The composition of pigment printing paste varies with the raw materials, and the printing color effect will also vary. In order to control the quality of the printing process, it is necessary to mix the colors of the color paste to meet specific appearance color requirements. This article brings you the method of mixing pigment printing paste. Interested users can take a look!

Composition and function of pigment printing paste:

The types of pigment printing paste used in production are simple, usually only consisting of coatings, adhesives, and thickeners. Other additives can be added when there are special requirements.

Coatings are a slurry formed by mixing and grinding pigments, wetting agents, dispersants, stabilizers, and water in proportion. The color that pigments give to printed fabrics determines the vividness of the product's color, and affects the fastness of the pattern to sunlight, climate, and sublimation. The basic requirements for printing on coatings are:

1. High coloring and covering power. Coloring power refers to the amount of color given, and the degree of color intensity that can be printed by a coating is one of the main technical indicators of the coating. Covering power refers to the ability of a coating to completely cover the printed fabric, often expressed as the amount of pigment required to cover the area being printed. The covering power of coatings is influenced by factors such as pigment dosage and particle size, and is another important technical indicator of coatings.

2. High light resistance, heat resistance, and weather resistance.

3. Good chemical stability, with some stability towards acids, bases, oxidants, reducing agents, and dry cleaning agents.

4. Appropriate density and dispersibility ensure that pigment particles do not float or precipitate in the dispersion system.

5. Good sublimation and smoke fading fastness.

Adhesive is a molding polymer compound, also known as adhesive, with an average relative molecular weight of around 100000, among which synthetic polymers are widely used. The common commercial adhesive is the lotion in which the polymer is dispersed in water in a fine state, with a solid content of 30% -40%. The function of the adhesive is to form a transparent film with strong adhesion after molding treatment, and fix the coating onto the fabric. Therefore, the adhesive affects the hand feel of hardened products, as well as the color fastness of soap washing, brushing, dry friction, wet friction, etc.

Thickener plays a carrier role in pigment printing, allowing the pigment binder and other additives to be evenly dispersed and transferred to the knitted fabric. There are two types of thickeners used: emulsified paste and synthetic thickener. The main problem with the use of synthetic thickeners is that they are not resistant to electrolytes. Electrolytes can cause the printing paste to become thinner, viscosity to decrease, and the printed patterns to seep, affecting the printing effect. In the production of full pigment printing, synthetic thickeners can be used. Electrolytes are present in the anti discharge pigment printing paste, which should be taken into consideration.

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How to prepare pigment printing paste?

Due to the different compositions of pigment printing pastes, there are significant differences in the color effects of the configured pigment printing pastes. In order to control the quality of pigment printing pastes, it is necessary to strictly control the pigment mixing process. At present, color paste mixing can be manually operated or completed through an automatic color paste mixing system. The automatic color paste mixing system is composed of a computer, color matching software, and a color measurement and matching system. The application of automated color paste mixing system can make printing color matching digital, accurate and reliable, and have high production efficiency, which is the development direction for pigment printing color paste mixing.

Preparation method of color paste:

1. Computer Color Matching

In the computer color matching system, a basic database of printing process should be established first, which means that each dye is printed with small samples at different concentrations, and then the printing samples are tested with a color tester, and stored as basic data in the computer for providing color matching formulas. The future sample will be tested on a colorimeter as a standard sample. The testing and matching system will search for the formula in the database according to the test results, perform printing and sampling based on this method, and then test the color difference between the sample and the standard sample. If the color difference is not within the allowable range, the testing and matching system will correct and adjust it. The color difference will be measured again until the color difference is within the allowable range. At this time, an appropriate amount of color adjustment will be provided to the color matching system.

2. Automatic slurry mixing

The mixing system is a very important part of the entire automatic color mixing system, which can be used in conjunction with the color measurement and matching system or separately. You can use the color matching system or input the required process formula through the keyboard to adjust the color paste. The system can be configured with dozens of high-level buckets. Before mixing, the original paste, dye solution, and auxiliary solution should be pumped into the corresponding high-level bucket and compressed air should be introduced to maintain uniformity. After the color matching system provides an appropriate amount of mixing, the mixing computer can start working. The electronic scale automatically moves along the track from left to right, adding the appropriate amount of original paste, dye, additives, and water. All feeding data can be displayed on the display screen of the computer console, and the mixing amount can also be printed using a printer. After the feeding is completed, the color paste is obtained by stirring with a mixer.