1. Causes and solutions to possible problems in the production process of yarn-dyed fabrics
1 Weaving defects
Weaving defects in the warp or weft direction appear regularly or irregularly on the fabric.
The main reasons:
①The yarn used is not strong enough.
②Poor sizing of the yarn (light sizing or heavy sizing).
③ Defective weaving equipment (faulty weaving equipment may cause yarn breakage and other problems).
④The repair of the gray cloth under the machine is incomplete.
⑤The acceptance of finished products is not careful.
Solution: Strengthen repairs.
2 Weft bias/weft arc (including large and small grids)
For woven and knitted fabrics All cloths with 2% weft skew/weft arc and greater than 3% skew cannot be classified as first-class products.
The main reasons:
① Poor weaving equipment (faulty weaving equipment will cause frequent downtimes, resulting in weft Oblique/weft arc)
② Mainly refers to weft oblique/weft arc caused by poor finishing equipment).
③Poor finishing (tilt/arc caused by operator’s irresponsibility during finishing).
Solution: Strengthen repair and rearrangement (weft correction).
3 The shrinkage rate is large
The shrinkage rate of the fabric in the warp and weft directions If the value exceeds the specified value, it cannot be classified as first-class product. Different fabrics will have different ranges.
Main reasons:
① Poor finishing.
② Defective pre-shrinking equipment.
Solution: Pre-shrink again (within the specified shrinkage rate)/shrink and wash the fabric, etc.
4 The feel of the finished fabric is not consistent with the standard sample
The feel is inconsistent with that of the standard sample, and there is an obvious difference.
Main reasons:
① Poor finishing.
②The raw materials are incorrect.
③The production process is incorrect.
Solution: Reorganize/reproduce.
5 Color fastness is unqualified
Fabric (dyed fabric (and dyed cloth) the color fastness cannot meet the requirements
The main reasons:
①Poor dyeing process.
②Dyeing raw materials are defective.
③Poor finishing.
④ Poor operation. (Especially obvious when scraping paint/dying paint)
Solution: re-fix the color/reproduce fabric/re-dye (dyed cloth is OK)/correct color (paint scraping) /Paint-dyed fabrics are OK).
6 The fabric style cannot be consistent with the standard sample
There is an obvious gap between the fabric style and the standard sample (bamboo style/ space dye style/thickness etc.).
Main reasons:
①Incorrect raw materials (incorrect slub yarn/incorrect yarn count)
②The production process is incorrect (the process of segment dyeing is incorrect/the arrangement of slub yarn or segment dyeing yarn is incorrect)
After ③ The finishing process is incorrect (when the raw materials and organization are correct, whether the finishing process is correct or not will affect the style of the fabric)
Solution: ① Re-produce the fabric ② After re-production tidy.
2. Causes and solutions to defects in printed and dyed fabrics (dyeing problems)
1 Skirt Wrinkles
The wrinkle strips are parallel to each other and flush from head to tail.
The wrinkle strips are large in the middle and pointed at both ends. There is a yarn tail at the junction of the wrinkle strip and the flat surface, which is shaped like a skirt wrinkle.
Skirt wrinkles mostly occur on fabrics containing chemical fibers and are not easy to find on original gray fabrics. It is only visible after printing and dyeing processing.
Main reasons:
①Differences in performance of chemical fibers themselves Or the high-temperature twist setting temperature in the textile factory is inconsistent, resulting in different shrinkage rates of the weft yarns;
② There are differences in the number or twist of the weft yarns used.
Solution: Re-invest the original gray cloth into production.
2 Seam head wrinkles
The wrinkle strips are connected to the seam head. One or more strips, different lengths. Some are at one end of the seam, and some are at both ends of the seam.
The main reason is that the seam head of the ground cloth operator is poor. The seam head is not straight, firm, the edges are neat, and the stitching is even.
Solution: Cut along with the seams, and do a sub-zero fabric treatment.
3 Printing and dyeing wrinkles
Strips that generally appear on the cloth surface There are not many of them, usually straight or diagonal strips, varying in length, width and width. The wrinkles produced before printing and dyeing or during the printing and dyeing process have a large color difference from the normal cloth surface; the wrinkles produced during the flat washing process after printing and dyeing have a smaller color difference.
