Immunizing Image Classifiers Against Localized Adversary Attacks
Innovative Concepts in Textile Dyeing and Printing
1. PROJECT REPORT
ON
“Innovative Concepts in Textile Dyeing and Printing”
Submitted in partial fulfilment of the
Requirements for the award of the degree of
BACHELOR OF TECHNOLOGY
in
TEXTILE CHEMISTRY
Submitted By
Vijay Prakash (1704460060)
DEPARTMENT OF TEXTILE CHEMISTRY
Uttar Pradesh Textile Technology Institute, Kanpur
July 2021
2. DECLARATION
I hereby declare that the Project Report entitled “Innovative Concepts in Textile
Dyeing and Printing.” Submitted to the Department of Textile Chemistry,
UPTTI, Kanpur is a record of original work done by me under the guidance of
Prof. Alka Ali.
The information and data given in the report are authentic to the best of my
knowledge.
This Project Report is not submitted to any other University or Institution for award
of any degree or Fellowship or publish any time before.
3. INTRODUCTION
Dyeing is the process of adding colour to textile products like fibres, 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. There are mainly two classes
of dye, natural and man-made.
For most of the thousands of years in which dyeing has been used by humans to decorate
clothing, or fabrics for other uses, the primary source of dye has been nature, with the dyes
being extracted from animals or plants. In the last 150 years, humans have produced artificial
dyes to achieve a broader range of colors, and to render the dyes more stable to resist washing
and general use. Different classes of dyes are used for different types of fiber and at different
stages of the textile production process, from loose fibers through yarn and cloth to
completed garments.
Acrylic fibers are dyed with basic dyes, Nylon and protein fibers such as wool and silk are
dyed with acid dyes, polyester yarn is dyed with disperse dyes. Cotton is dyed with a range of
dye types, including vat dyes, and modern synthetic reactive and direct dyes.
4. DYE TYPES
Acid dyes are water-soluble anionic dyes that are applied to fibers such as silk, wool,
nylon and modified acrylic fibers using neutral to acid dye baths. Attachment to the
fiber is attributed, at least partly, to salt formation between anionic groups in the dyes
and cationic groups in the fiber. Acid dyes are not substantive to cellulosic fibers. Most
synthetic food colors fall in this category.
Basic dyes are water-soluble cationic dyes that are mainly applied to acrylic fibers,
but find some use for wool and silk. Usually acetic acid is added to the dyebath to
help the uptake of the dye onto the fiber. Basic dyes are also used in the coloration of
paper.
Direct or substantive dyeing is normally carried out in a neutral or slightly alkaline
dyebath, at or near boiling point, with the addition of either sodium chloride (NaCl) or
sodium sulfate (Na2SO4). Direct dyes are used on cotton, paper, leather, wool, silk and
nylon. They are also used as pH indicators and as biological stains.
Mordant dyes require a mordant, which improves the fastness of the dye
against water, light and perspiration. The choice of mordant is very important as
different mordants can change the final color significantly. Most natural dyes are
mordant dyes and there is therefore a large literature base describing dyeing
techniques. The most important mordant dyes are the synthetic mordant dyes, or
chrome dyes, used for wool; these comprise some 30% of dyes used for wool, and are
especially useful for black and navy shades. The mordant, potassium dichromate, is
applied as an after-treatment. It is important to note that many mordants, particularly
those in the heavy metal category, can be hazardous to health and extreme care must
be taken in using them.
Vat dyes are essentially insoluble in water and incapable of dyeing fibres directly.
However, reduction in alkaline liquor produces the water soluble alkali metal salt of
the dye, which, in this leuco form, has an affinity for the textile fibre. Subsequent
oxidation reforms the original insoluble dye. The color of denim is due to indigo, the
original vat dye.
Reactive dyes utilize a chromophore attached to a substituent that is capable of
directly reacting with the fibre substrate. The covalent bonds that attach reactive dye
to natural fibers make them among the most permanent of dyes. “Cold” reactive dyes,
5. such as Procion MX, Cibacron F, and Drimarene K, are very easy to use because the
dye can be applied at room temperature. Reactive dyes are by far the best choice for
dyeing cotton and other cellulose fibers at home or in the art studio.
Disperse dyes were originally developed for the dyeing of cellulose acetate, and
are water insoluble. The dyes are finely ground in the presence of a dispersing agent
and sold as a paste, or spray-dried and sold as a powder. Their main use is to dye
polyester but they can also be used to dye nylon, cellulose triacetate, and acrylic
fibres. In some cases, a dyeing temperature of 130 °C is required, and a pressurised
dyebath is used. The very fine particle size gives a large surface area that aids
dissolution to allow uptake by the fibre. The dyeing rate can be significantly
influenced by the choice of dispersing agent used during the grinding.
Azoic dyeing is a technique in which an insoluble azo dye is produced directly onto
or within the fibre. This is achieved by treating a fibre with both diazoic and coupling
components. With suitable adjustment of dyebath conditions the two components
react to produce the required insoluble azo dye. This technique of dyeing is unique, in
that the final color is controlled by the choice of the diazoic and coupling
components. This method of dyeing cotton is declining in importance due to the toxic
nature of the chemicals used.
Sulfur dyes are two part “developed” dyes used to dye cotton with dark colors. The
initial bath imparts a yellow or pale chartreuse color, This is aftertreated with a sulfur
compound in place to produce the dark black we are familiar with in socks for
instance. Sulfur Black 1 is the largest selling dye by volume.
Fooddyes
One other class that describes the role of dyes, rather than their mode of use, is the
food dye. Because food dyes are classed as food additives, they are manufactured to a
higher standard than some industrial dyes. Food dyes can be direct, mordant and vat
dyes, and their use is strictly controlled by legislation. Many are azo dyes, although
anthraquinone and triphenylmethane compounds are used for colors such as green and
blue. Some naturally-occurring dyes are also used.
PRINTING
6. It is a process for mass reproducing text and images using a master form or template. The
earliest non-paper products involving printing include cylinder seals and objects such as the
Cyrus Cylinder and the Cylinders of Nabonidus. The earliest known form of printing as
applied to paper was woodblock printing, which appeared in China before 220 AD for cloth
printing. However, it would not be applie
TYPES OF FABRIC PRINTING
1. Stamp Printing
This method is pretty self-explanatory. A stamp is created, which is then used to imprint onto
the fabric. Similar to the ink pad stamps you used growing up, your design is cut into the
stamp, which is then dipped into the ink. Using even pressure, you transfer your design from
the stamp onto the textile. Although we’ve come a long way from ink stamps, the level of
detail that you can get from stamp printing is limited, so this is not suitable for the more
intricate designs.
2. Transfer Printing
Another method is using transfer paper. This is a special paper for purchase at supermarkets
or craft shops. You can use a standard household printer to print your design onto the transfer
paper, which can then be printed onto your chosen fabric with a standard, household steam
iron. Transfer printing can be upscaled and done professionally on larger runs; however, it
will leave a shiny film or surface texture on your fabric. Transfer printing is not a permanent
method of fabric printing, for it can crack and peel with multiple washes, and often fades.
