Ingredients of printing paste:
Just as it is necessary to prepare dye solution for dyeing cloth, it is also necessary to make printing paste for printing cloth. Good printing largely depends on its printing paste. https://bdfabric.com/function-and-properties-of-thickener-in-printing/
The names of the main components of printing paste are given below:
1. Dyestuffs or pigments
2. Wetting agents
4. Solvents dispersing agents
5. Defoaming agents
6. Oxidizing and reducing agents
7. Catalysts & Oxygen carrier
8. Acid & alkali
9. Carrier & swelling agents
10. Miscellaneous agents
Not all of the above materials are needed to make a printing paste. The use of materials depends on the grade of dye used, printing style, blending method of thickener, etc.
Table of Contents
1. Dyestuffs or pigments:
Dyestuffs are a type of unsaturated complex compound. It contains some chemicals “Azo” (-N = N -) Keto (> C = (O), etc.). This group is called the chromophore group. This results in changes in the chemical and physical properties of the material and the color of the material reflected by the rays of light. Active dyes etc. are soluble in water. Vat dyes, sulfur dyes, disperse dyes are insoluble in water. The pigment is a coloring material. These are organic or inorganic coloring products.
2. Ingredients of printing paste-Wetting agents:
It is necessary to reduce the surface tension of the water to make the dyestuffs soluble in water. Otherwise, the dye will not get wet in the stuff and will cause various problems. Products that reduce the surface tension of water when used are called weighting agents. E.g., T.R. oil.
3. Ingredients of printing paste-Thickener:
Thickener is a compound with a high molecular weight, which when combined with water can form a solution or paste in a thick adhesive. They are also called printing gum. If you want to apply dyestuff on clothes, you need a thickener in printing paste, starch, gum Arabic, British gum, carboxyl methylcellulose, etc. Thickener examples.
4. Solvents dispersing agents:
The solvent or dispersing agent is used in the printing paste to prevent the dye staff molecules from sticking together to form alloys or granules. Commonly used as solvents are acetone, glycerin, alcohol, urea-formaldehyde, etc.
5. Ingredients of printing paste-Defoaming agents:
The mixing of various wetting agents with thickeners in printing pastes, especially in the case of roller printing and screen printing, produces several bubbles, i.e. foams, during the use of the pastes and during mechanical handling, which interferes with the printing. Defoaming agents are the products used in printing paste to prevent the formation of such foams. Such as silicone, deformers, etc.
6. Oxidizing and reducing agents:
Oxidizing agents are used in printing pastes to stabilize dyes on fabrics printed by some dyes such as VAT, azo, aniline black, etc. Sodium hydrosulfite, a reducing agent, is used for VAT dye.
7. Catalysts & Oxygen carrier:
Some impregnators are used in the printing paste to dye the printed fabric through the steaming process, which in many cases is used to reduce the risk of oxidation of the fiber. Potassium, copper sulfate, etc. are used as inhibitors.
8. Acid & alkali:
The need for acid to develop the color of fabrics printed by certain dyestuffs. However, acid is not used directly in the printing paste, so the acid emitting agent is used. Also, strong alkali or medium type of alkali is used in printing paste.
9. Carrier & swelling agents:
The carrier is used by Disperse Dye to increase the penetration of the dye into the fiber during the printing of polyester fabrics. This is done by soaking the fibers so that the pores of the fibers become larger and the color can penetrate easily.
10. Miscellaneous agents:
Some more chemicals are added to the printing paste depending on the type of fabric printing, the method, the class of dyestuff, etc. For example Rangolite C, a complex compound with reducing power during printing by VAT dye.