STEC

1. Textile
A term originally applied only to woven fabrics, but the term textiles are now also applied to
fibers, filament, yarns and the products (natural or synthetic) of fibers.
Fiber
Fiber or fibre is a natural or synthetic substance that is significantly longer than its diameter.
So, the material which has a high length to diameter ratio is known as fiber.
Textile fiber
Textile fiber can be spun into a yarn or made into a fabric by various methods including
weaving, knitting, braiding and twisting.
The essential requirements for fibers to be spun into yarn include high length to diameter (at
least 1000:1), cohesiveness, flexibility, uniformity and sufficient strength.
Other important properties include elasticity, fineness, uniformity, durability, luster etc.
In another way,
Any substance, natural or manufactured with a high length to diameter ratio and with suitable
characteristics for being processed into fabric, the smallest component hair like in nature, that
can be separated from a fabric.
Classification of Textile fibers
1. Natural fibers:
Fibers which grow or develop and come from natural resources like plant and animals.
Example: Cotton, jute, flax, hemp, silk, wool etc
Natural fibers may be classified as three types
a) Animal fiber (Protein fiber)
example: silk, wool, hair of camel, horse, goat.
b) Vegetable fiber (Cellulosic fiber)
Example:
i) Seed fiber (cotton fiber), ii) Bast fiber (flax, jute, hemp) iii) Leaf fiber (Sisal, abaca)
c) Mineral fiber
Example: Asbestos
Asbestos is the only naturally occurring mineral fiber that was used extensively for making
industrial products but is now restricted due to its suspected carcinogenic effect.
2. Manufactured (or man-made) fibers:

2. Fibers produced by industrial processes, whether from natural polymers transformed upon
the action of chemical reagents (regenerated fibers) or through polymers obtained by
chemical synthesis (synthetic fibers).
Examples:
Regenerated fibers: viscose rayon, acetate,triacetate, modal etc
Synthetic fibers: Polyester, Nylon, acrylic, elastane etc.
Length of Textile fiber
All the fibers are classified according to their staple length into two categories, such as staple
fiber and filament.
Staple fiber
It has limited length that varies according to the type, such as cotton, wool, jute etc. there are
two types of staple fiber, one is short staple fiber and another is long staple fiber. Cotton is
mainly short staple fiber and other maximum natural fibers are long staple except silk. Silk is
only natural fiber that is filament.
Filament
A filament is a very long, continuous fiber strand of indefinite length. The length of filaments
may range from a few hundred meters, as in the case of silk, to several kilometers in the case
of man-made fibers. The thickness of filaments is similar to that of fibers. They exist either in
monofilament or multifilament.
Primary properties of Textile fiber
1. Length to diameter ratio
This ratio decides suitability of a fiber for spinning into yarn, provided, it first meets the
fiber length and thickness requirement. The smallest appropriate ratio of fiber length to
fiber width (diameter) is about 350:1. Ratio less than this indicate a fiber which will not
permit twisting of fiber into a yarn structure. But fiber ratio of 1000:1 or more spins into a
useful yarn. Fiber shorter than 1.3 cm (1/2 inch) are seldom used in yarn manufacturing.
2. Cohesiveness
With the current methods of yarn formation, stable fiber must be able to adhere to each
other. This property is known as cohesiveness or spinning quality. The surface contours of
fibers directly affect cohesiveness.
3. Strength
A fiber must possess enough strength to with-stand processing by available textile
machinery and provide the desire durability in its end use.
4. Tenacity or specific strength

