| Digital ink-jet printing technology for textile offers benefits such as speediness,flexibility, clear patterns and cleanliness,etc.It adapts to current textile market which requires individuation, small batch production,fast delivery and eco-friendliness.So ink-jet printing is considered to be one of the key technologies of textile industry in 21st century.Reactive dye inks are the most commonly used inks for textile ink-jet printing because of their good color performance,fastness,and easy manufacturing.However,the color yield of cotton fabric printed with reactive dye inks is not high since ink-jet method only brings little amount of dyes onto the fabric surface,and that reactive dyes have low fixation ratio to cotton. Besides,silk fabric is easy to bleed during ink-jet printing due to its fibers having smooth surface and lower ability to hold on water.Therefore,patterns printed with dye inks on it have poor outline sharpness and color depth.In this paper,low temperature plasma(LTP) technique was used to modify the surface properties of cotton and silk fabric respectively,and the treating conditions(including plasma gas, distance between polar plates,treating time,etc) influencing ink-jet printing performance of the fabrics were investigated.Experimental results revealed that,after 4 min O2 LTP treatment (discharge power was 60 W,distance between polar plates was 2 mm),dye fixation to the treated cotton fabric was remarkably increased,the color performance of printed fabric was also improved, and the amount of urea in pretreatment paste could be reduced.After LTP treatment,the whiteness of cotton fabric was slightly decreased,and the tensile strength and breaking elongation were increased.SEM observation indicated that the surface of cotton fiber was etched by O2 plasma and became roughened.Thereby the ink-jet printed fabric was endowed with hyperchromic effect. The results also revealed that,the anti-bleeding performance of silk fabric was markedly enhanced by LTP treatment.And the dye fixation and color performance were also improved. Moreover,the treated fabric had good level-printing properties and color fastness.After LTP treatment,the whiteness and tensile strength of silk fabric were slightly decreased,and the wettability was remarkably improved.XPS analysis showed that the enhanced wettability of silk fabric was mainly due to the oxygen containing polar groups(e.g.-CO-,-COO-) produced onto fiber surfaces by LTP treatment.Considering the features of ink-jet printing and some problems met in small batch steaming process for fixation,a contact-type dry heat fixation(CDHF) method for fixing reactive dyes was discussed in this paper.In CDHF process,the printed cotton fabric was firstly humidity-controlled in a consistent temperature and humidity room(25℃,80%RH) before placed between iron plates and heated(160℃,40 s).Experimental results revealed that the dye fixation effect obtained by CDHF method was similar to that by the steaming treatment.In addition,the possibility and effectiveness of one-step ink-jet printing and crease-resistant finishing of silk with citric acid containing chitosan were also discussed in this paper.The results showed that silk fabric had good anti-bleeding performance after treatment with acid solution containing 3 g/L chitosan.And the dye fixation and color performance were also improved appreciably.Moreover,the crease-resistance of treated silk fabric was improved evidently due to the deposition and cross-linking on fibers by the synergistic effect of citric acid and chitosan.
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