Droplet impact on thin fiber veils

Drops impacting on fibrous materials are ubiquitous phenomena that are interesting for a wide range of applications, ranging from bloodstain pattern analysis to coating of fibrous materials. While current literature extensively covers the capture phenomenon of a drop impacting a single fiber, the capture of drops by thin fibrous media has received less attention. We study experimentally the impact of droplets on thin fibrous veils. We consider both non-woven fibrous textiles and woven grids of controlled geometry. We look for a criterion for droplet capture as a function of the drop radius and velocity, as well as the characteristics of the textile (fibre radii and densities). The observed dynamics and the final wet diameter are a combination of spreading at the surface of the veil, imbibition within the fibrous matrix, and flow through the thin porous textile.