Alkali & Salt free dyeing of cotton fabric with reactive Dye.
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Page 1 of 39
“Alkali & Salt Free Dyeing of cotton fabric with Reactive Dye”
Table of Contents
Chapter Chapter Name Page No. Chapter – 1
Introduction 3 to 4
Chapter – 2
Literature Review 5 to 15
Chapter – 3
Materials and Method 16 to 21
Chapter – 4
Process Curve 22 to 25
Chapter – 5
Testing and Result 26 to 33
Chapter – 6
Discussion 34 to 38
Chapter – 7
Conclusion 39
Prepared By:
Name : Md. Al Hafij Prodhan ID : 12131107008
Subject : B. Sc in Textile Engineering
University: Bangladesh University of
Business & Technology (BUBT)
Email : [email protected]
Page 2 of 39
ABSTRACT
Dyeing of cellulosic materials with reactive and direct dyes is commercially very popular, but is
not eco-friendly. On the other hand, pigment colors cannot be applied by conventional exhaust
methods. These problems can be solved or minimized by increasing the affinity of cellulosic
materials. Cationization of cellulosic fibers improves affinity towards anionic dyes like reactive
dyes, direct dyes, and pigment colors dispersed with anionic dispersants.
Cellulosic fabrics dyed with reactive dyes require a large amount of salt, which pollutes fresh
watercourses. Due to the hydrolysis of the dye, the dyeing effluent consists of a large amount of
hydrolyzed dye, and it requires a high volume of water to remove the hydrolyzed dye in a wash-
off process. Cotton fabrics were dyed with reactive dyes using conventional methods and
pretreating the fabric with methylamine. Pretreated samples were dyed without using salt as an
electrolyte. The influence of pretreatment on wash fastness, rubbing fastness and crease
recovery were determined. It was found that pretreatment of cotton fabrics with methylamine
increases dye uptake and shows good wash fastness and rubbing fastness. When the fabric is
treated with methylamine, the primary hydroxyl groups of cellulose is (partially) modified into a
amide groups, which intern leads the cellulose to act like as wool fiber and hence reactive dyes
can be dyed on cotton at slight acetic pH in the absence of electrolyte and alkali.
Keywords:
Salt Free Dyeing, Reactive Dye, Methylamine, Cellulose, Amide Groups.
Aim of the project:
The fiber reactive dyes are known as the best for cotton for its wide range of application and
better fastness properties. However, all the reactive dyeing systems require huge amount of
electrolyte and alkali to exhaust and fix the dye respectively. Reactive dyeing thus pollutes the
environment by discharging highly colored reactive dye bath and higher electrolyte
concentration. So, no electrolyte and alkali are used in our research dyeing. Thus this overall
aim of the research is to consider eco-friendly dyeing.
Page 3 of 39
Chapter -1
Introduction
Page 4 of 39
INTRODUCTION
In current practice, cellulosic fibers are predominantly dyed with reactive dyes in the presence
of a considerable amount of salt and fixed under alkaline conditions. However, dye fixation
efficiency on cellulosic fibers is generally low (varying from 50 – 90%). This, results in a
highly colored dye effluent, which is unfavorable on environmental grounds. Furthermore, the
high concentrations (40–100gm/L) of electrolyte and alkali (5–20 gm/L) required in cellulose
fiber dyeing may pose additional effluent problems.
Cotton pretreatment before dyeing can offer a simple and effective method of improving dye-
fiber affinity, avoiding the need for salt in the dye bath. Cationizing cotton fiber increases the
substantively of anionic dyes due to presence of positive charges imparted to the fiber.
Cationization is the chemical modification of cotton to produce cationic (positively charged)
dyeing sites in place of existing hydroxyl (-OH) sites. Because protein fibers like wool and silk
were known to have good dye ability. Dyeing cationic cotton results in greater use of dye and
higher color values. In addition, the strong dye fiber interactions resulting from cationizing
cotton allow dyeing with no added electrolytes and minimal rinsing and after washing.
However, a fiber with great dye-attracting properties may continue to exhibit those attributes in
later use and become scavengers during laundering.
It has been found that pretreatment of cotton before dyeing can offer a simple and effective
method of improving dye-fiber affinity, avoiding the need for salt as an electrolyte in the dye
bath. It has been found that is a physical modifying agent. Its wide range of properties has found
use in catalysis, chelating, liquid chromatography, and treatment of wastewater, recovery of oil
and in polymeric dyes.
