THE SOUTH INDIAN CULTURAL
ASSOCIATION SCHOOL NO.3,
NIPANIA
SESSION: 2022-2023
CHEMISTRY INVESTIGATORY PROJECT
DYE PREPARATION:
TO DYE WOOL AND COTTON WITH MALACHITE
GREEN.
GUIDED BY: SUBMITTED BY:
MRS. ANNIE THOMAS AARUSHI SHUKLA
MRS. RITU ARORA
CERTIFICATE
It is hereby to certify that, the original and genuine
investigation work has been carried out to investigate
about the subject matter and the related data collection
and investigation has been completed solely, sincerely
and satisfactorily done by
AARUSHI SHUKLA of Class XII, SICA SENIOR
SECONDARY SCHOOL NO-3, regarding the project
titled, “DYE PREPARATION”
Signature of Guide Principal’s Signature
ACKNOWLEDGEMENT
The successful completion of any task would be
incomplete without mentioning the names of those people
who helped to make it possible. I take this opportunity to
express my gratitude in few words and respect to all those
who helped me in the completion of this project.
It is my humble pleasure and to acknowledge my deep
senses of gratitude and a kind thanks to my Chemistry
teacher Mrs. Annie Thomas and lab assistant Mrs. Ritu
Arora for their valuable support, constant help and
guidance at each and every stage, without which this
project would not have come forth.
I also register my sense of gratitude to our principal
Mrs. Ronika Valecha for her immense encouragement
that has made this project successful.
I would also like to thank my friends and family for
encouraging me during the course of this project.
Last, but not the least, I would like to thank CBSE for
giving us the opportunity to undertake this project.
INDEX
1.Introduction
2.Methods to apply dye
3.Characteristics of dye
4.Types of dye
Acid dyes
Basic dyes
Direct dyes
Disperse dyes
Fiber reactive dyes
Insoluble dyes
Vat dyes
Mordant dyes
5.Objective
6.Requirements
7.Procedure
8.Observations
9.Bibliography
INTRODUCTION
Dyes are colored substances which can adhere to
the surface of materials and are used to give color
to paper, foodstuffs, and various textiles such as
cotton, wool, synthetic fibers, silk etc. For example,
alizarin, indigo, Congo red, etc. Chemically, a dye
contains:
i. Some group (such as azo, indigoid,
triphenylmethyl, anthraquinone, etc.) which is
responsible for the color of the dye.
ii. ii. Some groups (such as –NH 2, -SO 3H, -
COOH, etc) which makes the dye stick to the
fabric by formation of some salt.
Dyeing is the process of adding color to textile
products like fibers, yarn and fabrics. The
temperature and time controlling are two key
factors in dyeing.
The primary source of dye historically has been
nature, with the dyes being extracted from plants
and animals. Since the 18th century, humans
produced artificial dyes to achieve a broader range
of colors and to render the dyes more stable to
resist washing and general use.
The dyed fabrics appear to be colored because a
particular dye absorbs radiations of some specific
wavelengths from the visible region of
electromagnetic radiations which fall on the
surface. The remaining radiations (complementary
colors) of light are reflected. The color which we
observe is due to the reflected light. For example, if
a dye absorbs the light in the wavelength region
corresponding to red, then it would appear green,
which is the complementary color of red. Similarly,
if a dye absorbs blue color, it would appear orange.
METHODS TO APPLY DYE
Dyes are applied to textile goods by dyeing from
dye solutions and by printing from dye pastes.
Methods include:
1. Direct application
2. Yarn dyeing
CHARACTERISTICS OF DYE
1. It must have a suitable color.
2. It must be capable of being fixed to the material.
3. When fixed it must be fast to detergents, soaps,
water, drycleaning solvents, light and dilute
acids.
TYPES OF DYE
The dyes are classified by dye manufacturers for
marketing into the following types:
1. ACID DYES:
These are azo dyes and are characterized by
the presence of acidic groups. The presence of
soluble and serves as the reactive points for
fixing the dye to the fibre. They are chiefly used
for dyeing wool, silk and nylon. For example,
Orange I and Orange II.
2. BASIC DYES:
These dyes contain NH 2 or NR 2 . In acidic
solutions, these form water soluble cations and
use the anionic sites on the fabric to get used
for dyeing wool, silk and nylon. For example,
aniline yellow, butter yellow.
