Textile materials are manufactured from fibers either obtained from nature, or are manufactured synthetically or regenerated from naturally occurring substance. For perfect coloration of textile materials without hampering their physical properties, a thorough knowledge of the fiber is absolutely essential.
2. TEXTILE FIBER
Textile Fiber; Fiber is a near microscopic hair-like substance that may be
natural or manmade. Fibers suitable for textile use possess adequate length,
fineness, strength, and flexibility for yarn formation and fabric construction, for
withstanding the intended use of the completed fabric. Other properties
affecting textile fiber performance include elasticity, crimp (waviness), moisture
absorption, reaction to heat and sunlight, reaction to the various chemicals
applied during processing and in the dry cleaning or laundering of the
completed fabric, and resistance to insects and micro-organisms.
4. https://www.bettermeetsreality.com/
COMMONLY USED FIBERS IN TEXTILE
Stats On Fiber Production & Consumption, & Most Common Fibers/Fabrics (By Type)
55%
27%
7%
4%
5%
2% 1%
In 2015, the global mill consumption of
fibers
Polyester
Cotton
Cellulosic Fibres
Polypropylene
Nylon
Acrylics
Wool
– waterfootprint.org
64.20%
24.10%
6.20%
4.40% 1.10%
In 2017, the distribution of fiber
consumption worldwide
synthetic fibres
cotton
wool based fibres
other natural fibres
wool fibres
– statista.com
5. It Aids Communication With Fabric Suppliers
Fabric Content Affects Fabric Price
You Know WhatYou’re Getting
Why is identifying fiber important?
6. IDENTIFICATION OF TEXTILE FIBERS
A number of methods are available for characterization of the structural, physical and
chemical properties of fibers.
The Non-technicalTest
Feeling test
BurnTest
TheTechnicalTest
Microscopic
test
Chemical
test
8. FEELING TEST
The feeling test requires perception if it is to be of any value.
Skilled perception is acquired only after handling many different
fabrics over a period of time. Limitations of this test become
apparent when examining and comparing fabrics of different
fiber content. Feeling test involves touching a fabric and feeling
the fabric to know its component fibers.
However, it requires a long experience of handling different
fabrics over a period of time for such skillful perception. Also, it
is difficult to examine and compare the fabrics made of different
fiber contents with the feeling test because the handling
properties can be changed due to applying finishing chemicals.
As example cotton gives cooling feeling in touch where wool
fiber gives warm feel.
9. BURN TEST
The primary purpose of the burn test is to determine if the
fabric swatch is made of natural or synthetic fibers. The
flame, smoke, odor and ash all help us to identify the fabric
being burned.
The burning test is more efficient than the feeling test but it
also has its limitations. We can only identify the fabric
fiber when the fiber is 100% pure. If a number of different
fibers or yarns are blended together, it is hard to distinguish
the individual elements.
In addition, if the fabric swatch has undergone a post-
finishing process, this might also affect the test result.
10. HOW TO CONDUCT THE BURN TEST
Cut the fabric swatch into a
small 3-4cm square.
Pull fibers from the fabric
swatch
Use a tweezer to hold one end of
the fiber ball
https://youtu.be/gwx2-NRAtjo
11. BURN TEST RESULTS OF NATURAL FIBERS
Cotton
Cotton ignites and burns quickly. The flame is round, calm and yellow. The smoke is white. After removing the flame, the fiber will
continue to burn. The odor is like burning paper. The ash is dark gray and can be crushed into a powder easily.
Hemp
A cellulose fiber, burns quickly with bright flame. It leaves no melted bead and after burning no sign of flame is seen. It smells like
burning leaves or wood. The ash is gray and smoke has no fume hazard.
Jute
Also a cellulose fiber, doesn’t shrink from flame. Other characteristics are similar to those of hemp fabric.
Linen (Flax)
A cellulose fiber, it takes longer to ignite. It is easily extinguished by blowing on it. Other properties are similar to hemp and jute.
Silk
Is a protein fiber which burns slowly and curls away from the flame. It leaves a dark bead which can be easily crushed. It is self-
extinguishing and leaves ash that is a dark, gritty, fine powder. It smells like burned hair or charred meat. It gives out little or no smoke
and the fume has no hazard.