The aim of this work is to determine the effectiveness of methyl amine as a pretreatment agent
of cotton fabrics in improving its dye ability with reactive dyes and in achieving evenness of
dye uptake.
Page 5 of 39
Chapter – 2
Literature Review
Page 6 of 39
Literature Review
Dyeing
Dyeing is the process of adding color to textile products like fibers, yarns, and fabrics. Dyeing is
normally done in a special solution containing dyes and particular chemical material. After
dyeing, dye molecules have uncut chemical bond with fiber molecules. The temperature and
time controlling are two key factors in dyeing.
Methods of dyeing
These are 3 application procedures available:
1. Discontinuous method-
Conventional method
Exhaust or constant temperature method
High temperature method
Hot critical method.
2. Continuous method-
Pad-steam method
Pad dry method
Pad thermofix method
3. Semi continuous method-
Pad roll method
Pad jig method
Pad batch method
Among the different method, exhaust method is most widely used for dyeing the knitted cotton
fabric in the industry of Bangladesh.
Dyeing of cotton fabric with reactive Dye:
Reactive dye is capable of reacting chemically with a substrate to form a covalent bond between
dye and substrate.
Here the dye contains a reactive group and this reactive group makes covalent bond with the
fiber polymer and act as an integral part of fiber. This covalent bond is formed between the dye
molecules and the terminal –OH (hydroxyl) group of cellulosic fibers on between the dye
molecules.
Important factors for Reactive Dyeing 1. PH of the substrate prior to dyeing
2. PH of the dye bath
3. Pretreatment of the substrate
Page 7 of 39
4. Solubility of the dyestuff
5. Dyeing temperature
6. Quality of water and salt
7. Electrolyte concentration
8. Dyeing time
9. Washing off sequence
10. Type of alkali
Dyeing mechanism of reactive dye
The dyeing mechanism of cotton fabric with reactive dye takes place in 3
stages:- 1. Exhaustion of dye in presence of electrolyte i.e. dyes sorption.
2. Fixation under the influence of alkali.
3. Wash-off the unfixed dye from material surface.
Dye exhaustion When fiber is immersed in dye liquor, an electrolyte is added to assist the exhaustion of dye.
Here NaCl is used as the electrolyte. This electrolyte increases the sorption of dyes. So when the
textile material is immersed into the dye liquor, the dye is exhausted on to the fiber.
Fixation Fixation of dye means the reaction of reactive group of dye with terminal –OH or-NH2- group
of fiber and thus forming strong covalent bond with the fiber. This is an important phase, which
is controlled by maintaining proper pH by adding alkali. The alkali used for this creates proper
pH in dye bath and work as the dye-fixing agent. The reaction takes place in this stage is shown
below:
D − SO2 − CH𝟐 − CH𝟐 − OSO3Na + OH − Cell= D − SO2 − CH𝟐 − CH𝟐 − O − Cell + NaHSO3
D − SO2 − CH𝟐 − CH𝟐 − OSO3Na + OH −Wool= D − SO2 − CH𝟐 − CH𝟐 − O −Wool + NaHSO3
Figure 1: Covalent bond formed between dye & fiber after dyeing with reactive dye
Page 8 of 39
Wash-off As the dyeing is completed, a good wash must be applied to the material to remove extra and
unfixed dyes from material surface. This is necessary for level dyeing and good fastness
properties. It is done by a series of hot wash, cold wash and soap solution wash.
Cotton fabric
Cotton is the most important of the raw materials for the textile industry. The cotton fiber is a
single biological cell with a multilayer structure. The layers in the cell structure are, from the
outside of the fiber to the inside; cuticle, primary wall, secondary wall, and lumen. The whole
cotton fiber contains 88 to 96.5% of cellulose, the rest are non-cellulosic polysaccharides
constituting up to 10% of the total fiber weight .
The primary wall in matured cotton fiber is only 0.5-1 µm thick and contains about 50% of
cellulose. Non-cellulosic constituents consist of pectins, fats and waxes, proteins and natural
colorants. The secondary wall contains about 92- 95% cellulose. The major portion of the non-
cellulosic constituents of cotton fiber is present in or near the primary wall.
Non cellulosic impurities, such as fats, waxes, proteins, pectins, natural colorants, minerals and
water-soluble compounds found to a large extent in the cellulose matrix of the primary wall and
to a lesser extent in the secondary wall strongly limit the water absorbency and whiteness of the
cotton fiber. Pectin is located mostly in the primary wall of the fiber.
