This document discusses methods for identifying different types of fibers, including cotton, wool, linen, silk, acetate, rayon, and polyester. The three main methods discussed are burn testing, microscopic analysis, and chemical tests. Burn testing examines how the fiber burns and what it smells like. Microscopic analysis looks at the fiber structure and appearance under a microscope. Chemical tests investigate how the fiber reacts to specific solutions to determine its composition. The document provides details on the characteristics examined for each fiber using these three identification methods.

1. Hamza sameen
Assignment of
Textile
Method of identification of fiber:-
 Through burn test.
 Through Microscopic Analysis.
 Behaviors in Solution.
Identification of cotton fiber by burn:-
Burns, but does not melt. It has the odor of burning
paper leaves, or wood. The residue is a fine, feathery,
gray ash.

2. Microscopic analysis:-
 The cotton fiber is a single elongated cell.
 Under a microscope, it looks like flat, spirally
twisted ribbon like tube with rough granular
surface.
 However, mercerized cotton doesn't 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 400
convolutions per inch.


3. Chemical test:-
 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.
WOOL FIBER:-

4. Burn testing:-
 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.
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5.  Wool 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.
Chemical Test:-
 The use of concentrated cold hydrochloric acid will dissolve
the silk and the wool fiber swells.

6. LINEN:-
Burn Test:-
 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.
Microscopic analysis:
 Under the microscope, the hair like flax fiber shows
several sided cylindrical filaments with fine pointed
ends.
 The fiber somewhat resembles a straight, smooth.

7. Chemical Test:-
 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.
SILK:-
Burning Test:-
 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.

8. Microscopic analysis:
 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 brim which
is held together by service.

9. Chemical Test:-
 The use of concentrated cold hydrochloric acid will
dissolve the silk and the wool fiber swells.
Man Made Fibers:-
Acetate:
Burning test:
 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.
Microscopic analysis:
 The cross sectional view has a bulbous or multi global
appearance with indentations.

10.  These
indentations appear as occasional markings.
Rayon:-
Burning test:
 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 .

11. Microscopic analysis:
 Rayon fibers have a glasslike luster under the
microscope and appear to have a uniform diameter
when viewed longitudinally

12. POLYESTERS:
Burning test:
 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.

13. Microscopic analysis:-
 Generally, polyester fibers are smooth and straight
and the cross-section is round.
 These general characteristics may be altered to
achieve certain characteristics.
CHEMICAL TEST:-
 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.