Assignment onIDENTIFICATION OF TEXTILE

FIBERS

IDENTIFICATION OF TEXTILE FIBERS

The Non technical Test BURNING TEST

The Technical Test MICROSCOPIC TEST CHEMICAL TEST

BURNING TEST

IDENTIFICATION OF FIBRES THROUGH BURNING TEST

Cotton : Cotton will burn like a candle wick and even after the

flame is extinguished, the material will continue to glow until it is completely put out.

- When approaching flame: Does not fuse or shrink from flame- When in flame: Burns- When removed: Continues to burn, has light gray smoke and an afterglow- Ash: Gray, feathery with a smooth edge- Odor: Burning paper 

Cotton Fiber

IDENTIFICATION OF FIBRES THROUGH BURNING TEST

Linen Fiber

Linen(Flax): A cellulose fiber, it takes longer to ignite. It is easily

extinguished by blowing on it. - When approaching flame: Does not fuse or shrink

from flame- When in flame: Burns- When removed: Continues to burn, has light gray smoke and an afterglow- Ash: Gray, feathery with a smooth edge- Odor: Burning paper

Silk:› It is a protein fiber and usually burns readily, not

necessarily with a steady flame, and smells like burning hair. The ash is easily crumbled. Silk samples are not as easily extinguished as cotton or linen.

Wool: › It is also a protein fiber but is harder to ignite than silk

as the individual "hair" fibers are shorter than silk and the weave of the fabrics is generally looser than with silk. The flame is steady but more difficult to keep burning. The smell of burning wool is like burning hair.

OVER ALL - When approaching flame: Curls away from flame

- When in flame: Burns slowly- When removed: May self-extinguish- Ash: Crushable black ash- Odor: Burning hair

It is also important to note that wool will react the same way as silk because it is a natural protein (like our hair).

IDENTIFICATION OF FIBRES THROUGH BURNING TEST

Silk Fiber Wool Fiber

Man Made Fibers Acetate: Is a protein fiber which burns quickly and can flare

even after flame is removed. The bead is hard, brittle, and can't be crushed. It melts into a very hot bead and drips very dangerously. No ash is left by it and the smell is like hot vinegar or burning pepper.

Rayon: It is a regenerated cellulose fiber which is almost pure cellulose.

Rayon burns rapidly and leaves only a slight ash. The burning smell is close to burning leaves

Because rayon is a cellulose-based fiber, it will burn in the same manner as cotton. In the above example, I used a WWII issued Army Ground Forces patch and reacted the same as the cotton example above.

- When approaching flame: Does not fuse or shrink from flame- When in flame: Burns- When removed: Continues to burn, has light gray smoke and an afterglow

- Ash: Gray, feathery with a smooth edge- Odor: Burning paper

 

IDENTIFICATION OF FIBRES THROUGH BURNING TEST

Acetate Fiber Rayon Fiber

Nylon: › Nylon melts and then burns rapidly if the flame remains

on the melted fiber. If i can keep the flame on the melting nylon, it smells like burning plastic.

› - When approaching flame: Melts and pulls away from flame- When in flame: Melts and burns- When removed: May self-extinguish- Ash: Hard gray or tan bead (uncrushable)- Odor: Smells "Celery like

Polyester:› Polyester melts and burns at the same time, the

melting, burning ash can bond quickly to any surface it drips on including skin. The smoke from polyester is black with a sweetish smell. The extinguished ash is hard.

- When approaching flame: Melts and pulls away from flame - When in flame: Melts and burns - When removed: May self-extinguish - Ash: Hard black bead (uncrushable) - Odor: Sweet odor 

 

IDENTIFICATION OF FIBRES THROUGH BURNING TEST

Polyester Fiber Nylon Fiber

MICROSCOPIC TEST

COTTON•Cotton fiber is a single elongated cell.

Under a microscope, cotton fiber looks like flat, spirally twisted ribbon-like tube with rough granular surface.

