteristic parameter of noise of the powder during measurement, plotting the measured values obtained over the temperature, and determining the sticky point from a resulting diagram.