PRESENTATION ON ECO-FRINDLY DYEING OF SILK

Natural Dyes in Ancient Egypt

Ancient Egyptians loved red

Old Kingdom tombs in the Nile Valley were filled with red linens

King Tut was buried with safflower seeds

Rubia tinctorum

Natural Dyes in Ancient India

India was famous for their blue textiles, which were highly valued (said to rival Phoenician purple garments)

Reasons for success: India was settled early Large labor force Blessed by natural

surroundingsWild cottonNatural metal

mordantsIndigofera tinctoria

Categorizing Natural Dyes

Methods: Maceration (chopping) Ebullition (boiling) Fermentation

Types: Substantive Vat (need a second

step) Ex: Indigo

Adjective (need the fibers to be treated with mordants) Ex: Madder &

LogwoodLogwood TreeNative to Caribbean

William Henry Perkin

•Accidentally produced and discovered mauve, the first synthetic dye

•More synthetic dyes were created after his discovery

•Natural dye use steadily declined

1856

Classification

Plant Dyes Mineral Dyes Animal dyes

Natural dyes

There are three primary sources for natural dyes—plants, animals and minerals.

natural dyes can be broken down into two categories— substantive and adjective.

Substantive dyes, also referred to as direct dyes, become chemically fixed to the fiber without the aid of any other chemicals or additives.

Adjective dyes, also referred to as mordant dyes, require an added substance known as a mordant to make the dyes colorfast.

Category of vegetable dye Natural dyes fall into the following

categories: Leaves and stems Twigs and pruning's Flower heads Barks Roots Outer skins, hulls and husks Heartwoods and wood shavings Berries and seeds Lichens

Preparation of Vegetable Dye

Collecting the parts of the plants (leaves, barks, stems, flowers, fruits, seeds).

Testing of raw material for assessment of colour contents,Dyeing.

Size reduction by pulverizing Separation of different size by vibrating screen, Extraction of colouring component Phase separation Fine filtering Drying of colouring matter (Dyes) in spray dryer, Packing:A) Liquid formB) Paste formC) Power form

Natural Indigo

Blue Dyestuff for Textile. This is one of the most ancient

Natural Dyes used by Man in textiles.

Indigo is about 2-3 feet long plant, the extract form of dye is supplied

in powder form. This give deep blue color on wool,

silk, cotton etc. This is the only Natural Dye, which

falls under Vat category of dyes.

Indigo is a blue dye derived from the leaves of a leguminous plant.

indigo has some of the best fastness properties—and in fact it is the only natural blue dye of permanence.

Indigo is insoluble in water. During the dyeing process it is made soluble.

Once the fabric is dipped into the indigo dye bath, dye is deposited into the fibers. When the fabric is removed the air oxidizes the indigo, returning it to its original natural insoluble state—permanently locking it in to the fiber.

Properties

Madder

Madder is considered the “Queen of the Reds.” It is one of the oldest and most frequently used natural dyes. 

It was the main source of red dye in large part because it could be easily cultivated

Madder is a member of the coffee family.

It is an herbaceous plant with an extensive fibrous root system in which the concentrated red colorant is stored.

The root is beaten into a paste. Depending on the mordant it can produce deep orange-red to deep red colors.

Madder can be used to dye cotton, wool and silk.

Turmeric Turmeric, a popular yellow spice, is a natural 

direct dye . It fades in the light The chemical that gives turmeric its colour is

called curcumin mix several tablespoons of turmeric into a

couple of gallons of water in your largest cooking pot, boil it for half an hour or an hour, strain the water through a coffee filter to remove particles of turmeric, add your silk to the resulting colour water,

gradually bring the temperature of the dye bath up to 180°F, stirring constantly,

while using a thermometer to make sure that you do not overheat the silk.

Hold the temperature for half an hour or longer, then let the silk cool in the dye bath.

wash thoroughly in cool water, until no more dye comes out of the fabric. 

Fustic

Fustic dye comes from a tree in the mulberry family and therefore is often referred to as mulberry.

The dye is obtained from the hardwood of the tree.

fustic was considered the best source for yielding a yellow color.

Various mordants can be used. Potassium bichromate is the most popular

mordant. The dye that is derived from fustic is colorfast

but a bit dull. Fustic can be used to dye cotton, wool and

silk.

Eclipta

Eclipta is a common weed which produces fluorescent green shades on silk.

