The document discusses various methods for characterizing the structural, physical, and chemical properties of fibers, focusing on both non-technical and technical tests for fiber identification. Non-technical tests include feeling and burning tests, while technical tests encompass microscopic and chemical analyses that require specialized equipment and expertise. The document details specific procedures for identifying natural and synthetic fibers through both types of tests, emphasizing their importance in textile analysis.

1. Assignment on

2.  A number of methods are available for
characterization of the structural, physical,
and chemical properties of fibers. Various
methods are used for fiber identification
like microscopic methods, solubility,
heating and burning method, density and
staining etc. End-use property
characterization methods often involve use
of laboratory techniques which are adapted
to simulate actual conditions of average
wear on the textile or that can predict
performance in end-use.

3. TYPES OF TEST
 The Non technical Test
○ FEELING TEST
○ BURNING TEST
The Technical Test
○ MICROSCOPIC TEST
○ CHEMICAL TEST

4. Tests for identification
 Handle/Feel Test
 Visual Examination
 Burning test
 Twist on Drying
 Floatation Test
 Microscopic analysis
 Chemical Analysis

5. Requirements for tests
 Preparation of test specimen
Apparatus for microscopic
examination Reagents used for
chemical tests Other tools and
equipment

6. THE NON-TECHNICAL TESTS
 Feeling test
 Burning test

7. 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.

8. BURNING TEST
 To recognize the composition of fabrics by the
burning test ,the sample of fiber, yarn of fabric
should be moved slowly towards a small flame and
the reaction to heat carefully observed .One end of
the sample should be put directly into flame to
determine its burning rate and characteristics. The
burning odour should be noted and the
characteristics of the ash such as amount ,form,
hardness and color should be examined

9. IDENTIFICATION OF FIBRES
THROUGH BURNING TEST
 Cotton :
○ When ignited it burns with a steady flame and
smells like burning leaves. The ash lefties easily
crumbled. Small samples of burning cotton can be
blown out as you would a candle.
 Linen:
○ Linen takes longer to ignite. The fabric closest to
the ash is very brittle. Linen is easily
extinguished by blowing on it as you would a
candle.

10. Cotton Fiber Linen Fiber

11.  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.

12. Silk Fiber Wool Fiber

13. Man Made Fibers
 Acetate:
 Acetate burns readily with a flickering flame that
cannot be easily extinguished. The burning cellulose
drips and leaves a hard ash. The smell is similar to
burning wood chips.
 Acrylic:
 Acrylics burn readily due to the fiber content and the
lofty, air filled pockets. A match dropped on an acrylic
blanket can ignite the fabric which will burn rapidly
unless extinguished. The ash is hard. The smell is
acrid or harsh

14. Acrylic FiberAcetate Fiber

15.  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.
 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.

16. Polyester FiberNylon Fiber

17.  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

18. Rayon Fiber

19. Fiber burn chart

20. LIMITATION OF BURNING TEST
 It is apparent that many fibers have similar
burning reactions that might cause doubt
and occasional confusion.

21. TECHNICAL TESTS
 There are certain technical tests performed for identifying
various fibers. These tests require high technology
laboratory equipment and are much more reliable than
the non technical fiber tests.
 Technical tests require high skilled personnel and
technical know how of handling chemicals and their
accurate analysis. These tests are very valuable for
those fabrics that are a blend of different yarns and also
have certain special properties including flame
retardance etc.

22. TYPES OF TECHNICAL TEST
 Microscopic test
 Chemical test

23. MICROSCOPIC TEST
 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

24. MICROSCOPIC TEST FOR NATURALFIBERS
 COTTON:
○ It is a single elongated cell. Under the microscope,
it resembles a collapsed, spirally twisted tube with
a rough surface.
○ The thin cell wall of the fiber has from 200 to
400convolutions per inch.
 LINEN:
○ Under the microscope, the hair like flax fiber
shows several sided cylindrical filaments with
fine pointed ends.
○ The fiber somewhat resembles a straight,
smooth.