3. The tenacity of a material is the mass stress at break, the unit being, of course, g/denier
or g/tex. An alternative term for tenacity is specific strength. In general strong fibers
produce strong fabrics.
5. Flexibility
The ability of a fiber to resist repeated bending or bowing without rupture is flexibility.
6. Uniformity: Fibers that are similar in length, strength, fineness, cohesiveness and
flexibility can be processed together with less difficulty than can dissimilar fibers. Fibers
conforming to the same specifications for those properties are said to exhibit uniformity.
Secondary properties of Textile Fiber
1. Luster: The gloss, sheen, or shine of a fiber is referred to as its luster. The way in
which light is reflected from the surface of the fiber determines the amount of luster
observed. A round fiber is shiner than a fiber with irregular cross-section because we can
see more of the light reflected by the round fiber.
2. Color: Although most are white and cream, fibers are available in a wide range of color.
Wool may be off-white, tan, brown, gray, or black; cotton is usually white or cream, but
there are brown varieties.
3. Moisture Absorption: The amount of water a fiber can absorb from the atmosphere or
an immersion pool may affect apparel comfort, Fabric care, textile processing and fiber
price. Fibers are usually categorized as hydrophilic, those that “like” or absorb water, and
hydrophobic, those that “dislike” or do not absorb water.
4. Moisture Regain: Moisture regain is defined as the weight of water in a material
expressed as a percentage of the oven dry weight.
Fibers Moisture Regain (MR%)
Cotton 8.5
Wool 15-18
Silk 11
Viscose 11
Nylon 4
Polyester 0.4
Jute 13.75
5. Moisture content: Moisture content is defined as the weight of water in a material
expressed as a percentage of the total weight. Let, Oven dry weight = D, Weight of water
= W, Moisture Regain = R, Moisture Content = M Then, R = W*100/D, M =
W*100/(D+W).
Why MR% is is different in different fibers?
6. Density: To compare substances of different volumes, it is important to express in
volumetric units-for example g/cm3
. The term density means the mass per unit volume of
a substance. The mass of most textile fibers is reported as density.

4. 7. Fineness: Relative size, diameter and linear density are measures of fineness of the
fiber. Cotton fiber fineness express in micronaire it means weight in microgram of one inch
fiber.
8. Linear density: Linear density express in terms of denier, tex and decitex, is the most
common method for comparing fiber fineness.
Denier is the weight in grams of 9000 meters of fiber or yarn. It gives the fineness or
coarseness of fibers. Small numbers refer to fine fibers; large number describes coarse
fibers. It is related with end use of fiber.
Tex is the weight in grams of 1000 meters of fiber or yarn.
Organic cotton fiber
Organic cotton fiber is the fiber that is grown without pesticides from plants which are not
genetically modified. Though organic cotton has less environmental impact than
conventional cotton, it costs more to produce.
What is the difference between natural cotton and organic cotton? Organic cotton is grown
from non genetically modified seeds. And the farmer didn't use synthetic fertilizers or
pesticides on the cotton crop.
Transition cotton
Organic cotton must be grown in fields that have been free of synthetic pesticides and
fertilizers for three years. As farmers switch over to and use organic farming methods the
cotton grown during this three year period is called transition cotton. Wal-Mart has been
purchasing millions of pounds of transition cotton. This has greatly help farmers to make the
transition to organic farming methods.
Green cotton
Green or natural cotton is not organic.
When you see cotton products labeled "natural", you are getting conventional cotton grown
with large inputs of chemicals, pesticides, and herbicides to control weed growth. The only
difference between green and conventional cottons, is in the processing: final product is
not supposed to be treated with formaldehyde or chlorine bleach.
Dye ability:
Direct, Reactive, Vat dyes are used to dye cotton fiber.
Mixing
When same kind but different grades of fibres are mixed together then it is termed as mixing
Example: mixing of Indian cotton fiber with American cotton fiber.

5. Blending
When different types of fibers are mixed together are within a particular ration then the
mixture is known s blending.
Example:
Nylon and cotton Blending
Polyester and nylon Blending
Differences between mixing and blending
Mixing Blending
Here, same kind but different grades of
fibres are mixed together.
Here, different types of fibre are mixed
together within a definite ratio.
Example:
Low graded cotton with high graded
cotton
Example:
35% polyester with 65% cotton
Yarn count
Count

6. The yarn count is a numerical expression which defines its fineness or coarseness i.e.
whether the yarn is thick or thin.
A definition of yarn count is given by Textile Institute “count is a number indicating the mass
per unit length or the length per unit mass of yarn”.
Basically there are two types of yarn counting system –
1. Direct system: Tex, denier, pound per spyndle.
2. Indirect system: English, metric, worsted.
1. Direct system
In this system the yarn count express the number of weight unit in one length unit. Thus
higher the count, coarser the yarn. This is used for man made fibre such as polyester, nylon
etc.
Here, N = yarn count
W = the weight of the sample
L = the length of the sample
l = the unit of the length of the system.
Tex
The yarn number or count in the tex system is the weight in grams of 1000m or 1 km or yarn.
Denier
The number or count in the denier system is the weight in grams of 9000m or 9km of yarn.
2. Indirect system:
In this system the yarn count express the number of length unit in one weight unit. Thus
higher the count, finer the yarn.

