The invention discloses a pretreatment liquid for direct injection of
polyester fiber through dispersive ink and a direct injection
digital printing process. The pretreatment liquid comprises, by
mass, 0.2-5 parts of thickener, 1-10 parts of dispersion
promoter, 2-5 parts of
sodium chloride and 76-95 parts of water. The pretreatment liquid is semi-thick liquid,
polyester fabric after going through impregnation or padding treatment liquid is dried, injection printing of dispersive dye ink is performed, high-temperature
steaming baking is performed for color fixing after
drying,
water washing is performed, and then
drying is performed to obtain a printing finished product. The pretreatment liquid is simple to prepare, convenient to use and suitable for direct injection process
digital printing of all fabric high in
polyester content, and the pretreatment liquid is easy to wash away after printing, so that hand feel of fabric is unaffected. Conventional
heat transfer printing is replaced by the dispersive direct injection process, and
transfer printing paper is not used, so that the direct injection
digital printing process is environment-friendly. The pretreatment liquid can effectively prevent ink from spreading around on the polyester fabric, so that patters are ensured to be exquisite and lines are ensured to be clear after printing; color
yield rate is high, printing is saturated and bright in color, and visual three-dimensional sense is high.