Research On The Effect Of Organic/inorganic Composite Paste On The Properties Of Inkjet Printing Processing

Textile digital inkjet printing is a novel technology which is combined with computer software, precision machinery and ink technology. Its colorful printing designs cater to the trend of individuation and fashion of textile clothes. It is necessary for fabric to spread paste before inkjet printing except the transfer printing fabric such as polyester. The properties of paste used for pretreatment, such as the holding water, the rheology, and the permeability have an important influence on color yield and clarity for fabric. The sodium alginate is widely applied in the pretreatment paste; as the price of sodium alginate is inflating, the cost of the printing is increasing as well. The research of organic/inorganic composite paste can not only reduce the processing cost of pretreatment, but also possesses a crucially theoretical and realistic significance for regulation of the effect of digital inkjet printing.In order to solve this problem, this thesis adopts the method of composite paste mixed with sodium alginate and bentonite to explore the application of composite paste in different fabric printing. Specific studies are as follows:First of all, the basic properties of composite paste intermingled with sodium alginate and bentonite were explored. It was found that sodium alginate and bentonite are typical pseudoplastic fluid, and the pseudoplastic of bentonite is stronger than that of the sodium alginate. In the process of composite, the more bentonite was utilized, the stronger pseudoplastic of composite paste became. Sodium alginate and bentonite were matched by100:0, 75:25, 50:50, 25:75 and 0:100 according to their mass, and applied them to screen direct printing of polyester fabric, and compared two effects of thermoset color fixation and of conventional steaming fixation of polyester fabric. With the dosage of bentonite increasing,K/S value of fabric was increased; otherwise, the K/S value of fabric was lower. Take the permeability and K/S value of fabric into consideration, it was found that the effect of fabric printing was desirable when sodium alginate and bentonit are mixed at the proportion of 25:75,and the effect of thermoset color fixation can be reached as effective as that of conventional steaming fixation.Then, the composite paste was applied in inkjet printing of polyester, and compared the effect of steaming and thermoset color fixation. It was found that the composite paste differently influents inkjet printing and direct printing. In polyester fabric inkjet printing, the influence on printing effect by the proportion of sodium alginate and bentonite is not so obvious. Using bentonite as pretreatment, fabric printing effect can reach to the level of sodium alginate. The higher K/S value of fabrics was reached when the paste dosage is 25%and the liquid rate is 100% in pretreatment. Compared with the 25% and 40% of paste dosage in pretreatment liquid, the influence on the liquid rate of printing was found that within a certain range, when the liquid rate increases, the paste on the fabric increases, and the K/S of polyester fabric increases. However, the K/S of polyester fabric was worse when the paste dosage was 40% in pretreatment liquid, so the paste dosage on fabric is not so effective when it’s too sufficient. Through the test of style and fastness of fabric, it was found that the addition of bentonite can also make the fabric gain good fastness and soft handle. Using two different methods of color fixation, for ink C, the K/S value of thermoset color fixation is higher than steaming; for ink M, Y, K, the K/S value of thermoset color fixation is lower than steaming.The thermoset color fixation can reach the effect of conventional steaming fixation.Finally, the composite paste was applied to inkjet printing of cotton and silk fabric in order to expand its application and explore its influence on printing effect. It was found that the influence of ratio of sodium alginate and bentonite on fabric printing effect was not obvious, when the dosage of bentonite in composite paste increases, the K/S value of fabric increased slightly, the permeability decreases slightly. And that can be changed by adjusting the ratio of the K/S value of fabrics and permeability. And using pure bentonite as pretreatment liquid, the effect of fabric printing can reach the effect of sodium alginate as pretreatment liquid.To sum up, in the prepress processing of polyester, cotton and silk spray digital printing,using bentonite partly instead of sodium alginate is feasible. By adjusting the proportion of sodium alginate and bentonite, it can regulate the color yield and permeability. After digital jet printing for polyester fabric, it is viable when using simple operation of thermoset fixation method instead of the conventional steaming fixation.