Dyes which reacts with acidic groups on fibers; sometimes called cationic dyes Basic dyes are used primarily for acrylic fibers, though they can be used on some types of polyester and some types of nylon, and occasionally for protein fibers. A wide range of bright colors is available. Color fastness on acrylic is generally excellent; fastness on natural fibers is generally poor. {Rev 3.0.0r}

Cellulosic fibers that come from the stem of a plant Linen, from the stem of the flax plant, is probably the most common bast fiber used for fine textiles. Others include ramie, hemp and jute. {Rev 2.0.0a}

Leaving goods saturated with dye solution for some period of time, typically hours, and typically at"room temperature" for the dye to fix to the fiber In commercial dyeing, batching often follows padding. In art dyeing techniques, batching is often used with direct application techniques such as tie dye, painting and printing. {Rev 3.0.0r}

A reactive dye that has more than one type of reactive group in the molecule. These reactive dyes are designed to have the ability to react with the fiber in more than one way. This increases how much of the dye in the bath is actually fixed to the fiber, rather than being wasted through hydrolysis. Although the dye can react with the fiber in more than one way, the reaction does not happen as easily as with the popular MX family, so the temperature used is typically around 60°C (140°F). These dyes may be preferred to MX dyes by industrial users because of the lower waste (less effluent treatment cost) and lower reactivity, which can mean easier process control. {Rev 2.0.0r}

A material, usually nearly colorless, that is typically used to attach a pigment to fabric Binders are more-or-less "glue" to hold the pigment in place. Paints consist of pigments mixed with binders. Many binders used in textile paints are acrylic polymers.

Black gets included in this glossary only because, in a way, it is a "problem" color. In many dye families, such as reactive dyes, there is no such thing as a "pure" black dye: blacks are made by using mixtures of other colors, often starting with a large proportion of a navy blue. To achieve a good dark black typically takes much more dye than for strong shades of other colors. It is not unusual to see recommendations between 6% and 10% owg. Because blacks are usually mixtures, discharge of black may yield unexpected results. Coppery colors are not uncommon. Reducing agent discharge may produce different results from oxidizing agent discharge. Some dye vendors offer black dyes that are specially formulated to discharge to almost white. Sulfur dyes are extensively used commercially for black cotton fabrics. {Rev 2.0.0r}

"longwave" ultraviolet light; wavelength typically about 365 nanometers Black light lamps made with a fluorescent tube that appears very dark purple can often be found reasonably inexpensively at novelty shops and even at stationery stores where they are sold for detecting counterfeit money. Black light lamps are useful for detecting optical brighteners in fabrics. {Rev 3.0.0r}

A solution of sodium hypochlorite in water; an oxidizing bleach Household chlorine bleach, about 5% sodium hypochlorite, suitably diluted, can be used for whitening cellulose fabrics prior to dyeing. It is also used in some art discharge processes (this author knows of no industrial use of chlorine bleach for discharge). Chlorine bleach can damage cellulose fibers, but is safe if strength and exposure time are limited, and the bath pH is maintained at about 9.5. Goods must be thoroughly scoured prior to chlorine bleaching, otherwise impurities may form compounds that are yellow and very difficult to remove. An antichlor should usually be used to assure complete neutralization of the bleach. DO NOT mix chlorine bleach with acids -chlorine gas will be liberated. Do not use chlorine bleach on wool, silk or spandex - fiber damage will result. Industrially, chlorine dioxide is sometimes used for bleaching. Although it is less likely to cause cellulose fiber damage, it is not suitable for home use because the bath is very corrosive to metals, and there is significant risk of chlorine gas production. In general, chlorine bleaching is obsolescent for industrial textile preparation. {Rev 3.0.0r}

A bleach based on an oxidizing agent, such as hydrogen peroxide or sodium hypochlorite. Most general-purpose household bleaches belong to this class.

A bleach based on hydrogen peroxide or a chemical derivative of hydrogen peroxide Oxygen bleaches typically are less damaging to fibers than chlorine-based bleaches. Most "color safe" bleaches are of this type. Dry powder bleaches and detergents of this class usually use a "peroxygen" compound such as sodium perborate , sodium percarbonate or potassium monopersulfate.

