Importance of Color in Textile

The Importance of Color We Wear
Colors have a demonstrable psychological effect. So, our automatic reaction to colors is so strong. The sight of red means warning and white mean simplicity and respective of title. Military uniforms are intentionally colored to give statement and impose authority. Colors are used in many ways to assert recognition because they are fairly easy to read and understand.

Not all colors are good for any individual because of different skin color tones. The best way to find your personal skin color is to ask a friend who can be objective about your situation. Your friend can “drape” you with big swatches of different colors. The most flattering colors are sometimes the good colors for you. Often, you’ll be surprised that the color you like best is also the best color for you.

Once you know your personal color, practice by understanding their association with seasonable colors (spring, summer, winter, and fall). They can give a set of guidelines for flattering effect of your clothes. You’ll also be able to forecast colors for the next season.

List of Popular Colors and How Our Emotions Respond

BLACK	Severe, mysterious, sophisticated, glum, depressing, deadly
BLUE	Serene, calming, cool, quiet, sleepy, sad
BROWN	Warm, earthy, drab
GRAY	Well-informed, subtle, dignified, gloomy, cold
GREEN	Fresh, successful, loving, greedy, restful, calm.
HOT COLORS	(ie. pink) Wild, sensual, daring, flashy, vulgar
ORANGE	Happy, cheerful, new, motivated, garish, warm.
PINK	Soft, innocent, delicate, feminine, delicious
RED	Alert, warning, sexual, aggressive, energetic, cheerful, angry, vital, exciting
VIOLET	Royal, rich, stately, passionate, subtle but sexy, impressive, alone
WHITE	Clean, pure, young, safe, simple
YELLOW	Sunny, bright, hopeful, optimistic, joyful, clear, positive, alive

It is important to understand that color has three properties. These properties do not affect the meaning of colors unless their appearances have actually changed (ie hot violet, frosted brown)

Color Guidelines According to Seasons

Summer	Think clear, contrast and bold colors.
Fall	Think soft, cool, slightly grayed colors.
Spring	Think bright, fresh and lively colors.
Winter	Think deep, dark and muted colors.

Comparison Between Reactive Dye and Azoics Dye | Comparison Between VatDye and Azoic Dye

Vat Dye vs Azoics Dye 

1. Azoics are economical than Vat dyes.
2. Bright reds , oranges and deep maroon shades are possible in Azoics.
3. Limited Shade range in Azoics.
4. Bright pinks , bright Blue . olive green , green and blacks are not possible in Naphthols.
5. No fear of photodegradation in Naphthols.

6. Rubbing na dlight fastness is inferior in Naphthol dyeing.

7. More Suitable for Tie-dye and space dyeing.

Reactive Dye Vs Azoics Dye
1. Limited shade range in Azoics.

2. Dyeing method is very complex with too many variables in naphtholation , diazotisation and developing baths.
3. Color fastness to Chlorine is better in naphthols.
4. Rubbing and Light fastness are inferior in azoics.
5. Dark and bright reds , maroons and ornages can be produced in azoics which are difficult in reactives.
6. Azoics are suitable for Tie-dye and space dyeing.

Introduction of Naphthol Dyes | Dyeing Procedure of Naphthol Dyes |Roles of Different Chemicals in Naphthol Dyeing

Naphthol dyes are insoluble azo dyestuffs that are produced on the fiber by applying a Naphthol to the fiber and then combining it with a diazotized base or salt at a low temperature to produce an insoluble dye molecule within the fiber. Naphthol dyes are classified as fast dyes, usually slightly cheaper than Vat dyeings; the methods of application are complex and the range of colors limited.

Azoic combinations are still the only class of dye that can produce very deep orange, red, scarlet and Bordeaux shades of excellent light and washing fastness.The pigments produced have bright colors, and include navies and blacks, but there are no greens or bright blues. Crocking fastness varies with shades but washing fastness is equal to Vat dyeings, generally with less light fastness than the Vats.

