‘Herringbone’ defect formation in planar-flow melt spinning

A short-wavelength, periodic feature (≈1 mm) similar in appearance to a herringbone pattern appeared on ribbon produced at high rates (≈10 m/s) by the planar-flow process. These marks corresponded to a high-frequency (≈10 kHz) disturbance to the process stream. Observations of herringbone formation came from ribbon profilometry, customized nozzle tests and high-speed meniscus imaging. These observations were compared against observations of the ‘crosswave’ feature formation which were subject to prior study. It is demonstrated here that herringbone marks, in contrast to the crosswave marks, were mainly influenced by the substrate motion of translation. Herringbone formation is also reported to have correlated with the pinning of the liquid puddle at the nozzle edge.