Properties of Xanthan Gum Thickening Agent in Polyester Fabric Direct Printing

Xanthan gum is a microbial polysaccharide produced by fermentation engineering with carbohydrates as the primary raw material (corn starch). It is mainly used in food, medicine, petroleum, and daily necessities and has great commercial value.

Disperse dye direct printing accounts for a high proportion of printed fabrics and is currently one of the leading printing methods. The pastes used for direct printing are mainly natural sodium alginate and starch and synthetic thickeners such as acrylates. The price of sodium alginate is rising day by day, and the source is limited. Acrylic thickeners cannot achieve good biodegradability, and the modified starch slurry has poor de-glueing properties and poor hand feeling. Therefore, the development and application of new pastes are necessary.

Ⅰ. The role of xanthan gum thickening agent in the fabric printing

With the increasing maturity of the xanthan gum industry, in terms of environmental protection and price, xanthan gum has great potential to replace the difficult-to-degradable chemical paste acrylics, and the expensive sodium alginate pastes with limited sources.

The application of xanthan gum as an ecological paste in textile printing is a new exploration, and the research in this area has just started.

A printing experiment Using xanthan gum as a paste on polyester fabrics was carried out. It was found that the xanthan gum thickening agent had a low penetration rate under normal printing conditions, but it could provide good edge definition. To study the synergy between xanthan gum and other types of pastes, it was compounded with sodium alginate, acrylic thickener, carboxymethyl starch, and polymaleic thickener in a particular proportion.

Experiments have found that the permeability of the composite paste is higher than that of the pure xanthan gum thickening agent, and the xanthan gum has a significant viscosity-increasing effect on the near-Newtonian fluid paste such as sodium alginate. It has a noticeable effect on the acrylic pseudoplastic paste. The thickening effect is not significant. However, the effect of compounding can not meet the requirements of various aspects of fine printing, especially in terms of the colour yield of the printing through the screen.

Ⅱ. The printing performance of xanthan gum thickening agent

To explore the reasons for the poor printing performance of xanthan gum thickening agent, the rheological properties of xanthan gum were studied. The viscosity, printing viscosity index, rheological curve, viscoelasticity, creep and recovery properties were investigated, respectively.

The results show that xanthan gum has an excellent thickening effect, large yield stress, apparent shear thinning. To use it as a printing paste, it is necessary to use its shear-thinning characteristics and minimize its yield stress.

After understanding the unique rheological properties of xanthan gum, the changes in the rheological properties of xanthan gum through physical and chemical methods were preliminarily discussed.

Experiments have found that adding an appropriate amount of surfactants such as penetrants can enhance its fluidity, reduce surface tension, and improve printing transparency. Still, the color paste is easy to permeate. Furthermore, the xanthan gum was modified by the method of hydrogen peroxide oxidation. The viscosity of the oxidized xanthan gum thickening agent is reduced, the fluidity is improved, the colour yield of the printing net is increased to a certain extent, and the impermeability is not affected. However, compared with the performance of traditional printing pastes, there is still a certain gap in the amount of color obtained, which cannot meet the requirements of practical applications.