Many people in the garment industry refer to denim defects as “yarn running” (such as loose warp, thick warp, broken warp, etc.).
01 Original yarn defects
Thick warp
The diameter of a certain warp yarn is thicker than other warp yarns, as long as All defects that can be seen during inspection should be evaluated as gross defects.
Coarse weft
The diameter of a certain weft yarn on the cloth is thicker, showing a faint The visible white streaks are rough weft defects.
Uneven strands
are vaguely visible on the cloth. The weft yarn presents a corrugated shape with uneven thickness, which is an uneven evenness defect. Some use bamboo joints as wefts, which can easily produce regular patterns and also affect the appearance of the cloth.
Yellow and white stalls
Due to differences in weft yarn mix or spinning reasons , causing an obvious yellow-white dividing line in the weft direction when the two weft yarns are changed (usually more obvious on the reverse side of the cloth), which is called the yellow-white line. If it is still obvious after washing, it should be downgraded.
White stars on cloth
Due to neps and impurities on the weft When woven into cloth, white spots appear on the cloth surface, which are white star defects on the cloth surface.
02 Defects in pulp dyeing
Color file
The cloth surface shows traces of full-width straight strips of different shades of color.
Color difference between the head and the tail
The color difference between the head and the tail of the cloth, overlap at both ends The color difference can be clearly seen when they are together.
Color difference between the two sides or the sides
The color difference between the two sides or the sides of the cloth There is a difference in edge color, and the color difference can be clearly seen when superimposed and compared.
Striped pattern
The cloth shows straight strips in the warp direction Dark or light stripes.
Slurry spots
Partial wrinkling of the cloth surface caused by slurry Strange.
03 Weaving defects
Driving marks
Also known as parking marks, when the loom is started, there will be straight weft traces on the fabric, which also look like wavy streaks.
Loose warp
When weaving, the broken warp yarn did not stop and continued weaving. When the warp is broken, due to the small tension of the broken warp yarn, small circles are produced on the cloth surface called loose warps.
Broken warp and double warp
On a certain point on the cloth There is one warp yarn missing in the warp direction or two warp yarns side by side in one place, which is obviously different from the surrounding warp yarn structure.
Baijiao
The twill weave on the cloth is missing one thread The weft yarn is called a hundred-foot defect.
Jumping yarn and jumping pattern
Warp and weft yarns on the cloth The structure is disordered, with several warp threads floating on the cloth surface or several weft threads separated from the cloth surface. Less than 5 threads are skipping yarns, and more than 5 threads are skipping patterns.
04 Post-finishing defects
Burning Top flowers
The singeing is uneven or dirty, and the cloth surface shows meridional hairy stripes or meridional striped shadows of different colors/the whole cloth has a rain-like meridional depth. Irregular stripes of color.
Ruffles
After pre-shrinking, the selvedge Stretching, causing the wavy selvage/denim to loosen on one or both sides and become undulating.
The color difference of singeing
The appearance of the fabric surface after singeing of denim fabric Black or yellow or the cloth surface is partially yellowed and has short fluff.
Color on both sides
Color on both sides of the selvedge of denim fabric There are obvious differences.
Wrinkling
Wrinkles often appear regularly or irregularly on the edges of the fabric. Regular wrinkle defects, as well as irregular diagonal creases in parts of the fabric surface.
Weft arc
The trajectory of the weft yarn after being stretched is not a straight line Shaped, with severely bowed or even zigzag-shaped defects.
Incorrect skewing
After skewing, the weft inclination angle Or the slope value fails to meet or exceeds the process requirements too much.
Insufficient shrinkage or unstable shrinkage
After pre-shrinking After machine finishing, the pre-shrinkage rate cannot meet the requirements of the process regulations, and the shrinkage amount fluctuates.
Fish scale spots
Irregular weft arrangement appears partially or even entirely on the cloth surface It has a uniform and rough texture like fish scales.
Yellow spots on the back
The denim fabric is not desized cleanly or is not washed enough , causing the back of the white denim fabric to be stained with slurry, causing yellow spots to appear after drying.
Aurora
The denim fabric contacts the drying drum too much or is stressed Excessive size causes abnormal glare reflections.
Basic concepts of fabrics
1. Warp direction, warp yarn, and warp density: the length direction of the fabric; The yarns in this direction are called warp yarns; the number of yarns arranged within 1 inch is the warp density (warp yarn density);
2. Weft direction, weft yarn, weft yarn density: fabric Width direction; the yarn in this direction is called weft yarn, and the number of yarns arranged within 1 inch is the weft density (weft yarn density);
3. Density: used to indicate shuttle The number of yarns per unit length of a fabric is generally the number of yarns within 1 inch or 10 centimeters. China’s national standards stipulate that the number of yarns within 10 centimeters is used to indicate density, but textile companies are still accustomed to using 1-inch yarns. The number of lines represents the density:p>
6 Hemming: The edges of the fabric are rolled up into a rope shape.
7 Side brace defects: The edge yarn is scratched, fluffed or broken, there are small holes, and the fabric is deformed.
8 Terry edge: The weft of the fabric is looped and outside the edge of the fabric.
5. Fix defects
1 Defects in repair: Operate during repair Improper, excessively wooly, wrinkled or otherwise undesirable appearance of the fabric.
