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 droplet spreading and were found to fit with an error between 2 and 20% with the predictions. Furthermore, 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.

An experimental study into the in‐flight evaporation and impact of equally sized inkjet printed droplets that consist of a systematically varied polystyrene concentration in either toluene or butyl acetate is presented. At low polymer concentrations, a linear relationship that decreased was observed between dried droplet diameter and printing height. However, increased concentrations revealed an initial exponential decay in the dried droplet diameter, which stabilized at greater heights. At higher concentration and height, the polymer forms a skin on the surface of the inkjet printed droplet, which causes inhibition of the in‐flight evaporation of the solvent.magnified image

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