It is composed of a high proportion of D-galacturonic acid residues, joined together by α
(1→4)-linkages. The carboxylic acid groups of some of the galacturonic acid residues are partly
esterified with methanol. Pectic molecule can be called a block-copolymer with alternating the
esterified and the non-esterified blocks .
Fig: Cotton Fiber
Page 9 of 39
Fig: Representation of cotton fiber showing its various layers.
In the primary cell wall pectin is covalently linked to cellulose or in other plants to
hemicelluloses, or that is strongly hydrogen- bonded to other components. Pectin is like
powerful biological glue. The mostly water-insoluble pectin salts serve to bind the waxes and
proteins together to form the fiber`s protective barrier.
Cotton fiber differs markedly from other cellulose fibers in morphological traits. Due to many
features, cotton even though it was discovered later than other fibers gained a superior position
and stimulated immense development of textile industry. Among the advantages of cotton fabric
we can name the following:
Cotton fabrics show good durability and utility (but still cotton fabrics are inferior to synthetic
fabrics in durability). Cotton is a chemically stable material; it stays undamaged even under the
continuous exposure of weak acids and alkalis. It has High water-absorbing capacity. In humid
atmosphere cotton fabric can absorb 27% of water without getting damp.
Cotton fabric has very good breathable characteristics, it is hypoallergenic, agreeable to touch,
and it is suits perfectly for people with skin hyper sensibility. It has low thermal-conductivity;
therefore it is an ideal material for both summer and winter clothes: in summer it prevents our
skin from heat, and in winter it preserves the warmth of our body. Cotton fabrics are easy to
dye. Cotton fabrics have very low elasticity characteristics, so they almost don't stretch. They
are easy washable and can be ironed even at high temperature.
Scouring
Scouring is the process where all natural and added impurities such as oil, wax, fat etc are
removed to make the fabric hydrophilic and clean the textile materials. The main purpose of
scouring cotton fabrics is to remove natural as well as added impurities of essentially
hydrophobic character as completely as possible and leave the fabric in a highly absorptive
condition without any damage. The other objects of scouring are removed the non-cellulosic
substances in case of cotton, make the fabric ready for dyeing, printing or finishing, and
produce a clean material by adding scouring agents to remove impurities such as oils, waxes,
gum, husks as nearly as possible.
Page 10 of 39
Scouring Process
1. Batch process
2. Semi continuous process
3. Modern process
Scouring Method
1. Kier boiler process or discontinuous process i.e. exhausts method.
2. Continuous process.
Among the different processes, exhaust method is most widely used for knitted cotton fabric in
the industry of Bangladesh.
Bleaching In the combined scouring-bleaching of cotton, the scouring process is accelerated in the
presence of H2O
2 and less time is generally required to achieve good absorbency of the material.
The advantages of this process are increased production with reduction of labor cost and
reduced treatment time; the loss in wt. and strength of material is less. H2O
2 is a powerful
oxidizing agent that rapidly destroys the natural colouring matters present in cotton without
undue oxidative damage to the fibers. Full use of the stabilizing properties of natural cotton
impurities minimizes peroxide consumption during bleaching. High alkalinity at elevated
temperatures produces efficient scouring action. Bleaching and leveling residual waxes are also
affected in this process. Hence a combined scouring bleaching process for cotton using peroxide
in winch and package has gained commercial success.
Mechanism involved in Scouring & bleaching: Under certain condition, particularly regard to 𝑃𝐻 hydrogen peroxide will liberate hydrogen ion
and perhydroxyl ions in the following manner.
H2O2 H+ + HO2
- Responsible for bleaching.
HO2- OH- + [O]
[O], it is called xymer Oxygen. Which remove the natural color from the fabric.
Methyl amine (CH3NH2):
CH3NH2 has been used as a physical modifying agent. Due to its wide range of properties,
CH3NH2 has found use in catalysis, liquid chromatography, treatment of wastewater, recovery
of oil and in polymeric dyes. It has been used in applications as diverse as papermaking and
biomedical research, but its use in the modification of cotton for salt-free dyeing as not been
previously reported. Interest in CH3NH2 arises from the presence of a large number of cationic
sites (CH3+NH2-). Nucleophilic sites involving primary amino groups within the CH3NH2
molecule are of particular value for achieving salt-free dyeing of cotton with reactive dyes. As
the pH increases, the proportion of CH3+NH2-groups in the molecule decreases and that of the
NH2 groups increases.
