Jet Overflow Dyeing 一 how many problems? 一how to solve them? 一 You will find the answers.

Jet Overflow Dyeing

            一 how many problems will appear and how to solve them?

            一 You will find the answers.

1. Foam problem 

Foam is produced by high energy turbulence caused by high speed operation and liquid circulation in high temperature and high pressure injection overflow dyeing machine.Foam formation factors include the type and amount of dyes and standardized agents, the amount of fiber treating agents on the fabric, and the foaming properties of the dyeing auxiliaries used.

Measure: Defoamer is necessory for this process. Good and suitable defoamers can help you to solve the foam problems and make sure the good quality. If you have any queries for defoamers. Please let me know.

2. Puckering(article wrinkled)

Polyester fabric will wrinkle during dyed by high temperature and high pressure jet overflow dyeing machine. Creases are often in the shape of chicken feet because of  the fabric being folded and stacked for too long. If the fabric is folded, permanent creases are most likely to occur when the fibers are cooled through secondary vitrification temperatures.

Measure: Don't overload the machine. In the stacking room, the rate of fabric turnover and movement should be quite high (The maximum turnover time generally accepted is 2-3min). Do not heat and cool too quickly, the latter being more important.

3. Color unevenly

The reason is that the heating is too fast, the heat preservation time is too short, the circulation speed of the cloth is too slow, the dye adsorption is not uniform, the cloth capacity far exceeds the standard capacity.

Measures: Reasonably determine the heating time and holding time, readjust the nozzle pressure, select the nozzle slot and cone tube, to increase the distribution speed. Reasonablly choose the dye. In the color of the selection , if dyeing rate of dispersant dye is difference largely, please increase dispersant or dyappropriatly, and moderate cloth capacity.

4. Low polymer

Low polymer is a low molecular weight polycondensation produced during polymerization. Low polymers dissolve in the dye bath at high temperatures and crystallize out of the solution, then deposit on the surface of machinery or fabric during cooling, especially in low flow areas. Deposition of low polymers on a machine, such as a heat exchanger, can constrain the flow of fluid, resulting in loss of heat exchange efficiency. Low polymers deposited on the surface of the fiber will become white spots.

Measures: The low polymers problem can be overcome by scouring the fabric with solvent before dyeing. Or when dyeing, control agent for low polymers is added to increase the solubility of low polymer in the dyeing bath or to produce a stable low polymer dispersion. When additives are used in the after finishing process, the resulting cleaning action also helps to remove the deposited grease and dyes.

5. Condensation of disperse dyes

Dye condensation will cause the fabric to produce color spots, reduce the dye absorption or prolong the dyeing time, reduce the rubbing fastness. Condensation is caused by too many electrolytes in the dye bath and the incompatibility of auxiliaries causes the precipitation of both auxiliaries and dyes. Non - ionic AIDS at high temperatures to promote precipitation and condensation or prevent staining. The dyeing time is too long. The dyeing rate is too fast. the processing quality of the dye is poor. The dye concentration is too high, and the dyeing bath is stained.

Measures: Reduce the electrolytes in dye bath as far as possible, choose the good compatibility of additives. Shorten the dyeing time, and do not dye too fast. Do well inspection and alnalysis, and increase the amount of dispersant. Clean the fabric thoroughly before dyeing, and strengthen the cleaning and maintenance of the equipment.

6. Snarling

Knotting the bunches can cause downtime, especially the full - filled machines. Some full - filled machines are equipped with anti - injection and control valves that control the stacking of fabric in the stacking area. Tangles are reduced only by operator experience and responsibility

7. Stains and spots

Stains and spots are caused by dye condensation, oligomer in the dye bath.

Measures: please find the #4&5

8. Fluff and bruise

The reason is that the diameter of the nozzle is too small, and the speed of distribution is out of proportion to the rotation speed of the guide wheel. Bump when handling grey cloth or semi-finished products, scratch when opening.

Measures: Select the appropriate diameter nozzle according to the unit weight of the dye. Make the injection pressure moderate. The distribution speed shall be commensurate with the rotation speed of the guide wheel. Handle grey cloth or semi-finished products with ease and open the width by hand.

9. Elongation

The reason is that the fabric capacity is too low, so that its transport distance becomes longer, and increase tension. The dye level is set too high, which increase the resistance between the water and the fabric.

Measures: Control moderate volume of cloth. Keep the liquid level as low as possible

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