Dyeing and finishing performance of different PTT/PET bi-component filament fabrics

Abstract

The dyeing and finishing performance of different bi-component polytrimethylene terephthalate/polyethylene terephthalate (PTT/PET) filament fabrics along with the elasticity of end-products have been studied. Three kinds of PTT/PET side-by-side bi-component filaments have been selected as weft yarn along with the polyester filament as warp yarn. Fabrics are then woven, dyed and finished under the same conditions. The weight reduction rate, widthwise shrinkage, elastic elongation and elastic recovery percentage of the above fabrics are observed to characterize the changes involved during the process. The results indicate that as denier per filament (DPF) increases, the weight reduction rate decreases but the widthwise shrinkage increases. The weight reduction rate decreases as the weft density increases. The elastic recovery decreases as the elastic elongation increases. Optical microscope, scanning electron microscope, different scanning calorimetry examinations show that due to the finer DPF and larger specific surface area, PTT/PET filament exhibits separation of the two components, due to the caustic corrosion during dyeing and finishing, and hence the high elasticity inherent in bi-component filaments is lost.