25. Cotton Fiber Linen fiber

26.  WOOL:
○ Under the microscope , wool’s cross section shows three
layers- epidermis, cortex and the medulla.
 SILK:
○ It appears somewhat elliptical and triangular in cross section
when we see under the microscope.
○ It is composed of fibroin, consisting of two filaments, called
brin which is held together by sericin.

27. Silk fiberWool fiber

28. 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.

29. Acetate fiber Rayon fiber

30.  NYLON:
 The basic microscopic appearance is generally
fine ,round, smooth, and translucent.
 It is also produced in multilobal cross-sectional
types.
 POLYESTERS:
 Generally, polyester fibers are smooth and
straight and the cross-section is round.
 This general characteristics may be altered to
achieve certain characteristics.

31. Polyester fiberNylon fiber

32.  ACRYLICS: The methods of manufacturing of the
acrylic fibers differ, the appearances vary
accordingly.
 ACRILAN ACRYLIC: It has a bean-shaped cross
section, its longitudinal appearance is straight and
smooth.
 ORLON ACRYLIC: It has a flat, nut-shaped cross
section.
 CRESLAN ACRYLIC: It has an almost round cross
section.
 MOD ACRYLICS: it is of two types verel mod acrylic
and SEF mod acrylic.

33.  SPANDEX: Spandex fibers are unique in appearance, they
appear to be groups of fibers fused together.
 GLASS: The fiber is smooth, round, translucent, highly
lustrous, and quite flexible.
 Asbestos fiber: This method is for the analysis of
asbestos in air by Phase Contrast Microscopy. Results are
reported as fibers per cubic centimeter and depend on the
volume of air sampled. PCM analysis is not asbestos fiber
specific and will count all fibers meeting the methods criteria for
fiber determination.

34. CHEMICAL TESTS
 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 under taken to
establish the identity of the fibers used.
 These tests give accurate and precise analysis.
 The tests are conducted in research laboratories.

35. TYPES OF CHEMICAL TEST
 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.

36.  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.

37.  Distinguishing animal from vegetable fibers with an acid :
 As strong alkali destroy animal substances, a 5%of soda
lye solution in water can be used to eliminate wool and
silk fibers from a sample that contains a mixture of fiber.
The vegetable fibers will not be affected by this solution.
 Distinguishing vegetable from animal fibers with an acid
 As dilute acid destroy vegetable fibers, a 2%sulphuric
acid solution can be used. A drop of solution is placed on
the sample, which is then pressed with a hot iron. The
spotted area will become charred if the sample is cotton
linen or rayon.

38.  DISTINGUISHING SILK FROM WOOL:
○ The use of concentrated cold hydrochloric
acid will dissolve the silk and the wool fiber
swells.
 DISTINGUISHING NYLON FROM OTHER
FIBRES:
○ If the fabric is thought to contain nylon, the
fabric may be immersed in a boiling solution of
sodium hydroxide. The nylon is insoluble in
such a solution

39.  DISTINGUISHING POLYESTERS
FROMOTHER 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.
 DISTINGUISHING ACRYLICS
FROMOTHER FIBRES:
○ Acrylic fibers will dissolve in 70 percent solution of
ammonium thiocyanate at 130 degree Celsius but the other
fibers will not.

40.  DISTINGUISHING LINEN FROM COTTON
○ Cotton 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.
 DISTINGUISHING GLASS FIBERS FROM
OTHERFIBRES:
○ There are two specific solvents for quick identification of
glass fibers, they are hydrofluoric acid and hot
phosphoric acid.

41.  Advantages:
•More reliable than the non technical tests.
•Used for both man made fibers and natural fibers.
•Easily conducted.
 Limitations
•Certain manufacturing and finishing processes like
mercerizing, affects the appearance of the fibers under the
microscope.
•Very dark colored fabrics cannot be identified under
microscope.
•Dye stuffs must be removed from fabrics.

42. Submitted To: Sir Imran
Raza
Submitted by: Huzaifa Amin
(Tmm-01)