Assignment # 01 BY : Zara Zaheer
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.
Flax Fiber (Linen)
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.
Flax Fiber (Linen)
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.
Flax Fiber (Linen)
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.
Silk Fiber
MICROSCOPIC STUCTURE :-
1. Rod like structure
2. Circular 3. High luster 4. Gum present on
the surface 5. No crimp.
Silk Fiber
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.
Silk Fiber
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.
Polyester Fiber
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.
Polyester Fiber
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.
Polyester Fiber
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.
Wool Fiber
MICROSCOPIC STRUCTURE:-
Wool fiber has irregular, roughly, cylindrical, multi cellular structure with tapered ends.
Wool Fiber
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.
Wool Fiber
BURN TEST :- Smell: paper/
burning leaves Ignites: burns
readily with a flickering flame that cannot be easily extinguished
Cotton Fiber
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-
Cotton Fiber
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.
Cotton Fiber
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.
Jute Fiber
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.
Jute Fiber
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
Jute Fiber
BURN TEST :- Action: melts Flame color:
orange/blue Residue: hard/light
color round bead Odors: celery
Nylon Fiber
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.
Nylon Fiber
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.
Nylon Fiber
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.
Leather Fiber
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.
Leather Fiber