IDENTIFICATION OF FIBERS

• BY BURN TEST

• BY CHEMICAL TEST

• BY MICROSCOPIC TEST

COTTON FIBER BURNING TEST: Is a cellulose fiber. It burns and may flare up when lit. No melted bead is left by it. After burning, it continues to glow. It gives out smell like that of a burning paper. The smoke is gray or white. The ash is fine, soft that can be easily crumbled.

MICROSCOPIC TEST: COTTON is derived from a cotton plant. The fibers appear as flat ribbons under the microscope that are slightly twisted. The fabric that cotton produces is soft, absorbs water, and wrinkles easily. Cotton is a fabric that is light and cool.

CHEMICAL TEST: Cotton are immersed in a 1% solution of fuchsine in alcohol to give red rose color. Later ,they are washed and immersed into ammonia, cotton does not retains the coloration.

LINEN FIBER BURNING TEST: A cellulose fiber, it takes longer to ignite. . Other properties are similar to hemp and jute. The fabric closest to the ash is very brittle. Linen is easily extinguished by blowing on it as you would a candle.

MICROSCOPIC TEST:

LINEN is derived from the stems of flax plants fibers are jointed, looks like a miniature bamboo. The fiber is shiny, strong, gets softer with use, absorbs water, and wrinkles easily. Linen gets softer with use and considered a cool fabric for warmer climate.

CHEMICAL TEST: 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 FIBER BURNING TEST: Is a protein fiber which burns slowly and curls away from the flame. It leaves dark bead which can be easily crushed. It is self-extinguishing and leaves ash that is dark, gritty, fine powder. It smells like burned hair or charred meat. It gives out a little or no smoke and the fume has no hazard.

MICROSCOPIC TEST: SILK is from the cocoons of silkworms. The fiber is double strands, smooth, and shiny. The fabric is lightweight but can keep its wearer warm.

CHEMICAL TEST: The use of concentrated cold hydrochloric acid will dissolve the silk .

WOOL FIBER BURNING 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.

MICROSCOPIC TEST: Under the microscope , wool’s cross section shows three layers- epidermis, cortex and the medulla. it looks like scaly corkscrews. The fiber is stretchable long lasting, doesn't wrinkle and springs back into shape. Wool easily absorbs water, and soft. Wool fabric is known for its ability to "breathe" keeping wearers warm in the winter and somewhat cool in warmer weather. Wool picks up static electricity easily when rubbed.

CHEMICAL TEST: The use of concentrated cold hydrochloric acid will Swells the wool fiber .

POLYESTER BURNING 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.

MICROSCOPIC TEST POLYESTER is derived from petroleum. Under the microscope the rod shaped fiber looks like nylon but is not clear. The fiber does not wrinkle, is silk-like, strong, and absorbent.

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 .

ACRYLIC BURNING TEST: Made from natural gas and petroleum, they flare up at match-touch, shrink from flame, burn rapidly with hot sputtering flame and drip dangerously. Beads are hard, dark, and with irregular shapes. They continue melting after flame is removed and are self-extinguishing. When burning, they give out strong acrid, fishy odor. Although no ash is left but their black smoke and fume are hazardous.

MICROSCOPIC TEST: ACRYLIC is made from petroleum. Under the microscope the fiber is dog-bone shaped with apparent cut ends. The fabric is lightweight, warm, and quick drying.

CHEMICAL TEST: Acrylic fibers will dissolve in 70 percent solution of ammonium thiocyanate at 130 degree Celsius but the other fibers will not.

NYLON BURNING 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.

MICROSCOPIC TEST: NYLON is derived from coal. The fibers under the microscope are smooth and clear rods. Nylon is shiny, tough, stretchable and melts under a hot iron. The fibers are nonabsorbent, quick drying, and doesn't wrinkle. the fabric is cool but clammy.

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

ACETATE BURNING TEST: Is a protein fiber which burns quickly and can flare even after flame is removed. The bead is hard, brittle, and can't be crushed. It melts into very hot bead and drips very dangerously. No ash is left by it and the smell is like hot vinegar or burning pepper. It gives out black smoke and the fume is hazardous.

MICROSCOPIC TEST: ACETATE is a created from wood. Under the microscope there are grooves that run the length of the fibers. Acetate is soft, smooth, and will melt under a hot iron. It does not absorb water. The fabric is cool

CHEMICAL TEST: Acetate it is not soluble in acetone, and unlike nylon it is not soluble in concentrated formic acid.