This article is developed from four aspects: the basics of fabric shrinkage (definition, principle, common…
Table of Contents
Common denim fabric classification
denim fabric can be divided into plain weave, twill weave, slub, etc. due to their different production processes, as shown in Figure 1.1. In terms of the ingredients contained in denim fabric, denim is divided into combed and carded, 100% cotton, cotton and linen blended with Lycra, etc. At present, the market is mainly popular ring yarn denim, warp and weft slub denim, overcolor and assorted denim, etc.
Figure 1.1 Types of denim fabric
Traditional denim vs. generalized denim
Traditional denim is a right twill fabric, which is made of indigo-dyed cotton warp yarns and white weft yarns interlaced three times. The woven yarn is woven with pure cotton natural fiber. The denim fabric has strong moisture absorption, good air permeability and no irritation to human skin. At the same time, indigo is a coordinated color that can match other colors. The thick special warp yarns are interwoven, and the color floats of the warp yarns and the white floats of the weft yarns are matched in proportion to form a cloth with clear blue and clear texture. In addition to the use of pure cotton yarn, denim fabric in a broad sense also use other fibers or synthetic fibers. The dyeing of warp yarns has also got rid of the traditional single indigo dyeing, and a variety of colors have appeared, making denim fabric from a single raw material, thick and single tone. Varieties are developing in a multi-variety and multi-color direction.
Characteristics of denim clothing
Due to factors such as raw materials, yarn characteristics, weaving methods, etc., the use of different processing techniques will cause denim fabric to have different appearance characteristics. The denim fabric is woven with coarse special yarn, and the finished product is thick and heavy. When tailored as a garment, the garment has a three-dimensional shape, unlike other fabrics, which is soft; at the same time, the denim fabric is wear-resistant, cost-effective, and is loved by consumers.
Common defect types of denim fabric
Denim fabric is a fabric that is woven with warp yarns dyed and sizing with indigo dye. In the production process of denim fabric, defects may occur in any process. The main defects of denim fabric are shown in Table 2.1.
|Denim fabric defect types||Defect specific names||Causes and appearance|
|Raw yarn defects||Thick warp||One warp is thicker than others|
|Thick weft||A weft yarn is thicker with faint white streaks|
|Uneven yarn||The cloth surface is unevenly wavy, with faintly visible nodular white marks|
|White star defects on cloth||The neps and impurities on the weft yarn are woven into the cloth, and the cloth surface shows white star defects|
|Dying defects||Shade bar||The cloth surface shows traces of different shades of color in the weft direction|
|Color difference between head and tail||Color difference between cloth head and cloth tail|
|Warp color streak||The fabric has a dark or light streak in the warp direction|
|Weaving defects||Weft crease||When the loom is turned on, there are continuous streaks in the weft direction on the cloth|
|Warp break||One or more warps are missing in the warp direction of the fabric|
|Weft missing||Missing a weft in the twill weave|
|Disorder warp and weft||The warp and weft yarns on the cloth are in disorder|
|Finishing defects||Uneven singeing||Uneven singeing, feather-like warp stripes|
|Edge color difference||There are obvious differences in color on both sides of the cloth edge|
Table 2.1 main defects of denim fabric
Table 2.1 shows the causes and manifestations of denim fabric defects. Starting from the causes of defects, preventing denim fabric defects will help improve the grade of denim fabric, reduce the cost of later manual inspections, and improve corporate efficiency.
Analysis of defect characteristics of denim fabric
From the previous chapter, we know that in the process of denim fabric production, defects may occur in any production process. Defect detection is an important part of denim fabric production and quality management. At present, manual inspection is easily affected by subjective factors and lacks consistency. At the same time, working under strong light for a long time has a greater impact on workers’ eyesight.
Due to the wide variety of defects and diversified shapes, the denim fabric image data set in this paper uses high-definition denim images collected by the first-line textile workshop. There are 9576 images in total, including 5913 images with defects and 3,663 images without defects. Including defects such as knots, three threads, holes, oil stains, etc., the defect data of denim fabric is manually confirmed by experienced fabric inspectors and manually marked. The image resolution is 2446*1000, the feature details are clear, and the corresponding xml format information is generated file. The data set covers all kinds of important defects in denim fabric, and each image of denim fabric contains one or more defects. Common defects in denim fabric are shown in Figure 2.2 below.
Fig 2.2 Common defects of denim fabric
Perform statistical analysis on the denim fabric data set. The statistics of various defects are shown in Table 2.2, and the statistical graph of the denim fabric defects is shown in Figure 2.3.
|Defect name||Count (pcs)||Defect name||Count |
|Defect name||Count |
|Defect name||Count |
|Cloth slot||1528||Break warp||243||Weft missing||106||Reed Mark||64|
|Trash fiber||1037||Pulp spot||234||Dead wrinkle||100||Slippage yarn||63|
|Thick weft||646||Stains||233||Oily||98||Bad weft||56|
|Broken spandex||317||Thick warp||213||Slippage star||93||Uneven singeing||50|
|Hole||305||Slub||174||Repair mark||78||Wavy shading||36|
|Loose warp||297||Piercing||148||Rubbing crease||74||Color difference shading||26|
|Piercing||283||Stretched warp||143||Filling floats||69||Double weft||14|
|Hiding shading||262||Flower springboard||109||Water stain||69||Clouded thick and thin yarn||11|
Table2.2 Statistics of denim fabric defects
Testing standards on denim fabric
ASTM D6554 / D6554M – 14 Standard Specification for 100 % Cotton denim fabric
Contact us to get the free Pdf standard.