Bicomponent Newtonian filaments

A model is introduced which captures the mechanical behavior of slender bic omponent filaments. The model is deduced from the three-dimensional free su rface boundary value problem through integration over the filament cross se ction, and applied to core and sheath fluids which are Newtonian with a bon ded interface. Through examples simulating filament manufacturing processes , we investigate different regimes of bicomponent filament behavior, examin ing the interplay of core and sheath viscosities and densities, and surface and interfacial tensions (which are found to have special importance). We focus on features which are special to bicomponent filaments, namely the tr action at the core/sheath interface, the partition of the axial force in th e filament between core and sheath, and dependence on sheath-to-core ratios of material properties. (C) 1999 American Institute of Physics. [S1070-663 1(99)02004-8].