Capturing of Real Image of Neck-Like Deformation from High-Speed Melt Spinning Line.

Abstract

Observation of high-speed spinline using a video camera was carried out to obtain directly the detailed diameter profiles of neck-like deformation. An optical system was developed by adding a set of cylindrical lenses to the usual telescope-type optical system. This system magnified the horizontal direction four times larger than that in the vertical direction. Using this apparatus, the image of the neck-like de formation in high-speed splinline of poly(butylene terephthalate) was successfully captured. Although the shape of the neck-like deformation was more moderate than that of the "necking" observed in the cold drawing of undrawn fibers, the calculated velocity gradient at the end point of the neck-like deformation showed extremely high values of ca.10 and 30 ms-1 for the take-up velocities of 4 and 5 km/min, respec tively.