fiber identification complete understanding, qualitative analysis of textile fibers

COTTON

QUALITATIVE ANALYSIS OF TEXTILE FIBERSSCOPE: Applied for Fiber Identification which are shown below :

.

� NATURAL FIBER:� VEGETABLE

FIBERS(CELLULOSIC):� Seeds: Cotton, Kapok.� Bast :

� Low Lignin Content: Flax, Ramie. � High Lignin Content: Jute, Hemp.

� Leaf: Sisal.

� ANIMAL FIBERS(PPROTEIN FIBERS):� Epithelial growth:

� Animal Hair: Cashmere, Mohair, Alpaca, Camel.

� Wool: Sheep.

� Animal Secretion: Silk

� MINERAL FIBERS: Asbestos

� MAN-MADE FIBERS:� REGENERATED (MODIFIED)

FIBER:� Rayon(Regenerated Cellulosic

fiber): Viscose, Modal, Lyocell(Tencel), Polynosic.

� Regenerated Cellulose Ester: Acetate, Triacetate.

� SYNTHETIC FIBER:� Polyester: PET( Dacron-

USA/Terylen-UK), PBT� Polyamide: Nylon� Polyvinyl Derivstives:

� PolyAcrylonitrile : Acrylic,ModAcrylic

� Polyurethane: Spandex� PVC, PVA, PS

ROKIBUL ISLAM,(ACCE,RU); QTEC DHAKA LAB 2

FIBER IDENTIFICATIONTEST METHODS: .

� Visual Appearance and Feeling Test

� Twist on Drying Test

� Floatation Test

� Swett’s Test

� Flame Test

� Chlorine Detection Test

� Burning Tests

� Stain Tests

� Kayastain(Q) Test

� Coloration Test With Iodine and Potassium Iodide

� Microscopic Analysis

� For Longitudinal Examination

� For Cross Section Examination

� Solubility Tests

� Refractive Index Method

� IR Spectroscopy Test

� Thermal Aalysis

� Differential Scanning Calorometry(DSC)

� Thermogravimetric Analysis(TGA)

� Density Measurement Test

� Melting Point Measurement Test

� X-ray Diffraction Test


FIBER IDENTIFICATION� PROCEDURE:

� The identification of fibers is usually carried out by subjecting specimen to a variety of selected tests until enough information is obtained to make a satisfactory judgment as to the generic class or specific type.

� The selection of tests and order in which they are performed can be changed depending on the knowledge already available and results of the preliminary tests.

� Most widely used methods are-

� Visual Appearance and Feeling Test:

� Twist On Drying Test:

� Burning Test:

� KayaStain(Q) Test(JIS method)

� Coloration Test With Iodine+Potassium Iodide Solution:

� Microscopic Analysis for Longitudinal Examination:

� Solubility Test


METHODS FOR FIBER IDENTIFICATION� Visual Appearance and Feeling Test:

� Only skilled personnel can percept the fibers by visualizing andtouching textile goods. But, possibility of misperception is very high.

� Twist On Drying Test:� Separate out a few parallel fibers.

� Dip in water and squeeze off excess.

� Tap the end of the bundle to make separate fibers flare out.

� Hold over a hot plate in warm air to dry the fibers.

� Hold the fibers so that the free ends point toward the observer.

� Note the direction of twist as the fibers dry.

� Flax and Ramie twist in a clockwise direction; hemp and jute twist in a counter clockwise direction.


METHODS FOR FIBER IDENTIFICATIONBurning Test:

� Take a small tuft of fibers forceps and place close to the side of a small flame.

� Note if the fibers melt or shrink from the flame.

� Move the fibers into the flame. � Note whether the fibers will burn when held in the flame.

� Remove from the flame very slowly and carefully.� Note whether the fibers continue to burn outside of the flame.

� Blow out the flame, if still burning, and smell the smoke.� Note the odor and examine the color of the smoke.� Note the color, and nature of any ash, or bead residue.


BURNING CHARTFIBER


METHODS FOR FIBER IDENTIFICATION

� Kayastain(Q) Test:� Bleach the textile by 1% sodium hydrosulfide(boil) solution, then squeeze

and dry.

� Heat the 1% Kayastain(Q) solution by Bunsen burner.