3. DIRECT DYES:
These are also azo dyes and are used to dye
fabrics directly by placing in aqueous solution
of the dye. These dyes attach to the fabrics by
means of hydrogen bonding.
4. DISPERSE DYES:
These dyes are applied in the form of
dispersion of minute particles of the dye in a
soap solution in the presence of phenol or
benzoic acid. These dyes are used to dye
rayons, Dacron, nylon, polyesters etc. For
example, celliton fast pink B and celliton fast
blue B.
5. FIBRE REACTIVE DYES:
These dyes are linked to the fibre by –OH or –
NH 2 group present on the fibre. These dyes
induce fast color on fabrics which is retained
for a longer time. These dyes are used for
dyeing cotton, wool and silk.
6. INSOLUBLE DYES: These dyes are directly
synthesized on the fibre. The fabric to be
colored is soaked in an alkaline solution of
phenol and then treated with a solution of
diazotized amine to produce azo dye. The color
induced by such dyes is not so fast. These dyes
are used for dyeing of cotton, silk, polyester
nylon, etc. For example, nitroaniline red.
7. VAT DYES: These dyes are waterinsoluble and
before dyeing these are reduced to colorless
compounds in wooden vats by alkaline
reducing agents. The fibre is then soaked in the
solution of the dye. Fibre is then exposed to air
or an oxidizing agent. By doing so the colorless
compound gets reoxidized to colored dye on
the fabric. For example, indigo.
8. MORDANT DYES: These dyes are applied
after treating the fabric with precipitates of
certain substances (mordant material) which
then combines with the dye to form a colored
complex called lake. Some of the mordants are
salts of aluminium, iron and tannic acids.
Depending on the mordant used, the same
mordant dye can give different colors and
shades. For example, alizarin gives red color
with aluminium and black violet with iron
mordant. Mordant dyes are used for dyeing of
wool, silk and cotton.
OBJECTIVE
To dye wool and cotton with malachite green.
REQUIREMENTS
500 ml beakers, tripod stand, wire gauze, glass rod,
spatula, wool cloth and cotton cloth. Chemicals
required: Sodium carbonate, tannic acid,
tartaremetic acid, and malachite green dye.
PROCEDURE
1. Preparation of sodium carbonate solution: Take
about 0.5 g of solid sodium carbonate and
dissolve it in 250 ml of water.
2. of tartaremetic solution: Take about 0.2 g of
tartaremetic and dissolve it in 100 ml of water by
stirring with the help of glass rod.
3. Preparation of tannic acid solution: Take 100 ml
of water in a beaker and add about 1.0 g of
tannic acid to it. Heat the solution. On heating a
clear solution of tannic acid is obtained.
4. Preparation of dye solution: Take about 0.1 g of
malachite green dye and add to it 4oo ml of
water. On warming a clear solution of the dye
results.
5. Dyeing of wool: Take about 200 ml of dye
solution and dip it in the woolen cloth to be
dyed. Boil the solution for about 2 minutes. After
that remove the cloth and wash it with hot water
3-4 times, squeeze and keep it for drying.
6. Dyeing of cotton: Cotton does not absorb
malachite green readily, therefore it requires the
use of a mordant. For dyeing a cotton cloth dip it
in sodium carbonate solution for about 10
minutes and then rinse with water. Then put the
cloth in hot tannic acid solution for about 5
minutes. Now take out the cloth from tannic acid
solution and keep it in tartaremetic solution for
about 5 minutes. Remove the cloth and squeeze
it with spatula to remove most of the solution.
Now place the cloth in boiling solution of the dye
for about 2 minutes. Remove and wash the dyed
cloth thoroughly with water, squeeze and keep it
for drying.
7. Dyeing of cotton directly: Take another piece of
cotton cloth and pit it directly into boiling
solution of the dye. Keep it dipped for about 2
minutes. Remove the cloth, wash with water,
squeeze and keep it for drying. Compare the
color of this cloth with that dyed by using
mordant
OBSERVATIONS
1. The color of wool cloth dyed directly by dipping
in hot solution of malachite green dye is fast.
2. The color of cotton dyed cloth directly (without
using mordant) by dipping in hot solution of
malachite green is not so fast to washing and is of
low intensity.
3. The color of cotton cloth dyed indirectly by using
mordant and then by dipping in hot solution of
malachite green is fast to washing and is of high
intensity
BIBLIOGRAPHY
1. Comprehensive practical chemistry (class 12)
2. www.wikipedia.org/wiki/Dyeing
3. www.scribd.com
