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“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 : hafij07bubt@gmail.com

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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.

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Chapter -1

Introduction

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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.

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Chapter – 2

Literature Review

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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

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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

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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

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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.

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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.

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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.

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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.

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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,

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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.

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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

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Chapter – 3

MATERIALS AND METHODS

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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

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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

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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)

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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

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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)

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Chapter – 4

Process curve

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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

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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

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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

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Chapter – 5

Testing and Result

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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 .

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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

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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.”

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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.

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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

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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.