3. Screen Printing
As we move towards the other end of the printing scale, we start to see methods that are used
more commonly within the professional world of textile printing. Silkscreen printing is most
common within the business industry. This method of printing uses a stencil and a nylon
mesh to create the print design. Waterproof material will block out the spaces that you want
your design to appear on, and then those blocked out spaces are flooded with ink. Due to the
way that this method is carried out, you can only use one color for each screen; however, it
does produce fantastic replications.
4. Dye Sublimation
7. This is a multi-step process that produces some of the best results of all the fabric printing
methods. Designs are printed onto a thermal transfer paper, known as dye sublimation paper.
The paper is used to print the design onto the fabric. Both heat and pressure are used to
permanently bond the inks to the fibers of the fabric, leaving your fabric as soft as it was
before it was printed on. The deep infusion technique penetrates special water-based inks
deep into the textile, making your print permanent. Perfect for intricate details as well as
colors
5. Pigment Printing
Pigment printing is one of the most popular printing techniques for use on cellulose fibers,
making them ideal for use on natural fabrics. This fabric printing method can also work on
synthetic materials, making it versatile. It is a localized technique which involves applying
dyes to the area of fabric that you want your design to be located. The process is repeated to
make the color appear stronger on the fabric.
6. Reactive Printing
Reactive printing is one of the heat-activated fabric printing methods. It is done by pre-
coating the fabrics with a binder (similar to that of pigment printing) and a printing additive.
It prints a dye or wax onto the fabric, and the heat reaction permanently bonds the image to
the textile. Put simply, it is similar to coating the fabric with the design, then steaming the
fabric to create a reaction which bonds the design to the material.
ADVERSE EFFECTS OF CONVENTIONAL DYEING AND PRINTING
Dyes may be defined as substances that, when applied to a substrate provide color by a
process that alters, at least temporarily, any crystal structure of the colored substances . Such
substances with considerable coloring capacity are widely employed in the textile,
pharmaceutical, food, cosmetics, plastics, photographic and paper industries . The dyes can
adhere to compatible surfaces by solution, by forming covalent bond or complexes with salts
or metals, by physical adsorption or by mechanical retention . Dyes are classified according
to their application and chemical structure, and are composed of a group of atoms known as
chromophores, responsible for the dye color. These chromophore-containing centers are
based on diverse functional groups, such as azo, anthraquinone, methine, nitro, arilmethane,
carbonyl and others. In addition, electrons withdrawing or donating substituents so as to
8. generate or intensify the color of the chromophores are denominated as auxochromes. The
most common auxochromes are amine, carboxyl, sulfonate and hydroxyl .
It is estimated that over 10,000 different dyes and pigments are used industrially and over 7 x
105 tons of synthetic dyes are annually produced worldwide . Textile materials can be dyed
using batch, continuous or semi-continuous processes. The kind of process used depends on
many characteristics including type of material as such fiber, yarn, fabric, fabric construction
and garment, as also the generic type of fiber, size of dye lots and quality requirements in the
dyed fabric. Among these processes, the batch process is the most common method used to
dye textile material.
In the textile industry, up to 200,000 tons of these dyes are lost to effluents every year during
the dyeing and finishing operations, due to the inefficiency of the dyeing process .
Unfortunately, most of these dyes escape conventional wastewater treatment processes and
persist in the environment as a result of their high stability to light, temperature, water,
detergents, chemicals, soap and other parameters such as bleach and perspiration . In
addition, anti-microbial agents resistant to biological degradation are frequently used in the
manufacture of textiles, particularly for natural fibers such as cotton . The synthetic origin
and complex aromatic structure of these agents make them more recalcitrant to
biodegradation . However, environmental legislation obliges industries to eliminate color
from their dye-containing effluents, before disposal into water bodies .
The textile industry consumes a substantial amount of water in its manufacturing processes
used mainly in the dyeing and finishing operations of the plants. The wastewater from textile
plants is classified as the most polluting of all the industrial sectors, considering the volume
generated as well as the effluent composition . In addition, the increased demand for textile
products and the proportional increase in their production, and the use of synthetic dyes have
together contributed to dye wastewater becoming one of the substantial sources of severe
pollution problems in current times .
Textile wastewaters are characterized by extreme fluctuations in many parameters such as
chemical oxygen demand (COD), biochemical oxygen demand (BOD), pH, color and
salinity. The composition of the wastewater will depend on the different organic-based
compounds, chemicals and dyes used in the dry and wet-processing steps . Recalcitrant
9. organic, colored, toxicant, surfactant and chlorinated compounds and salts are the main
pollutants in textile effluents .
In addition, the effects caused by other pollutants in textile wastewater, and the presence of
very small amounts of dyes (<1 mg/L for some dyes) in the water, which are nevertheless
highly visible, seriously affects the aesthetic quality and transparency of water bodies such as
lakes, rivers and others, leading to damage to the aquatic environment .
During the dyeing process it has been estimated that the losses of colorants to the
environment can reach 10–50% . It is noteworthy that some dyes are highly toxic and
mutagenic, and also decrease light penetration and photosynthetic activity, causing oxygen
deficiency and limiting downstream beneficial uses such as recreation, drinking water and
irrigation.
INNOVATIVE CONCEPTS IN DYEING
1. Application of liposome-based technology in textile dyeing process
There is increasing interest in the textile industry in the development of eco-friendly textile
processing, in which the use of naturally occurring materials such as phospholipids, would
become important . Phospholipids are natural surfactants and in the presence of water, they
organize themselves so as to reduce unfavorable interactions between their hydrophobic tails
and the aqueous solution; their hydrophilic head groups exposed to the aqueous phase
forming vesicles. Liposomes or phospholipid vesicles are featured by clearly separate
hydrophilic and hydrophobic regions .
Liposomes were first produced in England in 1961 by Alec D. Bangham, who was studying
phospholipids and blood clotting. He found that when phospholipids were added to water,
they immediately formed a sphere, because one end of each molecule was water soluble,
while the opposite end was water insoluble . From a chemical point of view, the liposome is
an amphoteric compound containing both positive and negative charges .
Liposomes are defined as a structure composed of lipid vesicle bilayers which can
encapsulate hydrophobic or hydrophilic compounds in the lipid bilayer or in the aqueous
volume, respectively . These structures are usually made up of phosphatidylcholine (PC),
which has a hydrophilic part consisting of phosphate and choline groups and a hydrophobic
part composed of two hydrocarbon chains of variable length.
10. Liposomes are often distinguished according to their number of lamellae and size. Small
unilamellar vesicles (SUV), large unilamellar vesicles (LUV) and large multilamellar vesicles
(MLV) or multivesicular vesicles (MVV) can be differentiated . The diameters of liposomes
vary from a nanometer to a micrometer . Multilamellar liposomes (MLV) usually range from
500 to 10,000 nm. Unilamellar liposomes can be small (SUV) or large (LUV); SUV are
usually smaller than 50 nm and LUV are usually larger than 50 nm. Very large liposomes are
called giant liposomes (10,000 - 10,00,000 nm). They can be either unilamellar or
multilamellar. The liposomes containing encapsulated vesicles are called multi-vesicular and
they range from 2,000-40,000 nm. LUVs with an asymmetric distribution of phospholipids in
the bilayers are called asymmetric liposomes . The thickness of the membrane (phospholipid
bilayer) measures approximately 5 to 6 nm .
