Digital textile printing: how to choose the right ink?
For many companies, entering the textile printing field seems to face many challenges. In addition to choosing the right printer, you must also consider choosing the right ink for the printer and fabric. On the contrary, ink and fabric also determine the choice of printer.
In textile printing, there is no “one size fits all” solution. There are many factors to consider when choosing ink. First, ask yourself: “What is the purpose of the product?” For example, the ink required for printing fashion products is very different from that for logo printing. Fashion products require ink to have good color fastness, and printed logos usually pay more attention to light fastness.
To figure this out, it’s time to make a decision. “Do I want to print on natural fabrics (such as cotton, silk, linen)? Or do I print on synthetic fibers (such as polyester)?” This question is often difficult to answer because many people do not like polyester and think they Very cheap. But that is not the case. A large number of existing polyesters on the market can successfully imitate natural fibers such as silk and cotton. Some polyesters can even be synthesized from 100% recyclable materials.
According to your answers to these questions, the choice of ink is usually divided into the following four types:
Acid dyes are commonly used to print fashion products. They are combined with the protein fibers in the fabric, such as the protein in silk and wool. Therefore, the applicable printing materials for acid dyes are very limited, but the printing effect is very good, such as printed neckties.
The fabric needs to be pretreated before printing and dyeing with acid dyes, which can allow the fabric to absorb the dye better and prevent lateral bleeding when touching the fabric. When the dye is printed directly on the textile, the color will usually appear dull, but it will change after post-processing.
Acid dyes require “wet” processing, including steaming and washing. During the steaming process, the dye is “fixed” on the fabric. At this stage, the fabric will change color, and the color will usually be brighter and brighter when taken out of the steamer.
Then, the fabric needs to be washed to remove the residue from the pretreatment and the excess dye that was not fixed during the steaming process.
Reactive dyes are used in cellulosic fabrics, such as cotton and linen. Compared with acid dyes, reactive dyes can print and dye more fabrics. Reactive dyes can even be used to print protein-based textiles, and are often used to print fashion and furniture.
Like acid dyes, the use of reactive dyes also requires pretreatment of the fabric and then directly printed on the textile. The processing process is also very similar, including cooking and washing, but because reactive dyes cure faster than acid dyes, the processing time will be different.
Pigment inks are very different from other dyes in that they cannot be completely immersed in the textile, but stay on the surface. In a sense, this is a good thing. Because the composition of the fabric will not be a restriction on the selection of dyes when printing, this means that pigment inks can be printed on a variety of textiles. However, the disadvantage is that the color fastness may not be so good.
Since pigment inks were first used in digital textile printing, there has been considerable development. Along with pre- and post-processing, the development of ink means that pigments have become a viable choice for many production applications and are one of the fastest growing branches of the market. Due to its good light resistance, pigment inks are particularly popular in the home decoration and home textile fields.
Unlike other direct printing solutions, pigment inks do not require pretreatment of textiles before printing. However, in order to obtain the best color fastness and the most vivid effect, pretreatment is still recommended.
Pigment ink adopts “dry” processing technology, which is “fixed” by heating, so it is favored by people. It can be processed with a hot press and a fixed drying device. In this process, the color generally does not change much, and the fabric can be made into a finished product after completion.
The sublimation market is another fast-growing field in the textile printing industry. The inks used are called disperse dyes and come in many different forms. Some are dedicated to direct printing (called “true disperse dyes”), some are used to transfer paper, and some are a mixture of the two.
The application of the product will determine which dye meets its own needs. For example, direct disperse dyes have good light resistance and ink permeability, so they are favored by logo printers. The transfer dye has a wide color gamut and clear printing, so it is favored by sportswear printers. Regardless of the dyes, they are mainly used in synthetic fibers such as polyester.
When disperse dyes are used to print fabric and paper, the initial color looks dull and soft. The color will become brighter during post-processing. Sublimation dyes need to be “dried” with heat, but direct disperse dyes can also use steam to fix the color.
Time, pressure and temperature are the three key factors affecting sublimation printing. In the use of flat heat press (for rigid substrates or textile panels), calender (for longer fabrics), curing device (for fabrics with direct disperse dye printing), and autoclaves (for direct printing) The effect is particularly significant when printing on fabrics.
“Sublimation” refers to the process in which a substance changes from a solid to a gas without entering the liquid phase, and then to a solid. Sublimation printing is one of the most diverse printing methods on the market. From exhibition signs to personalized product customization, people from all walks of life are using sublimation for printing production.