Development of a thixotropic adjustable disperse dye ink for direct inkjet printing on polyester fabrics without pretreatment

Abstract

A novel thixotropic adjustable disperse dye ink has been successfully developed for direct inkjet printing on polyester fabrics without pretreatment by utilizing a thixotropic viscosity response mechanism without stimulus source. The origin of the non-stimulated thixotropy is the weak cross-linking of the amino group in diethylenetriamine (DETA) with the carboxyl group in polyanion XIRAN®17,352, which improves the printing effect. Tests on the physical and chemical properties, rheological properties and printability of the inks have demonstrated excellent overall printability. Low-field nuclear magnetic resonance (LF-NMR) shows that the addition of DETA enhances the physical cross-linking of the ink, which can effectively limit the mobility of water molecules in the ink system, thus reducing the spreading of the ink on the fabric surface. The ink spreading process shows that DETA enhances the viscoelasticity of the ink and prolongs the infiltration time of the ink droplets on polyester fabrics, thus alleviating the problem of ink bleeding on fabrics and forming a deeper value of print colour depth. Printed fabrics using Y-0.1-1.2 and B-0.06-1.2 inks have excellent colour acquisition, print clarity and colour fastness. Therefore, this adjustable thixotropic ink technology is expected to provide an economical and environmentally friendly alternative for environmentally friendly printing of polyester fabrics.