2. Effectof ultrasonic energy on the dyeing process
Ultrasound-assisted textile dyeing was first reported by Sokolov and Tumansky in 1941. The
basic idea of this technology is that ultrasound can enhance mass transfer by reducing the
stagnant cores in the yarns. The improvements observed are generally attributed to cavitation
phenomena and to other resulting physical effects such as dye dispersion (breaking up of
aggregates with high relative molecular mass), degassing (expulsion of dissolved or
entrapped air from the fiber capillaries), strong agitation of the liquid (reduction in thickness
of the fiber-liquid boundary layer), and swelling (enhancement of dye diffusion rate inside
the fiber).
According to Vankar & Shanker (2008), ultrasound allows for process acceleration, obtaining
the same or better results than existing techniques, but under less extreme conditions, i.e.,
lower temperatures and lower concentrations of the chemicals used. Wet textile processes
assisted by ultrasound are of great interest to the textile industry for this reason , and Khatri et
al. (2011) showed that the dyeing of polyester fiber using ultrasonic energy resulted in an
increased dye uptake and enhanced dyeing rate .
Due to the revolution in environmental protection, the use of ultrasonic energy as a renewable
source of energy in textile dyeing has been increased, due to the variety of advantages
associated with it. On the other hand, there is a growing demand for natural, eco-friendly
dyeing for the health sensitive application to textile garments as an alternative to harmful
synthetic dyes, which poses a need for suitable effective dyeing methodologies.
11. Ultrasonic energy can clean or homogenize materials, accelerating both physical and
chemical reactions, and these qualities can be used to improve textile processing methods.
Environmental concern has been focused on textile processing methods for quite some time,
and the use of ultrasonic energy has been widely studied in terms of improving washing
fastness. The textile dyeing industry has long been struggling to cope with high energy costs,
rapid technological changes and the need for a faster delivery time, and the effective
management of ultrasonic energy could reduce energy costs and improve productivity .
Ultrasonic waves are vibrations with frequencies above 17 kHz, out of the audible range for
humans, requiring a medium with elastic properties for propagation. The formation and
collapse of the bubbles formed by ultrasonic waves (known as cavitation) is generally
considered to be responsible for most of the physical and chemical effects of ultrasound in
solid/liquid or liquid/liquid systems. Cavitation is the formation of gas-filled microbubbles or
cavities in a liquid, their growth, and under proper conditions, their implosive collapse.
It has been reported that ultrasonic energy can be applied successfully to wet textile
processes, for example laundering, desizing, scouring, bleaching, mercerization of cotton
fabrics, enzymatic treatment, dyeing and leather processing, together with the
decoloration/mineralization of textile dyes in waste water .
In addition, ultrasonic irradiation shows promise, and has the potential, for use in
environmental remediation, due to the formation of highly concentrated oxidizing species
such as hydroxyl radicals (HO•), hydrogen radicals (H•), hydroperoxyl radicals (HO2• ) and
H2O2, and localized high temperatures and pressures . Therefore, the use of ultrasonic energy
could indeed reduce the environmental impact caused by the textile industry.
3. Optimization of the dyeing processes to reduce the environmental Impact
of textile industry
The search and development of new methods to promote the treatment of effluents from the
textile industry with a maximum of efficiency of the process of decolorization and / or
removal of these compounds present in the medium can trigger further damage human health
and the environment is fundamental importance. The understanding of the composition of
waste generated is extremely significant to develop these methods of treatment due to the
high complexity by virtue of huge number of compounds which are added at different stages
of the dyeing fabrics.
12. Environmental problems with used dye baths are related to the wide variety of different
components added to the dye bath, often in relatively high concentrations. In the future, many
of textile factories will face the requirement of reusing a significant part of all incoming
freshwater because traditionally used methods are insufficient for obtaining the required
water quality.
However, due to dwindling supply and increasing demand of water in the textile industries, a
better alternative is to attempt to further elevate the water quality of wastewater effluent from
a secondary wastewater treatment plant to a higher standard for reuse. Thus far very little
attention has been paid to this aspect .
Therefore, the investment in the search for methodologies to more effective treatment of
these effluents can be much smaller than that spent in tertiary treatment to remove these
products in low level of concentrations and in the presence of much other interference. This
requires action that the cost / benefit are reviewed and the development of new techniques for
wastewater treatment capable of effective removal of these dyes is intensified and made
economically viable .
An alternative to minimize the problems related to the treatment of textile effluents would be
the development of more effective dye that can be fixed fiber with higher efficiency
decreasing losses on tailings waters and reducing the amount of dye required in the dyeing
process, reducing certainly improve the cost and quality of the effluent.
4. Imogo’s Environment-Friendly Innovation for Textile Dyeing
13. The patent-pending FlexDyer process is imogo’s most flexible solution for sustainable dyeing of
textiles. As digital textile printing gains ground because of the sustainability constraints of
traditional dyeing processes, the industry is coming up with innovative solutions for textile
dyeing concepts based on using nozzles and spray units similar to inkjets. One of the recognized
innovators in this field is Sweden based imogo.
The combination of high-speed spray application with the unique imogo autoclave fixation step
enables high output at considerably reduced costs. The FlexDyer process is flexible, not least
because of the range of fiber types and mixes that can be treated. Most types of traditional dye
classes can be used. FlexDyer can help in reducing the number of dyeing processes used today.
The process contains a Dye-Max application unit, a closed chamber where high-performance
spray valves apply the dye dispersion. The spray cassettes consist of precision nozzles for
accurate and consistent coverage combined with the patented imogo pro speed valve that controls
the volume applied. The chamber is equipped with an exhaust system and droplet separator to
ensure that the unit’s environment is free from sprayed particles.
The spray cassettes play a crucial part in the FlexDye line. The pre-moistening station features
similar spray cassettes. These are easily exchanged without the need for tools in less than a
minute. The efficient dye feed line and nozzle cleaning function enables quick changeovers also
between different colors. After applying the dye dispersion, the fabric is rolled onto a shaft.
The roll is moved to the fixation autoclave.
In combination with the Mini-Max spray test unit, dye tests are done of-line. After being tested
and verified without interrupting the production equipment, recipes are defined and loaded into
the Dye-Max HMI. The Dye-Max will reproduce the Mini-Max results.
The manufacturer claims that the FlexDyer is suitable for short sample runs with multiple
changeovers and long-volume runs. The autoclave can be configured for either requirement.
Change from one to the other is a simple maneuver.
5. Sustainable Dyeing Innovations: Greener ways to color textiles
14. Hybrid pigments:
Ecofoot has developed hybrid pigments composed of a dye chemically linked to a
polymer particle that reacts with cellulose fibres at temperatures as low as 25ºC. This
technology doesn’t require the use of salt, which otherwise is crucial to drive the dye
into the fabric. This technology can be applied for dyeing cotton garments at low
temperaturesand also to wool in a more ecological process. Ecofoot-Indigo, a hybrid
pigment used in dyeing denim, avoids using toxic reducingagents that are traditionally
used in convertingindigo pigment to a water soluble form. Common reducing agents
are considered environmentally unfavorable, as the sulfite and sulfate generated in the
dyebath can cause various problems when discharged into the wastewater.
Ecofoot also developed auxiliaries to prevent hydrolysis of the dye in the dyeing
process, which typically requires harsh washing-off procedures to remove the
hydrolysed dye. Together with hybrid pigments and auxiliaries, more than 50 percent
of water in the intermediate and final rinses can be saved in the total process of
preparation and dyeing.
