This document provides information about various types of dyes used in the textile industry, including their properties and dyeing processes. It discusses natural dyes extracted from plants as well as synthetic dyes like direct dyes, vat dyes, disperse dyes, and reactive dyes. For each dye type, the document outlines their key properties, how they interact with different fibers, and their advantages and limitations. It also mentions sustainability considerations like limiting chemical usage and following eco-label standards.
If we work with a cross section
of the color tree as CIELab space,
this space is divided by two
axes which intersect at a
grey neutral area in the centre.
“a” is the red-green axis which
is red on the positive side and
green on the negative side.
“b” is the yellow-blue axis which
is yellow on the positive end and
blue on negative end.
If we work with a cross section
of the color tree as CIELab space,
this space is divided by two
axes which intersect at a
grey neutral area in the centre.
“a” is the red-green axis which
is red on the positive side and
green on the negative side.
“b” is the yellow-blue axis which
is yellow on the positive end and
blue on negative end.
Classification of dyes; Dyeing of cotton, wool, silk, polyester, nylon and acrylic with appropriate dye classes; Dyeing of polyester/cotton and polyester/wool blends; Dyeing machines; Dyeing of cotton knitted fabrics and machines used; Dye fibre interaction; Introduction to thermodynamics and kinetics of dyeing; Methods for determination of wash, light and rubbing fastness.
Dyeing is the application of dyes or pigments on textile materials such as fibers, yarns, and fabrics with the goal of achieving color with desired color fastness. Dyeing is normally done in a special solution containing dyes and particular chemical material. … In dyeing, it is applied to the entire textile.
Softening agents are applied to textiles to improve their hand, drape, cutting and sewing qualities. An effective softener must be readily dispersible in rinse water and rapidly absorbed so that uniform deposition on the fabric can occur within a relatively short treatment time and generally, exhaustion should take place in about 5min for the softener to be effective and economically usable. It must impart softness, fluffiness and lubricity to the treated cloth and reduce static build-up, especially in the case of hydrophobic fibers like cellulose acetate, nylon, polyester and acrylic fibers. These effects should be obtained without the loss of fabric whiteness or brightness, and then the treated fabric should retain its ability to absorb in subsequent use for drying the body (bath towels) or other surfaces. Fabric softener (also called fabric conditioner) is used to prevent static cling and make fabric softer. It is available as a liquid or as dryer sheets. Popular brand names include Downy (Lenor), Snuggle, Bounce, Comfort and Sta-Soft.I believe that, the knowledge of this report will help future carrier of every textile engineer.
Classification of dyes; Dyeing of cotton, wool, silk, polyester, nylon and acrylic with appropriate dye classes; Dyeing of polyester/cotton and polyester/wool blends; Dyeing machines; Dyeing of cotton knitted fabrics and machines used; Dye fibre interaction; Introduction to thermodynamics and kinetics of dyeing; Methods for determination of wash, light and rubbing fastness.
Dyeing is the application of dyes or pigments on textile materials such as fibers, yarns, and fabrics with the goal of achieving color with desired color fastness. Dyeing is normally done in a special solution containing dyes and particular chemical material. … In dyeing, it is applied to the entire textile.
Softening agents are applied to textiles to improve their hand, drape, cutting and sewing qualities. An effective softener must be readily dispersible in rinse water and rapidly absorbed so that uniform deposition on the fabric can occur within a relatively short treatment time and generally, exhaustion should take place in about 5min for the softener to be effective and economically usable. It must impart softness, fluffiness and lubricity to the treated cloth and reduce static build-up, especially in the case of hydrophobic fibers like cellulose acetate, nylon, polyester and acrylic fibers. These effects should be obtained without the loss of fabric whiteness or brightness, and then the treated fabric should retain its ability to absorb in subsequent use for drying the body (bath towels) or other surfaces. Fabric softener (also called fabric conditioner) is used to prevent static cling and make fabric softer. It is available as a liquid or as dryer sheets. Popular brand names include Downy (Lenor), Snuggle, Bounce, Comfort and Sta-Soft.I believe that, the knowledge of this report will help future carrier of every textile engineer.
The dyestuff sector is one of the important segments of the chemicals industry in India, linked with a variety of sectors like textiles, leather, paper, plastics, printing inks and foodstuffs.
