Download - Quality Control in Textile
-
8/22/2019 Quality Control in Textile
1/17
QUALITY CONTROL
IN
WET PROCESSING
PART I
PRETREATMENT PROCESSOF FABRIC
C. R. MADHU
Textile Processing Technology Department
R.C. Technical Institute, Sola, Ahmedabad, Gujarat
-
8/22/2019 Quality Control in Textile
2/17
QUALITY CONTROL
Quality in business, engineering and manufacturing
has a pragmatic interpretation as the non-
inferiorityorsuperiorityof 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.
http://en.wikipedia.org/wiki/Pragmatichttp://en.wikipedia.org/wiki/Pragmatic -
8/22/2019 Quality Control in Textile
3/17
There are five aspects of quality in a businesscontext:
1. Producing :- providing something.
2. Checking :- confirming that something has beendone correctly.
3. Quality Control :- controlling a process to ensurethat the outcomes are predictable.
4. Quality Management :- directing an organizationso that it optimizes its performance through
analysis and improvement.5. Quality Assurance :- obtaining confidence that a
product or service will be satisfactory. (Normallyperformed by a purchaser)
-
8/22/2019 Quality Control in Textile
4/17
TOTAL QUALITY MANAGEMENT (TQM)
Total Quality Management, is an approach that extendsbeyond ordinary statistical quality control techniquesand 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 forcontinuously improving the quality of products andprocesses
http://en.wikipedia.org/wiki/Total_quality_managementhttp://en.wikipedia.org/wiki/Management_fadhttp://en.wikipedia.org/wiki/Quality_(business)http://en.wikipedia.org/wiki/Quality_(business)http://en.wikipedia.org/wiki/Management_fadhttp://en.wikipedia.org/wiki/Total_quality_management -
8/22/2019 Quality Control in Textile
5/17
QUALITY CONTROLFOR GRAY FABRIC
Visual Examination for certain defects as stains,
mildew contamination, metallic impurities
These impurities may be carried out to trace backtheir nature and origin at the grey stage
This will help in taking suitable corrective action
during processing and to adopt preventive measureas well.
-
8/22/2019 Quality Control in Textile
6/17
EXAMINATIONUNDERULTRAVIOLET(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
-
8/22/2019 Quality Control in Textile
7/17
DETECTIONOF 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 withchloroform
Yellow colour indicate presence of Cu
-
8/22/2019 Quality Control in Textile
8/17
QUALITY CONTROLIN PRETREATMENT
PROCESSOF FABRIC
Process Test to be carried out
Desizing 1. Desizing efficiency
Scouring
1. Absorbency
2. Wax content3. 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
-
8/22/2019 Quality Control in Textile
9/17
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 comes90% :- Excellent
80 90% :- Satisfactory
below 80% :- Poor
-
8/22/2019 Quality Control in Textile
10/17
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 inchdiameter.
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.
-
8/22/2019 Quality Control in Textile
11/17
WAX CONTENT AATCC TEST METHOD 97-2009
Extraction of about 10 g sample with suitable
solvent (Chloroform for Cotton & Petroleum etherfor Polyester blend) in soxhlet apparatus.
Extracted sample is dried in oven at 105C
Amount of residue is expressed as percentage wax
content on the original weight of sample.
Chloroform
Lab. Oven
-
8/22/2019 Quality Control in Textile
12/17
ASH CONTENT AATCC TEST METHODS 78-1989
5 g of sample incinerated in silica crucible in a
burner followed by complete ashing in a mufflefurnace at about 700C fro 10 minute
Amount of ash is expressed as percentage of the
original weight of sample
Muffle Furnace
Silica Crucible
-
8/22/2019 Quality Control in Textile
13/17
CUPRAMMONIUM FLUIDITYAATCC TEST METHOD 82-2012
Determination of chemical degradation of cotton
Cotton is dissolved in cuprammonium hydroxide in Xtype viscometer at 20C
Internal volume:- 20 ml, filled with water & at bottom 0.7ml 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
-
8/22/2019 Quality Control in Textile
14/17
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 (R670R430) Harrison
W = 430 (R670R430) Stephenson
In USA, Hunters coordinates
W = L3b HunterW = L + 3a3b Stensby
-
8/22/2019 Quality Control in Textile
15/17
BARIUM ACTIVITY NUMBERAATCC 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 HClusing 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.
-
8/22/2019 Quality Control in Textile
16/17
SHRINKAGEIN 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 100Lo = Original Length
Lf= Final Length
67/33
polyester/cottonblend fabric shows
shrinkage within 1 %
-
8/22/2019 Quality Control in Textile
17/17
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 blankY = ml of 0.01 N Iodine required for sample
W = Weight in g of sample