Powder dyes from textile fibers:
Officina+39, an Italy based company, developed the sustainable dye
range Recycrom using recycled clothing, fiber material, and textile scraps. It developed
a sophisticated eight-step system (patent pending) in which all the fabric fibers are
crystalized into an extremely fine powder that can be used as a pigment dye for fabrics
and garments made of cotton, wool, nylon, or any natural fiber. Recycrom can be
applied to the fabrics using various methods such as exhaustion dyeing, dipping,
spraying, screen printing, and coating. Recycrom is applied as a suspension while most
dyes are used as a chemicalsolution and hence can be easily filtered from water, thus
reducing the environmental impact.
15. Cotton pretreatment:
Cotton requires more water than other textiles for dyeing. About 200 litres of water are
required to produce 1kg of fabric. Dow has developed a pretreatment process
called ECOFAST Pure that is applied before the dyeing process to produce cationic
cotton. The pretreated cotton acquires a permanentpositive charge, enabling it to have
a higher affinity for negatively charged molecules such as dyes. This patented
technology decreases the use of dye and water by 50 percent for cotton
dyeing. ColorZen has innovated a technology for pretreatment of raw cotton fibers
using a solution comprisinga wetting agent, caustic soda, and an ammonium salt. This
pretreated cotton exhibits increasedability to retain the dye without the need of fixation
chemicals, thus reducingthe usage of toxic chemicals by 95 percent and water wastage
by 90 percent.
Natural or engineered microorganisms:
Colorifix employs a synthetic biological approach by using bacteria to color the textiles, which can
reduce the use of water by up to 10 times. The innovative steps in this process are to fix the dye-
producing bacteria directly onto the fabric using a carbon source solution, followed by deposition
and fixation of the dye onto fabrics with a single heating cycle by the lysis of the microorganisms.
This technology doesn’t require a dye extraction process, which uses organic solvents, or fixing
and reducing agents containing organic compounds. University of California researchers are
developing denim dyes using genetically modified E.coli bacteria to produce indican, which can
then be turned into indigo by an enzymatic treatment. This new process removes the need for
harsh chemical reducing agents for indigo dye solubilization, replacing it with an enzyme.
However, the process still needs optimization in the recoveryof indican for its sustainability.
Innovative dye and auxiliaries:
Huntsman Textile Effects introduced Avitera, a line of polyreactive dyes for cotton that readily
bond to fiber, in contrast to the conventional reactive dyes. Avitera dyes use tri-functional
chemical reactivity that provides a high reaction and fixation rate with cellulosic fiber, leaving
very little unfixed dye to be removed. This dramatically reduces water and energy usage by up to
50 percent, and uses up to 20 percent less salt. And Huntsman Corporation recently developed the
diffusion accelerant Univadine E3-3D, a dyeing auxiliary that enhances the diffusion of a dyeinto
16. polyester. This diffusion accelerant is said to achieve high-performance dyeing of polyester
microfibers and is free of hazardous chemicals, thus complying with current and anticipated
industry sustainability standards.
Digital printing:
Intech Digital introduced a new “waterless” textile printing technology using Blackjet
reactive pigment textile inks (nanopigment ink) to provide coloration. Blackjet textile
inks use a pigment that is insoluble in the ink carrier, rather than a dye, and contains
resin binders that help the pigment particles adhere to the fabric. This technology uses
a four-step process consisting of a fabric pretreatment, digital printing with reactive
pigment inks, and fabric heating for fixing the pigment onto the fabric, followed by a
post-treatmentprocess. DuPont Artistri digital textile inks are formulated with similar
pigments and dyes to those used in conventional textile printing to provide high-level
results in digitalprinting.
Future Challenges:
These innovationsare very promising and environmentally friendly, but there are still
many barriers to overcome. The textile industry being a manufacturing industry
working under pressure, there is cutthroat competition for garment prices. The
innovative technologies highlighted here still require a lot of optimization in terms of
achieving low-cost production and commercial viability while meeting customer
demands. Due to the rise in raw-materialcosts,manufacturersare finding it to be quite
challenging to produce a finished garment in a sustainable way without raising prices
beyond what consumers are willing to pay.
6.Different Coloration Techniques for Dyeing and Printing Industry
Modern techniques
17. Using nanoparticles: Nanotechnology is essential for textile coloration.
Textile fiber composites are basically bound in various types of molecules.
After textile coloration, nanoparticles are vibrated and displaced from the
actual position. So, dye molecules penetrate the fiber axis and change the phase
of the material. Particles which are 1-100 nanometer ranges are called
nanoparticles. Nanoparticles are used in two ways in textile coloration. They
are:
Nanosized pigment components in textile coloration
The durability of nanocomposites.
Below the pictures of nanoparticles are given
Nanoparticles are highly emerging particles which are used for textile coloration.
Actually, the nano-sized pigment is used in textile finishing. The advantages of using
nanoparticles are nanoparticles can be sized in any shape and they can be dispersed
well to avoid aggregation of the nanoparticles in dye baths.
Exhaust dyeing of cationized cotton with nanoscale component dispersion has been
shown good result recently and dyeing gives better soft handle and more brilliant
shade. So, nanoparticles are very much appropriate for textile coloration.
Using Supercritical Carbon di Oxide (ScC02): The using of ScC02 in
dyeing is very much eco- friendly in the textile industry. ScC02 coloration
technology has some potential to overcome many technical and environmental
issues in many textile applications like Yarn preparation, coloration and
finishing.
ScC02 is a unique media for either transporting chemical because super-critical fluids
take gas-like viscosities and diffusivities and liquid-like densities. Because C02 is non
18. –toxic, non-flammable, environmentally friendly and chemically inert under some
conditions.
This its production is less costly. Supercritical fluids are really produced by the effects
of gas and liquid changes in pressure and temperature. In the carbon phase diagram,
the triple point occurs where temperature, volume and pressure remain in the same
phase.
The critical point for carbon dioxide occurs at a pressure of 73.8 bar and its
temperature is 31.1-degree Celsius.
Using plasma technology: Plasma is a partially ionized gas which contains
ions, electrons and neutral particles produced by the interaction of the
electromagnetic field with gas under appropriate pressure.
The pretreatment and finishing of textile fabrics can be replaced against the wet
chemical method. One of the most expecting and advanced polymer modification
techniques is low-temperature plasma treatment, which allows the surface properties
to be varied over a wide range and the area of application of polymeric materials to be
considerably extended.
This surface modification increases the hydrophilicity of the treated fiber. An
important characteristic of plasma treatment is that it affects only the surface of a
material subjected to treatment and a very thin near-surface layer whose thickness
varies from 100A * to several micrometers, according to different estimates.
The conditions, retaining the mechanical, physio chemicals and electrochemical
properties of organic material. The UV photons emitted by plasma have sufficient
energy to break chemical bonds (e.g.: C-C, C-H) and to create radicals which can
transfer along the chain and regenerate. It is depended on the plasma conditions and
on the nature of the polymer.
Using Microwave Process: Microwave promoted organic reactions as well-
known as environmental methods that can enhance a great number of chemical
processes.
