Effects Of Pre-Treatment On Fabrics Inkjet Printing Performance

Patterns directly printed with pigment inks have poor color yields and easily bleed. In order to improve the inkjet printing sharpness of fabrics, pre-processing of fabric must be done before printing. Traditional pre-processing was to size the fabrics using solutions of some chemicals such as thickeners and cationic reagents. This process is very long and complicated, with huge energy and water consumption. At the same time, toxic substance and waste water would be produced during process, which lead to environmental pollution. In recent years, People have paid great attentions to environmental deterioration and ecology balance, especially the problem of water shortage and environmental pollution. The plasma technique, as one of environmental friendly process, has been widely used to modify the surface properties of polymers and textile materials over the past decade. Compared with traditional methods, plasma treatment have the following advantages: it only modifies the outmost thin layer of the surface, while the bulk properties will be kept untouched; lower chemical consumption and higher security; no waste water produced; less burden on environment and totally fit to the definition of textile ecological manufacturing. The aim of this research was to study the effect of pretreatment of silk and polyester fabrics on the samples'color performance by using low temperature oxygen plasma and pulse atmospheric air plasma, respectively.Plasma surface-treatment of silk fabric was carried out in an oxygen atmosphere under different experimental conditions. The samples were printed with magenta pigment ink after treatment. The results showed that the optimum treatment conditions we obtained were exposure time of 10 min at a working pressure of 50 Pa and a working power around 80 W. At such conditions surface-modified silk fabrics could obtain the effects of features with enhanced color yields and excellent pattern sharpness. Atomic force microscope (AFM) images indicated that low temperature oxygen plasma initiated modifications to the surface of silk fiber with more grooves. Dynamic contact angle (DCA) analysis showed that the hydrophilicity of silk fiber was remarkably improved after pretreatment with plasma.In order to extend this technique into industrialization, we present a study of the surface modification of silk and polyester fabrics using pulse atmospheric air plasma. Scanning electron microscopy (SEM) and X-ray photoelectron spectroscopy (XPS) were used to observe the change of fiber morphology and surface chemical composition, respectively. SEM and XPS analysis indicates that the enhanced wettability was mainly contributed by the oxygen containing polar groups induced onto fiber surfaces through plasma treatment. Consequently, the anti-bleeding performance of both fabrics for inkjet printing was markedly improved, and the pattern sharpness considerably increased. Thereby the surface modification method for both fabrics used here offers a potential way for pretreatment of fabrics for inkjet printing with the advantages of environmental friendly and energy saving over traditional pretreatment methods.