Unit operations and process involved in manufacturing of dyes and dye intermediates, wastewater characteristics of dyes and dye intermediates, effluent discharge standards, treatment technology for dye and dye intermediates, solid waste generation and Gaseous emissions.
DEFINITION: Pigment is a substrate in a particulate form which is insoluble in water but which can be dispersed in this medium to modify its color and light scattering properties. They are organic or inorganic coloring materials. They have no affinity to textile materials. They are fixed on the textile material with the help of binding agent in form a thin invisible coating.
Bleaching, a process of whitening fabric by removal of natural colour, such as the tan of linen, is usually carried out by means of chemicals selected according to the chemical composition of the fibre.
We are Textile Engineer, we only apply dyes and pigment on textile substrate but we need to know how dyes and pigment manufacturing. I have details about all dyes manufacturing.
Textile processing toxicity and health hazard. Green Environment Ideas (Bangl...md sohag miah
Textile processing toxicity and health hazard. (Bangladesh perspective)
Presentation on green chemistry: Donghua University, Shanghai. China.
This PPT mainly describes the textile dyes and chemically made health hazards to the workers and surrounding environmental peoples of the textile industry (of Bangladesh).
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Low power architecture of logic gates using adiabatic techniquesnooriasukmaningtyas
The growing significance of portable systems to limit power consumption in ultra-large-scale-integration chips of very high density, has recently led to rapid and inventive progresses in low-power design. The most effective technique is adiabatic logic circuit design in energy-efficient hardware. This paper presents two adiabatic approaches for the design of low power circuits, modified positive feedback adiabatic logic (modified PFAL) and the other is direct current diode based positive feedback adiabatic logic (DC-DB PFAL). Logic gates are the preliminary components in any digital circuit design. By improving the performance of basic gates, one can improvise the whole system performance. In this paper proposed circuit design of the low power architecture of OR/NOR, AND/NAND, and XOR/XNOR gates are presented using the said approaches and their results are analyzed for powerdissipation, delay, power-delay-product and rise time and compared with the other adiabatic techniques along with the conventional complementary metal oxide semiconductor (CMOS) designs reported in the literature. It has been found that the designs with DC-DB PFAL technique outperform with the percentage improvement of 65% for NOR gate and 7% for NAND gate and 34% for XNOR gate over the modified PFAL techniques at 10 MHz respectively.
Using recycled concrete aggregates (RCA) for pavements is crucial to achieving sustainability. Implementing RCA for new pavement can minimize carbon footprint, conserve natural resources, reduce harmful emissions, and lower life cycle costs. Compared to natural aggregate (NA), RCA pavement has fewer comprehensive studies and sustainability assessments.
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6th International Conference on Machine Learning & Applications (CMLA 2024) will provide an excellent international forum for sharing knowledge and results in theory, methodology and applications of on Machine Learning & Applications.
Hierarchical Digital Twin of a Naval Power SystemKerry Sado
A hierarchical digital twin of a Naval DC power system has been developed and experimentally verified. Similar to other state-of-the-art digital twins, this technology creates a digital replica of the physical system executed in real-time or faster, which can modify hardware controls. However, its advantage stems from distributing computational efforts by utilizing a hierarchical structure composed of lower-level digital twin blocks and a higher-level system digital twin. Each digital twin block is associated with a physical subsystem of the hardware and communicates with a singular system digital twin, which creates a system-level response. By extracting information from each level of the hierarchy, power system controls of the hardware were reconfigured autonomously. This hierarchical digital twin development offers several advantages over other digital twins, particularly in the field of naval power systems. The hierarchical structure allows for greater computational efficiency and scalability while the ability to autonomously reconfigure hardware controls offers increased flexibility and responsiveness. The hierarchical decomposition and models utilized were well aligned with the physical twin, as indicated by the maximum deviations between the developed digital twin hierarchy and the hardware.
4. Today, the textile industry, which uses on an average six hundred dyes
and chemicals for the production of consumer textiles, is considered
must polluting.
With the kind of awareness and restrictions coming in to ecology of
textiles world over, the first thing every textile processor need to
know prior to processing any materials are the nature of end use of
the textile being processed and the country which being exported.
Because each end use, e.g. baby wear, clothing in direct contact with
skin, furnishing fabrics etc. will have different specifications just as
each country will have different legislation.
