The document discusses various eco-friendly textile processing techniques. It describes preparatory processes like singeing, desizing, and scouring that use enzymes instead of harsh chemicals to remove impurities. For desizing, it discusses enzymatic, solvent, ultrasonic, and plasma methods. It also covers enzymatic scouring and bleaching techniques using enzymes like amylases, catalases, laccases, and glucose oxidases. Other eco-friendly techniques discussed are liquid ammonia mercerization, ozone bleaching, and peracetic acid bleaching. The document emphasizes that new sustainable technologies are needed in textile processing to be environmentally compliant with increasing regulations.

1. The
Presentation
On
“ECOFRIENDLYTEXTILEPROCESSING”
UNDERTHEGUIDANCEOF
Prof.(Dr.) M.D.TELI
BY
Omkar S.Parmaj
AlemayehuLeta

2. A good preparatory process has several objectives
•Removal of loose hairy protruding fibres from the surface of the
fabric to give a smooth, even and clean looking face.
•Removal of natural impurities like oils, fats, waxes,
greases, natural matter, lignin and sizing material
like starches.
•To obtain an absorbent fabric,this is ready
for dyeing or printing process.
•To obtain softer and proper white fabric,
depending on its application.

3. Singeing Desizing Scouring and Bleaching
MerserizationDyeingFinishing

4. The process of singeing is carried out for the
purpose of removing the loose hairy fibres
protruding from the surface of the cloth, thereby
giving it asmooth, even and clean lookingface.
Objectiveif singeingmachine
•Removingof protrudingfibre
•Improving luster
•Reducedyeing and printing problem
Typesof singeing process
1. Plate singeing machine
2. Rotary-cylinder singeingmachine
3. Gassingeingmachine

5. •Material ofburner: metal replaced by ceramic.
•Composition of gas fuel: air to petroleum chemical
ratio
•Fabric is pre heated to remove the moisture.
•Water cooling system is incorporated just behind
the ceramic material to control the temperature of
ceramic material.
•in case of power failure, both burners tiltaway
from the fabric simultaneously.
•Fabric passing path is variable for maintaining
contact angle for different kind of fabric.

6. Ecofriendly pre-treatment
Enzymes are a class of proteins that function as biocatalysts which
are biodegradable, very specific in action and are used in small
quantities. They are made up of 200-250 amino acids. They work
by lowering the activation energy of the reaction making it much
faster.
• They are produced by living organisms such as fungi or
bacteria.
• Enzymes are complex organic, soluble bio-catalysts, formed by
living organisms that catalyze chemical reaction in biological
processes.
• Enzymes are quite specific in their action on a particular
substance.

7. Enzyme Effect
Amylase Desizing(to decompose starches applied in sizing)
Catalase Act on H2O2to decompose it into water & oxygen
Proteases, lipases and pectinases When combined, act on proteins, pectin andnatural
waxes to effectscouring
Laccases Decomposesindigo molecules for wash-down effect on
denim
Cellulases Break down cellulosic chains to remove protruding fibres
by degrading &create wash-down effect by surface
etching on denims etc.
Cellulasesand Hemicellulases Bio stoning of jeans
Desizingof CMC
Stylish effect on cellulose fibres
Pectinases Breaksdown pectin in scouring
Proteases Scouring of animal fibres, degumming of silkand
modification of wool properties
Lipases Elimination of natural triglycerides (in scouring)or
present in desizing (tallow compounds)

8. E + S → ES → P + E
(Enzyme)(Substrate)(Enzyme-Substrate)(Product) (Enzyme)
Substrate entering
In active side of
enzyme
Enzyme
substrate
complex
Enzyme/substrate
complex
Prodcut release from
enzyme

9. The removing of size material which incorporated in pre-weaving process is known
as desizing.

10. There are three main advanced desizing method are
1. Enzymatic desizing
2. Solvant desizing
3. Atmospheric plasma desizing

11. •Amylases are the enzyme that hydrolyses and reduces the molecular
weight of cellulose.
hydrolyze starch molecules to give diverseproducts.
specific for starch, removing it without damaging to the support
fabric.
optimum temperature is 30-60°C,optimum pHis5.5-6.5.

12. Cont…
Enzymaticdesizingandutilisation of desizingliquor for H2O2
 To utilize desizing baths for bleaching in which glucose oxidase
enzymes generate hydrogen peroxide and gluconic acid using glucose as
a substrate.
 Amyloglucosidases are enzymes used in desizing to degrade starch
until it becomes glucose.
 Optimum conditions are 0.75% (o.w.f.) enzyme, pH 4.1, 62 °C and a
process time of 45 minutes.
Advantages:
 reducing the use of peroxide stabilizing agents with the help of gluconic
acid
 saving water and energy by using desizing liquor for bleach.