Naphthols :

The Naphthols are phenols, soluble in alkaline solution and substantive to cotton, particularly in the presence of salt. The anilides of BON acid(beta-oxynaphthoic acid or BON acid) are soluble in dilute NaOH solution and form the corresponding naphtholate ion. These relatively small molecules are of only low to moderate substantivity for cotton, but they diffuse rapidly into the fibres. In general, the higher the substantivity the better the rubbing fastness as less azo pigment forms on the fibre surfaces. The naphtholate ions are always coplanar and preferably have elongated molecular structures. They behave essentially as colorless, low molecular weight direct dyes. The substantivity increases with increase in the molecular size of the naphtholate ion, but the diffusion rate in the fibres and solubility in dilute aqueous alkali decrease. Addition of salt promotes better exhaustion of the bath, more being needed for Naphtols of lower substantivity.

Bases:

These are available as the free amine base or as amine salts such as the hydrochloride.Many of the amines used are simple substituted aniline derivatives with no ionic substituents. The so-called Fast Colour Bases require diazotisation. This usually involves reaction of the primary aromatic amine in acidic solution or dispersion with sodium nitrite, at or below room temperature. Successful diazotisation requires careful weighing of all the chemicals and regard for the supplier’s recommendations. Diazotisation of a primary aromatic amine is often difficult and solutions of diazonium ions are inherently unstable. They undergo decomposition even at low temperature and particularly on exposure to light. Storing prepared diazonium ion solutions is not usually possible.

General Dyeing Procedure of Naphthol Dyes
The application of the naphthols is consists of following steps,

1.Dissolution of the naphthol component.
2.Exhaustion of the naphthol dolution onto the substrate or absorption of the naphtholate ion by the cotton;
3.Removal of excess naphthol from the material by squeezing, partial hydroextraction or brine washing.
4.Diazotization of the base component.
5.Development or treatment with the diazonium ion solution to bring about coupling.
6. Neutralisation ,Soaping at the boil to remove superficial pigment, followed by rinsing and drying.

The process can be carried out in almost any type of dyeing machine determined by the form of the goods.

Dyeing Methods

Precautions in Naphthol Dyeing

1.The alkalinity of the naphthol bath shall not drop below the prescribed limit , otherwise the naphthol may presipitate.

2.Formaldehyde shall not be used when working at more than 50 Deg C or when the material is to be dried after naphthol application.

3.Material shall be protected from water spotting,steam,acid and chlorine fumes , and exposure to sunlight after naphthol application.

4.Use of excess salt in naphthol bath may result into precipitation of the bath.

5.The temperature is very important in base preparation stem , otherwise diazotization may not take place.

6.Sodium acetate must be added to the developing bath just before the use , otherwise base will become unstable due to fall in concentration of HCl.

7.Hydroextraction time must not be too long , which may result into light spots after development.

8.Material shall be rinsed without delay after developing , otherwise the mechanically held excess developing liquor will undergo some decomposition and cause deposition of dark colored spots , which will be difficult to remove.

9.It is important to use sufficient amount of alkali binding agents , otherwise it will result into presipitation of developing bath.

Stripping Process in Naphthol Dyeing
-Treat the dyed material with Non ionic detergent and 3-5 gpl caustic soda at boil for 15 min. cool to 85 degC
-Add 3-5% sod. hydrosulphite for 30-45 min at 85 deg.
-Rinse hot and cold
-Bleach with 1-2 Gpl Available chlorine for 20 min.
-Antichlore and neutralise.
-Soap at Boil for 15-20 min.
-Cold rinse.

Roles of Different Chemicals in Naphthol Dyeing

T.R. Oil :

Wetting agents for naphthol pasting and dissolution and penetrating agent in fiber in naphthol application.

Caustic Soda:

For solubilising of naphthols and keeping proper alkalinity of naphthol bath.

Formaldehyde:

Protective agent of naphthol impreganated material from effect of air.

Salt:

Electrolyte for exhaustion of naphthol during naphtholation and to prevent the desorption of naphthol in the bath during brine rinsing and development phase.

