stiffness

It is generally believed that the hardness below 50ppm has no effect, and 20ppm is already a very good water.

Bobbin yarn dyeing water quality is only so, but the content of copper and iron ions in the water should be paid attention to.

Usually active dyeing is better below 50ppm, the key is the content of metal ions, especially iron ions, will lead to changes in color light, it is recommended to measure the conductivity of water.

The wastewater discharged according to the standard is used in bleaching and dyeing production. The main reason why the product is easy to produce colored flowers is the high conductivity of water. The electrical conductivity of bleaching and dyeing wastewater should be paid attention to in its reuse. Conventional wastewater treatment methods can not effectively remove the metal ions that cause the high conductivity of wastewater, and must be removed by reverse osmosis membrane treatment.

If the water is too hard, water will form on the boiler wall 洉, and the calcium and magnesium ions in the water can precipitate the soap. Uneven dyeing, poor fabric feel, yellow fabric. Reduce the activity of enzymes used for desizing, reduce the solubility of sizing materials, and do not dissolve with the chemical agent of finishing formula.

The treatment method can use EDTA or sodium tripolyphosphate to try the dosage of 2g/l, and it is better to buy special metal ion blocking agent; Dyeing water such as not softened treatment, or thick cloth often contains metal ions often cause uneven (bad) effect of dyeing. Therefore, chelating dispersant is added in the dyeing process to prevent the influence of metal ions, and can promote the effect of yuan removal.

But EDTA(ethylenediamine diacetic acid),DTPA,NTA, phosphate. Gluconic acid and other chelating dispersants may chelate the metal ions in the dye, resulting in decreased daylight fastness and leg color change. Therefore, some netizens recommend the chelating dispersant of polyphosphates and polyalkyds.

Example:

At present, the cotton dyeing water in the factory is underground water, which has not been softened and filtered, and a layer of dirt can obviously be seen on the yarn dyed before. Now a small amount of bleach powder is added to the water, which has been slightly improved. However, after dyeing the yarn, the bottom layer of the yarn has a dull feel, light and dark color, positive and negative commissioning, and water softener has also been added, but the effect is not obvious. The hardness of the water at the bottom of the pre-treatment boiling is about 130ppm.

The reason:

Water quality is too hard, groundwater dyeing yarn, water quality is too hard and too many impurities, may lead to your color yarn bobbin inner yarn layer fouling, the best solution is to first pump the groundwater to the ground precipitation, soft water, and then filter the water filter, so there will be no problem, but the input should be larger.

Impurities and microorganisms

Cationic film working liquid is unstable in the river, which flocculates with microorganisms in the river, producing yellow flocculent, sticking on the fabric, after drying and shaping, it will form yellow spots on the fabric, so you can know why in May to June when the temperature is more suitable for easy algae reproduction is particularly prone to quality problems, and in the autumn and winter season there is rarely such a situation .

The quality of water quality has a great impact on the stability of the preparation of soft working liquid and the whiteness of the fabric after soft finishing, so the printing and dyeing factory tries to use treated water in the production.

Some manufacturers use the water filtered by activated carbon will still appear similar situation, this is because the microorganisms are very small, activated carbon can not completely adsorb, filter, so before water treatment in the sedimentation tank to add cationic surfactants to flocculate with the microorganisms in the water, and then through activated carbon filtration, you can improve the effect of water treatment; In addition, activated carbon must be cleaned or replaced regularly.

If the above methods are not feasible or still can not eliminate quality problems, it is recommended that the factory use non-ionic, anionic film or non-ionic film with silicone oil to finish the feel when the algae bloom is strong.

In the manufacturers with more macular production, this kind of situation did not occur when finishing with amino silicone oil.

Winter also does not bode well for printing and dyeing plants, with poor water quality.

pH value

For active dyeing, when the pH value is 7 to 9, the color difference of the product is normal, indicating that the pH range has little effect on the color difference of the product, and the presence of a small amount of alkali will not change or destroy the chromogenic base group of the reactive dye molecule.

When the pH value is 8.5, the color fastness and wet friction fastness of the fabric are 3 levels, which can not meet customer requirements; When the pH value further increases, the color fastness becomes worse, it is known that the alkalinity of the water increases, which will affect the color fastness of the dyeing product.

The water quality of the wastewater reuse plant generally requires a pH value of <9 to ensure that the microbial growth of the treatment system is not damaged by alkalinity and can operate normally, and the quality standard of the water reuse requires a pH value of 85, preferably close to 7.

salinity

The main salt in the recycling system is sodium sulfate, which comes from two sources:

(1) Adding agents in the dyeing process as dye promoters;

(2) The caustic soda and soda ash added to the bleaching and fixing processes are converted into sodium sulfate after being neutralized by sulfuric acid.

The limit salinity in the reuse system is 924mg/L, which does not affect the dyeing quality of the fabric.

Iron ionizer

Pretreatment of iron ions will accelerate the decomposition of hydrogen peroxide, resulting in holes in the cloth surface.

Iron ions will cause dyed cloth surface dark, prone to color spots. As for the removal method, it does not matter how the content is generally less than 15ppm, and if it is slightly higher, chelating agent can be added.

chloronion

Pure chloride ions have no effect on active dyeing, because some people use salt as a dye promoter, but it has an effect on the cylinder body, depending on whether the steel you use is chlorine resistant.

If it is like tap water, which contains effective chlorine for bleaching and sterilization, and exceeds a certain standard, it will affect the dye.