Abstract
Anisotropic viscosity caused by the orientation of fibers in fiber suspensions was experimentally investigated. A concentric cylinder system which is able to generate and measure a combined shear flow fields with Poiseuille flow and Couette flow has been designed and is set on a rheometer. The fiber suspensions were used for as a test sample. The matric is a silicon oil (kinematic viscosity : 1000 cSt) and the carbon fibers are dispersed into it. In the case of short fibers, the high concentration solution shows an increase of viscosity for transverse to main flow. For the long fibers, which are longer than 1/4 of the channel height, the transverse viscosity increase appears even 10 wt% solution. After cessation of the main flow, the transverse viscosity decreases to the viscosity in a no orientation state.