•Mercerized cotton does not have natural twist. The finishing process makes them swollen, straight, smooth and round with a shining surface.

•The thin cell wall of the fiber has from 200 to 400convolutions per inch.

Microscopic view of cotton

LINENLinen fiber, under a microscope, looks like having multiple sided cylindrical filaments with fine pointed edges.

The filaments show nodes at intervals.

It, in fact, looks like a bamboo stick having joints that results into a little unevenness.

Microscopic view of linen/flax

WOOLWool fiber has irregular, roughly cylindrical, multi cellular structure with tapered ends.

Under a microscope, three basic layers are shown- epidermis (outer layer), cortex (middle layer) and medulla (inner layer).

Medulla is seen only in coarse and medium wool fibers and that too under a highly powerful microscope.

MICROSCOPIC VIEW OF WOOL

SILK• Silk fibers are straight and

smooth.• Raw silk fiber, composed of

two filaments, has elliptical shape under the microscope.

• The two fine and lustrous filaments are shown clearly looking like transparent rods with triangular shape.

• Wild silk or tussah fiber has different appearance than the cultivated silk. It is flattened, coarse, thick and broader fiber having fine, wavy lines all across its surface whereas cultivated silk is narrower fiber with no marks on it.

MICROSCOPIC VIEW OF SILK

MICROSCOPIC TEST FOR MANMADEFIBERS

RAYONS: Rayon fibers have a glasslike luster under

the microscope and appear to have a uniform diameter when viewed longitudinally.

ACETATE: The cross sectional view has a bulbous or

multi global appearance with indentations. These indentations appear as occasional

markings.

MICROSCOPIC TEST FOR MANMADEFIBERS

Acetate fiber Rayon fiber

NYLONThe basic microscopic appearance is generally fine, round, smooth, and translucent.Sometimes it has shiny appearance. If it looks dull, it will also be dotted under the microscope. It is also produced in multilobal cross-sectional types.

MICROSCOPIC VIEW OF NYLON

POLYESTER• Polyester (aka Terylene ) is a category of polymers

which contain the ester functional group in their main chain.

• Generally, polyester fibers are smooth and straight and the cross-section is round.

• With various finishing processes, its appearance changes in context of texture and luster.

MICROSCOPIC VIEW OF POLYESTER

CHEMICAL TESTS

CHEMICAL TESTS

Solvent Test: The test involves treating the fibers in

certain solvents for identifying them. The technical test is becoming difficult to conduct as most of the manufactured fibers and their blends are chemically similar. There is no individual chemical or solvent test for separating or identifying the fibers in combinations.

CHEMICAL TESTS COTTON AND LINEN(FLAX):

DISTINGUISHING LINEN FROM COTTONCotton and linen are immersed in a 1% solution of fuchsine in alcohol to give red rose color. Later ,they are washed and immersed into ammonia, linen retains the red coloration but cotton does not.

CHEMICAL TESTS POLYYESTER AND ACETATE :

DISTINGUISHING POLYESTERS FROM OTHER FIBRES:

Polyester is soluble in hot meta cresol; however ,unlike acetate it is not soluble in acetone, and unlike nylon it is not soluble in concentrated formic acid.

CHEMICAL TESTS NAYLON AND RAYON :

CHEMICAL TESTS SILK AND WOOL : Zinc chloride At 45 °C, 75% zinc chloride solution dissolves silk that has not

been mercerized. Sulfuric acid At 20 °C, 60% sulfuric acid dissolves silk. Sodium hydroxide At 100 °C, a 5% solution of sodium hydroxide dissolves nytrils,

wool and other animal hair, and cultivated silk Hydrochloric acid At 20 °C, concentrated (12 M) hydrochloric acid dissolves

silk.

DISTINGUISHING SILK FROM WOOL: The use of concentrated cold hydrochloric acid

will dissolve the silk and the wool fiber swells.