2. BURN TEST :-
Burn with a yellow
flame, light smoke,
and have glowing
embers. Cellulosic
fibers do not melt
or draw away from
flames.The residue
is a fine, feathery,
gray ash.
3. MICROSCOPIC
STRUCTURE :-
Fiber look like a small
length of bamboo
under a
microscope.The
cellulose molecules are
folded back & forth in a
fairly regular
arrangement & they
show the property of
crystallinity.
4. CHEMICAL ANALYSIS :-
Flax fiber are weakened and destroyed by acids.
Acidic condition hydrolyze the flax polymer at
the glycoside oxygen atom , which links the tow
glucose units to form the cellobiose unit.
Mineral or inorganic acid being stronger that
organic acid , will hydrolyze the flax polymer
more rapidly.
Effect of sunlight.
Effect of alkalis.
Effect of bleaches.
5. BURN 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.
6. MICROSCOPIC
STUCTURE :-
1. Rod like
structure
2. Circular
3. High luster
4. Gum present on
the surface
5. No crimp.
7. CHEMICAL ANALYSIS :-
Silk is somewhat sensitive to heat.
This fiber is not affected by moisture. It does
not shrink or stretch when wet.
Effect of bleaches
Effect of alkalis
Effect of sunlight
Silk fiber is damaged by perspiration. Organic
acids do not harm silk, but concentrated mineral
acids will dissolve silk fiber.
8. BURN TEST :-
Has a somewhat
sweet chemical
odor. The residue is
initially a hard
cream-colored
bead that becomes
darker. Flames
gives off black
smoke.
9. MICROSCOPIC
STRUCTURE :-
Polyester filaments have
no identifiable
microscopic appearance.
The longitudinal
appearance of the fiber
is very regular and
featureless because of
the near circular cross-
section. The magnified
appearance of polyester
is similar to a glass rod.
10. CHEMICAL ANALYSIS :-
Acid: good resistance to acids in cold
condition.
Basic: good resistance to acids in cold
condition, but strong NaOH dissolves
polyester in boiling.
Polyester does not effected by bleaching
process.
Organic solvent does not effect on polyester
fiber.
Polyester could by dye with disperse, azoic
color and some pigments.
11. BURN TEST :-
Burns, but does not melt.
It shrinks from the flame.
It has a strong odor of
burning hair. The residue
is a black, hollow irregular
bead that can be easily
crushed into a gritty black
powder. It is self-
extinguishing, i.e., it
burns itself out.
13. CHEMICAL ANALYSIS:-
Wool is attacked by hot concentrated
sulphuric acid and decomposes it
completely.
It is sensitive to alkalis substances.
Wool affected by insects.
Wool fiber can be dye by organic dye,
direct dye and basic dye.
It affected with mildew if it remains wet
for a long time.
14. BURN TEST :-
Smell: paper/
burning leaves
Ignites: burns
readily with a
flickering flame that
cannot be easily
extinguished
15. MICROSCOPIC STRUCTURE :
Mature flat and ribbon like
with convolutions, thick
wall and small
lumenImmature very thin
wall and large lumen with
few convolutions-Kidney
Shaped
Elliptical
Very thin like a strip
Nearly round or circular-
16. CHEMICAL ANALYSIS :-
Cotton has an excellent resistance to
alkalis.
Cotton has high resistance to normal
cleaning solvents.
Cotton is not attacked by moth-grubs
or beetles.
Cotton is affected by fungi and bacteria.
17. BURN TEST :-
Burns quickly with
bright flame , does
not shrink from
flame. It smells like
burning leaves and
wood. The ash is
gray and smoke has
no fume hazard.
18. MICROSCOPIC
STRUCTURE :-
Mainly jute fiber are
composed of
cellulose, hemi-
cellulose and lignin.
It is harder than
other fiber because
of the presence of
lignin in its
structure.
19. CHEMICAL ANALYSIS:-
Easily damaged by hot dilute acids and
conc.: cold acid.
Fibers are damaged by strong alkali
Resistant to bleaching agents.
Color changes slightly in presence of sun
light.
Prevention ability id better than cotton and
linen.
Easy to dye. Basic dye is used to color jute
Fiber
21. MICROSCOPIC
STRUCTURE:-
The structure of rayon
fiber is generally is that of
smooth , inelastic filament
like glass rod. However
different processes ,
additives and finishes
techniques can vary the
physical appearance and
structure of the fiber.
22. CHEMICAL PROPERTIES :-
Rayon has moderate resistance to acids
and alkalis and generally the fiber itself
is not damaged by bleaches , however
dyes used in the fabric may experience
color change . As a cellulosic Fiber ,
rayon will burn but flame retardant
finishes can be applied.
23. BURN TEST:-
leather will not easily
catch flame, and it will
burn with a horrible
smell, like that of
burning hair. Synthetic
leather, on the other
hand, will melt and
smell like burning
plastic.
24. MICROSCOPIC STRUCTURE:-
A scanning acoustic microscope
(SAM) has been used to
investigate the structure of
thermoplastic leather. This
material is formed by pressing
fibers of leather under high
pressure and moderate
temperature. The result is a
matrix from transformed, melted
fibers in which leftover fibers act
as reinforcement. Unlike the
scanning electron microscope
(SEM), the SAM is able to
distinguish between completely
and incompletely transformed
fibers and also to penetrate the
material beneath the surface.
25. CHEMICAL ANALYSIS:-
Resistance to fire
- Leather is inherently resistant
to heat and flame.
Resistance to fungi
- Leather is resistant to mildew.
