Malvern Instruments has introduced a new range of low temperature control options for the Malvern Rosand range of capillary rheometers. High-pressure capillary rheometry is a well-established method for simulating the processing conditions of molten polymers at high temperatures. These two new low temperature control options, which are designed for the RH7-D/RH10-D and RH2000 rheometers, enable capillary rheometry to be applied to an extended range of materials. They comprise cooling coils with fluids circulator for measurements from 5Â°C to 50Â°C and an option for cryogenic cooling using liquid nitrogen for measurements to minus 40Â°C.
The new low temperature options are compatible with the full range of capillary dies for the Malvern Rosand rheometers and offer the possibility of measuring materials over a wide range of shear rates.
Temperature control at ambient or below is ideal for low viscosity materials (such as inks, paints, paper coating emulsions, plastisols and foods) when extension of the accessible range of shear rates to more than 100,000 s-1 may be necessary to simulate processing conditions, such as pumping or extrusion. A conventional rotational rheometer would not normally allow measurements at such high shear rates.
Malvern Rosand capillary rheometers RH7-D and RH10-D are research grade, floor standing twin bore systems that enable the widest range of shear rates to be tested, as well as complex rheological properties such as die swell and melt tension. These rheometers are used extensively for a range of applications including polymers, foods, coatings and ceramics. Malvern Rosand capillary rheometers are also available as bench top systems (the RH2000 series) for more routine measurement of shear viscosity for QC purposes. These compact systems, capable of most testing requirements encountered in capillary rheometry, are available in both single (RH2100) or twin bore (RH2200) configurations.