� Add the textile to the liquor before it boils.

� Allow the boiling to continue for 5 minutes.

� Then rinse and dry the textile without delay.

� Compare the shade of the textile with reference table below mentioned.


METHODS FOR FIBER IDENTIFICATION

� Coloration Test With Iodine+Potassium Iodide Solution:� Place a few fibers on a microscopical slide.

� Apply a drop of iodine solution and cover with a cover slip with taking care to avoid bubbles.

� Examine the fibers for staining.

� Cotton, ramie, and hemp stain violet; flax stains brownish violet; Jute stains brown; silk stains yellow brown.

� Most of the synthetic fiber does not absorb iodine solution due to lack of the porosity in their structure, that causes no stain.


METHODS FOR FIBER IDENTIFICATION� Microscopic Analysis for Longitudinal Examination:

� Sample Preparation for Identification:� If the sample is a fabric, separate out the yarns by unraveling or

cutting.

� If the sample is woven, separate warp and filling (weft) yarns.

� If yarns differ in color, luster, size, or other apparent ways, make a physical separation of these yarns separate identification.

� Test Operation:� Place a small quantity of fibers on a glass slide.

� Tease fibers apart, mount with a drop of iodine solution or other immersion fluid, cover a glass cover slip.

� Place the slide on the microscope stage, and examine the slide by scanning top to bottom, left to right.


Microscopic Analysis for Longitudinal Examination

� Observe the fiber characteristics and classify into five general classes:

�#1, Fiber with surface scales. These are the animal hair fibers including

wool, cashmere, mohair, alpaca, etc.

� Additional confirmation of this class may be made by Kayastain(Q) test, Burning test, and Solubility test etc.

�#2, Fibers with cross markings. These are the vegetable fibers (except

cotton) including Flax(Linen), Ramie, Hemp etc.

� To distinguish Flax and Ramie from Hemp, perform twist on drying test.

� Additional confirmation of this class may be made by Kayastain(Q) test, Burning test, and Solubility test etc.


Microscopic Analysis for Longitudinal Examination

�#3, Twisted fibers. This class includes cotton and silk. These two are

easily distinguished by Kayastain(Q) test, burning test, and solubility test.

�#4, Fibers with stripe or steak. These class are regenerated

cellulosic fibers including viscose rayon, modal, acetate etc.

�#5, Other fibers. This class includes all of the man-made fibers.

� The man-made fibers are best identified by burning test, solubility test, or other properties which relate to chemical nature rather than shape.


MICROSCOPIC VIEW

WOOL FLAX COTTON SILK

RAYON ACETATE LYOCELL MODAL

NYLON POLYESTER ACRYLIC SPANDEX


SOLUBILITY TEST


Origin, Properties, Pro and Cons of The Most Popular Fibers


COTTON


COTTON� Cotton is a vegetable based(cellulosic) natural fiber

which contain about 91% cellulose.� Cellulose is a natural polymer, whose monomer is ß-D-glucose.

� Degree of Polymerization(DP) is 9000-15000.

� The cotton fiber comes from the seeds of the cotton plant

COTTON SEED

CELLULOSE ß-D-glucose


Special Properties of Cotton

� Color to Kayastain(Q): Blue

� Burning Properties: � Shrink from flame, light gray smoke.

� Some light remaining after flame is gone.

� Paper burning smell.

� It has soft ash.

� Moisture Regain: 8.5%

� Solubility: 70%H2SO4.

� Average Crystallinity: 72-73%.

� Microscopic Structure:� Spirally twisted.

� Rough surface.

AFTER KAYASTAIN


Cotton with H2SO4� 63 %sulfuric breaks the hydrogen bonds and penetrate into noncrystalline

and crystalline domains of the polymer with forming of the complexes .

� By partial esterification of hydroxyl groups of cellulose, sulfate groups formed.

� 7o-75%%, H2SO4 at room temperature, the cellulose hydrolyzed with forming of water-soluble oligomers.

� The diluted acidic solutions permitted to convert the oligomers mainly into glucose.


