Absorption of Millimeter-Sized Droplet by Nylon Powder

摘要

Droplet impact on powder materials is a ubiquitous phenomenon in nature and engineering technologies. An important aspect of droplet-powder interaction is the absorption of liquid droplet by powder substrates due to capillary force. In this study, we have investigated the phenomenon of absorption of multiple solutions into the substrate material of nylon powder PA2200. Absorption of droplet by powders does not always occur even though a liquid may partially wet the surface of the powder substrate. The critical surface tension values for nylon powder bed having different porosities are obtained by experiments and discussed in detail. Our study shows that smaller surface tension or smaller porosity leads to faster absorption. We discuss the effects of surface tension and porosity of powder layer on the absorption.