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1. PIGMENT DYEING

2. Name : MAZADUL HASAN SHESHIR
ID: 2010000400008
Batch: 13th Batch (Session 2009-2013)
Department: Wet Processing Technology
Email: mazadulhasan@yahoo.com
Blog: www. Textilelab.blogspot.com
Southeast University
Department of Textile Engineering
PREPARED BY ©right

3. PIGMENT DYE
DEFINITION: Pigment is a substrate in a particulate form which is insoluble in water but
which can be dispersed in this medium to modify its color and light scattering properties.
They are organic or inorganic coloring materials. They have no affinity to textile materials.
They are fixed on the textile material with the help of binding agent in form a thin invisible
coating.
In pigment auxochrome groups are absent.
Pigment dyeing is not really "dyeing" in it's truest form because the pigments stick on the
fabric with the help of binders.. Pigments are insoluble in water. They exist in the form of
finely ground molecules, milled for garment dyeing purposes into a paste. When anionic
dispersing agents are added, a slightly negative charge is present, thus the foundation for
pigment dyeing is born.
When a positively charged cationic pre-treat is added to the fiber a magnetic bond is
formed. The process is complete when a cationic binder is added to "lock" the pigment into
place.In pigment dyeing no actual chemical reaction takes place between the dye and the
fabric.

4. ClASSIFICATION OF PIGMENT:

5. PIGMENT DYEING PROCESS:

6. TRADE NAMES:
Trade Names Manufacturer Country
Wintramin Winsol chem- Industries India
Helizerine BASF Germany
Neopralac Francolor France
Acramin Bayer AG West Germany

7. PROPERTIES OF PIGMENT:
1. Insoluble in water.
2. Organic or inorganic compounds.
3. No auxochrome group.
4. No direct affinity towards textile materials.
5. Binder is required for fixation.
6. Applicable to all kinds of fibers or textile materials.
7. No after treatment is required after coloration process.
8. Rubbing fastness is poor.
9. Water, wash and light fastness is very good.
10.A wide range of bright shades can be produced for some physical properties-
Particle size
Specific gravity
Boiling points
Melting points
: 0.2-0.4 µ
: 1.14-1.37 for most of the pigments
: Decompose at 190º- 345ºc
: Softeners ranges from the points 110º-175ºc

8. CHEMICAL PROPERTIES:
1. Most of the pigments are azoic compounds. Besides that it may be inorganic
oxide, inorganic salt phthalocyanine metal compounds etc.
2. Insoluble in water andother solvents like white spirit, per
chloroethylene, trichloroethylene, CCl4 etc.
3. Pigments are toxic. Some are oral toxic, some are dermal toxic, some causes
eye irritation etc.

9. REQUIRED PROPERTIES OF PIGMENTS:
1. Should have good covering power.
2. Should be chemically inert.
3. Should have freely mixing quality.
4. Should have good resistance to acid, alkali, bleaching agent etc.
5. Should have good fastness properties.
6. Should be applicable to all fibers and textile materials.
7. Should have well resistant to solvents.

10. DIFFERENCE BETWEEN DYES AND PIGMENTS:
DYES PIGMENTS
1. Water solubility is 70% 1. 100% water insoluble
2. Dyes have direct affinity to textile
material
2. They have no direct affinity to
textile materials
3. Auxochrome groups are present 3. Auxochrome groups are absent
4. Most of the dyes are organic 4. Most of dyes are inorganic
5. Costly 5. Cheap
6. No binding agent is required 6. Binding agent is required
7. Dye diffusions in the fabric 7. Pigment diffusions on the fabric

11. EXAMPLE OF VARIOUS PIGMENTS:
ORGANIC PIGMENT:
1. Dyes converted into pigment:
a) Dyes made insoluble by precipitation on substrate:
Peacok Blue Lake : CI pigment blue 24 ; Bronze red pigment : CI pigment 90
b)Vat dyes converted into pigment: Thio indigo red violet : Violet 36
Indanthrone blue : Blue 60
Perinone orange : orange 43
2. Quinacridone:
Cinquasia blue B, Cinquasia red Y
, Cinquasia violet R.
3. Azo pigments:
a)Metal free water insoluble azo- compounds (Group- I):
CI pigment red: Red 3; Fire red: Red 4;
Red tonner: Red 6;
Per matone orange : Orange 5
b)Metal containing water soluble azo compounds: Low solubility (Group- 2a):
Lithol red: Pigment red 49
Lake red: CI pigment red 56
4. High solubility (Group- 2b):
Precipitation of pigment from orange 11: CI acid orange 7