5. We are polluting our environment as well as destroying
our world by using non eco dyes and chemical
7. Because it create different problem:
• Health Problems
• Clothing dyes can cause the following health problems:
• skin rashes
• headaches
• trouble concentrating
• nausea
• diarrhea
• fatigue
• muscle and joint pain
• dizziness
• breathing difficulties
• irregular heart beat
• seizures
8. •Furthermore, children can experience the following:
•red cheeks and ears
•dark circles under the eyes
•hyperactivity
•behavioral problems
•learning problems
Because clothing is in constant contact with your skin, the chemicals are
absorbed into your skin through your pores. They can then enter your
liver, kidney, bones, heart and brain.
Most people have some sort of chemical sensitivity. Some are more
sensitive to chemicals than others. Those who are more sensitive will
notice the impact of clothing dyes more than others. Those of us who
aren’t as sensitive, may still experience some symptoms but just not
realize it.
9. A Dyeing process that is most suitable
and within the norms of Eco labels
standards is called Eco Dyeing.
10. Some of the useful tips all may consider are:
• Select dyestuff that does not contain Chlorinated benzene and toluene.
• Avoid using Carcinogenic dyestuffs in your combinations.
• Avoid using Allergic dyestuffs (some selected disperse dyes are allergic).
• Do not use chelating agents that contain phosphates.
• Use APEO and NPEO free surfactants as dispersing agents.
• Ascertain that your surfactant do not contain any ethoxylated products.
• Use Formic acid for neutralization purposes rather than Acetic acid.
• Do not use formaldehyde containing dye fixing agents after reactive/direct
dyeing.
• Use Natural dyes can be used and that does not have heavy metals etc,
give the first preference.
11. • Most important is to control and limit the use of water for
all purposes.
• If reactive dyeing is carried out, where ever possible go for
low salt and no salt dyeing/trials.
• Avoid reprocessing, save energy, money and water.
• Try and establish a system of Right First Time practice in
dyeing.
• In reactive dyeing, where ever possible you may try cold
dyeing to save energy. Preconditioning method is one such
procedure.
• In disperse dyeing avoid using phenolic carriers. Select
dyestuffs carefully.
• In wool and silk dyeing metal complex dyes' selection
should be optimistic.
• In all cases of wet processing, establish a suitable system of
water recycling either with an R.O.system or Nano System.
12. Government Eco-Labels Commercial Eco-Labels
Eco mark – Japan Oeko Tex 100 – Germany/
Austria
Green Seal – USA Tox Proof – TUV, Germany
Flower – EU GuT – Carpets, Germany
Different country maintain different Eco-Labels
13. No Eco parameter Permissible limits
01 Presence of banned amine <30 ppm
02 Presence of pentachlorophenol(PCP) <0.5 ppm (Baby wear : <0.05 ppm)
03 Presence of formaldehyde <300 ppm - material not in direct skin
contact,
<75 ppm – material in direct skin contact,
<20 ppm – baby wear.
04 Presence of heavy metals*
Customer specific
05 Residual pesticides <1.0 ppm (Baby wear 0.5 ppm)
06 Allergenic dyes Not to be used
07 Carcinogenic dyes Not to be used
08 Chlorinated benzene & Toluene <1.0 ppm
09 Presence of Phthalate <0.01 ppm
10 Organic Tin Compounds <1.0 ppm
11 pH
value of Aqueous Extract Should be nearly neutral (pH
-4.5 to 7.5)
12 Color fastness As per specification
Typical eco-parameters under the Eco-labels for finished textiles are,
18. Product based
Pertains to the limits of harmful chemicals which vary with the
intended use of textiles.
• Group 1
Baby wear, the limits are the lowest (stringent) for the cloths and
textiles for babies below age 3.
• Group 2
Material in direct skin contact, worn next to skin, for example –
underwear, bed sheets and night dresses etc.
• Group 3
Materials are not in direct skin contact. Textile worn as second layer
dresses, coats, articles with linings.
• Group 4
Furnishings articles and accessories for decorative purpose. e.g.
table wear, upholstery, curtains, textiles flooring and mattresses.
19. • These are recommendations for processes to be avoided such as
• Bleaching with hypochlorite.
• Use of chlorinated organic compounds as carriers in dyeing of polyester
• Optimum use of water and energy.
