Dyeing fault causes and remedies Dyeing Fault: Uneven dyeing: Causes •Due to improper pretreatment. • Very rapid addition of dyes and chemicals. • Lack of controlling dyeing parameters Remedies •Check addition of dyes and chemicals are at a steadily increasing rate. •Proper pretreatments. •Check the rope turnover time. •Proper washing after dyeing. Running shade: Causes •Machine loading is higher. •Running at lower nozzle pressure. •High bath draining temperature. Remedies •Proper cycle time should be ensured. •Nozzle pressure should be accurate. •Bath draining temperature should be moderate.

1. Dyeing Fault causes and remedies
Presented by:
Md: Fahimuzzaman
Department of Textile Engineering
Mawlana Bhashani Science and Technology university

2. Uneven dyeing
Causes
•Due to improper pretreatment.
• Very rapid addition of dyes and chemicals.
• Lack of controlling dyeing parameters
Remedies
•Check addition of dyes and chemicals are at
a steadily
increasing rate.
•Proper pretreatments.
•Check the rope turnover time.
•Proper washing after dyeing.
Fig: Uneven Dyeing

3. Causes
•Machine loading is higher.
•Running at lower nozzle pressure.
•High bath draining temperature.
Remedies
•Proper cycle time should be ensured.
•Nozzle pressure should be accurate.
•Bath draining temperature should be
moderate.
Running shade
Fig: Running Shade

4. Causes
•Excessive loading of fabric during dyeing.
•Sudden change in temperature during cooling.
•Due to lack of synchronization of winch speed
and pump pressure.
Remedies
•Follow the temperature gradation during the
whole cycle of dyeing.
•Fabric must be loaded according to loop length.
•Maintaining the proper synchronization between
the winch speed and pump pressure.
Crease mark:
Fig: Crease mark

5. Causes
•Due to presence of traces of Fe+ and Cu+ ions
in the process bath.
•If soda dosing is done at high temperature then
in presence of oxygen pin hole is created.
•Inadequate amount of stabilizer in H2O2
bleaching.
Remedies
•The water used in dyeing should be free from
water hardness.
• Soda dosing should be done at low temperature
(not more than 600C)
Pin hole
Fig: Pin hole

6. Causes
•Improper mixing and dissolving of dyestuff.
•Dye bath hardness.
Remedies
•Mixing and dosing of dyestuffs should be
done properly.
•Water of dye bath should hardness free.
Dye spot:
Fig: Dye Spot

7. Causes
•If soaping start before wash
•CaCO3 or MgCO3 in soaping bath
•Quick soda dosing
Remedies
•Soda particles should be dissolved
properly.
•After pre-treatment and dyeing,
proper neutralization should be done.
Soda spot
Fig: Soda Spot

8. Causes
•If dye is mixed in the dyeing floor then flying dust particles may come in
contact with the dissolved dyestuffs.
•If dyeing floor is too dirty.
Remedies
•Dyes should be dissolved in separate drum and in separate room.
•Dyeing floor must be neat and clean.
Fly dye stains

9. Causes
•Different types of yarns used in fabric and trims.
•Dye lot is different for trims and body.
•Improper recipe setting for trims and fabric.
Remedies
• Same type of yarn, dye lot, recipe, nozzle pressure ,uniform distribution to
each nozzle etc. should be used for both fabric and trims.
Trims shade not match with the body

10. Causes
•If pH is not maintained
•Poor emulsification of softener applied
•Inferior quality of softener
Remedies
•Ensure that the softener is uniformly dissolved in the water.
•Use the right softener and the correct procedure for the application.
•Maintain the correct pH.
Softener Marks

11. Causes
•High yarn tension
•Count variation
•Mixing of the yarn lots
Remedies
•Ensure uniform yarn tension to all the feeders.
•Ensure that the yarn being used for knitting is from the same lot.
Barrie Mark:

12. Causes
• This is because, dye class is not same for all ropes in a
batch or when collar/cuff is dyed using dyes from one lot
and body fabric is dyed using dyes from different lot.
Remedies
• To overcome this, one has to choose same dye class
which will give same shade at least under primary and
secondary light source.
Metamerism:

13. Causes
•Use of harsh metal chemicals for processing.
•Insufficient softeners application in dyeing machine.
Remedies
• It can be easily reduced by demineralization and can be improved by the
addition of softener.
Hand feel problem: