Combine pretreatment of woven fabric

2. Chapter -1

3. Introduction
 Background:
 Woven fabrics have a very wide range of applications, starting from
everyday clothing, through protective and work clothing, decorative and
furniture fabrics, up to technical textiles. Such a wide range of application
depends on their performance, appearance and above all cost. Cost is main
fact during the selection of textile product. At present lots of textile
industries competed with each other by giving low price with high quality.
In textile industries maximum cost goes on energy cost after raw material.
Moreover, our country at present is unable to give sufficient amount of
energy to fulfill the demand of the textile industries. As a result they often
have to set up energy plant by their own cost which increases their
processing cost. For this reason our country sometimes fall behind to other
country like China according to cost and quality. Our focus of this project
is to reduce processing steps, energy, water, time and different types of
chemicals.

4. Objetives:
 To reduce processing steps.
 To reduce time, energy, different types of chemicals
& cost.
 To get desized effect by using H2O2 instead to using
desizing agent(enzyme).
 To get high quality of desired final product.

5. Chapter 2

6. Literature review
Introduction
Comprehensive literature reviews of the investigation of
combined desizing, scouring, bleaching effect with H2O2
would be discussed in this chapter.
Desizing, Scouring and Bleaching are frequently undertakes
as three separate steps in preparatory stages of Textile Wet
Processing. Though chemical substitution and process
optimization, it is possible to combine two or three steps of the
processing, thereby reducing water and energy consumption
as well as shortening the process time. As combine bath
requires higher amount of H2O2, the overall processing
sequence generates less effluent harmful to environment.

7. Understanding Desizing, Scouring,
Bleaching and Combine bath
Desizing
Desizing is the process of removing sizing materials from
the fabric, which is applied in order to increase the
strength of the yarn which can withstand with the
friction of loom. Fabric which has not been desized is
very stiff and causes difficulty in its treatment with
different solution in subsequent processes. After singeing
operation the sizing material is removed by making it
water soluble and washing it with warm water. Desizing
can be done by either the hydrolytic method (rot steep,
acid steep, enzymatic steep) or the oxidative method

8. Objectives :
1. To remove the starch material from the fabric.
2. To increase the absorbency power of the fabric.
3. To increase the affinity of the fabric to the dry chemicals.
4. To make the fabric suitable for the next process.
5. To increase the luster of the fabric increase of dyeing and
printing.

9. Scouring
Scouring is a chemical washing process carried out on cotton fabric
to remove natural wax and non-fibrous impurities from the fibers
and any added soiling or dirt. Scouring is usually carried in iron
vessels called kiers. The fabric is boiled in an alkali, which forms a
soap with free fatty acids. A kier is usually enclosed, so the solution
of sodium hydroxide can be boiled under pressure, excluding
oxygen which would degrade the cellulose in the fiber. If the
appropriate reagents are used, scouring will also remove size from
the fabric although desizing often precedes scouring and is
considered to be a separate process known as fabric preparation.
Preparation and scouring are prerequisites to most of the other
finishing processes. At this stage even the most naturally white
cotton fibers are yellowish, and bleaching, the next process, is
required.

10. Objects
 To remove impurities such as oils, waxes, gum, husks
as nearly as possible.
 To increase absorbency of fabric or textile materials
without physical and chemical damage.
 To produce a clean material by adding alkali.
 To make the fabric ready for next process.
 To remove non-cellulosic substance in case of cotton.

11. Bleaching
 Bleaching improves whiteness by removing natural
coloration and remaining trace impurities from the
cotton; the degree of bleaching necessary is
determined by the required whiteness and absorbency.
Cotton being a vegetable fiber will be bleached using
an oxidizing agent, such as dilute sodium hypochlorite
or dilute hydrogen peroxide. If the fabric is to be dyed
a deep shade, then lower levels of bleaching are
acceptable. However, for white bed sheets and medical
applications, the highest levels of whiteness and
absorbency are essential.

12. Object:
 To produce white fabric by destroying coloring matter
with minimum fabric degradation.

13. Combine bath
 Till today the most common textile pretreatment
sequence are acid or enzyme desizing – alkali scouring
and bleaching. But as it take much time more energy
and more chemicals different approaches are made to
simplify this pretreatment. The most common one is
combine bath where all three process are taken places.
this system is likely to combine scouring and
bleaching but here we used higher amount of H2O2
and more process time.

14. Object
 Prepare textile for coloration with minimum cost.
 A pretreatment process with minimal time
consumption.
 Potential energy and chemical saving in pretreatment.
 A easy textile pretreatment process.

