Digital textile printing: colorfastness of reactive inks versus pigment inks
Digital textile printing is over-taking the printing industry with eco-friendly processes and ability to produce short runs. With its rapid growth, there is a constant need to reproduce consistent colors throughout different print runs and crucial for these colors to perform well and up hold under certain conditions. The purpose of this study was to research the colorfastness digitally printed reactive and pigment inks printed on cotton fabrics. Fabric swatches printed using the reactive and pigment inks were tested according to the AATCC standards for laundering, crocking, light, and perspiration.
The digital textile printing industry has slowly started transitioning from printing with reactive inks to primarily pigment inks. Printing with pigment inks is more cost effective and cheaper than reactive inks and has had a large impact on the printing industry. While reactive inks are printed on natural fibers, such as cotton and silk pigment inks, have the ability to be printed on natural and synthetic fibers.
To test the textiles, a Mimaki TX2 1600 digital textile printer was used to print the reactive ink samples while an outside printing company was used to print the pigment ink samples. One hundred and twenty-eight test samples sizes 2”x6”printed with a red, blue, and green geometric pattern were tested. Both the pigment and reactive samples were testing according to the AATCC standards for colorfastness to laundering, crocking, light, and perspiration.
Using a spectrophotometer, the samples were tested and the CIELAB color and ΔE* color change were obtained. The samples were also tested using the AATCC gray scale and 9-step chromatic transference scale. Using the Wilcoxin rank sum test the pigment and reactive samples were compared to record any statistical significance in color change.
The results revealed that the colors printed using pigment inks perform better than reactive inks. Pigment inks experienced much less color loss than the reactive inks in laundering, crocking, and perspiration. Light had little to no impact on the color of both the reactive and pigment samples. Evaluating the reactive and pigments ink types and their colorfastness benefits academia and the industry. This research provides recommendations of how these ink types may be best suited for certain types of apparel and products.