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Home » Knowledge Center »  Academic Reports »   Fabric Identification The Burn Test


Fabric Identification The Burn Test


Burn TestThose who are related to textile in any way, need to know the process of Fabric Identification. A Textile manufacturer, wholesaler or a retailer will have to know what fabric their prospective customers are going to buy and how they will test the end product- the finished fabric. This will equip them to make a fabric having quality that will pass the designated test for it. On the other hand, the customers who can be anyone- a fashion designer, textile designers, tailor, garment manufacturer, manufacturer of other textile products or simply a homemaker who wants to sew a dress at home, they all will need a particular type of fabric to make their ultimate desired product. It is better for them to test the fabric before putting it to use which will save both time and efforts in the long run.

Burn Test- Precautions and the Method
Burn test is the most accepted method for identifying the true nature of any fabric. This test is carried out to know whether a fabric is made up of a natural fiber, man made fiber, or a blend of natural and man made fibers.

Precautions
Burning Flame The burn test has to be carried out with great precaution. Arrangement of water near the site of test should be made. The test should be done in a metal bucket, an old tuna tin or a glass ashtray. Plastic containers should always be avoided. If the dish contains soda or even water at its bottom, its great.

The Method

To identify the fibers in an unknown piece of fabric, a snippet should be cut off from it. This specimen should be about 1" long and a triangle at most 1/4" wide. The snippet of fabric should be held in a pair of tweezers over the dish (which has already been made fireproof). With either a match or cigarette lighter, the snippet should be put directly into the flame long enough for it to catch on fire.

Most of the fabrics burn and they have to be extinguished. There are other fabrics that burn until there is nothing to burn, or they burn and go out on their own after a few seconds leaving remaining unburned fiber and are therefore self-extinguishing. There are certain other fabrics that does not burn even with a flame held directly to it.

Fibers can also be identified through the smell of the smoke it gives off in burning, and the ash or melted bead that remains after it has burned. Some of the fabrics are blends, and the blend of fibers may make the burn test rather unreliable test for fiber content. Moreover, some fabrics have chemical finishes and sizings applied to them that will change the way they burn, making the burn test further unreliable.

The fiber burn chart given below helps in identifying the nature of the fibers on the basis of their burning characteristics and the smell and other properties of the remains such as smoke, ash etc.

Reaction of Fibers to the Burn Test
Cotton
Burned Cotton 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.

Hemp
A cellulose fiber, burns quickly with bright flame. It leaves no melted bead and after burning no sign of flame is seen but it does not melts. It smells like burning leaves or wood. The ash is gray and smoke has no fume hazard.

Jute
Also a cellulose fiber, doesnt shrink from flame. Other characteristics are similar to those of hemp fabric.

Linen (Flax)
A cellulose fiber, it takes longer to ignite. It is easily extinguished by blowing on it. Other properties are similar to hemp and jute.

Rayon
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.

Silk
Burned Silk 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.

Wool
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.

Acetate, Triacetate
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.

Nylon, Polymide
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.

Polyester
Burned Polyester 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.

Acrylic, Modacrylic, Polyacrylic
Burned Acrylic 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.

As the procedure of fabric identification helps to ascertain the structure of the materials, it is essentially undertaken by the weavers and other textile companies. The textile industry uses various machines, such as, inspection machine, burn machine, fabric dyeing machine, fabric insulation machine and such other machines for carrying out the burn tests of fabrics. The fashion industry is one of its most important aspect as they make specific demands for special or usual cloth materials. The enormous reputations of many famous fashion designer brands are regularly rising all over the world and their clothing lines have special labels declaring to have passed fabric burn tests.