Page 11 of 39
Picture 4.1 surface modification by methyl amine
Reactive dye Reactive dye is the most popular dye for the coloration of cellulosic fibers. reactive dye, colored
organic substances, primarily used for tinting textiles, that attach themselves to their substrates
by a chemical reaction that forms a covalent bond between the molecule of dye and that of the
fiber. The dyestuff thus becomes a part of the fiber and is much less likely to be removed by
washing than the dyestuffs that adhere by adsorption
The general structure of reactive dye is: D-B-G-X.
Here,
D= dye part or chromogen (color producing part)
B = bridging part. Bridging part may be –NH- group or –NR- group.
G = reactive group bearing part.
X= reactive group.
Figure 3: Structure of mono functional reactive dye.
Page 12 of 39
During dyeing the H atom in the cellulose molecule combines with reactive group of the dye
molecule and the covalent bond formation occur. The dyes not only react with the cellulose but
also react with hydroxyl ions present in the dye bath and causes dye hydrolysis. Fiber reactive
dyes are the most permanent of all dye types. Unlike other dyes, it actually forms a covalent
bond with the cellulose or protein molecule. Once the bond is formed, the dye molecule has
become an actual part of the cellulose fiber molecule. Dyestuffs with only one functional group
are sometimes enough for getting high degree of fixation.
Table 1: Reactive dyes are categorized by functional group
Functional group Dyeing
Temperature
Producer
Monochlorotriazine 80° Basilen E & PCibacron EProcion
H,HE
Monofluorochlorotriazine 60° Cibacron F & C
Dichlorotriazine 30° Basilen MProcion MX
Difluorochloropyrimidine 40° Levafix EADrimarene K & R
Dichloroquinoxaline 40° Levafix E
Trichloropyrimidine 80-98° Drimarene X & ZCibacron T
Vinyl sulfone 40° Remazol
Vinyl amide 40° Remazol
Properties of reactive dye Reactive dyes are anionic dyes, which are used for dyeing cellulose, protein and
polyamide fibers.
Reactive dyes are soluble in water.
They have very good light fastness with rating about 6.
The dyes have very stable electron arrangement and can protect the degrading effect of
ultra-violet ray.
Textile materials dyed with reactive dyes have very good wash fastness with rating up to
5.
The dyes give brighter shades and have moderate rubbing fastness.
Dyeing method of reactive dyes is easy.
It requires less time and low temperature for dyeing.
It’s also comparatively cheap.
Thus reactive dying of cotton is currently the most widespread textile dying process in
the world.
Dye used in this project
Drimaren Red X- 6BN :
A new reactive dye in the Drimarene range for the exhaust and continuous dyeing of cellulosic
fibers.
Page 13 of 39
The features of Drimaren Red X- 6BN are:
High process reliability in term of salt, liquor ratio, temperature and time dependency
Very good reproducibility and efficiency
Easy washing off
High fastness level
Reddish yellow
Ternary combination element with Red CL-5B and blue elements
High economy
Versatile application, suitable for exhaust and continuous processes
Excellent migration
Easy washing off
Available as powder and as granules
Drimafon ECO: unsuitable
Drimafon CL (tow bath reverse process) : suitable
𝑃𝐻 sensitivity (rating Change): 𝑃𝐻 4.5 : 4-5 𝑃𝐻 8.5 : 4-5
Polyamide reserve (rating Change): PA 6 : 1-2 PA 6.6 : 1
Polyester reserve (rating Change) : 4-5
Dyes dead Cotton slightly paler
Pad batch group 2
Evaluation of L* a* b* value of Dyed Fabric :
The Basic information required for the measuring the color strength and color match prediction
is the relationship between reflectance of the dyed materials and concentration of the dyestuffs.
Color strength of dyed fabrics is determined in term of the K/S value by using
spectrophotometer. The most common spectrophotometers are used in the UV and visible
regions of the spectrum and some of these instruments also operate into the near-infrared region
as well.
Visible region 400–700 nm spectrophotometer is used extensively in colorimeter science. Ink
manufacturers, printing companies, textiles vendors, and many more, need the data provided
through colorimeter. They take readings in the region of every 5–20 nanometers along the
visible region, and produce a spectral reflectance curve or a data stream for alternative
presentations. These curves can be used to test a new batch of colorant to check if it makes a
match to specifications,
Page 14 of 39
Evaluation of fastness properties
Color fastness is the ability of a dye or pigment to retain its color or resistance of a textile
material after exposure to specific chemical or environment such as washing, dry cleaning,
exposure to light etc. The color fastness is usually rated either by loss of depth of color or color
change compare to original sample. It is often expressed by staining scale meaning that the
accompanying material gets stained by the color of the original fabric, when the accompanying
white fabrics of same or different nature are either in touch by some means of test procedure or
during usage.