• Dyestuffs when exhausted on fiber are fixed only to the extent of 50-
90%, the un-exhausted dye with chemical impurities contaminate the
effluent, hence there is a need to ensure that dyestuff and dye additives
that go in to the dyeing process are eco friendly.
• Ecological norms for the dye are considered assuming it’s concentration
up to 10% on textile and 2% dye diluted to 1:2500 in effluent.
• Fastness properties (washing and rubbing dry/wet) of dyes on finished
textiles also form part of eco norms considering their possible transfer
on the skin.
Process Based
20. Any of a class of colored, water soluble
compounds that have an affinity for fiber and
are taken up directly, such as the benzidine
derivatives. Direct dyes are usually cheap and
easily applied, and they can yield bright colors.
Wash fastness is poor but may be improved
by after treatment. Most packaged dyes sold
for home use are direct dyes.
21. Direct dyes are also called substantive dyes because of their
excellent substantively for cellulosic textile materials like
cotton and viscose rayon. This class of dyes derives its name
from its property of having direct affinity for cellulosic fibres,
when applied from an aqueous solution.
22. • Solubility in water.
• Affinity to cellulosic fiber.
• Easy penetration
• Washing fastness are not good enough
• It is applied in neutral as alkali medium
• Cheap
• This dye does not react with fiber. But create H-bond
R N H-----------O cellulose
A H
Direct dye
• Chemically, direct dyes are sodium salts of aromatic sulphonic acids and
most of them contain an azo group as the main chromophore. They are in
general duller than the fiber reactive dyes, and exhibit poor wash
fastness. Goods dyed with direct dyes unless; given a proper after
treatment tend to bleed with every wash. The direct dyes in many cases
exhibit a better light fastness as compared to the reactive dyes.
Properties of Direct Dyes:
23. Vat dyes are an ancient class of dye, based on the
original natural dye, Indigo, which is now
produced synthetically. Both cotton and wool, as
well as other fibers, can be dyed with vat dyes.
Not all vat dyeing is done with vat dyes! "Vat
dyeing" means dyeing in a bucket or vat. It can be
done whenever a solid even shade, the same
color over the entire garment, is wanted, using
almost any dye, including fiber reactive dye,
direct dye, acid dye, etc. The opposite of vat
dyeing is direct dye application, such as, for
example, tie dyeing.
Vat dye
24. Most vat dyes are less suitable than, say, fiber
reactive dyes, for the home dyer, as they are difficult
to work with; they require a reducing agent to
solubilize them. The dye is soluble only in its reduced
(oxygen-free) form. The fiber is immersed repeatedly
in this oxygen-free dye bath, and then exposed to
the air, whereupon the water-soluble reduced form
changes color as oxygen turns it to the water-
insoluble form. Indigo is an example of this dye class;
it changes from yellow, in the dye bath, to green and
then blue as the air hits it.
25. • Vat dye, being insoluble in water, cannot be directly applied to
textile materials. They have to be converted into their water soluble
form, having affinity for textile fibre such as cellulosic fibres. This
conversion is usually brought about in two steps,
• Reduction of the dye into the weakly acidic leuco vat form and
• Salt formation by neutralizing these acidic leuco vat dyes by sodium
hydroxide to give a water soluble product.
• Since the second step result in the formation of water soluble
sodium salt of the leuco vat dye it may be called the solubilising
step. Reduction followed by solubilising is called vatting of the dye.
For this purpose sodium hydrosulphite Na2S2O4( usually called
hydros) is used as the reducing agent and sodium hydroxide as the
solubilising (neutralizing ) agent.
Properties of vat dye:
26. They tend to be fairly hydrophobic (though this depends on the structure of R1 and R2), but not
as much as, say, a long hydrocarbon would be, since the -COOC- groups cause some polarity.
The polymer chains in a sample of polyester are highly crystalline (for a polymer) and quite
tightly packed together. The result of this is that polyesters have very little affinity for large
ionic dyes- the dyes simply cannot either distribute between the chains, or form satisfactory
intermolecular interactions. Therefore, acid and direct dye classes are useless for this
polymer. Disperse dyes have low solubility in water, but they can interact with the polyester
chains by forming dispersed particles. Their main use is the dyeing of polyesters, and they
find minor use dyeing cellulose acetates and polyamides. The general structure of disperse
dyes is small, planar and non-ionic, with attached polar functional groups like -NO2 and -CN.
