Assignment # 01BY : 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

CHEMICAL ANALYSIS:- Resistance to fire

- Leather is inherently resistant to heat and flame.

Resistance to fungi- Leather is resistant to mildew.

Leather Fiber