Studies on the melt spinning of nylon 6. II. Effect of heating the threadline upon orientation and crystallization

✍ Scribed by Tohru Ishibashi; Tsuneo Ishii

• Publisher: John Wiley and Sons
• Year: 1976
• Tongue: English
• Weight: 663 KB
• Volume: 20
• Category: Article
• ISSN: 0021-8995
• DOI: 10.1002/app.1976.070200205

✦ Synopsis

The effect of heating nylon 6 threadline in a spinning tube upon its orientation and crystallization behavior was studied by measuring the filament birefringence A ~H at the outlet of the spinning tube, the conditioned filament birefringence An-after take-up, the filament densities and crystallinities of the y-form, and by calculating the relative crystallinity of the threadline. Results were as follows: When the filament mean temperature B,(x) in the spinning tube was about 80"C, the birefringence A ~H showed a peculiar behavior in that, at this temperature, the A ~H value decreased due to partial melting of the semistable molecular structure of the threadline that had been formed before the inlet of the spinning tube. And, when the temperature was over about 8OoC, the A ~H value increased due to the setting in of crystallization. The relative crystallinity x of the threadline was calculated using the kinetic theory of nonisothermal crystallization neglecting the entropy effect of molecular orientation. Assuming that the crystal growth was spherulitic rather than fibroid, the calculated x values approximately agreed with the experimental results.