13. •Some solvent are used for desizing of textile substrate.
•Sonafab 1000). It is a unique Desizing Agent, having
excellent solvent and emulsifying action on all types of
stain. (Sonal Dye-ChemPvt. Ltd)
Perchloroethylene -- desizing solvent

15. •It is a very clean operation with no disposal problem, the
pollution effect is negligible.
•The time of desizing and floor area for the machinery is far less
than for conventional system.
•Due to quick and even solvent penetration the size removal is
more uniform.
•The solvents are recoverable and have less or no effluent load.
•This method is useful since energy consumption is low, time of
desizing is low.
•Acrylic and wool fabrics develop a lustrous, soft hand in solvent
without any felting.
•When solvent desizing is followed by bleaching, the caustic
scouring is omitted since pectin and wax

16. DISADVANTAGE OF SOLVENT DESIZING
•Although solvent desizing ranges are available
commercially, the price of the equipment is high.
•The majority of size systems used in aqueous process is
not readily applicable in solvent desizing.
•Cost of processing is higher than for water base process.

17. • Plasmais four states of matter
• Here material having in ionizedcondition
• Plasmais produce by applying electric field
on agas
• Plasmais etching the fabricsurface
• Etching is depend upon the voltage, type of
gas,time

18. Ultrasonicenergyare the highfrequencywavesrangeingfrom 20Khzto 50Mhz whichis
nnot audiable byhuman
•In liquids, longitudinal vibrations of molecules generate compression and
rarefaction, i.e., areas of high pressure and low localpressure
•Thelatter gives rise to cavities or bubbles, which expand and finally during the
compression phase, collapse violently generating shockwaves.
•The phenomena of bubble formation and collapse (known as cavitation) is generally
considered responsible for most of ultrasonic physical and chemical effects observed
in solid/liquid or, liquid/liquid systems.

19. Use of ultrasonic energy in
desizing
Amylase
wetting agent
Temperature
Time
- 0.75g/l
- o.5 g/l
- 55°C
- 20min.
Desizingefficiency 7 when USis
used.
•Energysavingsresulting from lower
processtemperatures and shorter cycle
times
•Reducedconsumption of dyesand
chemicals, which allows for a20-30%
reduction in the amount of effluent
• Water savingsof around20%
• Improvement in productquality
•Increased productivity becauseof shorter
cycle timesDesizingefficiency 2.5 when USis
not used.
Limitation
•Thisprocessrequires someassistancefrom temperature. Thisprocessdoesnot
involve complete elimination of temperature.
Recipe Advantage

20. Toremove natural aswell asadded impurities of essential hydrophobic
character(oil,fat,waxes) ascompletely aspossible and leave the fabric in high
absorptive condition without undergoing significant chemical or physical
damage
Tomakethe goodssuitable for removing the natural colouring matterof
the cotton during thesubsequent bleaching process.
Conventional method: Alkaliscouring.
Where 3-4% caustic soda is used at high temperature (90-95oC) forlong
duration (2-3hours)
Disadvantages of alkali scouring:
1) Damage to fibre.
2) Requirement of large quantity of water for washing.
3) Heavy effluent load (Salts of neutralization)

21. EnzymaticScouringor Bio-Scouringcansimply be defined asthe
application of living organisms and their components to remove
the natural andadded impurities.
Enzymesused for Bio scouring
Pectinase – (Pectins removal)
Protease– (Removalof proteins)
Combination of 2 or 3enzymes
maybe usedto get synergisticeffect.
temperatures and highConventional scouring requires high
consumption of chemicals.Suppliers.

22. Parameter Bio Scouring Alkaline Scouring
pH 7-8 12-13
Temperature 50-600C 950C
Residual Pectin 20-25% 10-11%
Weight loss <1.5% 4-6%
Handle Very soft Harsh and papery
Rinse Water
Consumption
30-40% of Alkalinescouring
TDS 50% of AlkalineScouring
BOD 50% of AlkalineScouring
COD 50% of AlkalineScouring

24. Advantages of bi-scouring
(BOD) and (COD) of enzymatic scouring process are 50 % as compared to
alkaline scouring (100 %). Total Dissolved Solid (TDS) of enzymaticscouring
process is 50% as compared to alkaline scouring(100%).
Handle is very soft in enzymatic scouring.
It also minimises health risks of operators as they are not exposed to hazardous
chemicals.
reduced water and wastewater costs, reduced treatment time and lower
energy consumption because of lower treatment temperature (the optimal
temperature is from 40 to 60°C).

25. Limitation of Bio scouring process
•The enzymes used for scouring are costly and they require temperature fortheir
action.
•The increase in temperature or pH may deactivate the enzyme which may alter the
process efficiency.

26. BLEACHING
Bleaching is to decolourise natural pigments and to confer apure white
appearance to the fibres. Themost common industrial bleaching agentis
hydrogen peroxide, which is usually applied at alkaline pHand
temperatures close to boiling.

