Viscous elastic fluid jets induced by sudden acceleration

Modern interest for 3D-manufacturing applications requires controlled ejection of liquids with viscous non-Newtonian properties, such as polymer solution and molten resin. In this study, we compare jet evolutions of two viscous polymer solutions with different elasticity but similar shear-thinning properties (i.e. elastic and inelastic). Both jets are ejected by using our novel jet generation system employing an impulsive force (Onuki {\&} Tagawa, Phys. Rev. Applied, 2018). The inelastic solution jets eventually pinch-off into droplets. In contrast, remarkably, jets of the elastic solution completely retract after ejection, even though the initial velocity of the jet is high (\textgreater 10 m/s). We rationalize these behaviors by considering high elongational rate of liquids, which is beyond an explored range of existing studies. This contribution may open a new door for developing new additive-printing systems.