Comparison of the properties of false twist textured super bright, semi-dull, grey and black dope terephthalate yarns dyed polyethylene terephthalate yarns

Dope-dyed polyethylene terephthalate (PET) set yarns, which are usually used for the production of fabrics dedicated to manufacture car seats, have better light and washing fastnesses when compared with those dyed with conventional methods such as carrier or high temperature dyeing. It is the aim of this paper to compare the properties of false twist-textured super bright, semi-dull, grey and black dope-dyed PET yarns including titanium dioxideand black pigments, respectively. X-ray diffraction (XRD) and DSC showed that the above mentioned additives lead to a rather looser microstructure. The loose structure exerted less resistance against the torsional and bending forces acting during the heat-setting of twisted yarn in texturing. The highest degree of crystalinity was observed for the super bright yarn. Titanium dioxide and black pigments led to an increase in the coefficient of friction of the false twist textured yarns. As a result of the additives, bulk and stretch ability of the textured PET yarn improved and its twist liveliness increased. Both the effects of additives on the fine structure as well as the coefficient of friction were held responsible for the differences seen as a result of dispersing titanium dioxide and black pigments in PET.