A bleach or decolorizing compound that is based on a reducing agent. This type of bleach is typically used for discharge or stripping. Usually they are not harmful to fibers, thoughsome processes require temperature or pH that may damage fibers. Wool is often bleached with reducing bleaches.Thiourea dioxide and sodium hydrosulfite are two compounds that find use as reductive bleaches. - Rev 3.0.0r

In general, to heat or maintain a solution at the temperature where the vapor pressure of a liquid equals atmospheric pressure, that is, its boiling point; in dyeing sometime called "atmospheric boil" to distinguish from boiling under pressure. In dyeing, unless otherwise specified, it is assumed that the solvent is water, so boiling occurs at 100°C(212°F), at sea level. At higher elevations the boiling point will be reduced. Dissolved solids (solutes) can increase the boiling point, but it is rare for dyeing or preparation liquors to contain enough solute to raise the boiling point by more than a few degrees. In order to get aqueous (water) solutions to a temperature higher than the normal boiling point, the pressure must be increased, using a closed vessel - a "pressure cooker". Closed pressure vessels are used extensively in dyeing of polyester with disperse dyes, and may be used in preparation processes such as scouring to7hasten the process. Operating temperature of around 130°C is quite common. - Rev 3.0.0a

See hydrogen bond, ionic bond, covalent bond; also see van der Waals forces. In general, of these bond types, hydrogen bonds are weakest, ionic bonds intermediate in strength, and covalent bonds are strongest. Van der Waals forces are something of a special case.

See dextrin

In chemistry, a compound that resists change in pH when moderate amounts of acid or base are added to a solution of it. Buffers help to keep the pH of a dye bath from changing significantly as the process progresses. Sodium acetate is one such buffer.

See etchant

Albright & Wilson trade name for sodium hexametaphosphate Calgon T from Albright & Wilson is sodium hexametaphosphate without additives. Water softener products sold at retail under the Calgon name usually contain additives such as fragrances and surfactants. - Rev 3.0.0r

Treatment of wool with acid and heat to remove plant materials. Preparation of wool sometimes include treatment of the wool with sulfuric acid, followed by partial drying and heating. The hot acid will degrade or ‘carbonize’ bits of plant matter in the wool, so that it is easily removed by subsequent mechanical methods. - Rev 3.0.0a

A modified starch (starch ether)Carboxymethyl starch has had some of the hydroxyl groups replaced with carboxymethyl groups, which improves solubility and the stability of pastes. This compound is suitable as a thickener for printing of disperse dyes and vat dyes. It also has some resistance to chlorine bleach, and may be used for thickening bleach for use in discharge techniques. Monagum is one trade name. - Rev 3.0.0a

With respect to disperse dyes, a chemical that aids dyeing at moderate temperature. In order to dye polyester with disperse dye in a reasonable time at the boil, it is necessary to use a carrier. Exactly how the carrier works seems to be a matter of some controversy, but it may work by swelling the fibers so that the dye can penetrate. The carrier will eventually evaporate from the fiber after dyeing is complete. Carriers are obsolescent in industrial process, partly because they are quite noxious and environmentally undesirable. Be sure to read and understand the MSDS for any carrier chemical you contemplate using. - Rev 2.0.0a

A chemical that speeds up a reaction without itself being consumed in the reaction. Catalysts are not common in dyeing, but are used in fabric preparation and finishing.

A positively charged ion. Many chemicals used in textile processing are described as cationic, meaning that when the compound ionizes in solution, it is the positively charged ion that is "functional". Many surfactants are cationic, as are many chemicals used as fabric finishes. (Also see anion.

See basic dye

Referring to a chemical that will "burn" skin; may be acid or alkali; in dyeing, caustic is also often used as an abbreviation for caustic soda (sodium hydroxide

Sodium hydroxide

An enzyme that catalyzes the breakdown of cellulose. Cellulase enzymes are used for de-pilling and defibrillation of cotton fabrics. They can also be used to permanently soften cotton fabrics, as an aid in or replacement for stone washing of denim, and in methods for"peaching" cotton fabrics. These enzymes are usually very difficult for the textile artist to obtain.

A polymer of a very large numbers of units, each of the general formula C H O 6 10 5Cellulose is a structural polysaccharide made by plants. Essentially, units very similar to glucose are assembled into huge molecules that form strong fibers. Among cellulose textiles are cotton, linen, ramie, jute and hemp. Rayon is a man-made cellulose fiber (actually regenerated cellulose - natural cellulose is the starting material). Each unit of the cellulose molecule has a number of hydroxyl (–OH) groups. These are the binding sites for reactive dyes.

Cellulose in which most of the hydroxyl (-OH) groups of cellulose have been replaced with acetyl (-OOCCH ) groups 3Cellulose acetate is usually dyed with disperse dyes at a temperature of around 80°C to 90°C. It is quite easily damaged in alkaline conditions and loses its desirable lustre if boiled. - Rev 3.0.0a

A temperature scale which places the freezing point of water at zero degrees, and the boiling point of water 100 degrees; formerly called centigrade. To convert to Fahrenheit: °F = (°C x 9/5) + 32To convert from Fahrenheit: °C = (°F - 32) x 5/9

See sequestering agent - Rev 3.0.0a