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Quality evaluation of bleached, dyed and printed textiles
R.B.CHAVAN
Department of Textile Technology
Indian Institute of Technology
Hauz-Khas, New Delhi 110016
E-mail: [email protected]
Identification of fibres
Burning test
Fibre Burning behaviour
Cotton Burn with continuous flame, smell burning paper
Wool Does not burn, smell burning hair, balck char
Silk Does not burn, rotten smell
Nylon Does not burn, melt, white hard bid
Polyester Does not burn, melt, white hard bid
Acrylic Burn, no melting, black char
Solubility test
Fibre Solvent
Cotton Cuprammonium hydroxide, cadoxene
Wool 5% NaOH, boil
Silk Saturated zinc chloride
Polyester Ortho chloro phenol (OCP)
Nylon Formic acid
Acrylic Dimethyl formamide (DMF)
Desizing enzyme activity
1. Rate of disappearance of blue colour of stach iodide solution
2. Rate of decrease in viscosity of starch solution
Desizing efficiency
Qualitatative
1. Staining with starch iodide solution of desized fabric
Quantitative
1. Determination of weight of sized and desized fabric of same dimensions
2. Quantitative estimation of residual starch on desized fabric.
Scouring efficiency
1. Time required for absorption of a drop of water on scoured fabric ( 3 seconds)
2. Sinking test (Yarn, Fabric)
Bleaching efficiency
1. Whiteness of bleached fabric (% reflection of light 70%)
Fibre degradation during scouring and bleaching
1. Carboxyl group estimation (Methylene Blue absorption)
2. Estimation of Aldehyde groups (Copper Number)
3. Loss in strength of fabric (Tensile strength)
Dyeing and printing
Colour strength of commercial dye
1. Comparison of dyeing of standard dye sample and test sample
2. Measurement of optical density of same concentration of standard and test dye sample
Fastness properties
1. Wash fastness
2. Light fastness
3. Rubbing fastness (Crock fastness)
4. Perspiration fastness
5. Fastness to chlorine
Fastness property evaluation
Grey scale
1. Grey scale for colour change
2. Grey scale for staining
Fastness grades
1-5 for all except light fastness
Grade 1 Poor
Grade 5 Best
Light fastness grade 1-8
Grade 1 poor, Grade 8 best
Blue wool standards from grade 1-8 essential for exposure of samples to light
Laboratory facilities
1. Spectrophotometer
2. Digital balance with accuracy upto three decimals
3. Fade-o-meter for light fastness
4. Landero-meter for wash fastness
5. Crock meter for rubbing fastness
6. Perspiro-meter for perspiration fasness
7. Tesnsile strength tester
8. Abrasion tester
9. Stiffness tester
10.Crease recovery angle tester
11.Pilling tester
12.Abrasion tester
Environment related parameters
1. Estimation of banned amine on dyed sample
Principle
Reduction of dye from dyed or printed sample with sodiun hydrosulphite and casutic soda under standard conditions. Estimation of liberated amine using
HPLC Or
GC-mass spectrometer
Comparison of peaks with standard amines