12. INORGANIC PIGMENT:
I. White pigment:
A. Barytes ( Barium sulphate),
B. Gypsum ( CaSO4 .2H2O),
C. Whitening (CaSO4),
D. China clay,
E. talc and silica.
2. Colored pigment:
Ultramine: China clay 30% + Sodium carbonate 32% +Sulphur 30% +Silica 4%
+Rosin 4%
EXAMPLE OF VARIOUS PIGMENTS:
3. Cadmium Pigment:
Color
Prime Rose
Yellow
Orange
Maroon
4. Iron Oxide:
i) α- FeOOH of Fe2O3 . H2O
ii) FeSO4. H2O (Red, Brown, Black)
components
CdS, ZnS
CdS
Cds, 0.2 CdSe RedCdS, 0.4 CdSe
CdS, 0.7 CdSe
iii) FeO, Fe2O3 and FeOOH (Mixed crystal)

13. INORGANIC PIGMENT:
REQUIREMENT OF WHITE PIGMENT:
1. Primary requirement is that it should not absorb any radiation in the visible part of
electromagnetic spectrum (400-700nm).
2. Second requirement is that it should be in the form of particles fairly uniform in the
size with the diameter of the order of 100 nm.
3. Third requirement is that it should have as high refractive index between 1.5-
2.3 throughout the visible spectrum as possible.
Example of White Pigment:
They includeBarytes(BaSO4), Gypsum(CaSo4.2H2O),Whitening(CaCO3), China clay, talc,&
Silica.

14. No. Organic pigments Inorganic pigments
1
These are natural pigments like the
Cadmiums, Cobalts, Earth Colors, etc.
These are pigments created in the
laboratory and include the Pthalocyanines,
Quinacidrones, Dioxazenes, Napthols, etc.
2
The main source of organic pigments
are plants and plant products
The inorganic pigments are manufactured
from topical cosmetic and also from dirt.
3
Carbon chains or carbon rings are
always present in the molecules of
the Organic Pigments.
In the molecules of the Inorganic Pigments,
the cat-ions of metal are found in an array
form with the non-metallic anions. This
arrangement doesn't allow these pigments
to dissolve in the solvent and plastic
4 have a high refractive index have much lower values
5 most inorganic pigments are opaque organic pigments are transparent
Difference

17. COlORED PIGMENTS:
At past- Yellow lead chromates and iron blue. They are not used for lead poisoning.
Colored pigments are used when organic pigments are unsuitable or can’t match.
ULTRAMIN:
1) Synthetic form of blue mineral “Lapis Lazuli” (Latin name) incorporated from China
and India.
2) Higher light fastness (Grade : 7-8).
3) Attractive blue color with excellent resistance to alkalies and all organic solvents.
4) Easily dispersible.
5) Non toxic.
6) Poor resistance to acid.

18. INGREDIENTS:
NOTE: 4-5 days at 8000c.
Requires absence of iron impurities.

19. CADMIUM PIGMENTS:
A range of mixtures containing CdS and varying amount of ZnS and CdSe can give
following colors:
COlOR COMPONENTS
PRIME ROSE CDS, ZNS
YEllOw CDS
ORANGE CDS, 0.2 CDSE
RED CDS, 0.4 CDSE
MAROON CDS, 0.7 CDSE
PROPERTIES:
1. Outstanding brightness
2. Higher heat stability than organic pigments (400c).
3. Better solvent fastness and high migration fastness.

20. BINDER:
Binders are film forming polymers which play important roles in achieving
optimum fastness properties. Pigments have no affinity towards textile materials.
So actually pigment particles are sticked on the surface of fabric. Binders are
those adhesive type coating forming polymeric materials which sticks pigment
particle on fiber / fabric surface. It forms a very thin invisible film on fabric
surface during curing. Under this film pigment particles are remain sticked.
Binders with a particle size range of 0.05 to 2 microns are usually available.
These contain about 6% by weight of reactive groups for cross linking of the
binder to textile. Cross linking increases the rubbing, washing & dry cleaning
fastness properties but it affects the handle of fabric.