19. In particular, the reaction time and energy input are supposed to be mostly reduced in
the reactions that are run for a long time at high temperatures under conventional
conditions. Microwave is volumetric heating fast whereas conventional is a surface
heating slowly.
Figure 8:
Microwave heating (volumetric) vs conventional heating (surface).
Using of the ultrasonic system: Power ultrasound increases a wide variety of chemical and
physical processes, mainly on account of the incident known as cavitation in a liquid medium
that is the growth and explosive collapse of microscopic bubbles. The sudden and explosive
collapse of these bubbles can make hot spots.
Finally, we can say that the coloration process is essential to our textile industry. The new
technology helps the industry to reduce environment pollution and this technology helps to
reduce M:L ratio. It is helpful to reduce cost in the dyeing industry. So, all dyeing industry
should launch the new technology of dyeing and printing also.
7.Ionic Liquids Can Significantly Improve Textile Dyeing
Owing to economic reasons, the textile dyeing industry generally employs traditional and
absolutely no-eco-friendly processes: very large quantities of water are indeed required
together with a large number of added chemicals which represent dramatic environmental
issues. In o rder to improve the sustainability of the process, we have investigated the dyeing
of wool, polyester, and cotton with disperse Red 13 using ionic liquids as the sole additive.
The results obtained in isothermal dyeing at 95 °C show an outstanding effect of the ionic
liquid 1-(2-hydroxyethyl)-3-methylimidazolium chloride. This ionic liquid assures efficient
dyeing of polyester and wool in open vessels, in the absence of whichever auxiliary agent
with total dyebath exhaustion, thus allowing in principle the recycling of the dye bath! The
environmental benefits arising from the substitution of a number of usually employed
auxiliary agents with only an ionic liquid are highlighted together with the economic ones.
20. This article reports for the first time, to the best of our knowledge, dyeing processes for
several kinds of fibers (cotton, wool, and polyester) employing exclusively three components:
pure disperse dye, water, and an appropriate ionic liquid.
8.Innovative Sustainable Apparel Design:Application of CAD and
Redesign Process
This chapter aims to provide insights for designers, researchers, and educators
seeking innovative ways to practice redesign activities within sustainable apparel
design methods. The authors of the chapter present theoretical concepts for
upcycling and applications of redesigning practices using innovative technologies,
including laser etching and cutting, digital textile printing, and pattern digitizing
through virtual computer-aided design (CAD) methods. The researchers further
discuss a sustainable redesign framework that highlights the use of CAD and
sequentially presents three design examples using (a) post-consumer textile waste
(leather and silk) by an engineering laser cutting technique, (b) post-industrial waste
(denim) by an engineering laser etching technique, and (c) post-consumer textile
waste (denim) by pattern digitizing and engineering digital textile printing
techniques. The presented redesign methods are sustainable as they reduce waste and
increase efficiency for surface design and garment construction processes. The
chapter concludes with some challenges of the redesigning process and suggested
solutions suggestions for redesigning at micro and macro levels of the apparel
industry.
9.Sustainable Production Processes in Textile Dyeing
Value addition for textiles is an important process and it is required for all products including
yarn, fabric, garment, fashion apparel, floor covering, and the majority of technical textiles.
Value addition may be either an additive or subtractive process. In the subtractive process
part of the fiber components may be removed by some physical or chemical process because
textile fibers have natural as well as added impurities during production. In the additive
process, either color or functional chemicals may be added to improve aesthetic as well as
21. functional properties. For each textile processing, the processor used enormous amounts of
chemicals and water in order to attain the desired result. After processing the residual
processed chemicals and waters are treated with effluent treatment and discharged into the
mainstream. The amount of residual unfixed dyes, metal compounds, formaldehyde-based
dye-fixing agents, hydrocarbon-based softeners, and all types of dye-bath auxiliaries as well
as their degradation nature against the environment are the deciding factors for its
sustainability. Technologies have been developed for the past five decades starting from fiber
to finished product in order to reduce the effluent load, energy, processing cost, and
manpower as well as increase the process efficiency and reproducibility. There are many
factors influencing the overall efficiency or value addition of a textile product, which play an
important role in its sustainability. This chapter deals with the basic theory of dyeing
processes, factors influencing their performance, potential pollutants, sustainable
technologies developed thus far, and future perspectives in dyeing.
MARKET SURVEY
Report Overview
The global printed textile market size was estimated at USD 146.5 billion in 2018 and is
expected to register a CAGR of 8.9% over the forecast period. The changing consumer
preferences pertaining to the adoption of printed textiles in the Asia Pacific and the Middle
East is anticipated to have a positive impact on market growth.
22. To learn more about this report, request a free sample copy
Printed fabrics provide better bonding of the color with the fibers in order to resist friction
and washing. Furthermore, the rising consumer disposable income in the emerging
economies, including China, India, and Brazil is estimated to augment the consumption of
printed clothing, thereby complementing market growth.
The increasing demand for unique clothing by the millennial population in the U.S. is
estimated to have a positive impact on market growth in the country. In addition, access to e-
commerce portals for shopping of apparels coupled with increasing imports of printed textiles
in the country is anticipated to augment the product demand over the forecast period.
The factors such as high reliability, uninterrupted printing, cost-effective production, and
design versatility contribute positively to the growth of printed textiles globally. Furthermore,
elimination of screen cost in sampling coupled with short-run production in digital textile
printing is anticipated to augment the penetration of the technique in mass customization,
thereby complementing market growth.
Rapid growth in the demand for digital technology in textile printing for garment and
advertising industries coupled with increasing demand for sustainable printing is anticipated
to have a positive impact on the product demand over the forecast period. Furthermore,
reduction in per-unit cost of printing along with shortening lifespan and faster adaptability
with the advent of digital printers is likely to complement market growth.
Rapid technological developments in the textile printing industry coupled with the
introduction of single-pass, high-speed large printers have resulted in the up-gradation of
traditional textile printing machines, thereby complementing the printed textile market
growth. However, high printing costs and harmful environmental impact associated with
traditional textile printing techniques are expected to hamper the industry growth.
Report Coverage & Deliverables
PDF report & online dashboard will help you understand:
Competitive benchmarking
Historical data & forecasts
Company revenue shares
Regional opportunities
Latest trends & dynamics
23. Ink Type Insights
Pigment dyes are independent of the type of fiber and are used to print on natural as well as
synthetic fabrics. In addition, these inks are majorly used in traditional printing techniques
owing to the process being the most economical. Furthermore, the ability of pigment printing
inks to be applied to all substrates, including leather, PVC, and glass fibers is expected to
boost the demand for pigment dyes over the forecast period.
Reactive dye inks are used majorly for printing on natural fibers such as cotton, silk, wool,
and viscose owing to its ability to react with the chemicals in the printing paste to bond the
colors to the fibers after being steamed. In addition, these inks provide high wash fastness,
which enables color retention even after washing, thereby increasing its penetration in the
printing of fabrics over the projected period.
Acid dye inks are estimated to account for 6.92% by 2025 owing to its ability to provide
vibrant colors to materials that do not retain the color after printing including, silk, wool, or
lycra fabrics. In addition, acid inks have a high tolerance to chlorine and water, thereby
increasing its penetration in printing for swimwear textiles over the forecast period.
24. The disperse dye inks are sprayed directly on the polyester fabrics at high temperatures for
the incorporation of the dye into the fibers. The application of these inks for printing on
fabrics used outdoors such as flags, banners, home textiles, and apparel is estimated to
augment the material demand in the printed textiles market.