Wool
Is a protein fiber which burns slowly. It sizzles and curls away from flame and may curl back onto fingernail. It leaves beads that are
brittle, dark, and easily crushed. It is self-extinguishing and leaves harsh ash from crushed bead. It gives out a strong odor of burning
hair or feathers. It gives out dark smoke and moderate fume.
12. Rayon
Is a manufactured cellulose fiber. It burns without flame or melting and may flare up. Unless there is a fabric finish, it doesn't leave
any bead. After the flame is removed, it may glow a bit longer than cotton. It smells like burning paper and leaves soft, gray ash. It's
smoke is a little hazardous.
Acrylic
Acrylic shrinks quickly when the flame approaches. The flame sputters and the smoke is black. After removing the flame, the fiber will
continue to burn. The ash is yellow-brown, hard and of an irregular shape.
Polyester
Polyester shrinks quickly when the flame approaches. It then melts and burns slowly. The smoke is black. After removing the flame,
the fiber will not continue to burn. It has a chemical odor, similar to burned plastic. The residue forms into round, hard, melted black
beads.
Nylon
Nylon shrinks quickly when the flame approaches. It then melts and burns slowly. There will be small bubbles when burning. The
smoke is black. After removing the flame, the fiber will not continue to burn. It has a celery-like, chemical odor. The residue forms into
round, hard, melted black beads.
BURNTEST RESULTS OF MAN-MADE FIBERS
15. MICROSCOPIC TEST
The microscopic test reveals the macroscopic features of the
fiber. When observed along the length (longitudinal section),
the surface features are revealed. When a fiber is cut in the
perpendicular direction and a thin cross-section examined on
the microscope, the shape of the cross-section and the
macroscopic features in the cross-section can help
identifying some fibers.
The microscopic test is a technical test that involves
identifying the fabric with the help of a microscope with a
magnification of minimum 100 power.
The test can easily distinguish between fibers.
The test identifies the natural fibers more easily as
compared to man-made ones.
Synthetic fibers are very similar in appearance and the
increase in the number of varieties makes it a little tough to
distinguish the fibers even under a microscope.
16. COTTON
Longitudinal view : Mature cotton looks like a flat, twisted,
ribbon or a collapsed twisted tube. A large number of
convolutions are usually found.
Immature cotton also looks like a flat twisted ribbon but has a
lower number of convolutions. Mercerised mature cotton is
almost cylindrical in shapes and has very few convolutions.
Cross – sectional view : Mature cotton has been or kidney –
shaped cross section, and a small lumen. Immature cotton also
has a bean – shaped cross section but a larger
lumen. Mercerised cotton looks almost round to oval, a small
point at or near the centre representing the lumen.
17. Flax:
Longitudinal View: Long, transparent, cylindrical, sometimes striated
appearance. It has harrow lumen running through centre.
Cross – sectional view : The cell wall appears thick and polygonal in shape.
Jute:
Longitudinal View: Cross wise marks called nodes or joints.
Cross – sectional view : The fibers have a small central canal similar to the
lumen in cotton. Several sided or polygonal with rounded edges.
Hemp:
Longitudinal View: Smooth and cylindrical with a cross marking nodes, no
lengthwise striations, broad lumen
Cross – sectional view : Partly polygonal
JUTE
FLAX
HEMP
18. Wool:
Longitudinal view : Irregular and roughly cylindrical,prominent scale marking or
flattened plates.
Cross – sectional view : Oval to circular with variation in diameter medulla is
concentric and variable in size.
Silk:
Longitudinal view : Uniform diameter with striation running parallel to the fibre axis.
Cross – sectional view : Differ in cross sectional appearance according to the
process used.Basically has a irregular cross section.
Viscose:
Longitudinal view : Uniform diameter with striation running parallel to the fibre axis.
Cross – sectional view : Differ in cross sectional appearance according to the
process used.Basically has a irregular cross section.
WOOL
SILK SILK TUSSAH
‘GALAXY’- a Y-shaped
viscose rayon
‘Viloft’- a flat cross-
sectional viscose rayon
19. Polyester:
Longitudinal view : Very regular, rod like appearance.
Cross – sectional view : Circular in cross section.
Nylon:
Longitudinal view : Very regular, rod like appearance.
Cross – sectional view : Circular in cross section.
Acrylic :
Longitudinal view : Rod like with smooth surface and profile.