21. TYPES OF BINDER:
According to origin:
1. Natural: Glue, Gelatine etc.
2. Synthetic: Acramin binder.
According to chemical groups:
1. IG binder: Emulsion copolymer of vinyl acetate & butyl acrylate with
modified urea formaldehyde.
2. AG binder: Emulsion copolymer of olifinic unsaturated monomers in
an aqueous medium.
Monomers include:
1. Acrylic acid ester
2. Styrene
3. Acrylonitrile
4. Vinyl chloeid etc.

22. PIGMENT DYEING PROCESS:
Dying Recipe:
Pigment → 2 gm/ lit
Binder → 20 gm/ lit
Levelling agent → 1gm/ lit
Temp (Padding) → Room to 60c
PH → 4-5
Drying → 100c
Curing → 140-180c for 2-3 min for cotton
160-180c for 2-3 min for synthetic
M:L → 1:20 to 1:30

23. Standard Recipe:
Binder → 25cc/L
Fixer → 7cc/L
Leveling Agent → 3cc/L
Acetic Acid → 3cc/L
Pigment → 5% owf
pH → <6.00
Tempeture → 80-90oC
Time → 45-60 min
M:L → 1: 30
PIGMENT DYEING PROCESS:

24. Procedure:
1. At first binder is weighted and diluted with cold water.
2. Then pigments and other ingredients are added to it.
3. The dyeing liquor is well filtered and stirred. Fabric is rolled on feed roller
and passed over guide roller below immersion roller and in between
padders.
4. Then the dye liquor is taken in immersion tray.
5. The fabric passes through the dye bath, takes up pigment solution and
then squeezed by padders roller which regulates pick up percentage.
6. After dyeing the fabric is dried at 90c- 100c and then curing is done at
cotton 160c and polyester 180c for 2-3 minutes.
Procedure:

25. Process sequence:

26. 1.Cationisation of the fabric or giving electric charge to the fabric by a powerful
cationic pretreatment.
Pigment dyeing is an electrical process whereby the goods to be dyed are given an
electrical charge opposite that of the pigment. When the pigment is added to the bath,
the opposite electrical charges attract each other, much like the north and the south
poles of two magnets. Because of the electrical nature of the process.
A typical recipe for cationizing Step
• Cationic Imparting Agent
• Wetter
• Acetic Acid for pH control
The cationic agent is applied with a wetting agent and acetic acid onto the fabric in the
batch or commercial dyeing machine. After a period of time, the fabric is rinsed.
The pigment dyeing process is generally a three step process such as:

27. 2.Pigment exhaustion on the fabric
The pigments are first mixed with water and a dispersing agent that imparts an anionic charge to
the pigments. This solution is added gradually to the dyeing machine. The temperature of the
bath is slowly increased and the machine is held at the dyeing temperature for up to 20
minutes. The fabric is held at an elevated temperature to increase the adsorption of the
pigments.
A typical recipe for this step
• Pigment colorants
• Dispersing agent
3.Binder application :-
A binder used in the exhaust pigment dyeing procedure for fixing pigment colors.Binders are
commonly acrylic polymers with nonionic and cationic nature. It improves crock and wash
fastness.After the pigment is exhausted , the binder is fed into the dyeing machine and
exhausted onto the fabric over a period of time. Acetic acid is added to the bath, which
facilitates binder polymerization, then the fabric is rinsed, the dyeing machine is drained, and
the fabric is extracted.
The pigment dyeing process is generally a three step process such as:

28. Dyeing Curve:

30. Application Principle : Pigment dyeing

31. Application Principle : Pigment dyeing

32. Application Principle : Pigment dyeing

33. The pigment dyeing process :

34. PIGMENT DYEING FAULTS:
1. Listing effects: It occurs along the width of fabric due to uneven pressure of padder
rollers which cause shade variation.
2. Tailing effect: It occurs along the length of fabric due to changing concentration of
pigment liquor. This also causes shade variation.

