Crystallization of poly(ethylene terephthalate) filaments by infusion of ethanol upon cold drawing

- Infusion of dyes with ethanol into low oriented PET filament during drawing.
- At the early stage of drawing multiple neck was formed in filament.
- Color appeared only in the drawn part of the filament.
- Infusion of ethanol into filaments increased with increasing DR.
- Crystalline reflection appeared only in filaments drawn in ethanol.

This paper focuses on the infusion behavior and structural development of low oriented amorphous poly(ethylene terephthalate) (PET) filaments drawn at room temperature in ethanol. Along with the transport of ethanol, dyes dissolved in ethanol were infused into the filament during the drawing process. In the early stage of drawing at low draw ratio (DR), multiple neck was observed in the filament containing undrawn and drawn segments of the filament. The color from dyes was observed only in the drawn segments. With further increase of DR the number of necks decreased. Drawing of filament in ethanol required a low drawing stress than the drawing in air and water. Infusion of ethanol into filaments was confirmed by DSC and TGA measurements. Occurrence of crystallization in filaments drawn in ethanol was confirmed by WAXD measurements. Filaments drawn at DR 4 showed distinct equatorial scattering intensity in SAXS pattern. On further increasing in DR the equatorial scattering intensity increased.