HCl Acid:

Dissolution of base and to produce nitrous acid in diazotization phase.

Sodium Nitrite:

Producing nitrous acid in diazotization process.

Sodium Acetate:

For neutralization of excess HCl in developing bath.

Acetic Acid:

As an alkali binding agent in developing bath.

Non Ionic Dispersing Agent:

To keep the azoic pigments in fine dispersion phase , which are formed by the coupling of free naphthol in developing bath. Also helps in better color fastness during soaping operation.

Fastness Properties on Cotton
Correctly prepared dyeings with azoic combinations on cotton have fastness properties often comparable, or only slightly inferior, to those produced using quinone vat dyes. They complement the vat dyes because of the wide range of orange, red and Bordeaux shades that they provide.

The fastness to washing of azoic combination dyeings on cotton is usually very good to excellent but only after careful elimination of particles of azo pigment loosely adhering to exposed fiber surfaces. Intermediate drying or rinsing of fabric containing the Naphtol, and the soaping of the final dyeing, are key processes ensuring optimum fastness. The same argument applies to rubbing fastness. Deep dyeing that have not been well soaped easily transfer color onto adjacent white fabric, even under conditions of gentle rubbing.

There are two other problems associated with the fastness properties of azoic combinations on cotton. In pale shades, the dyeings often have much reduced light fastness, particularly under humid conditions. Some sensitive azoic combinations also give dyeings of only fair resistance to chlorine and peroxide bleaching.

Introduction of Reactive Dye | History of Rective Dye | Uses ofReactive Dye

Dye that reacts with the textile fiber to produce both a hydroxyl and an oxygen linkage, the chlorine combining with the hydroxyl to form a strong ether linkage; gives fast, brilliant colors.

History of Reactive Dyes
Reactive dyes first appeared commercially in 1956, after their invention in 1954 by Rattee and Stephens at the Imperial Chemical Industries Dyestuffs Division site in Blackley, Manchester, United Kingdom.

Reactive dyeing is now the most important method for the coloration of cellulosic fibres. Reactive dyes can also be applied on wool and nylon; in the latter case they are applied under weakly acidic conditions. Reactive dyes have a low utilization degree compared to other types of dyestuff, since the functional group also bonds to water, creating hydrolysis of Reactive Dye.

Reactive dyes have good fastness properties owing to the bonding that occurs during dyeing. Cotton is made of cellulose molecules which react with the dye .During reactive dyeing the H atom in the cellolose molecule combines with the cl atom in the dyeing process and results in a bond. Trifunctional dyestuffs also exist.

Uses of Reactive Dye

Reactive dyes are used to dye cellulosic fibres. The dyes contain a reactive group, either a haloheterocycle or an activated double bond, that, when applied to a fibre in an alkaline dye bath, forms a chemical bond with an hydroxyl group on the cellulosic fibre.

Define Jute Fiber | Chemical Composition of Jute Fiber | Defects in Jute

A bast fiber used for sacking, burlap, and twine as a backing material for tufted carpets. Jute is one of the most affordable natural fibres and is second only to cotton in amount produced and variety of uses of vegetable fibres. Jute fibres are composed primarily of the plant materials cellulose (major component of plant fibre) and lignin (major components of wood fibre).

Chemical Composition of Jute Fiber

• Cellulose → 65.2%
• Hemi-cellulose → 22.2%
• Lignin → 12.5%
• Water Soluble matter → 1.5%
• Fat and Wax → 0.6%

Defects in Jute

Rooty Jute: in these jute the lower parts of jute fires contain barks.

Specky jute: this defects occur because of insufficient washing which causes the outer barks to adhere in some places

Croppy Jute: this is a defect where the top end of the fibre become rough and hard. It is usually caused by careless steeping.

Knotty jute: the jute fibres contain knots in places and it is caused by insect bite or punctures.