15. Some of the combine process
proposed were:A combine desizing, scouring and bleaching of medium and fine varieties of
cotton fabrics was suggested by
PARIKH which involves the use of DTPA as stabilizer for hydrogen peroxide.
BTRAdeveloped a single-stage process in kier which is claimed to produce high
degree of whiteness with minimum damage of cellulose.
SAHAKARI worked out a process which is based on solvent-nonionic emulsion
system known as Scourex process.
GULRAJANI ET AL suggested a solvent-assisted aqueous process in which sodium
hydroxide has been replaced by a solvent-nonionic surfactant-pine oil
combination along with hydrogen peroxide.
Other combined processes reported in the literature use tetrapotassium
perhydroxy phosphate (KPP), sodium dipersulfate (SPS) and various combinations
of sequestering agent, wetting agents and peroxide stabilizer.in almost all these
combined processes. The benefits of combining the processes are generally derived
at the expense of some quality. Hence, they were accepted by the industry with a
lot of reservations.

16. Chapter – 3
Materials

17. COTTON FIBERS
 INTRODUCTION
 Cotton today is the most used textile fiber in the world. Its current market share is
56 percent for all fibers used for apparel and home furnishings and sold in the U.S.
Another contribution is attributed to nonwoven textiles and personal care items. It
is generally recognized that most consumers prefer cotton personal care items to
those containing synthetic fibers. World textile fiber consumption in 1998 was
approximately 45 million tons. Of this total, cotton represented approximately 20
million tons. The earliest evidence of using cotton is from India and the date
assigned to this fabric is 3000 B.C. There were also excavations of cotton fabrics of
comparable age in Southern America. Cotton cultivation first spread
from India to Egypt, China and the South Pacific. Even though cotton fiber had
been known already in Southern America, the large-scale cotton cultivation in
Northern America began in the 16th century with the arrival of colonists to
southern parts of today's United States. The largest rise in cotton production is
connected with the invention of the saw-tooth cotton gin by Eli Whitney in 1793.
With this new technology, it was possible to produce more cotton fiber, which
resulted in big changes in the spinning and weaving industry,especially
in England.

18. Botanical name of cotton
 There are four commercially grown species of cotton, all
domesticated in antiquity:
 1. Gossypiumhirsutum – upland cotton, native to Central
America, Mexico, the Caribbean and southern Florida, (90%
of world production).
 2. Gossypiumbarbadense – known as extra-long staple cotton,
native to tropical South America (8% of world production).
 3. Gossypiumarboreum – tree cotton, native to India and
Pakistan (less than 2%).
 4. Gossypiumherbaceum – Levant cotton, native to southern
Africa and the Arabian Peninsula (less than 2%).

20. Types of Cotton:
 There are more than 30 types of cotton plants, ranging from small shrubs less than one
foot (30 cm) tall to trees more than 10 feet (3 m) high. Some of the better-known types
are described below.

1. Sea Island Cotton:With a staple of 1 3/8 to 2 1/2 inches (3.5–6.4 cm), has the highest
quality fiber but its susceptibility to insect attack makes commercial production
impractical. It is named for the Sea Islands (off the coast of the southeastern United
States), where it was grown until the boll weevil halted production in the 1920's.
 2. Egyptian Cotton: Has yellowish fibers that are only slightly shorter than those of Sea
Island cotton—1 1/2 to 1 3/4 inches (3.8–4.4 cm) long. This cotton is used in making
thread, raincoats, underwear, and hosiery. An American type of Egyptian cotton, called
American pima, is grown in the southwestern Cotton Belt under irrigation.
 3. Upland Cotton:Is the main type grown in the United States. It is also grown all over
the rest of the cotton-producing world. The fibers are white, 3/4 to 1 1/2 inches (1.9–3.8
cm) long. The plant is 2 1/2 to 4 feet (75–120 cm) tall. It is native to Mexico and Central
America.
 4. Asiatic Cotton: Has fibers less than one inch (2.5 cm) long and rather coarse in
texture. It is grown mostly in India, Iran, China, and Russia.

21. Commercial cotton may be classified broadly into three categories with reference
to the staple length :
 1. Staple length (26-65 mm): includes the fine luster fiber which forms the top
quality cottons. The fiber are generally of 10-15 microns diameter 1.1-1.8 dtex
(0.99-1.62 den). Sea Island, Egyptian and American Pima (American –Egyptian)
cottons are in this category. These high quality cottons are often the most
difficult to grow, and are in comparatively short supply.
 2. Staple length (12-33 mm): Includes medium strength, medium luster cottons
which form the bulk of the world crop. The fibers are generally of 12-17 microns
diameter, and are of 1.4-2.2 dtex(1.26-1.98 den). American upland and some
Peruvian types come into this category.

