The spreading of inkjet-printed droplets with varying polymer molar mass on a dry solid substratery Solid Substrate

An experimental study on the spreading of inkjet printed droplets of a polystyrene/toluene solution with varied molar masses on solid dry surfaces is presented. The polymer's number- averaged molar mass was varied between 1.5 and 545 kDa, which also caused a variation in the viscosity from 0.6 to 1.7 mPa· s. The results were compared with theoretical models for dro plet spreading and were found to fit with an error between 2 and 20% with the predictions. Further more, the in-flight evaporation of the free-falling droplet was investigated for polystyrene/toluene solutions that have a constant vapor pressure by printing from a systematically increased height. © 2009 WILEY-VCH Verlag GmbH & Co. KGaA.