Various fiber identification methods

1. Hand feeling visual measurement method

It is to identify the fiber according to its appearance, color, hand feeling and stretching characteristics. It can be divided into natural fiber and chemical fiber. For example, the length of natural fibers is poor, and the length of chemical fibers is generally neat. Among natural fibers, cotton fibers are short and thin, often with impurities and defects. The hemp fiber feels rough and hard. Wool fibers are curly and elastic. Silk is long, thin and shiny.

Among the chemical fibers, viscose fiber has a large difference in dry and wet strength, and spandex has a high elongation. Using these characteristics, they can be distinguished. It is difficult to distinguish other chemical fibers by hand feeling and visual measurement because of their similar appearance characteristics and human behavior.

2. Combustion test method

Combustion method is a simple and convenient method to identify Knitting Polyester Yarns. He roughly distinguished the fibers according to the different burning characteristics of the fibers. The identification method is to take a small bundle of unknown fibers, clamp them with tweezers, slowly approach the flame, observe the burning state of the fibers when they approach the flame, contact the flame, leave the flame, as well as the odor emitted during combustion and the characteristics of the residues after combustion, so as to roughly identify the fibers.

Acetate fiber: it melts and shrinks near fire. It burns in case of fire, and the combustion speed is slow. Although acetate fiber is also a cellulose fiber, it is a semi synthetic fiber after acetic esterification. The ash is black, loose and brittle. The unburned part becomes hard.

Polyester: it shrinks, melts and smokes when burning. The flame is yellow. When burning, it emits fragrant smell. The ash is black brown glass and round, which can be broken by hand.

Nylon (nylon): it melts on one side and burns slowly on the other side in case of fire. When burning, it is smokeless or slightly white smoke. The flame is small and blue. It smells of celery when burning. The ash is light brown glass round and spherical, which is not easy to be broken.

Nylon: it shrinks quickly when approaching the fire and goes out when leaving the fire. There is a pungent chlorine smell when burning. The ash is amorphous black hard block.

Vinylon: it shrinks quickly when burning, but burns slowly. There are few flames and black smoke. There is aldehyde smell when burning. The ashes are brown amorphous hard blocks that can be crushed.

Acrylic fiber: it melts while burning in case of fire, and the burning speed is very slow. The flame is white and bright. Sometimes there is a little black smoke and a fishy smell. The ash is a small black hard ball, which is very fragile.

It is easy to identify fibers by combustion method, but it is difficult to judge blended products. For the woven fabric, one yarn is taken from the warp and weft direction (i.e. the straight and horizontal directions) and burned separately

The combustion method is only applicable to single component fibers, yarns and fabrics, while for mixed component fibers, yarns and fabrics, as well as flame-retardant or other finished fibers and textiles, it is often difficult to identify them by combustion due to changes in combustion characteristics