General Properties of Cotton

• Comfortable & soft feel.• Highly absorbent.• Get strength in wet condition.• Acids can weaken and/or damage the fibers.• High resistant to alkalis and most organic solvent.• Long exposure to light turns fiber fade.• Fungus can grow on cotton. • Very little natural elasticity.• Dimensional stability is good.• Gets Printed well. • Washable.• Can be Dry cleaned


COTTONAdvantages Disadvantages

� Comfortable .

� Absorbent .

� Good color retention.

� Dyes & prints well.

� Washable .

� Easy to handle and sew.

� Inexpensive .

� Shrinks in hot water .

� Weakened by perspiration and sun light.

� Burns easily .

� Affected by mildew.


FLAX


FLAX(LINEN)� Flax(commonly known as Linen) is a Cellulosic Natural Fiber.

� Linen is obtained from flax plant.

� Flax is finer and has more texture than cotton.

� Flax requires more ironing.

� Flax is more expensive than cotton.

FLAX PLANT


Special Properties of Flax

� Color to Kayastain(Q): Blue.

� Burning Properties:

� Slow burning and there is a flame.

� Some light remaining after flame is gone .


� It has soft ash.

� Moisture Regain: 12%

� Solubility: 70% H2SO4

� Crystallinity: 65-75%

� Microscopic View:

� Flax looks like bamboo.


General Properties of Flax

� Stronger when in wet condition.

� Stronger than cotton.

� Good Dimensional stability but tend to crease.

� Attacked by hot dilute acids or cold concentrated acids.

� Resistance to alkaline solution and organic solvents.

� Moderate Abrasion resistance Moderate

� Huge amount of impurities, like pectin and gum than cotton.


FLAXAdvantages Disadvantages

� Strong , and Comfortable.

� Good absorbent.

� Stronger when in wet condition.

� Hand-washable or dry-cleanable

� More durable than cotton.

� Good conductor of heat.

� Can withstand high ironing temperatures .

� Creases & shrinks easily.

� Difficult to remove creases.

� Expensive.

� Wrinkles easily .

� Takes long time to dry.

� Affected by mildew and perspiration.

� Poor affinity to dyes.

� Flammable.


WOOL


WOOL� Wool is a natural protein fiber. This fiber obtained from the fleece of the

sheep/lamb, or hair of the Angora or Cashmere goat or camel or alpaca.

� Composed of amino acids by peptide bonds.

SHEEP

ANGORA

ALPACA

CASMERE GOATCAMEL

ALPACA


Special Property of Wool

� Color to Kayastain(Q): Blue

� Burning Properties:� Burns with crimping and shrimping.

� Smell is very similar to burning hair.

� Black swelling ash.

� Ash is not very hard but not as soft as cotton.


� Solubility: 5%NaOH, 5%NaOCl

� Microscopic Structure:� Irregular, roughly scale, similar to fish scales.

� Three layers: Epidermis (outer ), cortex

(middle), and medulla (inner)(in coarse wool).

AFTER KAYSTAIN


General Properties of Wool

� Composed of amino acids.� Excellent absorbency property, moisture regain

is high.� Warmer than other fibers.� Good resistance to acids.� Wool is very sensitive to alkali.� Requires frequent dry cleaning.� Weakest of all natural fiber. � Nonconducter of heat.� High shrinkage. � Burn slowly.


WOOLAdvantages Disadvantages

� Warm .

� Lightweight.

� Dyes well.

� Comfortable.

� Durable.

� Creases well.

� Recyclable .

� Affected by moths

� High shringkage.

� Needs special care, dry cleaning .

� Scratchy on skin .

� Harmed by chlorinated bleach.


VISCOSE RAYON


VISCOSE RAYON� Viscose Rayon is Produced by treating dissolving wood

pulp(about 94% Cellulose)with aqueous sodium hydroxide(NaOH) and carbon disulfide(CS2).


Special Properties of Viscose

� Color to Kayastain(Q): Lt. Blue

� Burning Properties:� No light remain after flame is gone.


� It has very little ash.(almost nothing)


� Solubility: 60%H2SO4

� Average Crystallinity: 60%

� Microscopic View:� There are many streaks along this fiber.

� Longitudinal Stripes.

� No twist.

� Not smooth surface. VISCOSE RAYON

BURNED RAYON


General Properties of Rayon

• Moisture regain(about 13%) greater than cotton.

• Loses strength when it is wet.• Reacts faster than cotton with Acid.