Product Insights
The properties of cotton fiber such as high durability, biodegradable, good absorbent, and
high insulating property aids in it being an ideal fabric for clothing and other household
application. In addition, and easy printing ability of the material aids in boosting the product
demand in printed textiles over the forecast period.
Polyester printed textiles are expected to account for a significant share owing to the
product’s properties such as high strength, low fabric cost, resistance to shrinking, wrinkles,
and abrasion. However, low absorbency of the product is anticipated to restrict its demand for
textile printing over the forecast period.
The increasing demand for silk printed clothing in the Gulf countries and Japan is likely to
contribute positively to the need for silk in printed textiles. However, the high cost associated
with the printing and manufacturing of silk fabric has restricted the usage of silk to certain
economies, thereby limiting the growth of silk printed textiles.
Hybrid or blend fabrics aid in providing aesthetic comfort properties of natural fibers with the
strength of synthetic fibers. The features of cotton blends such as resistance to tearing and
abrasion, low cost, high durability, and breathability aid in contributing positively to its usage
in textile printing over the projected period.
Technology Insights
Traditional printing technology is estimated to witness growth at a CAGR of 8.7% from 2019
to 2025, in terms of revenue on account of the presence of numerous techniques such as
block, batik, roller, and stencil being used extensively over the past few years. Furthermore,
the presence of skilled labor in economies such as India, Brazil, and Indonesia for printing
on textiles is anticipated to boost the growth of traditional printing.
Various traditional printed techniques including rotary screen textile printing, hand screen
printing, dye-sublimation transfer printing, and automatic flat screen printing are used for
mass printing of the textiles. Furthermore, the ability to use any ink as per requirement in this
printing technique for commercial printing is likely to boost the market growth.
25. To learn more about this report, request a free sample copy
The adoption of digital printing is expected to witness significant growth owing to its
attributes such as environment-friendly, low printing cost, and high precision in the desired
designs. In addition, the ability to print on any size or dimension fabrics using digital
technology is expected to aid market growth.
Digital printing offers high-resolution prints with unlimited color combinations and utilizes
less amount of ink, electricity, and water as compared to other techniques. In addition, the
space required for the printing machines is comparatively less, thereby enabling high-quality
printing in smaller areas. The aforementioned factors are expected to drive the demand for
digitally printed textiles over the forecast period.
Application Insights
The fashion industry is witnessing changes based on changing consumer preferences. The
increasing focus of the fashion designers and clothing companies on creating new designs to
increase their market share and customer base is expected to drive the demand for printed
textiles in the fashion industry significantly.
The increasing penetration of printed textiles in various household applications such as
upholstery, kitchen clothing, soft furnishing, and bedding is likely to contribute positively to
the market growth. Furthermore, rising demand for renovation and interior designing among
the consumers is anticipated to augment the demand for printed textiles.
Technical textiles accounted for 8.6% of the global revenue share in 2018 on account of the
increasing penetration of the product in construction, transportation, medical, and protective
26. applications. In addition, rising consumer awareness for using aesthetically appealing fabrics
in various applications is expected to boost the demand for printed fabrics over the forecast
period.
Printed fabrics are extensively used for soft signage application, wherein display boards made
of fabric is printed for decoration and advertising purposes. Furthermore, increasing
penetration of soft signage and growing demand for advertising is anticipated to boost the
demand for the product, at a CAGR of 8.2 % from 2019 to 2025, in terms of revenue.
Regional Insights
The demand for the product in Europe was valued at USD 75.89 billion in 2018 and is
dominated by the rapidly growing fashion industry in France, Italy, the UK, and Germany. In
addition, an increasing number of upcoming apparel companies and fashion designers in the
region is expected to have a positive impact on the demand for printed fabrics in the region.
Rising demand for printed home textiles in the United Arab Emirates is expected to
contribute significantly to the market growth in the Middle East & Africa region. In addition,
changing consumer preferences from plain solid clothing to printed clothing among the
people is anticipated to boost the demand for the product in the fashion application in the
region.
Asia Pacific is expected to witness growth at a CAGR of 9.5% from 2019 to 2025, in terms of
revenue on account of the increasing consumption of printed clothing in India, China, Japan,
Indonesia, and Thailand. In addition, the rising adoption of digital fabric printing in China
and India is anticipated to boost the market growth in the region.
Increasing sales volume of clothing goods and apparel through e-commerce portals in China,
India, Thailand, and Bangladesh is estimated to boost the industry growth. In addition,
favorable government regulations in China and India for promoting investment in fabric
manufacturing and printing is anticipated to complement market growth.
Key Companies & Market Share Insights
The major players in the market include Fabric Wholesale Direct, Seride Srl, Seiko Epson
Corporation, Kornit Digital, Roland DGA Corporation, Konica Minolta, Inc., Hollyflower,
Shahlon Group, and Globe Textiles (India) Ltd. These companies are engaged in providing
extensive, customized printed textiles in a wide range of fabrics and designs.
27. Companies determine the cost of printed fabrics based on various factors including the
printing technique used, ink types, base fabrics, customization, design complications,
application of the end product, and types of color dyes. Furthermore, the entire printing
process is customization based and varies according to the requirement of the customer.
Printed Textile Market Report Scope
Report Attribute Details
Market size value in 2019 USD 145.63 billion
Revenue forecast in 2025 USD 266.38 billion
Growth Rate CAGR of 8.9% from 2019 to 2025
Base year for estimation 2018
Historical data 2014 – 2017
Forecast period 2019 – 2025
Quantitative units Revenue in USD billion and CAGR from 2019 to 2025
Report coverage
Revenue forecast, company ranking, competitive
landscape, growth factors, and trends
Segments covered Ink Type, product, technology, application, region
Regional scope
North America; Europe; Asia Pacific; Central & South
America; Middle East & Africa
Country scope
U.S., Canada, Mexico, France, Germany, Italy,
Russia, Turkey, UK, China, India, Japan, Indonesia,
Thailand, Argentina, Brazil, United Arab Emirates, South
Africa
Key companies profiled
Fabric Wholesale Direct, Seride Srl, Seiko Epson
Corporation, Kornit Digital, Roland DGA Corporation,
Konica Minolta, Inc., Hollyflower, Shahlon Group, and
Globe Textiles (India) Ltd.
Customization scope
Free report customization (equivalent up to 8 analysts
working days) with purchase. Addition or alteration to
country, regional & segment scope.
