Dynamics and structure development during high speed melt spinning of nylon 6. I. On‐line experimental measurements

On‐line experimental measurements of filament diameter, temperature, and birefringence as a function of distance from the spinneret were carried out during melt spinning of two nylon 6 resins of differing molecular weight. Filament tension was also measured. A rapid diameter attenuation or “necking” was observed in the spinline for both resins at take‐up velocities above 6000 m/min. Evidence of crystallization in the spinline was also observed at these high spinning speeds. An analytical technique was used to extract apparent elongational viscosity for each resin and heat transfer coefficient for the melt spinning process from the experimental results.