7. Here, N = yarn count
W = the weight of the sample
L = the length of the sample
w = the unit of the weight of the system
l = the unit of the length of the system
English
It is defined as the number of hanks (840 yards) per pound. If one pound of yarn contains 20
hanks of 840 yards, then in English system count will be 201s
or 20 Ne. it is denoted by Ne.
Metric
It is defined as the number of hanks (1000m) per kg. If one kg of yarn contains 40 hanks of
1000m, then in metric system count will be 40 Nm. It is denoted by Nm.
Worsted
It is defined as the number of hanks (560 yards) per pound. If one pound of yarn contains 20
hanks of 560 yards, then in worsted system count will be 20 worsted.
The measurement of yarn number or count
The yarn count can be measured by the following four systems.
1. Wrap reel and balance method (indirect reading balance).
2. Quadrant balance method (direct reading balance)
3. Knowles balance method (direct reading balance)
4. Beesleys balance method (special balance)
Yarn Manufacturing Technology
Flow chart of carded yarn production:
Input Process/ Machine Output
Bale → Blow room → Lap

8. Lap → Carding m/c → Sliver
Sliver → Breaker Draw Frame → Sliver
Sliver → Finisher Draw Frame → Sliver
Sliver → Roving Frame
/Speed Frame/Simplex
→ Roving
Roving → Ring Frame → Yarn
Flow chart of combed yarn production:
Input Process/ Machine Output
Bale management
↓
Fibre → Blow room → Lap
Lap → Carding m/c → Sliver
Sliver → Pre comb drawing → Sliver
Sliver → Lap former → Lap
Lap → Combing → Sliver
Sliver → Post comb drawing → Sliver
Sliver → Simplex → Roving
Roving → Ring Frame → Yarn
Flow chart of Rotor yarn:
Input Process/Machine Output
Bale management
↓
Fibre → Blow room → Lap
Lap → Carding m/c → Carded sliver
Carded sliver → Draw frame → Drawn sliver

9. Drawn sliver → Rotor spinning → Rotor yarn
Bale management: Testing, sorting & mixing bales according to properties of fibre for
producing specific good quality yarn at minimum cost is called “Bale management”.
Importance of bale management:
If bale management is absent-
 Lot to lot variation will produce fabric barre effect.
 After weaving, shade variation will be found in case of dyed fabric.
 After knitting, colour variation may be found in case of dyed fabric.
Mixing: If different grade of same fibres are kept together, then it is called mixing.
e.g. 50% of
1
1
8

staple length of cotton + 50% of
1
1
4

staple length of cotton.
Types of mixing: Volume mixing, Wt. mixing, Hand stock mixing., Bin mixing, Mixing by
hopper, Lap mixing, Card mixing, Sliver mixing, Automatic mixing.
Blending: When different fibres of different grades are kept together, then it is called
blending.
Blending is possible in different stages of Processes:
Blending type Process stage
Bale mixing - Before the blow room
Flock mixing - Within the blow room
Lap ,, - Using doubling scutchers
Web ,, - At the ribbon lap m/c or
the blending draw frame
Sliver ,, - At the draw frame & sliver

10. Blending type Process stage
Lap or the comber
Fibre ,, - At the card or Rotor spgn
m/c
Roving ,, - At the ring spgn
m/c
Blow Room: Blow Room consists of a number of machines used in succession to open and
clean the cotton fiber to the required degree.
40 to 70% trash is removed in this section.
Operation in Blow Room:
I. Opening:
a. To open the compressed bales of fibers &
b. To make the cotton tuft a small size as much as possible.
II. Cleaning: To remove the dirt, dust, a broken seed broken leafs, stalks and another
foreign material from the fibers.
III. Bending or Mixing: To make good value of yarn and to decrease the production cost by
mixing different grade of fibers.
IV. Lap forming:
a. To transfer the opened and cleaned fibers into
a sheet form of definite width and uniform unit length which is called lap.
b. To roll the lap of predetermined length in a cylindrical shape around a lap pin.
c. To transfer the lap from the lap pin to a rod to suitable handle and feed it to
subsequence processing carding m/c.
Objects or Functions of blow-room:
The basic purpose of blow-room line is to supply following qualities of fiber tufts to the
carding process.
 Small fiber tufts
 Homogeneously mixed or blended tufts

