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Southeast University KNIT
DYEING
YARN DYEING
WOVEN DYEING
Prepared By : Mazadul Hasan sheshirID: 201000040000813th Batch (session 2009-2013)Department : Wet Processing Technology Email: [email protected] : www. Textilelab.blogspot.com (visit)
Southeast University Department Of Textile Engineering
I/A 251,252 Tejgaon Dhaka Bangladesh
Prepared By :
Faults in Dyeing SectorFaults in Dyeing Sector
Yarn Dyeing Faults
1. Package un-level 2. Package to package shade
variation 3. Color spot 4. Ring mark 5. Dirt mark
Yarn Dyein
g Fault
1. Package Unlevel
Causes:a. Tension variation while soft winding of the package
b. Lot mixing of yarns in the same package
c. Different counts of yarns in the same package
d. Pressure variation in the machine vessel
e. Improper pretreatment of the yarn
f. Improper quality of the dyes and chemicals
g. Improper acid treatment after scouring and bleaching
2. Package to Package shade variation
Causes:
a. Improper setting of yarn packages in the machine
b. Lot mixing of the packages
c. Count variation of packages
Causes:
a. Improper setting of yarn packages in the machine
b. Lot mixing of the packages
c. Count variation of packages
Package
Unlevel
3. Color Spot
Causes:
a. Floating of dye particles in the air
b. Improper per-oxide killing
c. Hardness of water
d. Improper mixing of dyestuffs
Package
Unlevel
P 2 P shade
variation
5. Ring Mark
Causes:a. Improper drying of the packages b. Improper peroxide killing
4. Dirt Mark
Causes:a. Dirty handling of the packages b. Presence of dust in the air
Figure: Dirt mark
Package
Unlevel
P 2 P shade
variation
Color
Spot
Woven Dyeing Faults
1. White spot 2. Color spot 3. Bug spot 4. Water mark 5. Crease mark 6. Long stripe 7. Uneven shade 8. Running shade 9. Listing effect 10. Dirty mark 11. Oil spot 12. Stop mark
Woven Dyeing Fault
Woven Dyeing Fault
11
22
33
44
55
66
77
88
99
1010
1111
1212
Causes:
a. Foreign particles present on fabric before dyeing
b. Foreign particles present in the solution
c. Hairiness present in fabric from brushing
1. White Spot
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2. Color Spot
Causes:1. Dyes & chemicals factors:
a. Poor Dispersion or Solubility Propertiesb. Unstable chemicalsc. Silicones in the dye bathd. Alkali residues in the goodse. Presence of iron
2. Improper Washing3. Operator negligence
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3. Crease Mark
Causes:
a.Lack of balance in construction of the fabric b.Pressure of padder rollerc.Direct Heating or Shock cooling
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4. Long Stripe
Causes:
a. Winding of yarn in padder roller
b. Improper pressure during brushing
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5. Uneven ShadeCauses:
a. Improper scouring
b. Improper bleaching
c. Improper mercerization
d. Low solubility of dyes & chemicals
e. Negligence of operators to solubilize dyes and chemicals
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6. Running Shade
Causes:
a. Change in pick-up percentage along the length of the fabric
b. Improper fabric Speed.
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7. Listing EffectCauses:
a. Improper padder pressure in different zones of padder roller (left, middle & right zone). b. Worn out squeeze roller.
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8. Dirt Spot 9. Oil spot
Cause:Oil dropped on the fabric
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Causes:Presence of Dirt in the airDirty handling of the fabric
12. Stop markCause:Stopping of machine unexpectedly during processing.
Figure: Water Mark
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11
12
11. Bug SpotCauses:1. Insect present in any bath (i.e. dye bath, chemical bath, washing bath)2. Falling of insects on the fabric during dyeing.
10. Water MarkCause:Water is dropped on the fabric after final drying.
1. Uneven Dyeing. 2. Shade variation.
i) Roll to roll shade variation. ii) Batch to batch shade variation. iii) Continuous shade variation in a roll (Running shade/Tailing effect/Ending effect) iv) Side center side shade v) Side to side shade.
3. Crease mark. 4. Dye spots. 5. Soda spots. 6. Hole
Knit Dyeing Faults
1. Uneven DyeingCauses:i) If uneven pretreatment is done, absorbency and whiteness of fabric will be different at different places and consequently uneven dyeing will occurred. ii) Very rapid addition of dyes and chemicals. iii) Lack of controlling dyeing machine like-
- Machine speed. - Temperature of the process. - Dosing time. - Circulation pump and reel speed. - Plaiting device. - M:L ratio. - Improper washing after dyeing.
Causes:- Machine over-loading. - Running at lower nozzle pressure - High bath draining temperature - Improper cycle time - Improper length of rope
2. Shade Variation
2.1. Roll to roll shade variationCauses:i) Not equal rope length in each chamber. Then cycle time will vary if reel speed will same and shade variation occur. ii) Not equal flow speed in each nozzle. Then cycle time will vary if length of each roll will same and shade variation occur.
2.2. Batch to Batch shade variationCauses:i) Different batches are pretreated in different machines. ii) Fabric of different batches has different dye affinity. iii) Liquor ratio, cycle time, dye lot, chemicals, dyeing procedure, temperature are different for each batch. iv) Low quality water especially PH, hardness and sodium carbonate content.
2.3 Running shade
Causes:- More cycle time, more time fabric will be in folded condition increase tendency to crease mark formation. - Faulty plaiting device. - Variation of heating & cooling rate. - Improper fabric movement. - For 100% cotton, if GSM>180, unbalanced structure, presence of lycra, not properly heat set increase the tendency to crease mark formation.
4. Dye Spot
Causes:i.Operator negligenceii.Dye bath hardnessiii.Improper Agitation of dyestuffiv.Dye molecule deposition on the fabric
Causes:1.Soaping start before wash2.CaCO3 or MgCO3 in soaping bath.
6. Hole6. Hole
Causes:1. Dye bath water hardness. 2. Deposition of ferrous or ferric ion on the fabric surface 3. Defective plaiting device of the machine.
Problem of dyeing
a. Problem of shade matchingCauses:
1. Dye factor2. Process factor3. Machine factor4. Man factor
b. Fastness problemProperties of Dyes & Chemicals affect fastness.
c. Hand feel problem
1. Yarn Manufacturing TechnologyLink : http://www.facebook.com/pages/Yarn-Manufacturing-Technology/485014954866808
2. Fabric Manufacturing TechnologyLink : http://www.facebook.com/pages/Fabric-Manufacturing-Technology/459520217425605
3. Garments Manufacturing TechnologyLink : http://www.facebook.com/pages/Garments-Manufacturing-Technology/472364799463126
3. Wet processing TechnologyLink : http://www.facebook.com/pages/Wet-Processing-Technology-Dyeing-/468645219825404
4. Fashion-Design-and-TechnologyLink : http://www.facebook.com/pages/Fashion-Design-and-Technology/587655294583875?ref=ts&fref=ts
My Facebook Textile related Pages
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