Three major identification methods of textile fabrics

The identification of textile fabrics can mainly start from three directions, the composition of textile fabrics, the front and back sides of textile fabrics, the warp and weft directions, and the appearance quality of textile fabrics. By identifying these three directions, fabric buyers can help fabric buyers find good fabrics with high quality and low price. .

Identification of textile fabric components

1. Sensory identification method

(1) Main methods

Visual inspection: Use the visual effects of the eyes to observe the luster, dyeing, roughness of the surface, and the appearance characteristics of the tissue, texture, and fibers of the fabric.

Hand touch: Use the tactile effect of hands to feel the softness, smoothness, roughness, fineness, elasticity, warmth and coldness of the fabric. You can also feel the strength and elasticity of the fibers and yarns in the fabric with your hands.

Hearing, nose and smell: Hearing and smell are helpful in judging the raw materials of certain fabrics. For example, silk has a unique silky sound; different fiber fabrics have different tearing sounds; acrylic and wool fiber fabrics have different smells, etc.

(2)Four steps

The first step is to initially distinguish the major categories of fibers or fabrics

The second step is to further determine the type of raw materials based on the sensory characteristics of the fibers in the fabric

The third step is to make a final judgment based on the sensory characteristics of the fabric

The fourth step is to verify the judgment results. If you are not sure about your judgment, you can use other methods to verify it. If the judgment is wrong, sensory identification can be carried out again or combined with other methods for identification

2. Combustion identification method

Combustion characteristics of common textile fibers

① Cotton fiber burns when exposed to fire. It burns quickly and produces a yellow flame with an odor. It has a slight gray-white smoke and can continue to burn after leaving the fire. After the flame is blown out, there are still sparks that continue to burn, but the duration is not long; burning It can maintain its original velvet shape and easily breaks into loose ash when touched. The ash is gray and soft powder, and the burnt part of the fiber is black

② Hemp fiber burns very quickly, softens, does not melt, does not shrink, produces yellow or blue flames, and has the smell of burning grass; it continues to burn rapidly after leaving the flame; there are few ash, and it is light gray or white grass ash powder

③ Wool does not burn immediately when exposed to flame. It curls first, then smokes, and then the fiber bubbles and burns; the flame is orange-yellow, and the burning speed is slower than that of cotton fiber. It stops burning immediately after leaving the flame, and is not easy to continue burning. It may burn hair and The odor of feathers; the ash cannot keep the original fiber shape, but is in the form of amorphous or spherical shiny dark brown brittle pieces, which can be crushed when pressed with your fingers. The amount of ash is large and has the smell of burning

④ Silk burns relatively slowly, melts and curls, shrinks into a ball when burned, and has the smell of burning hair; it has a slight flash when leaving the flame, burns slowly, and sometimes self-extinguishes; the ash is a dark brown crispy ball, which can be touched with your fingers Breaks into pieces

⑤The burning behavior of viscose fiber is basically similar to that of cotton, but viscose fiber burns slightly faster than cotton fiber and produces less ash. Sometimes it is not easy to maintain its original shape. Viscose fiber will make a slight hissing sound when burning

⑥ Acetate fiber burns quickly, has sparks, melts and burns at the same time, and has a pungent smell of acetic acid when burning; when leaving the flame, it melts and burns at the same time; the ash is black and shiny irregular lumps, which can be used with fingers crush

⑦Cupro ammonia fiber burns very quickly, does not melt, does not shrink, and has the smell of burning paper; it continues to burn rapidly after leaving the flame; it has less ash and is light gray or off-white

⑧ Nylon, when it is close to the flame, it causes the fiber to shrink. After contacting the flame, the fiber shrinks rapidly and melts into a transparent gel with small bubbles

⑨ Acrylic fiber melts and burns at the same time, and the burning speed is fast; the flame is white, bright and powerful, sometimes with a slight black smoke; it has a fishy or spicy smell similar to burning coal tar; it continues to burn after leaving the flame, but the burning speed is slow; Ashes are dark brown irregular brittle balls that are easily crushed with fingers

⑩ Vinylon, when burned, the fiber shrinks rapidly and burns slowly, the flame is very small and almost smokeless; when the fiber melts in large quantities, it will produce a larger dark yellow flame with small bubbles; it has a special smell of calcium carbide gas when burned; It continues to burn away from the flame and sometimes self-extinguishes; the ashes are dark brown irregular brittle beads that can be crushed with your fingers

⑪ Polypropylene, while curling, melts and burns slowly; there is a bright blue flame, thick black smoke, and gelatin dripping; it has a smell similar to burning paraffin; it continues to burn away from the flame, sometimes it will self-extinguishes; the ashes are not Regular hard lump, transparent, not easy to crush with fingers

⑫ Chlorine fiber is difficult to burn; it melts and burns in the flame and emits thick black smoke; it is extinguished immediately after leaving the flame and cannot continue to burn; it has an unpleasant pungent chlorine smell when burning; the ashes are irregular dark brown lumps, which are difficult to use with fingers Twist

⑬Spandex, when approaching the flame, first expands into a round shape, then shrinks and melts; it melts and burns in the flame, the burning speed is relatively slow, and the fire� It is yellow or blue; it burns while melting away from the flame, and slowly self-extinguishes; it has a special pungent smell when burning; the ashes are white sticky lumps

3. Density gradient method

The identification process of the density gradient method is: first configure the density gradient liquid. The configuration method is to properly mix two light liquids and heavy liquids with different densities that can be mixed with each other. Generally, xylene is used as the light liquid and carbon tetrachloride is used. Heavy liquid uses diffusion to diffuse light liquid molecules and heavy liquid molecules at the interface of the two liquids, causing the mixed liquid to form a density gradient liquid with a continuous change from top to bottom in the density gradient tube. Use standard density balls to calibrate the density values at each height. Then, the textile fiber to be tested is pre-treated such as deoiling and drying, and is made into small balls. The small balls are put into the density gradient tube one by one, and the density value of the fiber is measured and compared with the standard density of the fiber to identify the fiber. type. Because the density gradient fluid changes with temperature, it is important to keep the temperature of the density gradient fluid constant during testing

4. Microscopic observation

By observing the longitudinal shape of textile fibers under a microscope, the major categories to which they belong can be distinguished; by observing the cross-sectional shape of textile fibers, the specific name of the fiber can be determined

5. Dissolution method

For pure textile fabrics, when identifying, a certain concentration of chemical reagents should be added to the test tube containing the textile fibers to be identified, and then the dissolution of the textile fibers should be observed and carefully distinguished (dissolved, partially dissolved, slightly soluble, insoluble), and Carefully record the temperature at which it dissolves (dissolution at room temperature, dissolution by heating, dissolution by boiling)

For blended fabrics, when identifying, you need to first split the fabric into textile fibers, then place the textile fibers on a concave glass slide, unfold the fibers, drop in chemical reagents, and observe them under a microscope. Observe the dissolution of component fibers and determine the type of fiber

Since the concentration and temperature of chemical solvents have a significant impact on the solubility of textile fibers, when using the dissolution method to identify textile fibers, the concentration and temperature of chemical reagents should be strictly controlled

6. Reagent coloring method

The reagent coloring method is a method to quickly identify textile fiber varieties based on the different coloring properties of various textile fibers to a certain chemical reagent. The reagent coloring method is only applicable to undyed or pure spun yarn and fabrics. Colored textile fibers or fabrics must be decolorized

/Editor’s note: For scientific and systematic identification methods, please see relevant testing standards//

Identification of front and back sides and warp and weft directions of textile fabrics

1. Identification of the front and back sides of textile fabrics

It can be roughly divided into identification based on the organizational structure of textile fabrics (plain weave, twill, satin), identification based on the appearance effect of textile fabrics (printed fabrics, leno fabrics, towel fabrics), identification based on the pattern of textile fabrics, identification based on the characteristics of textile fabrics Fabric edge feature identification, identification based on the appearance effect of textile fabrics after special finishing (fleece fabrics, double-layered multi-layer fabrics, burnt-out fabrics), identification based on the trademarks and seals of textile fabrics, identification based on the packaging form of textile fabrics

2. Identification of warp and weft directions of textile fabrics

It can be based on the selvage identification of textile fabrics, the density identification of textile fabrics, the raw material identification of yarns, the twist direction identification of yarns, the structure identification of yarns, the identification of sizing conditions, the identification of reed marks, and the warp and weft yarn density of fabrics. , twist direction and twist identification, based on the stretchability of the fabric

Identification of Appearance Quality of Textile Fabrics

1. Textile fabric defect identification

Defects in textile fabrics include broken warps, sunken yarns, skipping flowers, open edges, cobwebs, holes, rovings, slub yarns, belly yarns, double wefts, tightly twisted yarns, uneven evenness, thinning, and thin wefts. Thin sections, dense sections, thick sections, edge defects, neps and impurities, stains, color strips, rungs, missing wefts, hundreds of feet, creases, shuttle rolling, damage, wrong weft, loose warp, reed path, reed Defects such as wrong threading, narrow width, reverse twill, pattern discrepancy, color difference, color bars, stripes, streaks, pattern discrepancies, fine dots, skew, printing deviation, desizing, color flowers, and staining can be repaired according to the appearance characteristics. Identify

2. Identification of deteriorated textile fabrics

The main methods are looking, touching, listening, smelling and licking

Look, observe the color and shape of the fabric, and whether there are any traces of deterioration. Such as wind stains, oil stains, water spots, mildew spots, staining, discoloration or unusual characteristics that are different from normal fabrics

Touch and hold the fabric tightly with your hands to feel if there are any symptoms of deterioration such as stiffness, moisture, or heat

Listen, the sound produced by tearing the fabric is compared with the crisp sound produced by the normal fabric. If the sound is dumb, dull, or silent, it may have deteriorated

Smell, by smelling the fabric, you can tell whether the fabric has deteriorated. Except for specially finished fabrics (such as coated with rainproof agent or treated with resin, etc.), any smell that has a strange smell, such as acid, mildew, bleaching powder, etc., indicates that the fabric has deteriorated

lick, passAfter licking the fabric, if there is moldy flour or a sour smell, it means it has become moldy

If you learn these methods, you will no longer be a fabric novice. Identifying fabrics can be done in minutes