The fastness of a color can vary with the type of dye, the particular shade used, the depth of
shade and how well the dyeing process has been carried out. It is therefore important to test any
dyed or printed product for the fastness of the colors that have been used in its decoration. The
fastness requirements, however, are largely determined by the end-use of dyed fabrics. Some of
the basic fastness properties required is as follows:
Rubbing fastness
This test is designed to determine the degree of color which may be transferred from the surface
of a colored fabric to a specific test cloth for rubbing. It can be done dry and wet condition. In
both wet and dry rubbing, rubbing of cloth is done according to test method and rating by
comparing the Staining with the gray scale.
Page 15 of 39
If the color fastness to rubbing is good then it’s other properties like washing fastness and
durability etc. improves automatically because the rubbing is a method to check the fixation of
the color on the fabric. So if the fixation is good it’s washing properties will be good.
There are two test methods for rubbing fastness.
1. ISO-105-X12,
2. AATCC-08
In ISO-105-X12 the wet pickup of the rubbing cloth is 100% .While in AATCC-08 the wet
Pickup of the rubbing cloth is 65%.Crock meter is used to determine color fastness of dyed
textile against rubbing or staining either under dry or wet conditions.
Wash fastness
A specimen of the textile, in contact with one or two specified adjacent fabrics, is mechanically
agitated under define conditions of time and temperature in a soap solution, then rinsed and
dried. The change in color of the specimen and the staining of the adjacent fabric are assessed
with the grey scales.
There are a number of ISO test for color fastness to washing. These are:
ISO test no-1 also known as hand washing test.
ISO test no- 2 was formally known as SDC test no 2
ISO test no- 3 also known as mechanical washing test A.
ISO test no- 4 also known as mechanical washing test B.
ISO test no- 5 was formally known as SDC test no-4
ISO 105 C06 –it is now most popular to all.
Color Fastness to Perspiration
The garments which come into contact with the body where perspiration is heavy may suffer
serious local discoloration. This test is intended to determine the resistance of color of dyed
textile to the action of acidic and alkaline perspiration. Before knowing about the Color Fastness
to perspiration you must have to know about Color Fastness to Wash and Color Fastness to
Rubbing.
Rating Property
1 Very poor
2 Poor
3 Fair
4 Good
5 Excellent
Page 16 of 39
Chapter – 3
MATERIALS AND METHODS
Page 17 of 39
MATERIALS AND METHODS
Materials:
In this research work the following materials were used throughout.
Fabric:
100% scoured and bleached cotton fabric.
Structure: Single Jersey.
GSM of the fabric is 160.
Stitch length 2.54 mm
Chemical:
Methyl amine(CH3NH2) was used as a cationizing agent.
Other Chemicals: Sodium Hydroxide, Green Acid(60% Acetic acid+ 40%
Sodium acetate), Sodium Carbonate, nonionic wetting agent,anti-creasing
agent,nonionicdetergent, water.
Dye used: Drimaren Red X- 6BN
Cationization of cotton fabric:
Methyl amine (40% concentration) - 40% (o.w.f)
Temperature : 60oc
Time: 60 min
M:L= 1:10
Fabric waight: 5gm
Dyeing recipe:
Drimaren Red X- 6BN : 2%, 4% Shade
Wetting agent : 1 gm/l
Sequestering agent : 1 gm/l
Anti-creasing agent : 1 gm/l
Acetic acid : 1 gm/L (for acid condition)
Alkali (soda ash) : 2cc//l (for Alkali condition)
M: L = 1:10
Temp : 60oC
Time : 60 min
Sample weight : 5 gm
Page 18 of 39
Soaping recipe:
Soaping agent: 1gm/L
Sodium carbonate 1% solution.
Temp: at 60oC
Time: 30 min
Cationization of cotton fabric procedure:
Taken sample was weighted 5 gm
Prepared cationizing agent methyl amine (CH3NH2) 40% o.w.f
Prepared the cationizing bath
Load on the machine (Lab Sample Dyeing Machine)
Temp. was raised from 350C at the rate of 1oC per min. to 60oC and
the cationizing was continued for further 60 min.
