Dyeing chromatic aberration, color stripes, color reproducibility, optimization of dyestuff additives, dyeing white spots, rotten cotton spots in the bleaching section, pleats, alkali spots, macula, alkali mud, wax strips, which are often encountered in the dyeing process, Defects such as singeing folds, track marks, etc. How to deal with such defects at the technical level? How to prevent, deal with and solve such defects in production, so as to improve the product quality of dyed fabrics and the success rate of one-time dyeing, so as to achieve the purpose of energy saving and consumption reduction?
Frequently produced return order colors:
The pre-treatment process must be stable and consistent to ensure that the semi-finished product has the same hair effect, whiteness and pH value each time. And each time before dyeing, the laboratory must perform a sample, and the different batches of dyestuffs used must be sampled for comparison. If there is no problem, the success rate of one color test will be high, and even normal production without color test (note that the dyeing production process and the machine are consistent).
Production of new colors:
The laboratory needs to make a small sample for confirmation, and make the sample before dyeing. It is best to make the sample with different proofers at the same time. If the two proofing prescriptions are the same, the first prescription is close, and the success rate of a color test will be high.
The origin and strength of the dyestuffs used should be determined, and it is not advisable to change the origin of the dyestuffs frequently. Because of the differences in dye quality, color and light stability, additives, production processes, etc. of various manufacturers, the use of dyes from different manufacturers will cause a large gap between the first prescription of the return order, and affect the success rate of the first color test.
Bleaching pleats are more common in high-count and high-density polyester-cotton fabrics and pure cotton thin fabrics. Due to the high hardness of water in production, scale is easy to form during steaming and easy to adhere to the cloth guide roller. Long-term production will form scale groove marks, which will cause the guide The fabric roll is not flat, and the fabric is easy to fold. Once folds are found during production, they should be cleaned up in time. If folds are found in the semi-finished product during dyeing, reasonable techniques should be used for repair.
Here are several methods of repairing the pleats:
If the bleached cloth is uneven, temporary creases or mercerized drying folds, if it is light, it is dyed directly, without considering the influence on dyeing, if it is heavier, it can be dyed and produced as long as it is pre-designed.
If the bleached cloth has obvious folds and no fabric damage, the dyeing bottoming machine is a black fold, if the folds form fabric damage, the bottoming machine is a white fold print. For this kind of pleats, use high-temperature over-width widening and then mercerizing for repair.
If the bleached cloth has serious dead folds, and the creases on the cloth surface have formed aurora prints, this kind of pleats is more difficult to handle, and the cloth can only be subjected to high-temperature super-width widening and then subjected to light sanding process to make the creases aurora prints. Smooth it, then re-boil and bleach to make the damaged fabric fiber puff and repair, and finally smooth the crease by high-concentration alkali mercerizing treatment.
For the repair of pleats, the cause of the pleats must be accurately judged first. Different pleats are treated with different prevention methods to avoid unnecessary process waste. For example, the mercerized drying folds are better to find, and you should deal with them in time after you find them. Don't leave the problem to be shaped before dyeing. If the drying pleats are not easy to handle, they can be rolled during mercerizing, so that the drying discounts will be flattened and the pleats will be ironed with the remaining temperature of the falling cloth, so that you can save the shape before dyeing.
There are double or multiple black pleats on the cloth surface after the dyeing is dipped in the pad dyeing solution, and there are fluffy white wool strips beside the black pleats, which are called singeing pleats. After the folds are baked, white marks will appear, and when the color is restored, they will become deep black folds. Singeing folds are caused by the unevenness of the cloth surface when singeing, and the folds on the cloth surface when passing through the fire. The high temperature of the fire will burn the places where the folds are formed. Because the creases cannot be burned inside, there are white strips next to the black folds. .
Prevent singeing folds from singeing when they are first singed, and formulating a reasonable production process according to different fabrics. For thick fabrics, they should be piled or boiled before singing to make the singeing into the cloth flat and reduce the possibility of singeing folds. . In addition, the singeing uses wet falling cloth to prevent the high temperature of the falling cloth and aggravate the formation of folds.
If you find singeing folds during dyeing, you must carry out pre-treatment and repair before dyeing. Once you drive rashly, the black folds will not be processed after dyeing. The pre-treatment method to repair the singeed folds is very simple. As long as the fabric is flattened and singed after high-temperature setting, the low-alkali mercerizing can eliminate the singeed folds.