assignment about textile fiber

1. SUBMITTED TO: SIR IMRAN
RAZA
SUBMITTED BY: RABIA
MEHMOOD
CLASS: AMM-01
DATE: 28TH APRIL 2016

2. Identification of textile fibers
 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.
TYPES OF TEST
 Chemical Analysis
 Microscopic analysis
 Floatation Test
 Twist on Drying
 Burning test

3. Cotton fiber
 BURNT TEST
Ignites and burns quickly, may flare, leaves a glowing ember after flame is
extinguished. Smoke is white or light colored and smells like burnt paper or
leaves. Ash is light gray or white and very soft.
 MICROSCOPIC TEST:
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. 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.

4.  CHEMICAL TEST:
Cotton is immersed in a 1% solution of fuchsine in alcohol to give red rose
color. Later ,it is washed and immersed into ammonia, cotton does not
retains any coloration.

5. FLAX FIBER
 CHEMICAL TEST:
Linen is 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.
 BURNT 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.

6.  MICROSCOPIC TEST:
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. SILK FIBER
 BURNT TEST:
Burns, but does not melt. It shrinks from the flame. It has the odor of charred
meat. The residue is a black, hollow irregular bead that can be easily to a
gritty black powder. It is self-extinguishing, i.e., it burns itself out.
 CHEMICAL TEST:
The use of concentrated cold hydrochloric acid will dissolve the silk and the
wool fiber swells.

8.  MICROSCOPIC TEST:
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. 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.

9. RAYON FIBER
 BURNT TEST:
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.
 CHEMICAL TEST:
All rayon's will dissolve in a 60% solution of sulfuric
acid or a concentrated solution of hydrochloric acid.

10.  MICROSCOPIC TEST
Rayon fiber has uniform diameter with glass like shine. If delustered then rayon
fiber shows marks similar to pepper, when viewed cross sectionally. Viscose
fiber of rayon looks irregular when viewed cross sectionally.

11. POLYESTER FIBER
 BURNT TEST:
Is a polymer produced from coal, air, water, and petroleum products. It burns
quickly and shrinks away from flame, may also flare up. It leaves hard, dark,
and round beads. After the flame, it burns slowly and is not always self-
extinguishing. It has a slightly sweet chemical odor. It leaves no ash but its
black smoke and fume are hazardous.
 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.

12.  MICROSCOPIC TEST:
Generally, polyester fiber is smooth, straight. It looks round cross sectionally.
However, with various finishing processes, its appearance changes in
context of texture and luster. This general characteristics may be altered to
achieve certain characteristics.

13. WOOL FIBER
 BURNT TEST:
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.
 CHEMICAL TEST:
As strong alkali destroy animal substances, a 5%of soda lye solution
in water can be used to eliminate wool fibers from a sample that
contains a mixture of fiber. The vegetable fibers will not be affected
by this solution.

14.  MICROSCOPIC TEST:
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.

15. NYLON FIBER
 BURNT TEST:
Are made from petroleum. Due to their fabric finish, they quickly burn and
shrink to flame. The beads are hard, grayish and uncrushable. After flame,
they burn slowly and melt. They are self-extinguishing but drip dangerously.
Their odor is like celery and they leave no ash but the fume is very
hazardous.
 CHEMICAL TEST:
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. A fiber stained with dilute acetic acid turns to a specific
color. The same fiber when stained with mild alkali like soda
carbonate turns to a different color again specific to that fiber only.

16.  MICROSCOPIC TEST: There are many variants of nylon fiber.
However, generally it appears 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.

17. ACRYLIC FIBER
 BURNT TEST:
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.

18.  CHEMICAL TEST:
Acrylic fibers will dissolve in 70 percent solution of ammonium thiocyanate at
130 degree Celsius but the other fibers will not.
 MICROSCOPIC TEST:
It has an almost round cross section. ORLON ACRYLIC: It has a flat, nut-
shaped cross section. ACRILAN ACRYLIC: It has a bean-shaped cross
section, its longitudinal appearance is straight and smooth.