Disperse dyeing quality problem analysis (practical)

Analysis of the Dyeing Quality of Disperse Dyes

1. What are the causes of color flowers and how can they be prevented?

1) Washing after scouring is not clean, and the pH value of the cloth causes uneven color.

prevention:

After slackening, the semi-finished products after scouring must be washed cleanly. The PH value of the cloth should be controlled between 7 and 7.5. If necessary, wash the water with 1% glacial acid to neutralize the residual alkali before washing. Practice, on duty staining.

2) Improper feeding of chemical materials causes color flowers.

3) Prevention:

1 Disperse dyes should be beaten with 1:10 cold water first, then warm water (<50°C=chemicals, fully stirred, dilute and filtered before adding to dyeing tanks.

2 Adding sequence, first add diluted glacial acid (or dyeing acid) → add dissolved auxiliary agent (leveling agent or dispersant) → finally add disperse dye.

3 If the temperature rises too fast, the holding time will not be enough to cause the color flowers (too fast heating will cause the dyeing rate too fast and cause color flowers, and the holding time is insufficient, so that the level dyeing is uneven and the dyeing is insufficient to cause color flowers).

Strictly according to the process requirements to do warming insulation.

4) The amount of dyeing capacity is too large, and when the dyeing is too long, knotted or dyed, the color flower is suspended.

prevention:

1 The appropriateness of dyeing and storage fabrics should be determined according to the thickness of different models and fabrics, and the general fabric volume should be controlled at about 80% of the original design volume.

2 The length of the dyeing cloth is generally controlled not to exceed 3mm in the length of each cloth.

3 Adjust the size of the nozzle in time according to the thickness of the fabric, so that the fabric can be smoothly carried out to prevent the nozzles from being stacked and causing confusion when the fabric is dyed.

2. What are the causes of chicken paw wrinkles (wrinkles) and how can they be prevented?

1) Cause: (emphasis on operational aspects).

1 The cooling rate is too fast, and the cooling and cooling after dyeing cause wrinkles

2 After dyeing, the amount of cloth is too much, and the nozzle is not properly used to cause wrinkles.

2) Prevention:

1 After dyeing, it should be cooled naturally (2°C/min) to below 80°C and then washed with side-by-side drainage.

2 Same as previous 1-4

3 The dyeing liquid can be added with a creping levelling agent of 0.51g/L to promote fabric settling lubrication, reduce chicken wrinkles, and at the same time improve fabric feel.

4 When dyeing, non-toxic swelling agent can be used to make the fiber fully expanded to overcome wrinkles.

5 The dyed fabrics are hot rolled and dried to reduce chicken paw marks.

6 If semi-finished products are inspected, and wrinkles are severely discreet, repairs should be carried out.

7 When possible, try to increase the speed of each lap cloth.

3, how to solve the wrinkle when dyeing?

There are two situations:

1) General wrinkles:

2) It should be counterstained once before forming. The process conditions: 135°C×30′, natural cooling (2°C/min) to 80°C, followed by washing.

Severe wrinkles;

The cylinder before forming is divided into two cylinders, and the hydrophilic finishing agent is added 1-2g/L and then processed according to the process.

4. Under what kind of conditions, disperse dyes and polyesters are washed in cylinders.

1) Clean the cylinder when it is dark and light.

2) To dye a color for a long time, wash the cylinder when transposing another color.

5, wash the cylinder to clean when you pay attention to what the problem

1) Dyeing cylinders should be divided into deep, medium and light special dyeing machines and cleaned once a week.

2) In order to facilitate the production of the machine table, the machine is often cleaned.

3) The heat exchanger filter should be cleaned once per shift.

4) When washing the cylinder, open the dyeing machine and the spray tube to spray the spray and wash the water until it is invisible.

5) Wash the tank level with full tank water for reduction and cleaning.

6) After washing, reduce the temperature to below 80°C. After pressure is discharged, clean the water in the machine into the chemical drum and clean the chemical drum and the feeding pipe.

7) Cold water wash machine and drum to clean.

8) Clear cylinder reference process

Light color dark color depth

Insurance powder (kg/cylinder) Cna2S2O4 5 8 10 12

Base (kg/cylinder) CNaOH 8 10 15 15

Or use the clear agent 8-15g/cylinder main process conditions: 130°C×30-60min

6, disperse dyes appear after color flowers should be how to solve.

1) The sculpting is bad and the color flower can be re-scrubbed to re-color in the high-temperature dyeing machine.

1 scouring: according to conventional techniques

2 Duplex: According to conventional dyeing process (130×30′)

3 Dyeing prescription:

Dyeing 5-10% (total amount of original dye)

Leveling agent 100-200% (total amount of original leveling agent)

Repair agent 0.5-2ml/L

PH value adjusted to 5-6 with glacial acetic acid

2) Slightly colored flowers:

1 How to deal with a small amount of colored flowers?

It can be dyed once with levelling agent SE or repair agent.

Reference process

Dye 3-5% (total amount of original dye)

Levelling agent SE 100% (total amount of original leveling agent)

Or repair agent 0.5-2g/L

Adjust the PH to 5 with HAL

Process conditions: 130°C×30'

2 Serious color treatment methods

A. Method: After stripping (decoloring) after treatment → Duplicate → Re-dyeing

B, stripping reference

Insurance powder (Na2S2O4) 5-6g/L

Caustic soda (NaOH) 3-4g/L

135°C×30'

3 The duplicates are the responsibility of the laboratory, and the counterfeit dyes are the responsibility of the dyeing laboratories.