Bath drop
No hot wash and cold wash. Just dry or squeeze
Then ready for the dyeing
Page 19 of 39
Cationization of cotton fabric procedure description:
First of all we took the cotton sample of Wight 5 gm to the pot of the machine. Then we
prepared the cationizing bath by adding 40% methylamine of the weight of fabric.
Cationizing process was started at 35oC and was raised at the rate of 1oC per min until 600C
for 60 min. After completing the cationization process bath was dropped without any kind of
washing. The excess bath contents were fending off by rinsing the fabric. Then it was ready
for the dyeing procedure. No salt and soda was needed during this process.
Fig: Sample dyeing machine (Lab)
Page 20 of 39
Dyeing of cationization of cotton fabric procedure:
Temp. was raised at the rate of 1oC per min from 350C to 60oC and
the dyeing was continued for further 60 min.
Load on the pot on the machine (Lab Sample Dyeing Machine)
Cationized fabric was given in the machine pot
Then dye was added in the machine pot
Drop on the other auxiliaries in the machine pot
Prepare dye bath according to dyeing recipe
Bath drop
After completing dyeing fabric was hot wash with soaped with
1gm/L at 60oC and neutralization with 1% Na 2CO3for 30 mins.
Then cold wash (normal wash)
Dried the fabric
Ironing properly
Taken 5gm cationized knitted fabric
Page 21 of 39
Dyeing of cationization of cotton fabric procedure description:
Treated cationizing fabric was taken 5gm as specimen. Then dyeing was bath prepared
according to the dyeing recipe. Load on the machine and then temperature was raised at the
rate of 1oC per min from 350C to 60oC and the dyeing was continued for 60 min. Then bath
was dropped. Completing dyeing the fabric was treated by hot and soaping agent at 60oC for
30 min. And the fabric was neutralized by washing it with 1% Sodium carbonate solution.
After that the fabric was given cold washed. Then dried the sample and ironing properly.
Fig: Salt free dyed fabric with reactive dye (Drimaren red X 6BN)
Page 22 of 39
Chapter – 4
Process curve
Page 23 of 39
Process curve for different process
Cationizing process curve:
60oC
60’ bath drop
1oC
350C
Curve11.1Cationizing process curve
Description:
In curve no 11.1 represent X axis depend on time and Y axis depend on temperature. First of
all methyl amine 40% o.w.f is inserted in the cationization bath. In the inclined line means
temperature raise at the rate of 1oC per min. to 60oC. Its run time is 60 min and then bath
drop.
Time
T
emp
.
Met
hy
l am
ine
- 2
0%
ow
f
Page 24 of 39
Dyeing process curve:
60oC
60’ Bath drop
1oC
350C
Curve11.2: Dyeing process curve
Description:
In curve no 11.2 represent X axis depend on time and Y axis depend on temperature. First of
all wetting agent, anti-creasing agent and dyes are inserted in the dye bath. In the inclined line
means temperature raise at the rate of 1oC per min. to 60oC. Its run time is 60 min and then
bath drop.
Time
Tem
p.
Dye
s
Wet
tin
g ag
ent,
seq
ues
teri
ng
age
nt,
anti
-cre
asin
g ag
ent
1 drop Added (green acid). pH
4.5-5.5
Page 25 of 39
Hot wash and soaping process curve:
60oC
30’
Bath drop
1oC
400C
Curve11.3 Hot wash & soaping
Description:
In curve no 11.3 represent X axis depend on time and Y axis depend on temperature. First of
all soap is inserted in the bath. In the inclined line means temperature raise at the rate of 1oC
per min. to 60oC. Its run time is 30 min and then bath drop.
Tem
p.
Time
Soap
+
Neu
tral
izat
io
n
Page 26 of 39
Chapter – 5
Testing and Result
Page 27 of 39
Testing and analysis of dyed sample
L*a* b* Differences of dyed sample :-
Fig: Spectrophotometer
For 4% shade:
Neutral Acid
Fig: 4% Neutral condition Fig: 4% Acid Condition
Spectrophotometer reading difference:
a*= 4.56
b*=1.55
This value taken by D65, 10Deg. From the value a*,b* of spectrophotometer graph and it is seen that
in acidic condition the shade is darker than neutral condition .
Page 28 of 39
For 4 % Shade :-
Neutral Alkali
Fig: 4% Neutral Condition Fig: 4% Alkali Condition
Spectrophotometer reading difference:
a*= 0.17
b*= 0.58
This value taken by D65, 10Deg.
