A drop generator was developed for the investigation of binary drop collisions of high-viscous and viscoelastic liquids.The drop generator operates based on the principal of periodic pulse jetting(i.e.liquid column cutting),and is functioning for Newtonian liquids with shear viscosities from 116 mPa·s to 729 mPa·s and viscoelastic liquids with a relaxation time of 2.4 ms.The produced drop train has a drop diameter from 1.4 mm to 2.0 mm,a drop velocity between 2 m/s and 3 m/s,and a number frequency from 50 Hz to 150 Hz.By arranging two droplet generators at defined angles the two droplet chains could be brought to collision.Drop collisions of viscous liquids were documented by two perpendicular arranged high-speed cameras,and the border lines between coalescence and stretching separation were derived for liquids of significantly higher viscosities than existing data in literature.It is found that no universal model exists for the investigated viscosity range.Drop collision of viscoelastic liquids was conducted,and the effect of the viscoelasticity was revealed through the formation of bead-on-string for a stretching drop.