Design and operation of a Rayleigh Ohnesorge jetting extensional rheometer (ROJER) to study extensional properties of low viscosity polymer solutions.

The Rayleigh Ohnesorge jetting extensional rheometer (ROJER) enables measurement of very short relaxation times of low viscosity complex fluids such as those encountered in ink-jet printing and spraying applications. This paper focuses on the design and operation of the ROJER. The performance of two nozzle designs is compared using Newtonian fluids alongside a study using computational fluid dynamics. Subsequently, a disposable nozzle is developed that overcomes issues of blockage and cleaning. The operability of this design is subject to a focused study where low viscosity polymer solutions are characterized. The test fluid materials are ethyl hydroxy-ethyl cellulose and polyethylene oxide mixed with water/glycerol solutions. Results obtained by the disposable nozzle are encouraging, paving the way for a more cost-efficient and robust ROJER setup. [ABSTRACT FROM AUTHOR]