Dezed or Dead fibres: due to over retting in moist condition, the fibre becomes dull, lose strength and becomes inferior for spinning.

Runners: this is a defect where long and hard barky ribbon of fibres remains in jute fibre.

Hunka: defects caused by non-removal of dried up base and hard bark from the fibres.

Mossy jute: fibres from short plants that cannot be properly stripped and cleaned contain broken piece of jute sticks etc.

Flabby or Fluffy jute: due to careless stripping, fibre loses firmness and becomes flabby and hairy

Heart damage: These defects occur when jute fibre contains excess moisture when baled. The centre of the bale becomes badly tendered and in some cases fibres are reduced to powder.

Features of Jute Fiber | Properties of Jute Fiber | Characteristics ofJute Fiber | Uses of Jute Fiber

Jute Fiber

Jute is a bast fiber used for sacking, burlap, and twine as a backing material for tufted carpets. It is a long, soft, shiny fiber that can be spun into coarse, strong threads. It is one of the cheapest natural fibers, and is second only to cotton in amount produced and variety of uses. Jute fibers are composed primarily of the plant materials cellulose, lignin, and pectin. Both the fiber and the plant from which it comes are commonly called jute. It belongs to the genus Corchorus in the basswood family, Tiliaceae. 

Properties of Jute Fiber:

1. Jute fibre is 100% bio-degradable and recyclable and thus environmentally friendly.
2. Jute is a natural fibre with golden and silky shine and hence called The Golden Fibre.
3. Jute is the cheapest vegetable fibre procured from the bast or skin of the plant’s stem.
4. It is the second most important vegetable fibre after cotton, in terms of usage, global consumption, production, and availability.
5. It has high tensile strength, low extensibility, and ensures better breathability of fabrics. Therefore, jute is very suitable in agricultural commodity bulk packaging.
6. It helps to make best quality industrial yarn, fabric, net, and sacks. It is one of the most versatile natural fibres that has been used in raw materials for packaging, textiles, non-textile, construction, and agricultural sectors. Bulking of yarn results in a reduced breaking tenacity and an increased breaking extensibility when blended as a ternary blend.
7. Unlike the fiber known as hemp, jute is not a form of (Cannabis). Therefore it can be much more easily distinguished from forms of Cannabis that produce a narcotic
8. Jute is one of the most versatile natural fibres that has been used in raw materials for packaging, textiles, non-textile, and agricultural sectors.
9. Jute stem has very high volume of cellulose that can be procured within 4-6 months, and hence it also can save the forest and meet cellulose and wood requirement of the world.
10. The best varieties of Jute are Bangla Tosha - Corchorus olitorius (Golden shine) and Bangla White - Corchorus capsularis (Whitish Shine), and Mesta or Kenaf (Hibiscus cannabinus) is another species with fibre similar to Jute with medium quality.
11. Raw Jute and Jute goods are interpreted as Burlap, Industrial Hemp, and Kenaf in some parts of the world.

The best source of Jute in the world is the Bengal Delta Plain, which is occupied by Bangladesh and India.

Uses of Jute Fiber
Jute is the second most important vegetable fibre after cotton; not only for cultivation, but also for various uses.

• Jute is used chiefly to make cloth for wrapping bales of raw cotton, and to make sacks and coarse cloth.
• The fibres are also woven into curtains, chair coverings, carpets, area rugs, hessian cloth, and backing for linoleum. 
• While jute is being replaced by synthetic materials in many of these uses, some uses take advantage of jute’s biodegradable nature, where synthetics would be unsuitable.
• Jute butts, the coarse ends of the plants, are used to make inexpensive cloth.
• Traditionally jute was used in traditional textile machineries as textile fibres having cellulose (vegetable fibre content) and lignin (wood fibre content). But, the major breakthrough came when the automobile, pulp and paper, and the furniture and bedding industries started to use jute and its allied fibres with their non-woven and composite technology to manufacture nonwovens, technical textiles, and composites.
• Jute can be used to create a number of fabrics such as Hessian cloth, sacking, scrim, carpet backing cloth (CBC), and canvas.
• Hessian, lighter than sacking, is used for bags, wrappers, wall-coverings, upholstery, and home furnishings.
• Sacking, a fabric made of heavy jute fibres, has its use in the name.
• Diversified jute products are becoming more and more valuable to the consumer today. Among these are espadrilles, floor coverings, home textiles, high performance technical textiles, Geotextiles, composites, and more.
• Jute is also used in the making of ghillie suits which are used as camouflage and resemble grasses or brush

