The role of viscoelasticity in drop impact and spreading for inkjet printing of polymer solution on a wettable surface

We investigate here for the first time the entire deposition process of a sub-30 mu m-sized polymer-containing drop on wettable surfaces over more than 7 decades of elapsed time, under conditions fully representative of inkjet printing. The drop deposition dynamics of a polystyrene solution on a highly or partially wettable surface are independent of the high-shear rheology of the fluid, while the final drop size is significantly affected by surface wettability. We show why the polymer chains do not become extended despite the high extension rate in drop spreading. This study provides a framework to evaluate the effects of viscoelasticity on the drop deposition process due to the presence of polymers in dilute solution.