| Digital ink-jet printing technology opens up new design capabilities around colours, patterns and images. By making it possible to print directly from the computer via printing nozzles onto textiles without the need to prepare printing screens, this new technology improves printing process flexibility, efficiency and environmental performance. It provides substantially integrated operations, shortens printing times and meets the demand for rapid reaction to market developments and for fewer intermediate stages in the manufacturing operationThe researches on textile ink jet printing are mainly focused on the pre-treating process, the apparatus, the printing ink and software support. In our country, the technology is still on the start and there are three urgent problems: the first is the research of fiber sorts suitable for ink jet printing and the pre-treating process; the second is manufacture of high speed, stable, low-cost printing apparatus; the last is low cost ink with good stability. In this paper, the pretreatment on the properties of pigment based ink jet printing for polyester fabrics was studied.Polyester fabrics were pretreated, in order to enhance anti-bleeding performance of ink-jet printing with nano pigment ink. By conventional padding-drying–ink jet printing-curing process, the image qualities of ink-jet printing for polyester were studied. The effects of pretreatment conditions such as concentration of pretreatment reagent, pH vale of bath, temperature and duration of treatment on the property of ink-jet printing were discussed. The results show that the edge acuity and the colour depth of ink-jet printing on polyester were improved with about 15 g/L pretreatment reagent and pH vale 7,treating 6 minutes under 30℃.The effects of pretreatment reagent on the edge acuity, colour strength, rubbing fastness and soaping fastness were discussed. Results show that the wettability of the polyester fabric is improved withθa decreased from 83.3o to 60.7o; the edge acuity and colour strength are improved obviously, the line width decreases by 522.6μm and K/S values increases by 4.48; the soaping fastness is acceptable, the dry/wet rubbing fastness decreases slightly; the test results of bending rigidity and hysteresis of bending reveal that the pretreated fabric has soft handle. Pretreatment imparts polyester fabric good wettability; The colour strength and anti-bleeding of ink-jet printing are improved obviously after pretreatment. The colour fastness and handle of the fabric are acceptable.The effects of pH vale of bath and temperature on the adsorption of pretreatment reagent are studied. The adsorption capacity is maximal under the conditions of adsorption for 6min and pH= 11.0. Pseudo second order model best describe the reaction rate,adsorption capacity calculated by the model is consistent with that actual measurement,the correlation coefficient(r) of which is 0. 9917. The adsorption isotherms of pretreatment reagent with different temperatureare divided to two parts. The experimental data with pretreatment reagent concentrations from 5×10-4～1×10-3 mol/L follow Langmiur isotherm model, the correlation coefficient(r) of which is 0.9917 at 20℃.The equilibrium adsorption capacity increases with increasing temperature from 20 to 50℃,which indicates that the adsorption process is endothermic.By conventional padding-drying-ink jet printing-curing process, polyester fabrics were pretreatment with different reagents, and the properties were studied. It is demonstrated that the edge acuity, brilliancy and fastness were improved after pretreating with pretreatment reagent.The cationic sol was synthesized by Ethyl silicate (TEOS),γ-Glycidoxypr- opyltrimethoxysilane (GPTMS) and Cetyltrimethyl Ammonium Bromide (CTAB), and the structure and surface element were characterized with FTIR, AFM and XPS. The changes of the edge acuity, colour strength, rubbing fastness and soaping fastness of ink-jet printing with nano pigment ink before and after pretreatment on the polyester fabrics were discussed. The effects of cationic sol on wettability and handle of polyester fabric were also studied. Results show that the edge acuity and colour strength of ink-jet printing of polyester fabrics are improved largely after pretreated with cationic sol. The dry/wet rubbing fastness and soaping fastness are good, while the wettability and handle of the polyester fabrics are improved.
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