2 Darning marks: obvious traces left after defects have been darned.
3 Wash marks: marks left by cleaning fabrics.
6. Dyeing defects
1 Bleeding: dye during dyeing Penetrate into surrounding parts.
2 Wrinkled color strips: The fabric is folded during dyeing and finishing, resulting in uneven color and warp stripes at the folds.
3 Dye traces: Due to the action of overly concentrated dyes or auxiliaries, the local color of piece-dyed fabrics appears as scattered color block traces that are different from adjacent parts.
4 Halo defects: Some parts of the dyed fabric appear lighter in color.
5 Water stains: The fabric has traces of watermarks.
6 Spots: There are differences in color absorption between fibers, causing local color spots on the dyed fabric.
7 Warp stripes: The warp direction of the dyed fabric shows irregular stripes with slight color difference.
8 Pinching: Due to the difference in color absorption of fibers, color differences are formed on the fabric.
9 Color difference between front and back: There is a difference in color between the front and back ends of a piece of fabric.
10 Color difference of cloth edge: There is a difference in color between the cloth body and the cloth edge.
11 Left and right color difference: There is a color difference between one side and the other side along the width direction of the fabric.
12 Warp streaks: Due to the weaving of one or more fibers or yarns of other properties, which absorb different colors, single or multiple irregularities appear on the surface of the dyed fabric. Color, wrong color.
13 Rain-like streaks: Due to the unevenness of the warp yarns, rain streaks appear in the warp direction after dyeing.
7. Printing defects
1 Desizing: on printed fabrics Some patterns are missing color.
2 Glue slurry: The slurry is stained on the printed fabric outside the pattern.
3 Scraper stripes: There is excess color paste or warp stripes on the surface of the printed fabric.
4 Color files: There are color files of different shades on the fabric.
5 Inaccurate pattern registration: The relative positions of the patterns on the printed fabric are not accurate to each other.
6 Bleeding: The front and rear color pastes are not accurately connected, or two adjacent colors bleed at the boundary, so that the pattern of the printed fabric is blurred, or a third color appears. color.
7 Unpainted creases: Printed fabrics show unpainted narrow strips.
8 Lining printing: Imprints with different shades of color.
8. Finishing defects
1 Blanket marks: Appear on the fabric Texture or other indentations in the blanket tissue.
2 Loss of gloss: The fabric has lost its luster.
3 Scratch marks: marks left by the fabric being squeezed and scratched during the dyeing and finishing process.
4 Fuzzing: During the finishing process, the surface of the fabric is raised by friction.
5 Indentation: Due to uneven pressure during the finishing process, a certain part of the fabric is lighter or thinner than other normal parts.
6 Rope-shaped scratch marks: Due to improper rope-shaped handling, long longitudinal marks appear on the fabric.
7 Streaks: The fabric shows regularly spaced warp streaks.
8 Pinholes: There are pinholes near the cloth.
9 Deep needle marks: The needle marks penetrate into the fabric body, reducing the effective width.
10 Cloth clip marks: There are traces of scratches, shiny and different colors near the edge of the cloth.
11 Chicken scratch marks: There are varying degrees of chicken scratch-like wrinkles on the surface of the fabric.
12 Weft skew: The weft yarn is tilted or bent.
9. General defects
1 Jumping yarn or pattern : The warp and weft yarns are not interlaced according to the organization rules, showing irregular floating yarns. 1-2 warp (weft) yarns skipping 4 or more weft (warp) yarns are called skipping yarns, and the floating yarns formed by 3 warp and weft yarns each are called skipping patterns.
2 Spider web: 3 or more longitude and latitude roots are not intertwined according to the organizational rules and form a block.
3 Star jump: 1 warp (weft) skips 2-4 weft (warp) yarns without following the organization rules, and is interwoven into a star point shape.
4 Weft shift: The weft yarn shows irregular deviation.
5 Snagging: The yarn or fiber is hooked by foreign matter, forming a loop or the head end is exposed to the fabric surface.
6 Shuttle marks: marks caused by the shuttle being rolled between the buckle and the fabric, causing the fabric structure to be damaged.
7 Pilling: The fiber ends protrude and become entangled on the surface of the fabric to form a ball.
8 Foreign fibers are woven in: Fibers of different properties are mixed in during spinning or weaving, and will form different colors on the foreign matter after dyeing.
9 Holes: holes formed by the breakage of warp and weft yarns.
10 Stains: The fabric is stained with oil dust or other debris.
11 Uneven pile: Some of the fabric is stained There is excessive velvet in some areas, or insufficient velvet in some areas, resulting in uneven suede.
12 Inverted pile: The local pile of pile fabric is inverted.
13 Uneven velvet: The velvet surface of the fleece fabric has long protruding naps with inconsistent lengths.
14 Knife hair: The blade is unfavorable when cutting velvet, and part of the velvet on the velvet surface is slanted and loose.
15 Wrinkle rails: Due to the weft wrinkles of the fabric, they are not pulled down when brushing, forming a lint-free cross rail.
16 Local uneven pile density: The weft density in some parts of the fabric is larger or smaller, resulting in irregular rungs.
17 Skirt wrinkles: There are skirt wrinkles in the weft direction of the fabric.
18 Dead creases: finishing creases that cannot be removed.
This results in irregular rungs.
17 Skirt wrinkles: There are skirt wrinkles in the weft direction of the fabric.
18 Dead creases: finishing creases that cannot be removed.
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