From the value a*,b* of spectrophotometer graph and it is observed that in alkalian condition
result is better than neutral condition.
For 2% shade :
Neutral Acid
Fig: 2% Neutral Condition Fig: 2% Acid Condition
Page 29 of 39
Spectrophotometer reading difference :-
a*= 4.80
b*= 0.14
This value taken by D65, 10Deg.
From the value a*,b* of spectrophotometer graph and visible we can say that in acidic
condition result is better than neutral condition.
For 2 % shade :-
Neutral Alkali
Fig: 2% Neutral Condition Fig: 2% Alkali Condition
Spectrophotometer reading :-
a*= 2.40
b*= 0.27
This value taken by D65, 10Deg.
From the value a*,b* of spectrophotometer graph and visible we can say that in alkalian
condition result is better then neutral condition .
Comment :-Above this discussion its strongly say that methyl amine treaded cotton fabric
give better result while it dyeing acidic condition .
Note: This test result prepared by “Switch Color (Pvt.) Ltd.”
Page 30 of 39
Color Fastness to Wash Test:
Test Method: ISO105F10
M/C Name: Washing & dry cleaning
Brand Name: James H. Heal
Fig: Washing Machine
Required materials:
1. Sample size 10X 4 cm
2. Multifiber at 10 X 4 cm
3. ECE detergent – 4gm/L
4. Sodium Perborate (Na2BO3) - 1g/L
5. Distilled water
6. Normal cold water
7. Stainless Steel balls
Required instrument:
1. Washing machine
2. Scissor
3. Stitch machine
Procedure:
1. Cut sample &multifibre at 100 × 400 mm and then stitch.
2. ECE detergent & Sodium per borate is taken with the sample. the solution is taken
by the following formula: (Sample fabric + Multifibre weight) × 50 ml (1:50
liquor ratio)
3. The sample is kept in 60oC for 30 min.in Wash Machine
4. Rinse the sample twice with cold water.
Flat iron pressing but temperature should not be more than 150°C.
Page 31 of 39
Color the Fastness to Rubbing (Dry & Wet) Test: Test Method: ISO105 X12:1993
Sample:
Dyed fabric – 15 cm X 5 cm
White Test Cloth - 5 cm X 5 cm
Fig: Rubbing test machine
Procedure:
1. White test cloth is put on to the grating and stag by steel wire.
2. The sample is run twenty times manually for ten seconds and the rubbing fastness
ofthe sample cloth and degree of staining is accessed.
3. For rubbing fastness (Wet), the rubbing cloth is placed in the water and socked
andsqueeze. The wet rubbing cloth is placed on to the grating and stag with stainless
steel wire and run ten times manually then assesses the staining on to the rubbing
cloth andthe rubbing fastness of the sample cloth is accessed.
Color Fastness to Perspiration Test:
Test Method: ISO105 E04: 1994
Test specimen:
Sample fabric – 10 X 4 cm
Multifibre fabric – 10 X 4 cm
Cut the multifibre into two piece
Sandwich the test specimen between two piece of multifibre
Fig: Perspiration Test Mechine
Page 32 of 39
Testing Solution:
Alkaline Solution:
l-histidinemonohydrochloride monohydrate (C6H4O2N3 HCI.H2O)– 5.00 g/L
NaCl – 5.00 g/L
Sodium dihydrogen orthophosphate dihydrate (NaH2PO4.2H20)– 2.5 g/L
Sodium chloride (NaCl)-5g/l
PH – 8 (Adjust by 0.1 N NaOH)
Acidic Solution:
l-histidinemonohydrochloride monohydrate (C6H4O2N3 HCI.H2O)– 5.00 g/L
NaCl – 5.00 g/L
Sodium di-hydrogen orthophosphate (NaH2PO4.2H2O) – 2.2 g/L
Sodium chloride (NaCl)-5g/l
PH – 5.5 (Adjust by 0.1 N NaOH)
Procedure:
1. The composite specimen is put in a peri dish (2 specimen of a sample).
2. Solution (Alkaline & Acidic) is taken in the two peri dish. Here, M: L is taken 1:50.
3. Bubble is made out from the specimen by tapping.
4. The specimen is put for 30 minutes.
5. A glass plate is placed on the composite specimen for 15 min. at room temp.
6. Excess solution is poured off.
7. Peri dish with composite specimen & glass plate is placed into the incubator at
(37±2)oC for 4 hours.