Cotton can also be dyed with Eclipta. Variety of green shades can be

produced. Eclipta dye exhibits relatively good

fastness to rubbing, light and washing, making it well suited for cotton

Himalayan Rubrub

Common Name is Dolu, Himalayan Rubrub

 Yellow dyestuff for Textiles. Dolu is about 1.5 to 3 meter

high stout herb. It is grown at an altitude of

about 3000 to 5000 meters high.

The color is extracted from its wood.

Mordent- alum and chrome and ferrous sulfate

The dyeing was performed for 30 and 45 minutes. The best dye extraction medium was the acidic medium

H. patens dye produced various shades on silk yarns by using the different mordants and mordanting methods.

Logwood

The logwood tree grows naturally in Central America, Mexico and northern parts of South America.

Depending on the mordant used a variety of violets, silvers, greys and black shades can be produced.

The most important application of logwood was dyeing fabric black.

Brazilwood Brazilwood refers to a dye

obtained from several different trees and shrubs from a wide variety of origins.

Clear Christmas reds to deep garnet red can be obtained with an alum mordant.

A variety of pinks are produced when tin is used.

Orchil

Orchil is a very old dye that was initially obtained from several different varieties of the lichens found on coastal rocks and cliffs along the Mediterranean coast.

Orchil is one of the few substantive dyes which produce a wide range of purple shades.

Mordants can be used to yield other colors.

Mordanting with tin produces a dull colorfast red shade.

Woad

Woad was used for all shades of blue.

It is the name of a plant with yellow flowers which grows up to 1.5 meters tall. It grows wild around the Mediterranean sea

The dye comes from the leaves which were crushed and boiled in urine at a constant temperature for 30 hours.

Weld  The upper part of the plant, including

the leaves and seeds, was used to produce a variety of bright yellow hues.

The color produced is dependent on the fiber and mordant.

A chrome mordant used with either wool or cotton produces an olive-yellow hue.

A titanium mordant used with silk produces bright yellow.

Weld was used for yellow dyes. The plant is cut down, dried and

chopped up. It is placed into boiling water and simmers for an hour at 80ºC to 100ºC.

Mangosteen

Extracted dye from the dried fruit hulls of mangosteen was used as a natural dye for the dyeing of cotton and silk yarn.

The optimal conditions for dye extraction were to extract the dried fruit hulls of mangosteen at 80°C for 1 hour with citric acid solution in a 1:4 ratio of mangosteen powder to solvent.

Good fastness properties were also obtained using a post-mordanted silk with calcium hydroxide.

Kamala

 Orange yellow or golden yellow dyestuff for Textiles.

Kamala is taken from fruit of the plant Mallotus. This is an evergreen tree growing upto 25 meter high.

It imparts beautiful color on wool and silk.

On cotton Kamala does not give as deep color as on wool or silk.  

Marigold

Selection of dye:- 60 gm freshly collected Mari gold

petals were dried in shade and powdered.

Selection of mordants:- Natural mordant - Dried juice of

Aloe veraSelection of fibers:- Silk 20 gms of the dried Marigold

flower powder was extracted with 100 ml of distilled water and heated for 1 hour at 1000C.

The extract was filtered to obtain a yellowish brown dye

Major Animal Dyes

Cochineal (red) - from bodies of cochineal insects.

Tyrian Purple (purple or crimson) - from the bodies of some types of marine snails.

Sepia (brown) - from secretions of several types of cuttlefish.

Lac-from insects

Tyrian purple

Tyrian purple is a purple dye made in the ancient Phoenician city of Tyre from a secretion of Spiny Dye-Murex (Murex brandaris), a marine snail.

A similar dye, "Hyacinth Purple" was made from the related Banded Dye-Murex Murex trunculus.

The fast, non-fading dye The main chemical constituent of the

Tyrian dye was discovered by Paul Friedländer in 1909 to be 6,6'-dibromoindigo

Conchineal

In 1518, the Spaniards discovered the indigenous people of Mexico using cochineal “seeds” as a dye.

The bug thrived on the nopal or opunti cactus. As the insect matured the wingless dye-yielding

females were swept off the leaves to which they were attached and plunged into hot water.

The dead insects were then laid in the sun or placed in a bag and put in the oven to dry. After the insects were dried they were ground into a fine powder.

It takes 70,000 dried insects to produce a pound of dye. 

Dark burgundy to bright red to soft lilac and pink can be obtained from cochineal.

A deep crimson dye is extracted from the female cochineal insects.

Cochineal extract's natural carminic-acid content is usually 19–22%.

