What type of dyes are used for different textile fibers

Synthetic dies are man-made dyes and are classified according to their chemical composition as well as the method of their application in the dyeing process. Natural dyes, on the other hand, are categorized into three types: natural dyes that come from plants and are called Indigo; those that come from animals are called cochineal, and those that were gained from minerals are called Ocher.

Your email address will not be published. What is dyeing? Leave a Reply Cancel reply Your email address will not be published. Dye: Soluble chemicals that contain chromophores, or color-containing compounds. Dyes are mixed with other additives in a color solution. They can be derived from natural sources, such as plants, but are more commonly human made. Different classes of dyes are used for different fibers and stages of the textile production process.

Direct dye: A class of dye that can be applied directly to cotton or other cellulosic fabrics such as rayon, silk, and wool. Direct dyes are applied in a neutral or alkaline bath of hot water. They do not require mordant or fixatives for fastness; instead, they attach with hydrogen bonds and van der Waals forces. Direct dyes are soluble salts of complex sulfonic acids, including diazo or polyazo chemicals. Disperse dye: A category of nonionic dyes used to color synthetic yarns and fabrics such as polyester.

These organic chemicals, mostly monoazo dyes, are nonsoluble and rely on dispersing agents to spread the color molecules in water. Reactive dye: A class of colored synthetic organic chemicals that attach to textile fibers via a chemical reaction that forms a covalent bond.

Reactive dyes are the most permanent of all dye types and are the most common type of dye used on cotton and other cellulose fibers. They are categorized by their functional group, such as dichlorotriazine or vinyl sulfone. Dye exhaustion or dye fixation: The mass of dye taken up by the yarn or fabric divided by the total initial mass of dye in the water bath. Once the dyeing process reaches equilibrium, a portion of the dye remains in the dye bath and becomes part of the dye process wastewater.

The exhaustion ratio depends on the quality of the dye and the characteristics of the fiber. Leveling agent: Used in disperse dyeing to regulate or slow the uptake of dye onto synthetic fibers to ensure that the color level is uniform. Leveling agents are often nonionic surfactants that increase the solubility of the dye and slow adsorption.

Mordant: Also called a dye fixative, a substance used to chemically bond a dye to natural fibers to ensure fastness. Mordant chemicals include alum, caustic soda, and metal salts. The mordant forms a coordination complex with the dye, increasing its molecular weight and making it insoluble. Pigment: Insoluble materials, usually in powder form, that add color to inks, paints, plastics, cosmetics, and foods.

When used on textiles, they require binders or other additives to attach to the fibers. Pigments can be derived from minerals but can also be made synthetically. Because they are not soluble in water, they can last longer than dyes. To reduce this burden, Huntsman has developed a line of dyes for cotton called Avitera that bonds to the fiber more readily. According to the company, the colors require one-quarter to one-third less water and one-third less energy. Thanks to these extra reactive groups, the dye step lasts about four hours, compared with seven hours for conventional dyes.

Still, it takes a lot of legwork to sell customers on a new suite of dyes. Different regions and countries have different cost structures, he says. Another way to improve the bond between dyes and cotton fibers is a process called cationization. In North Carolina, textile industry veteran Tony Leonard is taking that approach.

Leonard is the inventor and technical director behind ColorZen, a start-up that has developed a cotton pretreatment step. ColorZen treats raw cotton fiber right from the field after the seeds are removed. After treatment, cotton is spun into yarn at customer facilities.

It also cuts out almost half the dye compared with processes that call for salts in the dye bath. The company has a partnership with the manufacturing technology firm Jabil to help it scale up its plant in Mebane, N. It is also in a program run by the apparel start-up incubator Fashion for Good. Hohenstein developed Oeko-Tex, a series of standards and tools for certifying nontoxic textiles.

The first version of the standard was called Oeko-Tex for the number of chemicals it tracked. Oeko-Tex certification is now up to more than chemicals. Synthetic indigo, used to make blue jeans blue, is an example of a dye that can release unreacted chemicals downstream of manufacturing. Indigo is unlike most dyes in that in its unreduced form it is not soluble.

So companies like Archroma upgrade it into easier-to-use, prereduced solutions that are more water soluble. The company became concerned after seeing published reports that about metric tons of aniline per year escapes the dyeing process from 70, metric tons of indigo.

Archroma developed a technology for prereducing indigo to prevent aniline from carrying through as a contaminant. Finished textiles colored with the dye contain a nondetectable amount of aniline, whereas competitor dyes can contain up to 2, ppm of the chemical, according to Archroma. Basic dyes are cationic dyes and are commonly used to dye fabrics such as wholesale pure silk fabric , nylon , wool, and other modified acrylic fabrics.

This is one of many types of fabric dyes and is a common choice in the textile industry. Usually, acetic acid is added to the dye bath to increase the absorption of the dye. This dye is also commonly used in the coloration of paper. This type of fabric dye requires a mordant which increases and improves the fastness of the fabric dye against the light, water, and perspiration.

It is important to choose the mordant carefully as it can change the color of the wholesale fancy fabric. It can be used to dye fabrics such as polyester, silk, rayon, acrylic wool, and nylon, the dye has excellent quality of color adherence but is not as bright as acid dyes. Sulfur is the most commonly used fabric dyes out of a list of all fabric dyes. It is inexpensive and has good wash-fastness.