8. The specimen is dried (Temp ≤60oC)
Result
Washing Fastness Test Results:
Wash fastness test result for 2% Shade
Color change 2% Neutral Condition 2% Alkali Condition 2% Acid Condition
4 4 4
Wash Fastness test result for 4% Shade
Color change
4% Neutral Condition 4% Alkali Condition 4% Acid Condition
4 4 4-5
Page 33 of 39
Color Fastness to Rubbing (Dry & Wet) Test result:
CF to Rubbing test result for 2% Shade
Rubbibg Fastness
2% Neutral Condition 2% Alkali Condition 2% Acid condition
Wet 3 4 4
Dry 4 4-5 4-5
CF to Rubbing test result for 4% Shade
Rubbibg Fastness
4% Neutral Condition 4% Alkali Condition 4% Acid condition
Wet 3 4 4
Dry 4 4 4-5
Perspiration Fastness Test Results:
CF to Perspiration Test result for 2% shade
Perspirstion Fastness
2% Neutral Condition 2% Alkali Condition 2% Acid Condition
Acid- 3 Acid- 4 Acid- 4-5
Alkali- 3 Alkali- 4-5 Alkali- 4-5
CF to Perspiration Test result for 4% shade
Perspiration fastness
4% Neutral Condition 4% Alkali Condition 4% Acid Condition
Acid- 3 Acid- 4 Acid- 4-5
Alkali- 3 Alkali- 4 Alkali- 4-5
Page 34 of 39
Chapter – 6
Discussion
Page 35 of 39
Discussion
Washing Fastness Test discussion:
Comment:
2% Shade Grade
2% Neutral Condition 4 Good
2% Alkali Condition 4 Good
2% Acid Condition 4 Good
4% Shade Grade
4% Neutral Condition 4 Good
4% Alkali Condition 4 Good
4% Acid Condition 4-5 Very good
Sample picture attachment:
Page 36 of 39
Color Fastness to Rubbing (Dry & Wet) Test discussion: Comment:
For 2% Shade Dry Grade
2% Neutral Condition 4 good
2% Alkali Condition 4-5 very good
2% Acid Condition 4-5 very good
Wet
2% Neutral 3 Poor
2% Alkali Condition 4 Good
2% Acid Condition 4 Good
For 4% Shade
Dry Grade
4% Neutral Condition 4 Good
4% Alkali Condition 4 Good
4% Acid Condition 4/5 Very Good
Wet
4% Neutral Condition 3 Poor
4% Alkali Condition 4 Good
4% Acid Condition 4/5 Good
Sample pictures attachment:
Page 37 of 39
Fig: Wet condition
Perspiration Fastness Test:
Comment:
Change in color (acid & alkali)
For 2% Shade Grade
2% Neutral Condition Acid-3 (poor), Alkali-3 (poor) 2% Alkali Condition Acid-4 (good), Alkali- 4/5 (very good) 2% Acid Condition Acid- 4/5 (very good), Alkali-4/5 (very good) For 4% Shade 4% Neutral Condition Acid- 3 (poor), Alkali-3 (poor) 4% Alkali condition Acid-4 (Good), Alkali-4 (good) 4% Acid Condition Acid- 4/5 (Very good), Alkali- 4/5 (very good)
Fig: Perspiration Test Sample
Page 38 of 39
Effect of cationization on environment:
The effluent clearly depicts that the process with methyl amine produces effluent with an
effluent load is more of less equal. Hence the dyeing effluent need not be sent to the effluent
treatment plant which reduces the needs of plant capacity and investment. It leads to a
substantial reduction in the dyeing cost. But in normal dyeing process produces more
effluents. The effluent of cationized cotton dyeing method poses lesser loads than that of
conventional dyeing. It is because of no addition of salt and alkali in the dye bath. The most
beneficial part of the cationization technique is the reduction of TDS in the effluent as this
cannot be removed from the effluent easily , which need capital intensive and cost consuming
treatments like reverse osmosis , nano filtration , ion exchange etc.
Page 39 of 39
Chapter – 7
Conclusion
Conclusion
The purpose of this paper is to give an overall idea about the pre-treatment of cotton with a
methylamine could enhance the dye ability of the fiber with reactive dyes. The methylamine
contains primary amino groups, with which theoretically, a reactive dye should be able to
react under acidic pH conditions. It is also decided to examine whether or not the
methylamine could, under appropriate ph conditions, assume a positive charge and so permit
“salt & alkali free” dyeing.