Magnetic orientation of polymer fibers in suspension

The magnetic orientation of superdrawn polyethylene fiber suspended in a water/ethanol mixture is studied by introducing a modified equation of motion. The shape of the fiber is approximated with a prolate ellipsoid, and the aspect ratio dependence of the hydrodynamic torque is considered explicitly. The solution of the equation gives the alignment rate as a function of the aspect ratio. The experimental observation of the fiber-length dependence of the alignment rate is discussed on the basis of the modified equation of motion.