11.  Clean fiber tufts
 Convert fiber tufts into a fibrous sheet, is called lap.
Action in blow-room:
The actions of the machines in any blow room range fall into one or more of four main
groups namely:
1. Action of opposite spike: (opening)
The action of opposite spikes is opening the cotton fiber. By this action, the large pieces of
cottons have been reduced in size.
2. Action of Air current: (Transport + Cleaning)
During processing, the movement of cotton from machines to machine is done by air current.
It also helps the separation of lint and trash.
3. Action of Beaters: (Cleaning & Opening)
Beaters are responsible for removing almost all of the impurity extracted in the blow room.
Beater also helps in opening of cotton fiber.
4. Action of regulating motion: (Uniform output)
The action of regulating motion gives the uniform output of cotton fiber by the help of swing
door and swing paddle
Carding: Heart of Spinning:
Carding is the one of the most important process in cotton spun yarn manufacturing,
because it determine the quality of yarn. This is the process, by which fiber are prepared
to manufacture a yarn. In this process, fibers are opened at almost single, removal of dust,
trash, neps and short fiber to produce a continuous strand of fiber called sliver. Carding
machine is called heart of spinning, because it prepares the fiber in such a way, which is
ready to manufacture yarn because disentanglement, cleaning and intermixing of fiber are
happened here.
Objectives or Functions or Tasks of carding machine:
1. Opening the tufts into individual fibers and individualization of the cotton fiber
at a single fiber staple state.
2. Elimination of Impurities and dust: Elimination of foreign matter occurs mainly
in the region of the taker in.
3. Disentangling of neps i.e. removal of neps.
4. Elimination of short fibers.
5. Fiber blending.
6. Fiber orientation.

12. 7. Finally produce a continuous strand of fibers called sliver of.
Draw frame
Drawing: It is a process of yarn manufacturing in which the sliver is elongated when passing
through pairs of rollers, each pair faster than the previous one.
This permits combination of several slivers and drawing and elongating them to straighten
and to create greater uniformity.
Necessity of draw frame or objectives of using Draw frame:
 Crimped, curled and hooked fibers are straightened,
 Parallelization of fibers,
 Reduction of sliver weight per unit length,
 Reduce irregularities of fibers by doubling and drafting,
 Remove remaining dust from sliver,
 Blending of fiber to provide compensation of raw material variation.
To parallisation of fibre and blending carded→ Carded sliver.
In carded sliver, fibre present in hook form i.e. trailing hooks and leading hooks.
To parallel those hook, draw frame is used.
Majority of the fibre hooks in a carded sliver are trailing while leading hooks are
comparatively less. Trailing hooks are also known Major hooks. While leading hooks are
known as Minor hooks.
Tasks of draw frame:
I) Equalizing.
II) Parallelizing.
III) Blending.
IV) Dust removal.

13. Actions involved in Draw frame:
I) Drafting: The process of attenuating or increasing length per unit weight of sliver. It
is mainly due to peripheral speed of the rollers.
II) Doubling: The process of combing two or more carded sliver into a single form is
called doubling. In draw frame m/c generally six slivers are fed and converted into
one i.e. six doubling.
III) Drawing: In the cotton Industry, the term is applied exclusively to processing on the
draw frame, where the operation is one of doubling and drafting.
Drawing = Drafting + Doubling.
Combing: Combing may be defined as to removed of short fibres , neps and remaining
impurities of card sliver by using comb with the help of knives , brushes and rollers.
Objects of combing:
1. To remove short fibres below a pre selected length so that the spinner enables to
produce finer/ better yarn.
2. To remove reps and foreign matter from the sliver.
3. With the help of drawing and doubling, combed sliver is uniform and the fibres are
straight and parallel.
4. Improve the uniformity and strength of yarn
5. Improve yarn smoothness and lusture.
6. Reduce hairiness of yarn.
Objects / Necessity of lap former:
1. To reduce the strain to delicate comber reduce.
2. To reduce fibre damage.
3. To reduce chance of good fibres waste.
4. To reduce short fibres.
5. To reduce thick and thin places in the sliver.
6. To control wastage.
7. To parallel and straight of fibre in corded sliver by changing pushing of fibres .
8. Not freely opening of fibre from sliver.

