Deposition of Liquid Drops on a Long Cylindrical Fiber

Abstract

The way in which the deposition of drops from a dispersion onto the surface of a collecting fiber varies with system parameters is discussed, using as a starting point previously published analyses of the properties of a single drop deposited on a fiber. The deposition of drops may involve coalescence with either the fiber alone or with drops already attached to the fiber, and marked differences are predicted for the rate of variation of the drop/fiber contact area for the two cases. The relative predominance of a particular deposition mechanism depends on the stage of the overall process, and stages are identified where the contact area changes are insensitive to the contact angle. The effects of drop size polydispersity and the presence of surfactant in the system are discussed. While increasing the complexity of the problem, neither of these influences poses insuperable obstacles to the theoretical interpretation of the processes. Possible applications of this work include filtration and deposition on fibers from aerosols or emulsions. Deposition onto an optical fiber as a means of monitoring particle concentrations in dispersed systems is also considered.