Main reasons:
① The original wrinkles in the semi-finished products before printing and dyeing;
② During the printing and dyeing process, the mechanical tension and roller pressure are not properly adjusted; the parallelism of the guide roller and drying cylinder is not well controlled;
③ The preparation and cleaning are not done well.
Solution: Re-production.
4 Mercerized wrinkles
After printing and dyeing, it will appear dark in the middle and light on both sides. Straight or oblique fine wrinkles
Main causes:
① Mercerizing machine to remove alkali steam box, flat washing tank The cloth guide roller is uneven or stained with yarn ends and alkali dirt;
②The tension of the mercerizing machine is improperly adjusted;
③Alkali removal and steaming The direct opening of the steam pipe in the box will greatly impact the fabric and cause wrinkles.
Solution: supplement the birth.
5 Fengyin
Printing and DyeingThe exposed part of the object is different from the normal color of the cloth. Generally, irregular light-colored stalls or color bars appear at the folds of the cloth or on both sides of the cloth.
Main causes:
Certain printing and dyeing semi-finished products and in-process cloth tapes used for reactive dyes and disperse dyes Alkali, or the action of reducing gases in the air, affects the fixation of fabrics and dyes, resulting in light-colored patches on exposed parts. Reactive dyes are prone to wind marks.
Solution: supplement the birth.
6 Color difference in edge, left, middle and right color difference
Printed and dyed fabrics The color in the middle or left, middle and right sides is the same.
The main reasons:
①The roller or printing pressure of the dye solution is inconsistent at both ends;
② During pre-baking or hot-melt baking, the temperature and air volume in the middle and both sides of the cloth are inconsistent, resulting in inconsistent dryness and wetness on the left and right sides of the cloth or the left, middle and right sides;
③Color-matching dyes The dye transfer performance is inconsistent under the same processing conditions, resulting in changes in color depth or shade.
Solution: Color correction
7 Dark and light edges (center Color difference)
The color of the edge of the cloth is darker or lighter than the color of the normal cloth surface.
The main reasons:
① The edges of the cloth roll are uneven during jig dyeing;
② During dyeing, the curling of the fabric causes shallow edges;
③ The edge tissue is thick and the liquid content is large, resulting in deep edges.
Solution: Color correction and cropping to avoid color difference.
8 stripes of flowers
A full width along the warp direction of the cloth surface Characteristic, irregularly shaped, strip-shaped or rain-shaped defects of varying shades. Stripes are divided into gray cloth stripes and dyed stripes. The position of the head and tail of the billet remains unchanged, but the seam ends are the same, and the colors on both sides are similar. The dyed stripes pass through the seam, and the two sides have different shades.
The main reasons:
① The poor uniformity of the dyed fiber raw materials and fabric structure causes dyeing stripes;
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② There are gaps in the flame of the selected wool, causing singe strips;
③ When the material is mercerized, the alkali removal is uneven and the cloth surface absorbs Uneven color causes streaks in dyeing;
④ Uneven wind force at the air outlet causes regular streaks in a straight line
⑤ Post-drying The drying is rapid and uneven, and dye migration causes streaks
Solution: Color correction.
9 Color Blocks
Dyeing fabrics have uneven widths or uniform shades along the weft direction Color file.
The main reasons:
① Poor operation when starting the weaving or poor beat-up device of the loom, resulting in weft density or Sparse or dense, the color after dyeing is different from the color of the normal cloth;
② Stopping the dyeing process to produce a color gap;
③ The excess rate of jig dyeing and pad dyeing is too large, forming regular dark shades;
④ Semi-finished products are left for too long, and the folds are contaminated and form color shades;
⑤After mercerization, the fabric is not washed and dried in time, and the folds are air-dried, resulting in color gaps after dyeing.
Solution: Fix the color.
10 color points
There are regular or irregular patterns on the printed and dyed cloth Small, darker spots appear on the ground. The defects are either localized or diffuse. Usually occurs on light-colored fabrics.
The main reasons:
① Poor dissolution when making dyes and color pastes;
②Materials and color pastes are left for too long to cause agglomeration;
③The equipment is poorly cleaned.
Solution: Fix the color. </p
