Development of Binder-Free Pigment Inks for Direct Inkjet Printing on Cotton Fabric without Pretreatment.

Inkjet printing technology is widely used in the textile digital printing application today though the current technology still requires pretreatment and postwashing procedures before and after printing. Additional chemical treatment generates a large amount of wastewater and complicates the process. Among the many potential approaches for reducing chemical waste, pigments with self-dispersing capability were prepared and formulated into binder-free inkjet inks that require no pretreatment or after-washing process when printing cotton fabrics. The new self-dispersing pigment inks were tested and evaluated on cotton fabrics. The distribution of particles was between 122.2 and 188.5 nm, and inks have excellent storage capability. Printed fabrics' light fastness and acid/alkali resistance are about grade 5, and printed cotton's washing and rubbing fastness are above grade 3. The mechanism and performance of ink drops were investigated by LF-NMR and ink-drop observation methods. This work provides a possible solution for reducing wastewater in the textile industry.