Everyone knows that in the printing and dyeing process, Cheng Yaojin will appear from time to time, that is, colored flowers! This defect often brings trouble to the printing and dyeing factory masters. Let’s discuss the color flowers below:
1. The combined reasons are:
1. Problems with process formulation and operation:
The formulation process is unreasonable or improper operation produces color flowers;
The process is unreasonable (such as The temperature rises and falls too quickly)
Poor operation, knotting during dyeing, and power outage during dyeing;
The temperature rises too fast and the holding time is not enough;
The scouring water cannot be washed Clean, the PH value of the cloth surface is uneven;
The gray cloth contains a large amount of oil slurry, which has not been completely removed after scouring;
The uniformity of the pre-processed cloth surface
2. Equipment problems:
Equipment failure
For example, after polyester is dyed with disperse dyes, the temperature in the oven of the heat setting machine is different, which can easily produce color differences, color patterns, and ropes. Insufficient pump power of the dyeing machine can easily cause color flowers, etc.
The dyeing capacity is too large and too long;
The dyeing machine runs slowly;
The circulation system is clogged, the flow rate is too slow, the nozzles are not suitable, etc.
3. Raw material issues:
Fiber raw materials and fabric tissue uniformity
4. Dyes Problem:
Dye is easy to aggregate, has poor solubility, poor compatibility, is too sensitive to temperature and pH, and is prone to color flowers and color differences. For example, active green orchid KN-R is easy to produce colored flowers.
Dyeing reasons include poor dye levelness, dye migration during dyeing, and dye fineness that is too fine
5. Water quality issues:
Poor water quality may cause dyes to combine with metal ions or dyes to condense with impurities, resulting in colored flowers, light colors without sample attachment, etc. Improper adjustment of dye bath PH value;
6. Problems with auxiliaries:
Improper dosage of auxiliaries; for auxiliary problems, printing and dyeing learning and communication and The additives related to color flowers mainly include penetrants, leveling agents, chelating dispersants, pH control agents, etc.
2. Solutions to various colored flowers
( 1) Uneven cooking and opaqueness will cause discoloration.
Uneven scouring and uneven removal of impurities on the fabric will cause different moisture absorption rates in parts of the fabric, resulting in colored flowers.
Measures:
1. Inject the scouring additives quantitatively in batches, and the auxiliaries must be in uniform. The injection effect of hydrogen peroxide is better at 60-70 degrees.
2. The cooking and heat preservation time must be strictly in accordance with the process requirements.
3. The dead cloth wrapping process should continue to be kept warm for a while.
(2) The scouring water stains are not clear, and the gray cloth is dyed with alkali and causes colored flowers.
Measures:
After washing the water, neutralize the residual alkali with 10% glacial acetic acid and then wash the water to make the cloth surface PH7-7.5.
(3) After boiling the cloth, the residual oxygen on the cloth surface is not clean.
Measures:
Nowadays, most of them use deoxygenase additives to complete the deoxygenation treatment. In the normal procedure, glacial acetic acid is quantitatively injected for 5 minutes, and the temperature is raised to 50 degrees and run for 5 minutes. Inject deoxidizing enzyme into the clean water quantitatively, keep it warm for 15 minutes, and take a water sample to measure the oxygen content.
(4) The chemical materials are uneven and the dye is not dissolved enough, causing color flowers.
Measures:
Stir with cold water first, then dissolve with warm water. Adjust the temperature of the chemical material according to the properties of the dye. The temperature of the normal reactive dye material should not exceed 60 degrees, and special dyes should be cold-hydrated. Materials, such as brilliant orchid br_v, can be used as separate materials, which must be thoroughly stirred, diluted and filtered before use.
(5) The dyeing accelerator (yuanming powder or table salt) is added too fast.
Consequences:
Too fast will cause the dyeing accelerator on the surface of the rope-like fabric, with different concentrations, resulting in different dyeing promotion rates on the inside and outside, resulting in color flowers.
Measures:
1. The dye should be added in batches, and each addition should be slow and even.
2. Adding in batches should be less at the beginning and more at the end. Each addition should be 10-15 minutes apart to promote uniform dyeing.
(6) Adding the fixing agent (alkali agent) too quickly or too much will cause color blooming.
Measures:
1. Normally, the alkali is injected quantitatively in 3 times, with the principle of less first and then more. The first dosage is 1%10. The second time is 3%10. The final dosage is 1%. 6%10.
2. Each addition should be done slowly and evenly.
3. The heating rate should not be too fast. Differences in the surface of the rope-like fabric will cause different color absorption rates and cause color blooming. It is strictly required to control the heating rate (1-2℃/min) to adjust the amount of steam on both sides.
(7) The bath ratio is too small, resulting in color differences.
Many factories now use air flow cylinder dyeing equipment.
Measures: Control the water volume according to process requirements.
(8) Soaping colored flowers.
The washing water after dyeing is not clear, the pH content is high during soaping, and the temperature rises too fast, causing color blooms. After heating to the specified temperature, it must be kept warm for a certain period of time.
Measures:
Wash clean, neutralize some factory-used acidic soaping agents, run in the dyeing machine for about 10 minutes, and then heat up, sensitive colors such as lake blue, color If conditions such as blue are convenient, try to test the pH before soaping.
Of course, with the emergence of new soaping agents, there are low-temperature soaping agents on the market, which is another matter.
(9) Dye bath washing water is not Clear, causing color flowers and spots.
After soaping, the residual liquid is not washed clearly, so the concentration of the residual color liquid on the outside and inside of the fabric is different, and it is fixed on the fabric during drying to form color flowers.
Measures:
Wash thoroughly after dyeing to remove floating color.
(10) Color difference (cylinder difference, stripe difference) caused by added colors
1. Causes of color difference:
A. The feeding speed is different. If the dosage of dyeing promoter is small, it will have an impact whether it is added in batches. If it is added at one time, the time is short, the dyeing promoter is not enough, resulting in color flowers.
B. The two sides of the feeding material are rubbed unevenly, causing stripe differences, such as dark color on one side.�, the smaller side is shallower.
C. Holding time
D. Color difference caused by different cutting and color matching techniques. Requirements: Cut the sample and match the color using the same technique.
For example: cut the sample to match the color after being kept warm for 20 seconds, and the degree of washing after cutting is different.
E. Different liquor ratios cause color difference. Small liquor ratio: dark color Large liquor ratio: light color
F, the degree of post-processing is different. If the post-processing is sufficient, the floating color is sufficient to be removed, and the color will be lighter than if the post-processing is insufficient.
G. There is a temperature difference on both sides and in the middle, resulting in strip differences
Add color slowly, at least 20 minutes for quantitative injection, and 30-40 minutes for sensitive colors.
2. Add ingredients to chase the color.
1) Light color condition:
A. First, check the original process prescription, and weigh the dye according to the degree of color difference and the weight of the fabric.
B. The color chasing dye must be fully dissolved, fully diluted, and filtered before use.
C. When chasing colors, add materials at room temperature. The materials should be added slowly and evenly to prevent recoloring caused by excessive operation.
2) Color depth situation
A. Strengthen soaping and sufficient post-processing.
B. Add Na2CO3 for slight decolorization. </p