Thus, jute is the most environment-friendly fibre starting from the seed to expired fibre, as the expired fibres can be recycled more than once.

Another diversified jute product is Geotextiles, which made this agricultural commodity more popular in the agricultural sector. It is a lightly woven fabric made from natural fibres that is used for soil erosion control, seed protection, weed control, and many other agricultural and landscaping uses. The Geotextiles can be used more than a year and the bio-degradable jute Geotextile left to rot on the ground keeps the ground cool and is able to make the land more fertile.

What is Spinning? | Types of Spinning | Dry Spinning | Wet Spinning |Melt Spinning | Gel Spinning

Spinning is manufacturing process for creating polymer fibers. It is a specialized form of extrusion that uses a spinneret to form multiple continuous filaments. There are four types of spinning: wet, dry, melt, and gel spinning.

First, the polymer being spun must be converted into a fluid state. If the polymer is a thermoplastic then it is just melted, if not then it may be dissolved in a solvent or chemically treated to form soluble or thermoplastic derivatives. The fluid polymer is then forced through the spinneret, where the polymer cools to a rubbery state, and then a solidified state.

Types of Spinning
There are different types of spinning. Such as:

1.Dry Spinning
2.Wet Spinning
3.Melt Spinning
4.Gel Spinning

Now they are descrived below:

1.Dry Spinning
Dry spinning is also used for fiber-forming substances in solution. However, instead of precipitating the polymer by dilution or chemical reaction, solidification is achieved by evaporating the solvent in a stream of air or inert gas.

The filaments do not come in contact with a precipitating liquid, eliminating the need for drying and easing solvent recovery. This process may be used for the production of acetate, triacetate, acrylic, modacrylic, PBI, spandex, and vinyon.

2.Wet Spinning
Wet spinning is the oldest process. It is used for fiber-forming substances that have been dissolved in a solvent. The spinnerets are submerged in a chemical bath and as the filaments emerge they precipitate from solution and solidify.

Because the solution is extruded directly into the precipitating liquid, this process for making fibers is called wet spinning. Acrylic, rayon, aramid, modacrylic and spandex can be produced by this process.

3.Melt Spinning
In melt spinning, the fiber-forming substance is melted for extrusion through the spinneret and then directly solidified by cooling. Nylon, olefin, polyester, saran and sulfar are produced in this manner.

Melt spun fibers can be extruded from the spinneret in different cross-sectional shapes (round, trilobal, pentagonal, octagonal, and others). Trilobal-shaped fibers reflect more light and give an attractive sparkle to textiles.

Pentagonal-shaped and hollow fibers, when used in carpet, show less soil and dirt. Octagonal-shaped fibers offer glitter-free effects. Hollow fibers trap air, creating insulation and provide loft characteristics equal to, or better than, down.

4.Gel Spinning
Gel spinning is a special process used to obtain high strength or other special fiber properties. The polymer is not in a true liquid state during extrusion. Not completely separated, as they would be in a true solution, the polymer chains are bound together at various points in liquid crystal form.

This produces strong inter-chain forces in the resulting filaments that can significantly increase the tensile strength of the fibers. In addition, the liquid crystals are aligned along the fiber axis by the shear forces during extrusion. The filaments emerge with an unusually high degree of orientation relative to each other, further enhancing strength. The process can also be described as dry-wet spinning, since the filaments first pass through air and then are cooled further in a liquid bath. Some high-strength polyethylene and aramid fibers are produced by gel spinning.