14. M/c’s used for lap preparation :
1. Conventional system –
i. Sliver lap m/c.
ii. Ribbon lap m/c .
2. Modern System –
1) Super lap former
Object of pre comb drawing:
 To parallelize the hooked fibres
 To reduce the loss of long fibres
 To convert the leading hook into trailing hook
 To remove short fibres
Objects or functions of speed frame:
 Attenuation of drawframe, sliver to form roving of required hank by drafting,
 Insert small amount of twist to give required strength of roving,
 Winding the twisted roving on to bobbin,
 Build the roving in bobbin such a form, which will facilitate handling with drawing
and transfer to the next process.
Advantage of Ring spinning system:
 Any type of material (fibre) can be spun
 Wide range of count can be processed
 It delivers a yarn with optimum characteristics.
 Idealized twisting system
 It is uncomplicated and easy to operate
 Higher yarn strength can be achieved
Disadvantage of Ring spinning system:
 Low production
 Machine generates more heat
Limitations:
 In ring spinning machine twisting and winding are done simultaneously. That’s why

15. the power consumption is higher
Operation involved in ring frame
The Following Operation Are Involved:
I Creeling
II Drafting
III Twisting
IV Winding
V Building
VI Doffing
Main Features of Rotor spinning process:
 Yarn Coarser than carded or combed yarn
 Low count. Generally 12 to 20 English count
 Yarn Use for coarser fabric
 Low manufacturing coast.
 Produced by low graded fiber
 High productivity
 Less wastage percentage
 No need of Simplex machine
 Less labor
 High capital cost
 Mainly use to manufacturing Denim jeans fabric
 Low price
 Machine speed very high

16. Wet Processing Technology
Flow chart of wet process for woven fabric
Grey Fabric
Inspection & batching
Singeing
De-sizing
Scouring
Bleaching
Mercerizing Dyeing Printing
Finishing
Final Inspection (QC)
Ready for delivery
Inspection: To check the fabric for naps, warp& weft missing, End breakage,
Hole, Spot.

17. Batching: To Weight the fabric according machine capacity on the basis of
shade, yarn lot & production planning.
Singeing: To remove the loose hairy fibers from woven fabric.
De-sizing: To remove the size material.
Scouring: To remove the impurities & increase fabric absorbency.
Bleaching: To improve whiteness of fabric or yarn by destroying natural color.
Coloration: Dyeing & printing.
Finishing: To improve the overall quality & to satisfy the consumers.
Steps of Wet processing
Pretreatment Coloring Finishing
1. Singeing 1.Dyeing 1. Chemical finishing.
2. Desizing 2.Printing 2. Mechanical finishing.
3. Scouring
4. Bleaching
5. Mercerising.

18. Singeing:
Singeing is the process carried out to remove loose hairy fibres from surface of the yarn or
fabric. It is necessary for level dyeing and to increase lusture of the fabric. It is generally
carried out for woven fabric.
Objects of singeing:
1. To remove loose hairy fibres from surface of yarn or fabric.
2. To obtain smooth surface.
3. To increase lusture of finished fabric.
4. For level dyeing and printing.
Machines used for singeing:
1. Plate singeing machine.
2. Roller or Rotary cylinder singeing machine.
3. Gas or Flame singeing machine.
Desizing:
Desizing is the process of removal of size materials (starch, gum etc) from the warp yarn of
woven fabric. Desizing is the first treatment of wet process in textile.
Objectives of desizing:
1. To remove sizing materials from the warp yarn of woven fabric.
2. To increase absorbency of the fabric.
3. To reduce stiffness,
4. To make soft and pliable.
5. To make the fabric ready for the next process like scouring, bleaching,
dyeing and printing.

