Bicomponent Polyesters Filaments with High Performances: Study of Their Stability before and after Dyeing with Low, Medium, and High Energy Disperse Dyes

Bicomponent polyesters filaments are increasingly used in the textile fields due to their technical and high performances (mechanical, physical, and chemical properties) comparing to conventional polyethylene terephthalate and Elasthane™ thermoplastic polyether polyurethane used in denim fabrics. The purpose of this work is to evaluate the stability of the mechanical and physical properties of bicomponent filaments before and after dyeing with three disperse dyes having different molecular weights (low, medium, and high). Bicomponent filaments composed of two filaments extruded side by side with two unequal proportions 60 % polyethylene terephthalate (PET) and 40 % polytrimethylene terephthalate (PTT) are used in this study. A full factorial experimental design was established to analyze the dyeing parameters effect (temperature and pH value of dye bath) and optimize the color strength (K/S) while maintaining the stability of the mechanical and physical properties of bicomponent filaments. After dyeing, these properties were evaluated and their stability was proved using several analysis techniques such as SEM, DSC, and XRD.