Rheometric test rig - used for plastic melts with orifice tube resting on piezoelectric load cell

摘要

The rheological properties (viscosity) of plastic melts are determined by using capillary nozzles for their passage. The capillary orifice tube rests on a piezoelectric load cell which measures the axial force due to the shearing stress applied to the wall. The tube can be arranged coaxially in a heated chamber, if the effect of temperature is to be studied. A stepped capillary tube (4) with an elastic nozzle section (3) rests on a piezoelectric load cell (7) by a collar (6). A membrane (8) supports the tube at the far end. An electric heating spiral (11) surrouns a tubular heating chamber (9). ADVANTAGE - This causes little expense and has a high resolution for a direct determination of the rheological properties. (7pp Dwg.No.1/4)