27. BIOBLEACHING
alysesthe following
Enzymescanalso be used in bleaching.
Glucoseoxidase
 Glucoseoxidases(GODs)are flavoproteins with a Flavin-adenine-
dinucleotide (FAD)active site.
Theenzyme is highly specific for B-D-glucoseandcat
reaction for hydrogen peroxidegeneration.
 Ph - 4.5-7
 temperatures - 40°C

28. Cont….
• Gluconic acid acts as bleach stabilizer
• it would allow for the reuse of sugar contaminated effluent
from other wet processing steps (desizing bath containing
glucose)
The actual bleaching process involves 2 steps:
• Peroxide generation by GOD at the enzyme optimum
conditions.
• PH adjustment to 7.5-8 and bleaching process at 85-90°C for
60-120 minutes with the enzymatically hydrogen peroxide.

29. Cont…
Laccase
Laccase (EC 1.10.3.2) is a multi-copper oxidase enzyme which
oxidizes a broad range of aromatic compounds as substrates and
oxygen as a terminal electron acceptor.
Rapid bleaching with laccase–hydrogen peroxide enhances the
whiteness of cotton fabrics.
Bleachclean-up
 Traditional method:
Bleach --> Rinse --> Rinse --> Rinse --> Dye
 There are two methods for bleach clean-up
• After completion of the process the bleached liquor was drained out,
then the fabric was rinsed with water a number of times to remove
the H2O2 from the bleached fabric.
• use of a mild reducing agent to neutralise the bleach.

30. Cont…
 Catalasehave been used to decompose residual hydrogen
peroxide in fabric prior todyeing
 Catalase enzyme catalyzesthe decomposition of hydrogen
peroxide to water and oxygen. Onecatalase molecule can
convert millions of molecules of hydrogen peroxide to
water and oxygen eachsecond
 Useof Catalase enzyme made it possible to reduce the
temperature and volume of the secondwash after
bleaching from 80-950Cto 30-400C,resulting in a9-14%
saving of energy, a17-18%saving of water and anoverall
cost saving of 9%

31. OZONEBLEACHING
Industrial production of ozonecanbe accomplished by applyingaplasma
discharge to oxygen inair.
Ozoneis anatural substanceand it is astrong oxidising agent andit
decomposesrapidly.
Process
Fabric having 24%moisture content is placed
in application chamber and exposedto 100
g/m of concentration of ozoneoxygen gas
mixture.
pH– 5 with aceticacid
Time – 1-7 min
Temperature- 30°C

32. ADVANTAGESANDLIMITATIONOFOZONE
BLEACHING
Advantages
Thequality of theprocessed
fabric iscomparable.
Greypreparation with ozone
canbe completed in one ortwo
minute.
Thisprocess hasadditional
advantages suchassavings in
thermal energy, water and
chemicals
Limitations
Theyield of ozone generatoris
low (6-12%from oxygen and 4-
6%from air), and ozone
concentration is low aswell.
Ozonehasto be generatedon-
site becauseits problems to be
stored and transported.
Energyconsumption for
production of O3: Basedonpure
oxygen, the costs will be 6 to 15
kWh/kg O3.

33. PERACETICACIDBLEACHING
• Per acetic acid is also known as peroxyaceticacid.
• It is colorless in nature.
• It is miscible with water and most of organic solvents.
• It is very powerful oxidizing agent.
• It is also used as germicide for protecting fruits/vegetables against spoilage.
• General formula is C2H4O3.
• It corresponds to acetic acid with additional oxygen atom per molecule.
i.e. CH3COOOH (peracetic acid)
• It is highly unstable at pH 5-5.5. But stable at lower pH of1.5-2.
• A concentration of 35% to 40% is dangerouslyexplosive.

34. Mechanism of oxidation with peracetic acid, it gives extra
oxygen atom and acetic acid is formed as co-product.
CH3COOH CH3COOH + [O]
Procedure for bleaching with peracetic acid:
1)Peracetic acid being unstable has to be prepared before bleachingbeing
carried out as per above procedure.
2) Bleaching is carried out with
MECHANISMOFPERACETICACID

35. LIQUIDAMMONIA MERCERIZATION
In this technique the fabric is first passed through drying cylinders to reducethe
moisture content of fabric then through a cooling station.
Afterwards it is impregnated with liquid ammonia in a closed chamber and then
the fabric is passed through felt calendars in which 90-95% of ammonia isremoved.
Advantages over alkali mercerization:
Quick process
Low shrinkage post washing
Superior in the degree of improvement in strength
 Durability of dimensionstability
Soft handle

36. LIQUIDAMMONIA MERCERIZATION

37. Togo towards the eco friendly and sustainabletextile
processing, New technology hasto be incorporated in
the textile processing
All over the world, the environmental regulations
are becoming more and more stringent and are
forcing the shift of technology towards lesspolluting
or non-polluting areasof technologicaldevelopment.
Rapidchangesin technology adire need to
conserve water and energy haveforced thetextile
industry to give up the old conventional processes
and try out newmethods
CONCLUSION