it gives information about quality control and tests for that in pretreatment process for textile material

1. QUALITY CONTROL
IN
WET PROCESSING
PART – I
PRETREATMENT PROCESS OF FABRIC
C. R. MADHU
Textile Processing Technology Department
R.C. Technical Institute, Sola, Ahmedabad, Gujarat

2. QUALITY CONTROL
 Quality in business, engineering and manufacturing
has a pragmatic interpretation as the non-
inferiority or superiority of something
 also defined as fitness for purpose
 Quality is a perceptual, conditional and somewhat
subjective attribute and may be understood
differently by different people
 Quality control, or QC for short, is a process by
which entities review the quality of all factors
involved in production.

3. There are five aspects of quality in a business
context:
1. Producing :- providing something.
2. Checking :- confirming that something has been
done correctly.
3. Quality Control :- controlling a process to ensure
that the outcomes are predictable.
4. Quality Management :- directing an organization
so that it optimizes its performance through
analysis and improvement.
5. Quality Assurance :- obtaining confidence that a
product or service will be satisfactory. (Normally
performed by a purchaser)

4. TOTAL QUALITY MANAGEMENT (TQM)
 Total Quality Management, is an approach that extends
beyond ordinary statistical quality control techniques
and quality improvement methods
 TQM is only one of many acronyms used to label
management systems that focus on quality
 CQI (continuous quality improvement)
 SQC (statistical quality control)
 QFD (quality function deployment)
 QIDW (quality in daily work)
 TQC (total quality control)
 TQM is an integrative philosophy of management for
continuously improving the quality of products and
processes

5. QUALITY CONTROL FOR GRAY FABRIC
 Visual Examination for certain defects as stains,
mildew – contamination, metallic impurities
 These impurities may be carried out to trace back
their nature and origin at the grey stage
 This will help in taking suitable corrective action
during processing and to adopt preventive measure
as well.

6. EXAMINATION UNDER ULTRAVIOLET(UV) LIGHT
 This may be provide the origin of a stain by its
characteristic fluorescence
 Mineral oil :- Strong Violet/White
 Vegetable oil :- Yellowish
 Metallic soap :- Yellowish
 Fluorescent brightening agent :- Strong Violet/Blue
 Mildew growth :- Yellow
 Metal stain :- Very dark area against a lighter background

7. DETECTION OF COPPER & IRON
 Copper & Iron is likely to cause damage of cellulosic
fibres, due to catalytic effect in peroxide bleaching
 Fe :- Potassium thiocynate/Potassium ferrocyanide test
 Dilute HCl, Potassium thiocynate (Pink)
(10%)/Potassium ferrocyanide(10%) (Dark blue)
 Cu :- Ashed smaple
 Dissolved in dilute HCl & treated with Sodium
diethyldithiocarbamate followed by extraction with
chloroform
 Yellow colour indicate presence of Cu

8. QUALITY CONTROL IN PRETREATMENT
PROCESS OF FABRIC
Process Test to be carried out
Desizing 1. Desizing efficiency
Scouring
1. Absorbency
2. Wax content
3. Ash content
4. Cuprammonium test
Bleaching
1. Absorbency
2. Cuprammonium test
3. Whiteness
4. Yellowness
Mercerising 1. Barium activity number
Heat Setting 1. Boiling water shrinkage
2. Iodine absorption test

9. DESIZING EFFICIENCY
 Indian Standard No. 199, AATCC Test Method 79-1995
 Sample is to be solvent extracted in a soxhlet with chloroform
 % Desizing efficiency
= % Original Size - % Residual Size X 100
% Original Size
 Desizing efficiency comes
90% :- Excellent
80 – 90% :- Satisfactory
below 80% :- Poor

10. ABSORBENCY AATCC TS-018
 Allowing a drop of water to fall from a fixed distance (2.5 cm)
to the fabric mounted on embroidery frame of about 6 inch
diameter.
 Drop absorbency test
 Drop absorbency of about 5 sec is generally considered as
satisfactory
 Berdnt & Golob, Dugal et.Al. suggested methods for
hydrophobic fibre also by using C.I. direct Blue 86 and Black
disperse dyestuff.