19. Chemicals used in desizing:
a) amylase enzyme
b) acid
c) alkali
d) water.
Scouring:
Scouring is the process where all natural and added impurities such as oil, wax, fat etc are
removed to make hydrophilic and clean the textile materials.
Objects of scouring:
1. To remove natural and added impurities such as oils, wax, fat etc.
2. To increase water absorbency of fabric or yarn without undergoing physical and
chemical damage.
3. To produce clean material.
4. To make the fabric ready for uniform dyeing, printing and finishing.
Chemicals used in scouring:
1. Alkali.
2. Wetting agent.
3. Detergent.
4. Sequestering agent.
5. leveling agent.
Bleaching:
Bleaching is the process for improving the whiteness of textile materials by removing the
natural colouring matters. Bleaching produces a pure and permanent white effect on fabric
which is suitable for level dyeing, and sharp printing. During bleaching it should be carefully
observed that the bleaching agent does not reduce the tensile strength of fabric.

20. Object:
1. Destruction of natural colouring matters from the fabric.
2. To impart a pure and permanent white effect to the fabric or yarn.
3. To obtain permanent white colour of the fabric or yarn.
4. To increase absorbency of textile material for uniform dyeing, printing and finishing.
Bleaching agent:
Substance which carry out the bleaching process is called bleaching agent.
1. Hydrogen per oxide, H2O2.
2. Bleaching powder, Ca(OCl)Cl,Ca(OH)2
3. Calcium hypochlorite, Ca(OCl)2.
4. Sodium hypochlorite, NaOCl.
Mercerization:
Mercerization is a physio-chemical treatment of cellulosic textiles in yarn or fabric form
where it is treated with a concentrated solution of caustic alkali (550
– 650
Tw) at a
temperature of 200
– 300
c. It is necessary to hold the fabric under tension and wash
thoroughly while still under tension.
Benefits obtained by mercerization:
Mercerization is a beneficial process to cotton textile material except that it occurs
shrinkage if it is not carried out under tension. The benefits obtained by mercerization are
mentioned below:
1. improved tensile strength.
2. improved hygroscopicity.
3. improved dye affinity.
4. improved surface smoothness and handle.
5. improved lusture.
6. improved dimensional stability.

21. Difference or Comparison between Dyeing and Printing:
The differences between dyeing and printing are as below:
Sl.No. Dyeing Printing
1 In dyeing process color is applied
uniformly all over the fabric.
In printing process, color is applied in one
side according to the design only.
2 There is no localized application. There is localized application.
3 Color is applied in form of solution. Color is applied in form of thick paste.
4 Thickener is not used. Thickener must be used.
5 In dyeing process, color penetrates
through the fabric.
Color is applied only on the surface.
6 A particular temperature is maintained
during dyeing process for knit fabric.
There is no particular temperature
controlling system in printing.
7 Generally after dyeing, steaming, and
curing are not required for knit fabric.
After printing, steaming and curing is must
for fixing the dye molecules to the goods.
8 Huge amount of water is required. Less amount of water is used.
Dyes
A Dye is a coloring substance, either from natural or synthetic that imparts its color throughout a
material by penetration. It is a colored, unsaturated organic chemical compound that is responsible for
the color of dyed & printed textile materials. They are made to react with or deposit within a substrate
in order to impart colour to that substrate with some degree of permanence. Dyes are soluble or
dispersed in its medium of application (usually textiles) and are designed to be absorbed by that
medium.
Dyes can be formed synthetically from relatively cheap products where specific functional group in the
dyes determines or affects the applicability & fastness.
Pigment
Pigment is a substance in particulate form which is substantially insoluble in a medium but which can be
mechanically dispersed in that medium to modify its colour and light scattering properties.
Pigment is a coloring matter, usually in the form of insoluble fine powder mostly from mineral origin &
used from the earliest time for the coloration of metal, wood, stone & other surface as paints in
association with oils or water & applied by means of a binding agent.

