many reasons of fabric dyeing problem

In the dyeing and finishing production of textiles, due to the large number of links before and after dyeing and finishing, there are also many factors affecting the dyeing and finishing results. In addition to the frequent occurrence of color quality problems such as color difference defects, other quality problems often occur. Therefore, dyeing and finishing defects can be basically divided into the following three categories according to the phenomenon:

1. Color quality:


Color difference, color unevenness (color flowers, spots, spots) and color fastness, etc.


2. Internal quality:


Fiber damage, loss of elasticity, skew of warp and weft, thin and dense road, shrinkage rate, gram quality, door width and so on.


3. Other quality aspects:


Finishing agent spots, pilling, crepe printing and finishing not up to standard.


Cause of dyeing defects

360截图20200930130453738



1. Quality of yarn (silk) and grey cloth




The quality of both yarn (silk) and grey cloth affects the quality of dyed products, which is latent and often exposed after dyeing. Moreover, such influence often overlaps with the problems in dyeing and finishing, which increases the complexity of the dyeing diseases and makes it more difficult to find the causes of the defects. Some dyeing diseases caused by the quality problems of yarn (silk) and grey cloth, such as the width, warp and weft inclination and expansion rate, are caused by the quality problems of yarn (silk) and fabric. Although it can be slightly regulated in the finishing link, but can not fundamentally solve the problem. Therefore, the source of raw materials should be strictly controlled to ensure the quality of yarn (silk) and grey cloth up to the target, to avoid the occurrence of defects in the subsequent dyeing and finishing process.






2. Dyeing and finishing process


The quality of dyeing and finishing process is influenced by both hardware and software.






Hardware: First, the applicability and integrity of mechanical equipment, instruments and other hardware; The second is the quality of dyes, additives and other raw materials testing and selection.




Software: mainly reflected in the implementation of such as process prescription, production process, operating procedures, etc. It is also reflected in the level of management (including technical management, discipline management) and the overall quality of grass-roots staff.






Must have clear understanding to the breed adaptability of dye-finishing equipment above all. Because dyeing and finishing machinery for different fibers and different types of textiles have a difference and specificity to understand the dyeing and finishing machinery can be added fiber and adapt to woven or knitted fabrics, if it is suitable for knitted fabrics. It is also necessary to distinguish between warp knitting, weft knitting and horizontal knitting; It should also be understood whether the equipment is limited to a single variety or a combination of several categories of varieties.




Such as:


The high speed and high pressure jet dyeing machine is suitable for the dyeing of polyester warp knitted fabric, and also suitable for the dyeing of medium thick wool-like fabric of polyester filament. But it is not suitable for polyester filament class low density of thin woven fabric (like yarn, terri lun), such as silk like dyeing, also does not apply to stick, polyester-cotton blended polyester fiber fabrics and weft knitting class knitted fabric dyeing, otherwise it is easy to appear crack and clear after dyeing Pi seam (filament low density thin woven) or pilling glue (polyester, polyester/cotton blended fiber fabric) or make elastic characteristics of original fabric loss (weft knitting fabric).






The dyeing machine is suitable for the dyeing of small batch and various kinds of woven fabrics with a wide range of weight and thickness. But not for knitted fabrics of coil structure.






Overflow dyeing machine is suitable for weft knitting fabrics, polyester viscidity, polyester/cotton blended fibers and knitted fabrics with high elasticity requirements, but not suitable for dyeing warp knitting and woven fabrics. Silk woven fabrics should be dyed by the roll dyeing machine, but the crepe fabrics and knitted silk fabrics woven by the same type of silk should be dyed on a specially designed machine which is obviously different from the cotton overflow dyeing machine.




Next, the fiber that different dye applies is different, and applicable deep, medium, light colour and lustre also is different. Therefore, the need to choose different types of dye varieties. For example, S type in disperse dye is suitable for deep and thick color dyeing, E type dye is suitable for medium and light color dyeing; BES of type B reactive dyes is suitable for medium and light colors, while B-D is suitable for deep and dense colors. As a result of the different fiber and fabric varieties discussed above, the different dyes and the different dyeing and finishing machinery equipment, will also lead to the choice of additives are not the same.






It is necessary to fully understand and recognize the differences in raw materials, equipment, dyes and additives, and improve the quality and level of users, so as to ensure the dyeing and finishing quality of textiles and avoid the occurrence of defects.




source: Shen Dun Sha Xian