Pricing and purchase options Avail customized purchase options to meet your exact
28. research needs. Explore purchase options
Segments covered in the report
This report forecasts revenue growth at global, regional, and country levels and provides an
analysis of the industry trends in each of the sub-segments from 2014 to 2025. For this study,
Grand View Research has segmented the global printed textile market based on ink type,
product, technology, application, and region:
Ink Type Outlook (Volume, Million Square Meters; Revenue, USD Million; 2014
- 2025)
Acid dye
Disperse dye
Pigment dye
Reactive dye
Others
Product Outlook (Volume, Million Square Meters; Revenue, USD Million; 2014 -
2025)
Cotton
Silk
Polyester
Others
Technology Outlook (Volume, Million Square Meters; Revenue, USD Million;
2014 - 2025)
Traditional printing
Digital printing
Application Outlook (Volume, Million Square Meters; Revenue, USD Million;
2014 - 2025)
Fashion
Household
29. Technical textiles
Others
Regional Outlook (Volume, Million Square Meters; Revenue, USD Million; 2014
- 2025)
North America
o The U.S.
o Canada
o Mexico
Europe
o France
o Germany
o Italy
o Russia
o Turkey
o UK
Asia Pacific
o China
o India
o Japan
o Indonesia
o Thailand
Central & South America
o Argentina
o Brazil
Middle East & Africa
o South Africa
30. o United Arab Emirates
Effluent Treatment in TextileDyeing
The textile industries of the world release wastes during different stages of
production. Water pollution has always been a rising concern, and many new technologies
have been introduced to combat the problem of effluent wastes of textile dyeing. The industry
is assumed to consume more than 80,000 tons of reactive dyes every year. Stringent laws and
increasing ecological awareness is making textile dyeing units, switch to more sustainable
options of dyeing and treating waste water to
upcycle.
The dyeing of fabrics or fibre uses water to
transmit dyes in the form of vapour to heat the
treatment baths. Printing being a subset of
dyeing also contributes to releasing toxic
wastes. Hence textile pre-treatment, printing,
dyeing, and finishing processes are responsible
for using and discharging all kinds of chemical waste. These processes generate effluents that
comprise of high concentration of salts, and demonstrate high biological oxygen demand
(BOD) or chemical oxygen demand (COD) values. Water treatment plants and processes
must be incorporated by textile industries.
Most of the textile dyeing waste gets discharged into water bodies like lakes and rivers. The
waste water disposed reduces the depths of the penetration of sunlight and results in
decreasing the process of photosynthesis, and consequently dissolves oxygen. Several
techniques are developed to treat water waste and effectively reduce chemicals before
releasing them into rivers. The following are a few processes widely used in the textile
industry.
Physiochemical effluent treatment, where the first step is to mix and equalize the effluent
waste that is released from different stages at different intervals and time. Another primary
treatment used is equalization and homogenization, where in waste substances that have
similar characteristics in terms of pollution, temperature, and pH are separated. Floatation is a
technique that divides fibre from the waste water. This process releases micro-bubbles to
31. form substances in three phases of water, gas, and solids. To remove organic substances
coagulation flocculation treatments are used conventionally. This process adequately
eliminates insoluble dyes but does not remove soluble dyes.
With the amount and extent to which textile industries churn out effluents in water, more
advanced and efficient methods to treat water are required. The following are some
developed and proficient procedures adopted to meet desired waste water treatment
standards.
Adsorption is the most commonly used method in which soluble organic pollutants and color
can be removed. Toxic chemicals like pesticides, phenols, reactive dyes and azo dyes, and
cyanides can be done away with using this process. An adsorbent used more often than not is
Active carbon. Apart from this kaolin and silicon polymers are also used. By using
adsorption, 92.17% of the chroma and 91.15% of the COD can be decreased and be brought
to minimum levels and the water can be re-used for washing purposes. The high cost of
activated carbon makes the adsorption technique an expensive process.
Membrane filtration is a relatively new approach to treat waste water. It provides the
potential applications of incorporating treatment of waste water with in-plant water circuits.
Depending on the end outcome, the different courses of membrane process like reverse
osmosis, nanofiltration, ultrafiltration, and microfiltration can be chosen. The ability to
separate harmful substances from waste water is higher using these processes. Membrane
filtration techniques consume less energy, can be operated with ease, and cause no pollution.
Reverse osmosis membranes have a higher retention rate of 90% and induce a high quality of
permeate in case of ionic compounds. By this simple process the waste can be decolorized
and the chemical auxiliaries can be removed. Higher the amount of dissolved salt greater is
the energy required for separating. Mineral salts, hydrolyzed reactive dyes, and chemical
auxiliaries can be eliminated with reverse osmosis.
Nanofiltration is used for treating water that is highly concentrated and has complex solutions
in the textile industry. Nanofiltration membranes absorb organic compounds with low
molecular weight, large monovalent ions, divalent ions, hydrolyzed reactive dyes, and dyeing
auxiliaries. This treatment to a large extent can be the possible solution to the problem of
accumulation of dissolved solids in streams of water. It is also in favor of meeting
environment regulations.
32. Ultrafiltration helps in getting rid of macro molecules but does not do complete justice while
treating dyes. Hence the water after this process can be used for rinsing and washing,
where water salinity is not an issue. It can be used as a pretreatment process for reverse
osmosis or in combination with biological processes. Microfiltration also works in similar
manner as ultrafiltration, and can be only used for pre-treatment or in combination processes.
Ozonation uses one of the strongest oxidizers, Ozone, to purify palatable water. Ozonation
breaks detergents, phenols, and complex organic molecules into simpler compounds. Besides
this, it is also used to deodorize and decolorize the waste water from industries.
Multiple effective evaporation is a method in which the waste water is evaporated and the
concentrated liquid is then sent to the next level of evaporation, so on and so forth, until the
liquid is circulated again and again, in order to meet a required concentration of salt or
desired density. The liquid is evaporated at a low temperature because of the vacuum created
by condensers.
Crystallization is another new technique to dispose chemicals and purify the water. The
liquid is first supersaturated in order to crystallize, wherein the liquid contains more dissolved
solids than it normally accommodates at that temperature. The process can extract chemicals
like sodium sulphate, sodium chloride, calcium chloride, and calcium sulphate from effluents.
Using such unique techniques and technologies the textile industry can improve poor
recycling practices, substantially reduce the water pollution, and meet ecological standards
set by governments. With increasing demand for textiles manufactured in an environment
friendly way, the textile industries must adopt these treatments to reduce effluents and to cut
back on wastages.
COSTING AGAINST TRADITIONAL
Cost Reduction in Dyeing of Cotton with Reactive Dyes
Reactive Process Dyeing
The process for reactive dyeing of cotton can be divided into three steps: the pre-treatment,
the dyeing and the rinsing after dyeing. Traditionally, the consumption of energy, chemicals
and water in rinsing is crucial; approximately half of the total energy consumption and of the
33. total water consumption are attributed to the rinsing process after dyeing. Therefore there is
much scope for cost reduction in rinsing operation.
Water consumption in reactive dyeing
During the pre-treatment, the cotton fabric is scoured and bleached and washed. After some
rinses, the dyestuff is poured into the dye bath and a diffusion of the dyestuff molecules
between the cellulose fibres takes place. After some time, salt is added to obtain adsorption of
the dyestuff to the cellulose fibre. After this, adjusting temperature (50-80C) and pH (10,5-
11,5) completes the reaction between the dyestuff and the cellulose. Some of the dyestuff will
be hydrolysed during this dyeing process, and the adsorbed hydrolysate must be removed in
the succeeding rinsing after dyeing.
The rinsing traditionally consists of several baths, as in Table
The large water consumption in the rinsing after dyeing is primarily caused by the large
number of baths but also by the common use of overflow rinses. Before the temperature is
raised in the rinse, the dyestuff producers recommend neutralisation to pH around 8, when
dyestuffs with vinyl sulphone reactive groups are used. This neutralisation has, however, in
some dye-houses, become usual practice for all sorts of reactive dyestuffs.
