On Fiber Alignment Using Fluid-Dynamic Forces

Abstract

A simple approach to the alignment of short fibers moving in an air stream was explored, in which transverse air jets acted to alter main stream velocity and direction in a desired manner. An approximate analysis was developed for the effects of aerodynamic forces on fiber motion and was combined with a theory for the influence of transverse air jets on the main flow. Experiments on fiber alignment using this approach were performed, the principal data being multiflash photographs of the fiber motion. The approximate theory is in qualitative agreement with the experimental results. These results showed that fiber alignment parallel to the main stream can be achieved for a wide range of initial fiber angles. Further, this alignment can be performed with low-speed air flows, which may facilitate fiber handling in many applications.