There are many methods for identifying fibers, including combustion method, microscope observation method, density measurement method, dyeing method, reagent coloring method and dissolution method. With only one method, it is generally not possible to immediately determine the type of fiber, and a comprehensive analysis must be performed based on the test results of several methods. For the initial identification, you can first use the less time-consuming combustion method or microscope observation method. When this method cannot meet the requirements, other methods are used to supplement the identification.
Combustion characteristics of various fibers:
| Fiber name | Burning state | Smell | Ash state |
| Cotton, viscose, linen, cuprammonium fiber | Fast burning, automatic spread, the burnt part is dark brown | Smell of burning paper | Off-white powder |
| Silk, wool | Curling and burning, foaming and burning at the same time | Smell of burning hair | Crunchy black lumps or round beads |
| Acetate fiber | Melt and shrink near the flame, touch the flame and burn, leave the flame and continue to burn | Smell of acetic acid | Loose and crisp black ash, unburnt part is black |
| Nylon fiber | The flame melts and shrinks near the flame, and the flame burns and melts slowly when contacting the flame. | Smell of ammoniate | Like a transparent glass ball, stretched linearly before cooling |
| Polyester fiber | Near flame melting and shrinking, burning slowly when contacting flame, leaving flame to continue burning | Aroma | Hard black round beads |
| Acrylic fiber | Near flame melting and shrinking, contact with flame melting and burning black smoke | Off-odor | Unshaped black hard block |
| Vinylon fiber | Close to the flame, it shrinks on one side and burns on the other, with black smoke | Smell of special sweetness | Irregularly shaped black ashes |
| Polyvinyl chloride fiber | Close to the flame to melt and contract, contact with the flame to burn, leave the flame to extinguish by itself | Off-odor | Crisp black ashes |
| Polypropylene fiber | Burning while melting near the flame | Slight bitumen odor | Hard yellowish brown balls |