Parameter |
Check point |
Method of
Checking |
Standard/
Frequency of check |
Necessary
Action(s) |
Fabric preparation |
Prior to dyeing |
pH of the cloth Uniform whiteness Absorbency Selvedge crease/ Body creases |
Near Neutral Uniform whiteness Good Absorbency No creases/ Each bleach lot |
Ensure good
fabric preparation |
Batching |
During Batching |
Visual
|
Random check |
Knife edge batching Ensure no slippage Proper working of expander Uniform tension at the time batching |
Batch Size |
During batching |
Measurement of yardage |
Maximum permissible load Random check |
Ensure that jigger is not overloaded |
MLR |
Prior/During Dyeing |
Check for water level Check for weight of fabric load |
Once a shift |
Maintain constant MLR Prevent water leakages |
Selection of end cloth |
Prior to dyeing |
Length and colour of end cloth Compatible with the shade |
Random check |
Ensure proper selection and length of end cloth |
Crease-free working of jiggers |
During dyeing |
Visual |
During each round |
Adjust alignment expanders Adjust roller alignment Remove crease manually, if possible |
Recipe |
Prior dyeing
|
Scrutinizing of chemical slip should compatible with
shade |
Once a day |
Take corrective measure |
Colour Preparation |
During Colour preparation |
Visual/Spotting on filter paper |
Random check |
Ensure proper dissolution of dye Strain of the dye Investigation method of dissolution Ensure proper vatting of vat dye |
Colour/Chemical Addition |
During Dyeing |
Visual
Vat yellow/ Congo red Paper
Phenolphthalein paper |
Random check |
Carry out colour addition in equal parts Effect proper stirring of colour Predissolve all solid chemicals and add |
Concentration of chemicals |
During dyeing |
Titration |
During round |
Ensure proper concentration |
Temperature |
During dyeing |
Thermometer Thermocouple Thermistor All of the above |
During each round |
Regulate steam supply Carry out heating at the end of turn Prefer thermocouple |
pH |
During dyeing |
pH paper Direct – 10.4 Reactive – 11.2 Vat – 11.4 |
As per the class of dyestuffs |
Take corrective measure Give adequate time/ number of ends |
Time |
During dyeing |
Time record, number of ends |
As per the class of dyestuffs |
Take corrective measure Give adequate time/ number of ends |
Correction of shade |
During process |
Visual |
Whenever Possible |
Maintain the MLR Add extra colour |
After treatment |
After dyeing |
Laboratory analysis |
As per class of dyes |
Direct – dye fixing treatment Azoic – thorough soaping with dispersing agent Reactive – (NID) soaping for preventing the tinting Disperse – reduction clearing treatment |
Redyeing |
During Process |
Production record |
Minimum redyeing |
Investigate the reason of for redyeing |
Reference: Orientation Programme in Wet Processing (Quality and
Process Control) organised by BTRA, Mumbai
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