It is also easy to apply and is commonly used for cotton fabric. The dyeing process of fabric using sulfur dye includes various steps which include reduction, dyeing, washing, oxidization, soaping, and final washing. Sulfur dyes normally result in dull-colored fabrics and are also used in printing.

Here was a list of all fabric dyes commonly used in the textile industry. Different types of dyes are used for different purposes. Dyes are mainly classified according to their solubility and chemical properties. However, one prominent classification of dyes is natural and synthetic dyes. Textile Infomedia is a portal that has enlisted manufacturers of dyed textile fabrics throughout India.

The portal allows wholesalers to procure dyed textiles of high quality directly from the wholesalers. People can also procure dyed textiles at the best rates from the wholesalers, through Textile Infomedia. Based in Weesp near Amsterdam, it is a leader in water-free and chemical-free textile dyeing. Printing is a process of decorating textile fabrics by application of pigments, dyes, or other related materials in the form of patterns.

Although apparently developed from the hand painting of fabrics, such methods are also of great antiquity. Textile printing has become highly sophisticated and has involved the skills of many artists and designers. The four main methods of textile printing are block, roller, screen, and heat transfer printing. In each of these methods, the application of the color, usually as a thickened paste, is followed by fixation, usually by steaming or heating, and then removal of excess colour by washing.

Printing styles are classified as direct, discharge, or resist. In direct printing, coloured pastes are printed directly on the cloth. For discharge printing, the cloth is first dyed with a background color, which is destroyed by reagents, or reducing agents, carried in a print paste.

This action may leave the discharged design white on a colored background, although print pastes may also contain coloring matters not destroyed by the discharging agent, producing a colored design. In the resist process, the cloth is first printed with a substance called a resist, protecting these printed areas from accepting color.

When the cloth is dyed or pigment padded only those parts not printed with the resist are dyed. Wooden blocks, carved with a design standing out in relief, are made from solid pieces of wood or by bonding closely grained woods with cheaper ones. When designs include large areas, these are recessed and the space filled with hard wool felt. Fine lines are usually built up with copper strips, and other effects are obtained with copper strips interleaved with felt.

To facilitate registration of successive prints, or lays, each block has several pitch pins arranged to coincide with well-defined points in the pattern. The cloth is printed on a table covered with several thicknesses of fabric or blanket, the whole covered with a thick sheet of tightly stretched synthetic rubber.

The cloth to be printed is spread on the rubber, either gummed in position or pinned to a backcloth attached to the table.

Colour is applied evenly to the block, and the pattern is stamped on the fabric to be printed, using the handle of a small heavy hammer, or maul, to aid penetration of the paste. More color is then applied to the block and the process is repeated using the pitch pin to obtain true registration.

After the fabric has been entirely printed with one color, other colors are applied in the same way until the design is complete. Although block printing is becoming too laborious and costly for commercial use, some of the most beautiful prints have been made in this way.

This technique is used whenever long runs of fabric are to be printed with the same design. The modern machine, based on one originally devised in , consists of a large central cast-iron cylinder over which passes a thick endless blanket providing resilient support for the fabric. Backing fabrics, called back grays, are placed between the blanket and the fabric to prevent undue staining of the blanket.

Although formerly made of cotton fabric, most modern back grays are continuous belts of nylon. The blanket and back gray are appropriately tensioned so that the fabric moves through the machine as the central cylinder rotates. Engraved printing rollers, one for each color, press against the fabric, and the central cylinder. The pattern on the roller is etched on the surface of a copper shell supported on a mandrel. High-quality engraving is essential for good printing.

Each printing roller is provided with a rotating color-furnishing roller, partially immersed in a trough of printing paste. Finely ground blades doctor blades remove the excess color paste from the unengraved areas of these rollers, and each also has a lint blade.

The printed fabric passes from the main cylinder and through a drying and steaming chamber to fix the color. Although this machine prints only one side of the fabric, the Duplex roller machine, essentially a combination of two roller machines, prints both sides. Modern printing machines are smooth-running precision machines fitted with carefully designed roller bearings and hydraulic or pneumatic mechanisms to ensure uniform pressure and flexibility.

The pressure is regulated from an instrument panel, and each roller is controlled independently. Automatic registration is effected by electromagnetic push-button control, and modern electric motors provide smooth-running, variable-speed drives. Spray printing is the application of color from spray guns through stencils and has limited but occasionally profitable use. The popularity of polyester fabrics led to the development of a completely new form of printing: heat transfer printing, which prints the pattern on paper with carefully selected dyes.

The paper is then applied to the fabric by passing the two together through a type of hot calendar, and the pattern is transferred from one to the other. This method opens up new possibilities, such as the production of halftone effects. In all textile printing, nature and, particularly, the viscosity of the print paste is important, and the thickeners employed must be compatible with all the other components. For conventional methods the thickeners are such reagents as starch, gum tragacanth, alginates, methylcellulose ethers, and sodium carboxymethyl cellulose.

Many types of dye can be applied, including direct cotton, vat, mordant, and reactive dyes, as well as pigment colors. Most dyes are fixed by steaming or aging, by a batch or continuous method, and more rapid fixation is effected by flash aging—e. After steaming, the fabric must be thoroughly washed to remove loose dye and thickener, ensuring fastness to rubbing.