High shear rate viscosity measurement of inks by visual microfluidic rheometer

 
Understanding rheological behavior of inks guarantees high-quality results and limiting process issues (bleeding, clogging of the printing head). FluidicamRHEO is designed for viscosity measurements of products from fluid to thick formulations as a function of shear rate (up to 10 5 s-1) and temperature.A sample and a reference are pushed through a microfluidic chip at controlled flow rates. Images of the resulting laminar co-flow are acquired and the position of the interface is measured. The position is related to the viscosity and the flow rate ratio allows viscosity determination. Ceramic inks and sprayable coating solutions were measured at shear rates and temperatures corresponding to process conditions of the printing head and roller coating. FluidicamRHEO discriminates viscosity with 0.5 mP precision and can idnicate shear thinning behavior that occurs only at high shear rates.