• Resistant to base and organic solvents.

• Rarely attacked by moulds and mildew.

• The elasticity less than 2-3%.

Rayon in H2SO4


VISCOSE RAYONAdvantages Disadvantages

� Soft and comfortable

� Highly absorbent

� Dyes and prints well

� No static problems

� Inexpensive

� Weakens when wet

� Fabric shrinks if washed

� Heat sensitive

� Susceptible to mildew


MODAL


MODAL� Modal is a second generation regenerated

cellulosic fiber and a variation of rayon that has high tenacity and high wet modulus.

�Modal rayon uses only beech trees wood.

�On the other hand, Viscose rayon uses wood pulp material from a variety of trees.

�High wet-modulus rayon.


Special Properties of Modal

� Color to Kayastain(Q): Lt. Blue

� Burning Properties:� No light remain after flame is gone.


� It has very little ash.(almost nothing)


� Solubility: 60%H2SO4

� Average Crystallinity: 60%

� Microscopic View:� Centrally single longitudinal stripe.


General Properties Of Modal

� Soft, smooth, and breathable fabric.

� Super-absorbent, plus resistant to shrinkage.

� Resistance to alkalis but sensible to acids.

� Single or blend with other fibers like CTN/PU.

� High breaking strength.

� Remains absorbent, soft & supple after repeated washing.

� Good color stability.

� High Wet-Modulus fiber.


MODALAdvantages Disadvantages

� Super-absorbent.

� Resistant to shrinkage.

� High breaking strength.

� Soft, smooth, and breathable.

� The color stays for long and does not fade easily.

Modal doesn't really have any

major disadvantages.

� Prone to stretching and pilling.

� After washing, it is necessary to iron modal clothes, just like cotton.


LYOCELL


LYOCELL� Lyocell is the newest regenerated cellulosic fiber

which consist of wood pulp and organic solvent.

� Trade name is Tencel® .

� Produced in a closed loop chemical process.

� About 99% of solvent recyled.

� N-Methylmorpholine N-oxide(NMO)

is a key solvent in the Lyocell Process.


Special Properties of Lyocell

� Color to Kayastain(Q): Lt.Blue

� Burning Properties:� No light remaining after flame is gone.

� Smell like burning paper.

� Little ash.

� Moisture regain: 13%

� Solubility: 60% H2SO4� Microscopic View:

� Smooth surface may have irregular shape.


General Properties of Lyocell

� Soft, strong, good absorbent.

� Excellent wet strength.

� Eco friendly, biodegradable.

� Natural breathability.

� Wrinkle resistant.

� Resistant to alkalis but sensible to acids.

� Either washable or dry-cleanable.

� Extremely smooth surface, and static free.

� Prevents the growth of bacteria naturally.


LYOCELLAdvantages Disadvantages

� Excellent wet strength.

� Soft and pleasant

� Anti-microbial

� Eco friendly

� Strong,

� Good absorbent.

� Either washable or dry-cleanable

� Lyocell is more expensive than most eco fabric alternatives.


POLYESTER


POLYESTER� Polyester is a category of polymers that contain

the ester functional group in their main chain.� Two Major Types:

� PolyEthylene Terephthalate (PET/PETE):

� Dacron(USA);Terylene(UK).

� PolyButylene Terephthalate (PBT)

PBT


Special Properties of Polyester

� Color to Kayastain(Q): Lt.Yellow.

� Burning Properties:� Its melts when burns.

� Black smoke coming out.

� Smell like burning plastic.

� Hard black ash.

� Moisture Regain: 0.4%

� Solubility: m-Cresol.� Microscopic View:

� Rod like structure.

� Smooth, straight, and round cross section.


General Properties of Polyester

� Extreme low water absorption.

� Dimensional stability.

� Very good color stability.

� Excellent resistance to chemical attack.

� Very low creep, even at elevated temperatures.

� Very good heat and heat ageing resistance.

� Shiner appearance.

� Excellent electrical properties.


POLYESTERAdvantages Disadvantages

� Strong and durable.

� Resists stretching and shrinkage .

� Washable or dry-cleanable .

� Quick drying.

� Abrasion resistant .

� Resistant to most chemicals .

� Colorfast (color stability).