35. ADVANTAGE OF PIGMENT DYEING:
1. A wide range of color can be produced by pigments.
2. Pigments can be applied to any kind of fiber. It is the only coloration process of
glass fiber.
3. Pigments are cheap and available.
4. No washing or rinsing is required after printing.
5. Pigment dyeing process is speedy and fast.
6. The curing and drying process is simple and easy.
7. Water consumption is less.

36. DISADVANTAGES OF PIGMENT COLORATION:
1. Pigments are water insoluble.
2. Bad rubbing fastness.
3. Fabric handle and aesthetic feeling is bad.
4. Unhygienic polymers are used sometimes.
5. Less resistant to chemical finishing and cleanings.
6. Binder qualities contaminates dyeing qualities.

37. REQUIRED PROPERTIES OF BINDER:
The binder must have certain qualities. For example-
1. It should not get coagulated due to shear forces.
2. The binder film must be clear / transparent.
3. The binder film must be of even thickness, smooth, neighther too hard
nor too soft.
4. It should be elastic in nature and should have good adhesion to the
substrate without being tacky.
5. It should have good resistance to chemical and mechanical stresses.
6. It should easily removable from equipments.

38. Limitations of Pigment Dyeing
1. Color fading could be a problem if not desired, and can only be kept intact
with further chemical treatments.
2. The abrasion resistance and hand could be unsatisfactory depending upon
the pigment, binder and softener used.
3. Dark and deep shades are better produced with other dyestuffs rather
than pigments.
Limitations of Pigment Dyeing

39. 1. Its applicable to a wide range of textiles and wide gamut of colors
available. Some brilliant fluorescent pigments are available for special
applications and fashion items.
2. The process of pigment dyeing can also be relatively cheap.
3. The process chemicals are less toxic , environmentally friendly and
least polluting.
4. The color fades with the repeated use , just like denims.
Advantages of pigment dyeing

40. The primary difference between these colorants is their solubility. Pigments used in printing
inks are colorants that are insoluble in water and most solvents. For instance, copper
phthalocyanine blue is the primary blue colorant used in packaging and is quite insoluble in
water and organic solvents. As the name indicates, it is a blue pigment that includes copper.
The rest of its structure is a highly complex aromatic structure of benzene rings that include
nitrogen atoms.
Unlike pigments, the number of dye colorants is seemingly infinite. Dyes are organic
colorants that are soluble, and they are commonly used in the textile industry and in office
products, such as ink jet printers. In packaging applications, dyes do not have the product
resistance of pigments. Dyes provide brilliant color and are used in products that do not
require long-term resistance. Most have inferior solvent bleed and oxidation resistance.
Many dyes are chemically acids or bases and usually are found in the form of salts. For
example, sodium salts of sulfonic or carboxylic acid groups are used to solubilize certain
dyes. Dyes used in printing paper can be made insoluble chemically by reacting with
components in the paper. For instance, presence of calcium ion or tetra-alkyl ammonium ion
will make the dye insoluble and “cement” it to the substrate.
The basic difference between dyes and pigments is their solubility. Whereas pigments are
insoluble and must be used as dispersions in inks and coatings, dyes are soluble colorants.
What is the difference between pigments and dyes?

44. Universally
 applicable on nearly all fibres and fibre blends by basically the same
method
Wide range of uses
 direct, discharge, resist printing, coating and dyeing
 printing alongside other classes of dye
 printing of special effects (e.g. matt white, matt coloured, lacquer, gold
and silver, pearlescent, relief printing; black for outlines)
Economical procedure
 simple handling / application
 fixation conditions easy to meet
 no washing-off of the prints in direct printing
 time-/ energy-saving process as a whole
 low investment

45. Environmentally acceptable
 little waste water / waste air pollution with white-spirit-free /
 low-content white-spirit printing systems
High performance
 high fastness level (upon selection)
 high colour yield with high brilliancy (upon selection)

46. 1. Complete offer of pigment preparations
2. "High conc" products
3. Highly precise particle size and distribution
4. Migration of pigment preparation is only to handle well in an optimised recipe
5. Careful selection of auxiliaries
6. Selected range shows very good dyeing on PES/PEC/Cotton
7. Highest fastness results with Imperon HF
8. Very good results after brush wash test with selected pigments
9. in an optimised recipe (Imitates household washing)
Criteria of pigment dye selection