After neutralisation, the rinsing consists of a number of soaping sequences: hot soaping,
warm rinse and overflow rinse. In the hot soaping steps 6 and 9 in table1 soaping additives
are used, in the form of surface active agents (detergents), complexing agents and dispersing
34. agents. The reasons for the use of these auxiliary agents are protection against hardness in
the water and/or the cotton, and keep the unfixed dye in dispersed form.
The process is completed with neutralisation to pH around 7 and treatment with softening
agents, necessary for the subsequent sewing process.
Cost saving rinsing operation
New water saving, chemical free, high temperature and high speed rinsing steps are shown in
Table 2
50 industrial scale trials with the new recipe documented that a chemical free, high
temperature rinse, using a reduced number of rinses, and thus saving water, chemicals and
process time can be implemented in the dye house with no adverse effect on product quality.
When implementing the water saving, chemical free, high temperature and high speed rinse
after reactive dyeing of cotton in batch, the following cost reduction and cleaner production
options should be considered:
A) Change from overflow rinsing to stepwise rinsing.
Rinsing by overflow, i.e. pouring clean cold water directly into the process water in the
machine while excess water is drained out of the machine, is used both for rinsing and for
cooling purposes. Overflow is quick but causes unnecessary water consumption.
35. B) Omit the use of detergents in the rinsing after reactive dyeing of cotton.
Surplus and un-fixed reactive dyestuffs are highly water-soluble, in spite of this, detergents
are often used during rinsing after dyeing. In international literature, it has been documented
that detergents do not improve removal of hydrolysed reactive dyestuffs from the fabric.
More than 50 full-scale dyeings carried out at various dye-houses without the use of
detergents. All have successfully proven that detergents can be omitted without negative
impact on product quality.
C) Omit the use of complexing agents in the rinsing
If soft water with a quality of below 5 dH is used, complexing agents can be omitted without
any negative effects on dyed fabric. However, if hardness builders e.g. calcium and
magnesium are present in the dyeing processes and in the rinsing after dyeing, they might
have a negative effect on the dyeing result, e.g. change in shade or problems with
reproducibility. For that reason, soft water is recommended as standard procedure in the
dyeing processes. However, water softening in the dyeing machine by using complexing
agents, forming bonds with the hardness-builders, are both economically and environmentally
a bad solution. Water softening can profitably be done in a separate plant by the ion-exchange
technique or the membrane filtration technique.
D) Use only neutralisation after dyeing when using Vinyl sulphone (VS) reactive
dyestuffs
Neutralisation in the first rinse after dyeing can be restricted to the vinyl sulphone (VS)
reactive groups. Some VS dyestuffs have poor alkaline washing fastness (low bond stability)
and thus sensitive to high pH and high temperature simultaneously. Nevertheless, it is not
uncommon that all recipes for reactive dyeing in a dye-house include neutralisation in the
first rinse after dyeing, whether VS reactive dyestuffs are used or not.
The dyeing can be successfully carried out without the use of neutralisation in the first rinse
after dyeing. This in spite of the fact that more than half of the dyeings were carried out with
36. dyestuffs based on VS-groups. As it is not possible to put forward general guidelines on when
to neutralise dyestuffs based on VS-groups, it is recommended always to neutralise these.
There is no reason to neutralise in this step when all other reactive dyestuffs are used, e.g.
based on monochlorotrazine (MCT), dichlorotriazine (DCT), trichloropyrimidine (TCP) or
difluorochloropyrimidine (DFCP).
In general, it is recommended to select dyestuffs with a superior alkaline washing fastness
when selecting VS-dyestuffs.
E) Chemical-free high speed rinsing after reactive dyeing of cotton
Tests have shown that rinsing is more effective and faster at elevated temperatures - e.g.
around 30% more unfixed hydrolysed reactive dyestuff is rinsed out after 10 minutes at 95C
than at 75C.
Tests using hot 90-95C rinsing after reactive dyeing of cotton have proved that the technique
has no negative effects on the dyeing results. Most often the fastness of the goods were better
after the hot rinsing than after the traditional rinsing with overflow, detergents, complexing
agents and neutralisation in the first rinse. Furthermore, when using 90-95C rinsing water, a
few stepwise rinses (table 2) can reduce the rinsing time by around 50% compared to a
standard recipe (table 1).
Main achieved cost and environmental benefits
The benefits of the new rinsing operation are shown in Figure
37. 1. Reduction in water consumption and wastewater generation.
2. Cost saving in chemical consumption and reduction in pollution load of waste water
3. Time and energy saving.
2.1.4Applicability
1. The new process can be implemented in all types of textile companies involved in reactive
dyeing of cotton.
2. The new process can only be implemented if the company do have availability of soft
groundwater or is operating with a soft-water system (which is normally the case).
3. It is recommended always to neutralise in the first rinse when dyestuffs based on VS-
groups are used. There is no reason to neutralise in this step when all other reactive dyestuffs
based on monochlorotrazine (MCT), dichlorotriazine (DCT), trichloropyrimidine (TCP) or
difluorochloropyrimidine (DFCP).
Economics
1. The economic feasibility is obvious. 50-70% reduction in the consumption of water for
rinsing. Total savings will depend on the number of reactive dyeings at the company.
2. Omit the use of detergents, complexing agents and acetic acid. Savings will depend on the
number of reactive dyeings at the company.
Driving force for implementation
1. High costs for water and wastewater discharge and/or low availability for water of
appropriate quality.
2. High costs for chemicals and wastewater load.
3. A desire for reduced operation time per lot and increased capacity per machine.
38. REFERENCES
1. CBSE BOOK Textile Chemical Processing In collaboration with NIFT.
2. GOOGLE SCHOLER
3. GOOGLE ADVANCE
4. FONG WEBSITE
5. V.A.Shenai Technology of dyeing.
6. Vinay Nagar Archroma Articles
7. IHS Markit Polyester FIbers Chemical Economics
Handbook 2018; 5-31
8. Kan CW ,Impact on textile properties of polyester with laser. Opt Laser Technol 2008;40
:113-119
9. Wikipedia
10. Internet
39. SUGGESTIONS
1. Make Use of Employee Feedback.
2. Encourage Relationships Among Co-workers.
3. Organize Team Building Exercises.
4. Be Flexible.
5. Promote from within, allow lateral moves.
6. Friendly Environmental.
7. The concerned employees to be provided with suitable safety gadgets to minimize
Respiratory problems.
8. Weakly Games organise for employee.
40. CONCLUSIONS
The main requirement for innovative concepts in textile dyeing and printing because
conventional method of dyeing and printing uses large amounts of electricity, fuel,and water,
with corresponding greenhouse gas emissions (GHGs) and contaminated effluent.
Emerging energy-efficiency, greenhouse gae (GHG), and pollution mitigation technologies
will be crucial for the textile industry as it respond to population and economic growth that is
expected to spur a rapid increase in textile consumption over the coming decades and a
corresponding increase in the industries absolute energy use and GHG and other ollutant
emissions.
So by keeping this bad influences in mind new concepts of dyeing and printing were
developed
Which saves energy , environment and other benefits, cost, commercialization status, and
reduse the industrys energy use and environmental emissions. By the use of these innovative
concepts we reduce the water pollution , air pollution and other environmental degradation
which were emerges by conventional method of dyeing and printing.