A simple and easy way to identify fabric composition is combustion.
     
Methods: a piece of cloth yarn containing warp and weft yarn was drawn at the edge of the garment, ignited with fire, observed the state of the burning flame, sniffed the smell of the yarn after burning, and observed the residue after burning, so as to judge whether the fabric composition marked on the clothing durability label was consistent, so as to distinguish the authenticity of the fabric composition.
      
Cotton fiber and hemp fiber
     
Both cotton and hemp fibers are just burning near the flame, burning fast, the flame yellow, emitting blue smoke. The difference between the two odours and the ashes after burning is that the burning of cotton gives out the smell of paper, and the burning of wood gives off the smell of grass and ashes. After burning, cotton has very little powder ashes, black or gray, and a small amount of ash and ashes.
        
Two. Wool and silk
     
When the hair is smoked and smoked, it burrows when burning, burning slowly, emitting the odour of burning hair. After burning, most of the ashes are glossy black spherical particles, and fingers press and crush. Silk shrunk in the fire, burning slowly, accompanied by hissing sound, emitting a hairy burning smell, burning black brown small spherical ashes, hand twist is broken.
     
Three, nylon and polyester fiber
     
Polyamide fiber, a polyamide fiber, is rapidly curled into a white colloid. It burns, burns and bubbles in the flame. There is no flame when it burns. It is difficult to continue burning after leaving the flame, and it gives off the celery flavor. After cooling, the light brown melts are not easy to be broken.
Polyester fiber name is polyester fiber, easy to ignite, near the flame that melt shrinkage, burning when melting black smoke, a yellow flame, emitting aromatic odor, burned black brown hard lump, with fingers can be twisted.
      
Four. Acrylic fiber and polypropylene fiber
     
Acrylonitrile polyacrylonitrile fiber, which melted and melted near the fire, ignited black smoke after burning. The flame was white, burning rapidly from the flame, emitting the bitterness of burning meat, burning ashes for irregular black lumps, hand twisting and fragile.
Polypropylene fiber is known as polypropylene fiber, which is near flame, which is melted and flammable. It is flammable. It burns slowly from the fire and smoked black. The flame is yellow at the top and blue at the bottom, emitting oil smell. The burnt ashes are hard round brown, and the hands are twisted and fragile.

Five, vinylon and polyvinyl chloride
     
Polyvinyl formal fiber is not easy to ignite, and the flame is melted and contracted at the top. There is a little flame at the top of the flame. When the fibers are melted into a jelly flame, it has a thick black smoke and a bitter fragrance.
The polyvinyl chloride fiber, known as the polyvinyl chloride fiber, is difficult to burn. It is extinguished from fire. The flame is yellow, and the lower part is green and white. It gives off pungent, pungent, sour taste. After burning, the ashes are dark brown, irregular hard lumps, and fingers are not easy to twist.

Six, spandex and fluorine fiber
     
The spandex name is polyurethane fiber. It burns near the edge of the fire. When it burns, the flame is blue, leaving the fire to continue to melt and emit a special pungent odor. After burning, the ash is soft and fluffy. Polytetrafluoroethylene (PTFE), known as fluorine fiber, is called fluorite fiber by ISO. It is only melting near flame. It is hard to ignite and burn. The edge flame is blue-green and carbonized and melted and decomposed. The gas is poisonous, and the melting material is hard round black bead. Fluorine fiber is commonly used in the textile industry to produce high-performance sewing thread.
        
Seven. Viscose fiber and cuprammonium fiber
     
The viscose fiber is flammable, the burning speed is very fast, the flame is yellow, it sends out the scent of burning paper, and the ashes are less after the burning. Cuprammonium fiber, commonly known as tiger kapok, burns near flame, burning fast, flame yellow, emitting acid taste, burning little ash, only a small amount of gray ash.