Overall the pigment ink rendered very good quality of printing. Width of the lines on most of the fabric was comparable to that on high quality ink jet paper. Line width gain for most of the fabrics relative to ink jet printing paper was negligible. The maximum line width gain that was observed was 34 %. Excessive drop spreading and higher line widths were observed where continuous and narrow capillaries exist on the surface of yarns. Ink jet drop spreading or wicking occurs along the direction of fibers. Number of drops impacted on the same location did not result in any increased drop spreading. This feature can be helpful where higher color depths are required. Darker color shades can be achieved without hampering printing quality. This feature can also prove to be important for smart applications where higher quantity of the material being applied is required on the surface of the fabrics for appropriate enhancement of functional performance. In general cotton fabrics gave the best printing quality. This perhaps comes from the fact that ink diffuses inside the fibers before substantial wicking or spreading can occur. The hairy nature of the cotton fabric, however, gives the irregular, inhomogeneous printing. Use of cellulosic filaments such as viscose rayon may overcome these problems and can give excellent printing quality due to their hydrophilic nature, where ink can diffuse faster before it can wick. Coating of yarns or fabrics by anti-wicking agents especially for twistless filament yarns can render better quality of printing. We observed around 25 % improvement in the line width gain due to the presence of size coating which acts somewhat similar to anti-wicking agent.We compared the width of lines that were printed on the fabric with wicking and drop test measurements performed on constituent yarns and corresponding fabrics. Drop spreading study was found to simulate the spreading of ink jet drops fairly well. However detailed behavior of all the governing factors needs to be understood for exact prediction of the ink jet drop spreading.
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