1. SOUTHEAST UNIVERSITY
Department of Textile Engineering
Assignment
Topic on:Process parameter
Course Code: TEX3021
Course Title: Wet processing technology-II
Prepared for:
Md. Sahidul Islam
Lecturer, Department of Textile
Southeast University
Prepared by:
Rifad Hossain
ID:2013000400011
Sec: 1/A
Batch:22nd
Submission date:27-08-2015
2. Process parameter:
Introduction
Fabric dyeing usually requires three basic dyes in a mixture to achieve the desired hue and shade.
Dyes with similar reactive groups and same exhaustion properties will be said to be compatible
with each other and are ideal for use in such mixtures. Selecting compatible dyes is a part of
ensuring an optimum dyeing recipe which will most efficiently utilize the dye, produce optimal
dyeing results and will reduce the number of chemicals that enter the wastewater.[1]
This work has been under taken to optimize dyeing of knit fabrics varying different dyeing
process and parameters like M:L, temperature, scouring, bleaching, enzyme treatment, recipe,
dyes, auxiliaries, etc. The dyestuffs molecules, which contain reactive groups is called reactive
dye. Reactive dye is very suitable for cotton fabric because of its very good fastness properties.
Reactive dye reacts with OH-radial of cotton fabric by covalent bond formation.
Cotton fiber and its generated finished goods are more comfortable than other fibers products.
Cotton knit fabric dyeing is carried out as the following flow chart:
Fabric receiving
↓
Fabric inspection
↓
Batching
↓
Demineralization
↓
Scouring
↓
Bleaching
↓
3. Per-Oxide kills Wash
↓
Neutralization
↓
Dyeing
↓
Neutralization after dyeing
↓
Softening
↓
Fixing
↓
De watering / Squeezing
↓
Drying
↓
Stentering / Compacting
↓
Final Inspection
Here I have given the full wet processing techniques of knit dyeing. Pre treatment, dyeing, after
treatment and finishing process are expressed combinedly.
a. pH:
1. During H2O2 bleaching pH 9 – 11
2. During reactive dyeing pH 10.5 – 12
3. During disperse dyeing pH 4.5 – 5.5
4. 4. During Leveling pH 5.5 – 6.0
5. During Salt pH 6.0 – 6.5
6. During Soda pH 10.5-11.5
7. During Soaping pH 6.0 – 6.5
8. During Dye bath pH 10.5 – 11.5
9. During Softener pH 4.5 – 5.0
10. During Fixing pH 5 .0 – 5.5
b. Temperature:
1. For cotton scouring 900-950C
2. For cotton Enzyme wash 550 C
3. For cotton cold wash 300 – 400C
4. For cotton hot wash 700-800C
5. For cotton acid wash 600-700C
6. For cotton dyeing 800-900C ( For hot brand )
7. For cotton dyeing 600C ( For Medium brand )
8. For cotton dyeing 800C ( For Turquoise/ Blue RSPCL/CNR )
9. Polyester dyeing: 1000-1300C
c. Time:
1. For scouring 60-90 mins
2. For reactive dyeing 60-90 mins
3. For disperse dyeing 60-90 mins
4. For Enzyme treatment 60-90 mins
d. M:L ratio:
For reactive dyeing M:L ration maintained 1 : 3 ( polyester - Airflow
Dyeing )
1 : 4 ( Cotton- Airflow Dyeing )
1 : 6 ( Lab-Knit Dyeing/Yarn Dyeing)
1 : 6 ( Bulk Yarn Dyeing )
1 : 7 ( Pretreatment /washing )
1 : 8 ( Knit Dyeing – Atm/HTHP )
e. Pressure:
1. Steam pressure : 5 – 6 kg/cm2 G
2. Water pressure : 1.2 – 2 kg/cm2 G
10. Chemical parameter
Chemicals are second important materials for dyeing knit fabrics. Chemicals are different in their
properties. Chemicals are mixed in dyeing machine with the dyes. All chemicals are not suitable
for all types of dyeing. Specific dyes need specific chemicals. Use of chemicals depends on the
dyes type. Some chemicals are strong alkaline some are weak and some are moderate in nature.
I have given some chemicals name list which is widely used for getting better dyeing
performance. They are as follow:
Basic Chemicals
1. AceticAcid
2. OxalicAcid
3. Soda Ash
4. SodiumHypochloride
5. SulphuricAcid
Bleaching Agent
1. Hydrogenperoxide50%
Salt or Electrolytes
1. Glubar salt
2. CommonSalt
3. RefinedSalt
4. CausticSoda
5. CausticSoda Pear
12. 2. LeophenMC
After Soaping Agent
1. CibaporR Liq
2. SandopourRSK
3. GeicleanAW
Enzyme Finishing Agent
1. BiopolishAL
Optical Brightener for Cotton
1. Uvitex BBT
2. Uvitex CIDN
3. Uvitex BHV
Optical Brightener for Polyester
1. Ultraphore BN Liq
2. Uvitex BHT
3. Ultraphore SFG Liq
4. Ultraphore SFR
Leveling Agent for polyester
1. Baso WinchPEL
2. Osimol ROL
3. Uniperol EL
4. Prote-Gal DP505
Decolourant For Effluent Treatment
1. ColflocRD
Above chemicalsare manufacturedbydifferentchemicalsmanufacturer.Beforebuyingthe chemicals
onesshouldbe confirmaboutthe propertiesof chemicals.Chemicalspropertiesshouldbe checkedin
labfor ensure aboutthe qualitybecause qualifiedchemicalscan give qualifiedoutput
13. Machineparameter
General Parameters of Dyeing machines:
1. Capacity per nozzle: theoretically 250 kg but practically not more than
200 kg should be used.
2. Nozzle pressure: 4-6 psi
3. Steam pressure: 7 bar (inlet of heat exchanger)
4. Cold water temp.& pressure: 25 c & 3 bar
5. Maximum temp. : 140 for high temp. M/c : 100 for atmospheric
6. Reel/Winch speed: 150-250 rpm/450- JamboTech
7. Main motor efficiency: 80-85% (Loding
![Process parameter:
Introduction
Fabric dyeing usually requires three basic dyes in a mixture to achieve the desired hue and shade.
Dyes with similar reactive groups and same exhaustion properties will be said to be compatible
with each other and are ideal for use in such mixtures. Selecting compatible dyes is a part of
ensuring an optimum dyeing recipe which will most efficiently utilize the dye, produce optimal
dyeing results and will reduce the number of chemicals that enter the wastewater.[1]
This work has been under taken to optimize dyeing of knit fabrics varying different dyeing
process and parameters like M:L, temperature, scouring, bleaching, enzyme treatment, recipe,
dyes, auxiliaries, etc. The dyestuffs molecules, which contain reactive groups is called reactive
dye. Reactive dye is very suitable for cotton fabric because of its very good fastness properties.
Reactive dye reacts with OH-radial of cotton fabric by covalent bond formation.
Cotton fiber and its generated finished goods are more comfortable than other fibers products.
Cotton knit fabric dyeing is carried out as the following flow chart:
Fabric receiving
↓
Fabric inspection
↓
Batching
↓
Demineralization
↓
Scouring
↓
Bleaching
↓](data:image/gif;base64,R0lGODlhAQABAIAAAAAAAP///yH5BAEAAAAALAAAAAABAAEAAAIBRAA7)