The Thermo ScientificTM HAAKETM MiniLab Series is well known for being the ideal equipment, if it comes to compounding and processing of very small sample quantities of just about 7 ml.

The HAAKE MiniLab 3 is a small conical twin screw extruder, equipped with a back flow channel and a bypass valve, which allows to control the residence time ofthe sample in the compounder.

The patented design of the back flow channel has a slitcapillary flow channel and two pressure transducers, which are used to measure the pressure drop in the capillary. From the pressure drop and the geometry of the slit capillary, a shear stress can be calculated. From the selected screw

speed and the measured back pressure, a shear rate is correlated. The shear stress and the shear rate values are used to calculate the relative sample viscosity at different screw speeds.

This lab report shows the correlation between the relative viscosity measurements done on the new HAAKE MiniLab 3, with results of absolute rheological measurements performed with a Thermo ScientificTM HAAKETM MARSTM 60 retational rheometer.