The shape makes it easier for the dye to slide between the tightly-packed polymer chains, and
the polar groups improve the water solubility, improve the dipolar bonding between dye and
polymer and affect the color of the dye. However, their small size means that disperse dyes
are quite volatile, and tend to sublime out of the polymer at sufficiently high temperatures.
The dye is generally applied under pressure, at temperatures of about 130o
C. At this
temperature, thermal agitation causes the polymer's structure to become looser and less
crystalline, opening gaps for the dye molecules to enter. The interactions between dye and
polymer are thought to be Van-der-Waals and dipole forces. The volatility of the dye can
cause loss of color density, and staining of other materials at high temperatures. This can be
counteracted by using larger molecules or making the dye more polar (or both). This has a
drawback, however, in that this new larger, more polar molecule will need more extreme
forcing conditions to dye the polymer.
Disperse dyes
27. • Non soluble
• Non ionic
• Molecularly disperse
• Used for manmade fibre dyeing ex-polyester, polyamide fibre.
• Hydrophobic textile material dyeing.
• Fair to good light fastness (4-5)
• Color fastness, wash fastness (3-4)
Properties of disperse dye:
28. REACTIVE DYE
Unlike other dyes, reactive dye actually forms a covalent bond with the cellulose or
protein molecule. Once the bond is formed, the dye molecule has become an actual
part of the cellulose fiber molecule. No wonder you can safely wash a garment that
has been dyed in bright fiber reactive colors with white clothing, a hundred times,
without endangering the whites in the least - even if it is all different bright colors, or
even solid black! The official definition of a "fiber reactive dye" is provided by Rys
and Zollinger in chapter VII of their book, The Theory of Coloration of Textiles
(1975) from the Dyers Company Publications Trust, England. A fiber reactive dye "is
a colored compound which has a suitable group capable of forming a covalent bond
between a carbon atom of the dye ion or molecule and an oxygen, nitrogen, or
sulphur atom of a hydroxy, an amino or a mercapto group respectively of the
substrate." They point out that the definition excludes mordant dyes and 1: 1
chromium azo dye complexes which, in dyeing protein fibers may form covalent
bonds between metal ion and nucleophilic groups of the fiber. What all this means is
that a fiber reactive dye reacts to form a true bond (not just a plus or minus charge
attraction or an entrapment in the fiber) with the fiber involved. In the case of
cellulose the bond is with the hydroxyl (-OH) groups present in vast numbers on the
cellulose molecule and in the case of protein fibers with the amino (-NH3 ) group
present on the protein molecule.
29.
30. • Reactive dyes are highly soluble in water.
• Dye creates on covalent bond with fiber.
• Reactive dye can be used for dyeing cellulosic cotton, wool nylon.
• Fixation occurred in alkaline solution.
• Reactive dye can produce all types of shades.
• Dyeing method is easy for reactive dye.
• Light fastness is very good; rating 6 out of 8.
• Wash fastness is also good (rating: 4-5).
• Fixation occurred in alkaline solution.
Properties of reactive dye
31. The dyeing principle is based on fiber reactivity and involves the reaction of a functional group of the
dyestuff with a site on the fiber to form a covalent link between the dye molecule and the
substance.
The Four structural feature of typical reactive dyes molecule are:
• 1. The chromophoric grouping, contributing the color
• 2. The reactive system, enabling the dye to react with hydroxy group in cellulose.
• 3. A bridging group that links the reactive system to the chromophore.
• 4. One or more solublising group, usually sulphuric acid substituent attached to the chromophoric
group for their color, although the azo chromophore –N=N- is by itself the most important.
All the reactive dyes contain sodium sulphonate group for solubility and dissolve in water to
give colored sulphonate anions and sodium cations. Most reactive dyes have one to four of these
sulphonate group, General form of reactive dye is as follows:
S------R----B----X
Where, S = Water solubility group
R = Chromophore
X = Reactive System
B = Bond between reactive system and Chromophore
Mechanism of Dyeing
32.
33. Natural Indigo Madder Lac Catechu
Pomegranate Kamala Mayrabolan Himalayan Rubrub
Natural dye Extract From This plant