There are two principal forms of cochineal dye: cochineal extract is a colouring made from the raw dried and pulverised bodies of insects, and carmine is a more purified colouring made from the cochineal.

To prepare carmine, the powdered insect bodies are boiled in ammonia or asodium carbonate solution, the insoluble matter is removed by filtering, and alum is added to the clear salt solution of carminic acid to precipitate the red aluminium salt.

Lac

The female insects attach themselves to the twigs of trees where they reproduce rapidly, exuding a thick gummy red resinous substance.

It was the dye used to produce crimson for Persian carpets.

Mordants

Few natural dyes are colour-fast with fibres. Mordants are substances which are used to fix a dye to the fibres.

They also improve the take-up quality of the fabric and help improve colour and light-fastness.

The term is derived from the Latin mordere, to bite.

Mordants are prepared in solution, often with the addition of an ‘assistant’ which improves the fixing of the mordant to the yarn or fibre.

Types of Mordents

Metallic mordants Metal salts of aluminium, chromium, iron,

copper and tin are used.Tannins Myrobalan and Sumach are the

commonly used tannins employed as mordants in the dyeing of textile fibres.

Oil mordants Oil mordants are used mainly in the

dyeing of turkey red color from maddar. The main function of the oil mordant is to form a complex with alum used as maddar. The sulfonated oils, which possess better metal binding capacity than the natural oils due to the presence of sulfonic acid group, bind to metal ions forming a complex with the dye to give superior fastness and hue.

Mineral mordent

Alum: (Aluminum Potassium Sulfate)This is the most widely used mordant. Be careful not to use too much with wool

Copper: (Copper Sulfate)This mordant is used to bring out the greens in dyes. It will also darken the dye colors, similar to using tin, but is less harsh.

Chrome: (Potassium Dichromate)Chrome brightens dye colors and is more commonly used with wool and silk

Chrome should not be inhaled and gloves should be worn while working with chrome. It is treated as hazardous waste.

Iron: (Ferrous Sulfate)Dulls and darkens dye colours. Using too much will make the fiber brittle.

Glaubersalt: (Sodium Sulfate)Used in natural dyes to level out the bath. Also use in chemical dye.

Tara Powder: (Caesalpinia Spinosa)Tara Powder is a natural tannin product. It is needed for darker colors on cotton, linen and hemp.

Tartaric Acid: A must for cochineal. This mordant will expand the cochineal colors.

Tin: (Stannous Chloride)Tin will give extra bright colors to reds, oranges and yellows on protein fibers. Using too much will make wool and silk brittle. To avoid this you can add a pinch of tin at the end of the dying time with fiber that was premordanted with alum. Tin is not commonly used with cellulose fibers.

Calcium Carbonate: Is to be used with indigo powder for the saxon blue color. It can also be used to lower the acidity of a dyebath.

Why mordents??

Iron is used as a ‘saddener’ and is used to darken colours.

Copper sulphate also darkens but can give shades which are otherwise very difficult to obtain.

Tin brightens colours. Tannic acid, used traditionally with other

mordants, will add brilliancy. Chrome is good for obtaining yellows. Oxalic acid is good for extracting blues from

berries.

Plant as mordent -Pomegranate •  Yellow dyestuff for

Textiles.• The dye is extracted

from its fruit rind. • The color obtained

exhibit good fastness to washing rubbing and light

• At times this dye is also used as mordant and is over dyed with other Natural Dye to improve fastness of later.

Aloe vera juice

Fresh leaves of Aloe vera are used. The outer green surface was

peeled off and the linear white mass was collected.

150 gm of the collected material was crushed to a semi-solid consistency which was subjected to filtration.

Teak

Harda

Manjuphal

Catechu

Catechu, also known as cutch, was first introduced around 1800 in Germany.

It is a vegetable dye that produces a variety of brown shades on silk.

Yellow-brown is produced when alum is used; reddish-brown is produced when a chrome mordant is used.

A brownish-black can be obtained with iron and a medium brown with copper.

Bengal catechu is derived from the heartwood and pods of a leguminous tree. Bombay catechu is obtained from betel nuts from an Asian palm.

It has historically been used to dye cotton and silk.

Babool

Maddar nut

Arjun

Mordent from animal-lac

Colours used in Silk dyeing White  If a bright white was required, the silk had to

be washed twice in a soap solution of 30 pounds of soap per 100 pounds of silk. During this boiling process, indigo was added to give it extra brightness. For the very highest grade of whiteness, the silk was put in a sealed room in which sulfur was burned. For eight hours, the silk was exposed to the fumes of the sulfur. One to two pounds of sulfur was enough the give 100 pounds of silk the desired brightness.