� Low absorbency .

� Static problems .

� Difficult to dye.


ACRYLIC


ACRYLIC� Acrylic fibers (polyacrylonitrile) are copolymers

of vinyl acetate and methyl acrylate.� The acrylonitrile (-CH2-CH[CN]-)x is usually combined with small

amounts of other chemicals to improve the ability of the resulting fiber to absorb dyes.

� Minimum of 85% acrylonitrile in their chemical structure .


Special Properties of Acrylic

� Color to Kayastain(Q): Red

� Burning Properties: � Burns & melts, black smoke.

� Smell like meat burning.

� Hard and brittle black ash.


� Solubility: 65%KSCN, DMF.

� Microscopic View:� Glass rod like structure.

� Slight irregular striations along its length.

� Variation in diameter.

AFTER KAYASTAIN

ACRYLIC


General Properties of Acrylic

� Outstanding wickability & quick drying to move moisture from body surface.

� Flexible aesthetics for wool-like, cotton-like, or blended appearance.

� Resistant to moths, oil, and chemicals.

� Dyeable to bright shades with excellent fastness.

� Superior resistance to sunlight degradation.

� Easily washed, retains shape.

� Best for winter season ever more than wool.


ACRYLICAdvantages Disadvantages

� Lightweight, soft, warm.

� Machine washable, quick drying .

� Resists shrinkage and wrinkles.

� Flexible aesthetics .

� Resists moths, oil, chemicals .

� Low absorbency .

� Develops static , and Pilling.

� Heat sensitive .


NYLON


NYLON� Nylon is also known as polyamide fiber, because it

is derived from amine and carboxylic acid.

� Most Popular nylon: Nylon 6, Nylon 66


Special Properties of Nylon

� Color to Kayastain(Q):Green

� Burning Properties:� Melts then slowly burns.

� White smoke, Hard bead

� Vegetable or plant like smell.

� If ash is burned, smells like plastic.

� Moisture Regain: 4%.

� Solubility: 20% HCl, m-Cresol.

� Microscopic View:� Smooth, regular surface.

� Rod like structure.

BURNED NYLON

NYLON


Properties Of Nylon

� Ability to be very lustrous, semi lustrous or dull.

� Produced in both regular and high tenacity.

� Retains its shape, no shrinkage .

� Highly sensible to Acid.

� Low absorbency.

� High resistance to insects, fungi.

� Substantially inert to alkalis.

� Excellent abrasion resistance.

� Thermoplastic fiber.


NYLONAdvantages Disadvantages

� Lightweight

� Abrasion resistant

� Easy to wash

� Resists shrinkage and wrinkles

� Fast drying, low moisture absorbency

� Insulating properties

� Static and pilling

� Poor resistance to sunlight

� Low absorbency

� Heat sensitive


POLYURETHANE


POLYURETHANE�Polyurethane (PUR/PU) is a polymer composed

of organic units joined by carbamate (urethane, –NH–(C=O)–O– ) links.

�Polyurethane polymers are formed by reacting a di-or polyisocyanate (Isocyanate,R–N=C=O) with a polyol.


Special Properties of Polyurethane

• Color to Kayastain(Q): Greenish Yellow.

• Burning Properties:� Burns and melts.

� Chemical odor.

� No ash but gummy and sticky residue.

• Moisture Regain: 1.0%

• Solubility: 80%H2SO4, DMF(100°C).

• Microscopic View:� Looks like fused multi filaments.

� Individual fibers are dotted.

� Longitudinally straight.


General Properties of Polyurethane

� Can be stretched several times its original.

� Thermoplastic fibers.

� Excellent resistance to sunlight.

� Chlorinated bleach can attack the fiber.

� Resistant to insects and microorganisms.

� Resistant to cold dilute Acids, weak and cold alkalis.

� Attacked by concentrated acid or strong Alkali.


SPANDEXAdvantages Disadvantages

� Lightweight .

� Retains original shape .

� Abrasion Resistant .

� Stronger than rubber .

� Soft, smooth, supple .

� No static or pilling .

� Heat sensitive .

� Harmed by chlorine bleach.

� Nonabsorbent .

� Can’t make fabric alone.


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fiber identification complete understanding, qualitative analysis of textile fibers

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