The color ink containing the dye is printed on the paper in a selected pattern by a printing method. There are four printing methods: plain printing, gravure, embossing and screen printing. Among them, the pattern obtained by the plain printing is the finest, but the color ink layer is thin, and the requirements for the dye in the color ink are also high. The gravure color ink layer is thick. After the transfer, the fabric has a high color yield and can also print a finer pattern. Screen printing can print thicker patterns for easier printing. Printing and dyeing plants print their own method of using gravure printing and screen printing.
The printing ink contains a dye, an adhesive, a thickener, and the like. The inks used are water-soluble inks, alcohol-soluble inks, and oil-soluble inks.
In water-soluble inks, sodium alginate or etherified soap gum can be used as a binder, and some polyacrylate adhesives can also be used to make printing inks. They are suitable for screen printing, gravure printing and convex printing. Plate printing legal transfer paper.
Alcohol-soluble inks are prepared from binders and dyes dissolved in suitable alcohols, such as ethyl cellulose dissolved in n-butanol and isopropanol as binders. At the time of preparation, the dye was milled with n-butanol (1:3) and then made into an ink with ethyl cellulose in isopropyl alcohol solution. Alcohol-soluble inks are widely used.
Oil-soluble inks are formulated with an oil-soluble resin (such as long oil linseed oil, isophthalic acid alkyd resin, varnish, and medium-viscosity linseed paint), calcium carbonate, and dyes in a three-roll mill. Print transfer paper on lithography. The ink for the convex plate printing can be made of castor oil, alkyl benzene, etc. into resin oil, and then it can be ground with a dye, calcium carbonate, and super boiling point oil in a three-roll mill.
The dyestuff in the ink should be fully ground, otherwise there will be color spots or stripe disease on the printing paper, which becomes more obvious after being transferred. However, when the dye is too fine in the ink, the solubility of the dye particles in the ink is increased, and the flocculation of the dye is also increased, resulting in crystallization during storage and use.
Author: Li Xiaochun