Numerical investigation of droplet impact spreading in spray coating of paper

Impact spreading of droplets in spray coating of paper was investigated using numerical simulation based on a volume-of-fluid (VOF) model. The results include the effects of droplet size, droplet impact velocity, liquid viscosity, liquid surface tension and paper web velocity on droplet spreading. Pressure and strain rate fields as well as timescales of spreading are reported. The results help understanding the parameters and mechanisms that control the droplet spreading and provide information on possible operating windows of the spray coating process.