11. WAX CONTENT AATCC TEST METHOD 97-2009
 Extraction of about 10 g sample with suitable
solvent (Chloroform for Cotton & Petroleum ether
for Polyester blend) in soxhlet apparatus.
 Extracted sample is dried in oven at 105°C
 Amount of residue is expressed as percentage wax
content on the original weight of sample.
Chloroform
Lab. Oven

12. ASH CONTENT AATCC TEST METHODS 78-1989
 5 g of sample incinerated in silica crucible in a
burner followed by complete ashing in a muffle
furnace at about 700°C fro 10 minute
 Amount of ash is expressed as percentage of the
original weight of sample
Muffle Furnace
Silica Crucible

13. CUPRAMMONIUM FLUIDITY
AATCC TEST METHOD 82-2012
 Determination of chemical degradation of cotton
 Cotton is dissolved in cuprammonium hydroxide in X –
type viscometer at 20°C
 Internal volume:- 20 ml, filled with water & at bottom 0.7
ml mercury is filled.
 C = F1 X d1 X t1, ,
for liquid of known fluidity
 where, C = Viscometer Constant
F1 = Fluidity
d1 = Density
t1 = time of flow
 Fluidity of cotton F = C/t
 For bleached fabric F = 5 – 8
is satisfactory

14. WHITENESS AATCC TEST METHOD 110-2011
 This is attributed to the luminosity or freedom from
yellowness
 It is measured by reflection of the specimen against
standard white (MgO)
 In blue region
W = 100 – (R670 – R430) … Harrison
W = 430 – (R670 – R430) … Stephenson
 In USA, Hunter’s coordinates
W = L – 3b … Hunter
W = L + 3a – 3b … Stensby

15. BARIUM ACTIVITY NUMBER
AATCC TEST METHOD 89-2012
 Degree of swelling of cotton material during mercerization is
determined by B.A.N. test
 3 g of specimen is extracted with carbon tetrachloride in soxhlet
 2 g of specimen is transferred to a conical flask and 30 ml, 0.25
N Ba(OH)2 is added to it.
 This mixture is allowed to stand for 2 hours.
 From above mixture 10 ml of sample is titrated against 0.1 N HCl
using phenolphthalein.
 Blank determination is also carried out without specimen in flask.
 BAN = [(a – b)/(a – c)] X 100
a = volume of acid required for blank
b = volume of acid required for mercerized specimen
c = volume of acid required for unmercerized specimen
 A well mercerized cotton shows BAN in the range 125 – 135.

16. SHRINKAGE IN BOILING WATER
AATCC TEST METHOD 135
 Test was originally recommended by Du Pont
 Blended fabric sample is marked in warp & weft
direction & then boiled in water for 30 minute.
 % Shrinkage = [ ( Lo – Lf) / Lo] X 100
Lo = Original Length
Lf = Final Length
 67/33
polyester/cotton
blend fabric shows
shrinkage within 1 %

17. IODINE ABSORPTION TEST
 For assessing degree of heat setting this test is carried out.
 1 g sample taken in 250 ml stopper flask, 0.1 N 30 ml Iodine is
added to this flask & allowed to stand for 2 Hrs.
 Sample is taken out and added in 50 ml chloroform, then 10
ml 0.1 N Sodium thiosulphate is added to this mixture
 This mixture is titrated against 0.01 N Iodine solution using
starch as indicator.
 Blank determination is also carried out.
 Iodine Absorption (mg/g) = [ (X – Y) X 0.01 X 127 ] / W
X = ml of 0.01 N Iodine required for blank
Y = ml of 0.01 N Iodine required for sample
W = Weight in g of sample