22. Characteristics of dyes
1. Must have a chromophore group or ability to give color to a substance.
2. Must be soluble in water at some point or make a solution by any means.
3 must have substantivity or affinity for textile fibres.
4. Should have some good fastness properties.
Differences between dyes and pigments
The followings are the differences between dyes and pigments –
Dyes Pigments
1. Most of the dyes can are organic
compounds and some are inorganic.
2. Most of the pigments are inorganic
mineral matters.
2. All dyestuffs are made by longer
chemical reactions. So they are costly
2. Pigments are derived from mineral
compounds. So they are cheap.
3. All dyestuffs are soluble in water. Some
are insoluble.
3. Pigments are mostly insoluble but in
some special cases soluble.

23. Color
Theory
1:
Additiv
e color
Additiv
e
color u
ses the
primar
y colors found in light (red, green and blue) and adds them together (i.e., combines them) to create all
other colors. White results from combining red, green and blue light in equal intensities. The secondary
colors of additive color are magenta, yellow and cyan.
Red + Green = Yellow
Red + Blue = Magenta
Green + Blue = Cyan
Color Theory 2: Subtractive Color Theory or pigment color theory
Subtractive color is the basis for creating colors when mixing paint, dye or ink. Color is created when
some wave lengths of light are subtracted (i.e., absorbed) while others are reflected. The color display
on a surface (a wall, a piece of cloth, a sheet of paper) depends on which colors are reflected by it and
therefore made visible.
4. Dyes contain both chromophore and
auxochrome groups.
4. Pigments have chromophore groups but
not have auxochrome group.
5. All types of fabric can not be dyed by
dyestuffs.
5. Pigments can dye all types of fabric.
6. No binder is required for dyeing with
dyes.
6. Binder is required for dyeing with
pigment.
7. Dyes are absorbed by fabric. 7. Pigments diffuse on fabric surface.

24. Printing
Printing is the production of a design or motif on fabric or garments by the use of colorant and other
chemicals in paste form in a predetermined pattern.
Printing may be also regarded as localized area of dyeing.
Thickener
Thickener is the main ingredient of the print paste. It is a thick, viscose substance which imparts
stickness to the print paste. The main functions and objects of a thickener are –
 To maintain a sharp outline of printed design.
 To prevent bleeding or spreading of color.
 To prevent the premature reactions among the various chemicals of the print paste.
 To hold the ingredients of the print paste on the surface of fabric and in print paste.
Example: Na-alginate, fine gum, starch tragacanth, British gum, C.M.C etc.
Printing paste
The purpose of thickener is to produce a medium for the dye paste and the resultant product is called
the printing paste. The printing paste is an emulsion of thickener and hydrocarbon (e.g. spirit or very
light hydrocarbon oil) plus a surface active agent.

25. Style of Printing:
The different styles of printing are –
1. Direct style of printing
2. Discharge style of printing: a) white discharge, b) color discharge
3. Resist style of printing: a) white resist, b) color resist
Methods of Printing:
1. Hand block printing
2. Hand screen printing
3. Semi-automatic screen printing
4. Automatic Screen printing
5. Rotary Screen Printing
6. Roller printing
7. Heat transfer printing
8. Ink jet printing
Classification of different types of screen printing machines:
There are four types of screen printing machines. They are –
1. Hand screen printing machine (flat)
2. Semiautomatic screen printing machine.
3. Automatic (fully) flat screen printing machine.

26. 4. Rotary screen printing machine.
Finishing:
In broad sense all the processes after weaving or knitting fall in the wide range of finishing. It is a very
wide range of operation carried out by 3 different stages as below:
1. First stage: pre-treatments such as scouring, bleaching, desizing etc.
2. Second stage: colouration such as dyeing, printing.
3. Third stage: finishing. This is the final stage of treatment of fabrics to prepare them for consumers,
such as raising, calendaring and mercerizing.
Objects or effects of finishing on fabric properties:
By finishing the following effects are produced on fabric –
1. To improve the attractiveness.
Fabric attractiveness is improved by the following ways –
a) By modification of fabric appearance e.g. by calendaring, by using optical brightening agents etc.
b) By alteration of fabric handle e.g. by softening, stiffening.
c) By controlling fabric dimension e.g. by shrink resistant treatment, sanforizing, resin treatment,
chemical setting.
2. To improve serviceability of fabric.
Serviceability of fabric is related to weather, time, fashion, durability and many other aspects. It can be
improved by different ways.