Cross – sectional view : Nearly round or bean shaped.
POLYESTER
NYLON
ACRYLIC
20. MICROSCOPICAL VIEW OF VARIOUS TEXTILE FIBERS
FIBER LONGITUDINAL CROSS-SECTIONAL
Cotton
Ribbon shaped with periodic twists called convolutions. After mercerization,
the fibers become cylindrical.
Collapsed tube or bean shapes, central channel or lumen may be
visible. For mercerised cotton, the corss-section is approximately
circular.
Flax, Jute
Multiple fibers cemented together, bamboo-like with cross-markings called
nodes.
Bundles of polygons with large lumen in the centre.
Wool Crimped solid rod with fish-like scales on the surface. Circular or eliptical, vairable in diameter.
Raw Silk Rough filaments cemented in pairs, separated in places. Triangular with rounded corners, in pairs.
Degummed Silk Structure-less, like a hollow glass rod. Sparated fibers, triangular, runded corners.
Viscose Rod-like with striations Commonly serrated
Polyester,
polyamide, and
acrylic
Featureless rod-like, depends o spinneret shape and spinning conditions.
Circular or other shape depending n spinneret shape and spinning
conditions.
21. CHEMICAL TEST
Chemical tests are another technical means of
identifying fibers. But chemical tests are not
intended for the general consumers.
Different types of chemical tests are undertaken
to establish the identity of the fibers used.
These tests give accurate and precise analysis
and conducted in research laboratory.
Stain Test
Solvent Test
22. STAIN TEST
Also known as the Double Barrel Fiber Identification (DBFI), the test is based on the
theory that each fiber has its own distinct two- color reaction when treated with stain. A
fiber will turn to a particular color in the presence of dilute acetic acid and to some other
specific color when stained in the presence of a mild alkali.
Stain method is applicable for those fiber which shows specific behavior in acid and
alkali.
Fibers have differing dyeing characteristics and affinities dependent on the chemical and
morphological structure of the fiber.
23. 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.
The chemical structure of polymers in a fiber
determines the fiber’s basic solubility characteristics.
24. SOLVENT TEST
FIBER TYPE SOLVENT IDENTIFICATION OF FIBERS
Vegetable
+
Animal
Acid Vegetable fiber destroyed
Alkali Animal fiber destroyed
Cotton
+
Linen
Sulphuric acid & weak ammonia
Cotton dissolved and
linen unaffected
Iodine & Zinc Chloride
Cotton stained reddish purple and
linen stained blue to purple
Caustic Soda (NaoH)
Cotton remains white and
linen turns to yellowish
Silk
+
Wool
Concetrated cold hydrochloric acid (HCl)
Silk will dissolved in the solvent
Wool fiber become swell
Viscose Rayon
+
Acetate
Sulphuric acid & equal amount of iodine
Dark-blue color indicqates viscose rayon
Yellow color indicaes acetate
Di-acetate
+
Tri-acetate/
Modacrylic
80% Acetone
Di-acetate will dissolve
Tri-acetate/ Modacrylic will not dissolve
Nylon
+
Acetate
Acetone
Acetate will dissolve
Nylon will not dissolve
Nylon
+
Wool
Boiling solution of NaOH
Wool will dissolve
Nylon will not dissolve
Polyester
+
Other Fiber
Hot metacresol/ Acetone/ Formic Acid
Polyester, acetate, nylon soluble in hot metacresol
Acetate soluble in acetone but not polyester
Acrylic
+
Other Fiber
70% solution of Ammonium thiocyanate
Acrylic will dissolve but cotton, wool, silk, rayon, acetate, nylon, polyester will not
dissolve
26. SPECIFIC GRAVITY TEST
Fiber density or specific gravity test may be used as an aid to fiber
identification. A series of solvent mixtures of varying density may be
prepared. If the specific gravity of the fiber is greater than that of a
particular solvent mixture, it will sink, and if less, it will float.
27. OTHER ANALYTICAL TESTS
In addition to the discussed simple tests, a number of sophisticated analytical methods ae in use for the
thorough characterization of structural, physical and chemical properties of the fibers, such as:
Optical and electron microscopy
X-ray diffraction
Infra-red spectroscopy
Ultraviolet-Visible spectroscopy
Thermal analysis
Elemental and end-group analysis, etc.