Tuesday, June 20, 2017

Important Checking Points of Dyeing

Dyeing is the process of imparting colors to a textile material like fibers, yarns, and fabrics. It is one of the complex processes for textile engineers. During dyeing, textile engineer should give deep concern on the some points. He should give proper instruction to his supervisor or operator to do all the work as per schedule. If any faults occur during dyeing process then it will impact on overall process. Following checking points must maintain during dyeing process.

Dyeing operation
Fig: Dyeing operation
Checking Points of Dyeing:

Checking instrument/type
Points
Requirements
pH: measured by digital pH meter & pH measurement strip/paper
1.      Enzyme/bio-polishing
2.      Cotton leveling
3.      Salt in side tank
4.      Dye bath
5.      Fixing
6.      Softening
7.      Unload
4. 5
6. 5
7. 0
As per alkali
5. 5
5. 5
6-6.5
Residual peroxide: by peroxide measurement strip
After per oxide killer
0-10 mg/v
Hardness: by hardness measurement strip & titration process
1.      Line water
2.      Dye bath
3.      Salt/soda
Less than 30 ppm
Specific gravity: by hydro meter
1.     Salt in side tank
2.     Dye bath
As per SG graph
Weighting of colors & chemicals: by digital weighing balance

As per requirements
Sample check
1.     Before load
2.     Bleaching
3.     Enzyme
4.     Dyeing shade check
5.     Hot wash
6.     Fixing
7.     Unload
Information
1.      Batch parameters in dye line
2.      Operator name
3.      Load/unload date/time/shift, total duration
4.      Information’s attached in unload folder
Before start dyeing
1.     Condition of machine
2.     Pressure of air, steam, water line etc
3.     Machine ok from maintenance
4.     Batch ready for dyeing
5.     Lap dip, color, batch information etc ready for dyeing.
During dyeing
1.      Programme & process for that particular batch and color.
2.      Liquor ratio, chemical & color amount, time and
temperature of specific process steps
3.      Cycle time, fabric absorbency, bleaching whiteness, fabric running inside the machine
4.      Color &c hemical dissolving, transferring &
dosing. filtration of color, checking monitor information during processing whatever necessary to maintain
5.      Responsible operators, helping must be present in
front of machine during processing specially for dyeing.
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