Blue

  The silk-dyer used eight pounds of indigo, six pounds of very

pure potash, two pounds of madder, and eight pounds of bran. The bran was washed It was put on the bottom of the kettle. In another kettle, the

madder and potash were cooked for 15 minutes. The indigo, which had been soaking in warm water for two days, was crushed in a mortar until it became a smooth paste that could be mixed with the other ingredients and poured onto the bran.

After this mixture was stirred thoroughly, it was allowed to cool to a lukewarm temperature.

When it turned a little greenish, it was stirred again and left alone for 3 or 4 hours.

Silk that was to be dyed blue did not need the aluminum sulfate bath, because the indigo already contained enough salts to allow the threads to absorb the dye.

 

Yellow

In order to produce yellow dye, the dyer mainly used the roots of the mignonette (reseda luteola) plant.

For each pound of silk he needed two pounds of this plant. It was cooked for twenty minutes, then filtered through a sieve into another tub.

After this solution had cooled to lukewarm, it was ready to be used.

Orange

The rocou plant was used to make the color orange. Originating in the Caribbean the Rocou plant was called "bija" by early Caribbean Indians, thus the plants's current scientific name: Bixa.

Its crimson seeds were crushed together to make a red body paint that had a religious and magical significance to many tribes. To be used as a dye, rocou had to be dissolved in alkaline salt, such as potash.

Thus, silk to be dyes with rocou did not need a prior bath in aluminum sulfate. If silk immersed in rocou solution turned red, that meant more potash should be added. 

Carmine-red 

This color was derived from Cochineal, which was the dried scale-insect Coccus cacti, which lived on certain of the cactus plants of Mexico and elsewhere.

Once the Cochineal had cooked, one ounce of cream of tartar and one ounce of tin were added per pound of Cochineal, to make the color a bit more yellow. 

There was a second way to produce the carmine color. That was a process similar to the way orange dye was made from the rocou plant. The only problem was that the use of cream of tartar as a color enhancer did not have that same amazing effect as it had with Cochineal. Some dyers had found a solution for that by using white oak galls, which had about the same effect.

Oak galls also produced an extra softness, similar to what cream of tartar could give to the silk. 

ECO-FRIENDLY TESTING

After the natural dyeing process is over it is time for testing the fabric. The testing of the fabric is done to test the fastness of color. The fastness of the color is tested in three different ways : 

Washing fastness Dyeing fastness Rubbing fastness

Advantage

Utilizing natural dyes to impart color onto fabric has a number of advantages over synthetic dyes.

Natural dyes are generally more eco-friendly than synthetic dyes. Synthetic dyeing procedures can be polluting and certain diazo dyes are carcinogenetic.

Almost all natural dyes are free of azo compounds which are carcinogenetic.

Most natural dyes are known antioxidants. Clothes dyed with natural dyes have the potential to be sold at a

higher price. Depending on the dyeing procedure and the type of mordant

used, a variety of colors can be produced using one natural dye source. Each natural dye source provides an amazing diversity of shades. From one dye you may obtain between 5-15 varying colors and shades.

Natural dyes are seen as more eco-friendly since, unlike their synthetic counterparts, they are all derived from natural sources.

Inconsistencies in color could be marketed as unique or one of a kind.

Disadvantage

The quality and effectiveness of natural dyestuffs depends upon a great many factors.

Natural dyes have limited availability. natural dyes are obtained from plants and are dependent on

growing seasons. Although natural dyes initially produce bright colours in a variety of

shades, fabrics tend to fade quicker than fabrics colored with synthetic dyes when exposed to light and home laundering.

Consistency of color is a challenge when dyeing with natural dyes. No two dye lots are identical, due to impurities in the natural dyes.

Some mordants may present unacceptable levels of toxicity. The more toxic mordants, such as chromium and tin, are required for some of the brighter colors. It is important to note that not all mordents are toxic, for example, alum is relatively safe to use, though not entirely non-toxic.

Although some fibers, such as silk and wool, can be colored simply by being dipped in the dye, others fibers such as cotton require a mordant.

Synthetic fibers usually cannot be dyed with natural dyes.

Conclusion

natural dyes are an eco-friendly way to impart almost any colour to a textile product.

With the recent interest in environmental concerns, natural dyes might be a good way to produce unique products with a green slant.

THANK YOU