 3. Staple length (3/8-1 inch or 9-26mm): Include the coarse, low grade fibers
which are often low in strength and have little or no luster. The fibers are
generally of 13-22 microns diameter and are of 1.5-2.9 dtex (1.35-2.61den).

22. CHARATERISTICS OF COTTON
 1. Good moisture absorbency
 2. Non allergic
 3. Good heat resistance
 4. Good washing endurance
 5. Soft feel
 6. Shrinkage tendency
 7. Crimping tendency
 8. Medium dyeing fastness

23. RAW COTTON COMPONENTS
Constituents Percentage
Cellulose 80-90%
Water 6-8%
Waxes and fats 0.5 - 1%
Proteins 0 - 1.5%
Hemicelluloses and pectin’s 4 - 6%
Ash 1 - 1.8%

24. REPEAT UNIT OF CELLULOSE

25. Woven Fabrics
 Introduction
Most fabrics are made by weaving or knitting yarns, although non-woven
fabrics are made by bonding or felting fibres together. A fabric's
appearance, properties and end use can be affected by the way it was
constructed.
Woven fabrics are made up of a weft - the yarn going across the width of
the fabric - and a warp - the yarn going down the length of the loom. The
side of the fabric where the wefts are double-backed to form a non-
fraying edge is called theselvedge.
Woven fabrics are produced by the interlacing of warp (0°) fibres and
weft (90°) fibres in a regular pattern or weave style. The fabric's integrity
is maintained by the mechanical interlocking of the fibres. Drape (the
ability of a fabric to conform to a complex surface), surface smoothness
and stability of a fabric are controlled primarily by the weave style.

26. Properties of woven fabric
1.Smooth surface
2.Wares well
3.Ravels less
4.Wrinkels more
5.Less absorption

27. Hydrogen peroxide
 Hydrogen peroxide is a chemical compound with the formula H2O2.
In its pure form it is a colorless liquid slightly more viscous than water;
however, for safety reasons it is normally used as an aqueous solution.
Hydrogen peroxide is the simplest peroxide (a compound with an oxygen-
oxygen single bond) and finds use as a strong oxidizer, bleaching agent
and disinfectant. Concentrated hydrogen peroxide, or 'high-test peroxide
is a reactive oxygen species and has been used as a propellant in rocketry.
Hydrogen peroxide is often described as being “water but with one more
oxygen atom” a description which can give the incorrect impression that
there is a great deal of similarity between the two compounds. Pure
hydrogen peroxide will explode if heated to boiling, will cause serious
contact burns to the skin and can set materials alight on contact. For these
reasons it is usually handled as a dilute solution (household grades are
typically 3-6%). Its chemistry is dominated by the nature of its
unstable peroxide bond.

28. Structure
Structure and dimensions of
H2O2 in the gas phase
Structure and dimensions of H2O2 in the
solid (crystalline) phase

29. Applications:
About 60% of the world's production of hydrogen peroxide is used for
pulp- and paper-bleaching.[18] The second major industrial application is
the manufacture of sodium percarbonate and sodium perborate which are
used as mild bleaches in laundry detergents.It is used in the production of
various organic peroxides with dibenzoyl peroxide being a high volume
example. This is used in polymerisations, as a flour bleaching agent and as
a treatment for acne. Peroxy acids, such as peracetic acid and meta-
chloroperoxybenzoic acid are also typically produced using hydrogen
peroxide.Hydrogen peroxide is used in certain waste-water treatment
processes to remove organic impurities. This is achieved by advanced
oxidation processes, such as the Fenton reaction,[31][32] which use it to
generate highly reactive hydroxyl radicals (•OH). These are able to destroy
organic contaminates which are ordinarily difficult to remove, such
asaromatic or halogenated compounds.[33] It can also oxidize sulphur
based compounds present in the waste; which is beneficial as it generally
reduces their odour.

30. Bleaching Process with Hydrogen Peroxide
Hydrogen peroxide bleaching can be done by
1.Batch wise,
2.Continuous
3.Semi continuous method.

31. Enzyme
 "Biocatalyst" redirects here. For the use of natural catalysts in organic
chemistry,
 The enzyme glucosidase converts sugar maltose to two glucose sugars.
Active site residues in red, maltose substrate in black, and NAD
cofactor in yellow.
Enzymes are macromolecular biological catalysts . Enzymes
accelerate, or catalyze, chemical reactions. The molecules at the
beginning of the process are called substrates and the enzyme converts
these into different molecules, called products. Almost all metabolic
processes in the cell need enzymes in order to occur at rates fast
enough to sustain life. The set of enzymes made in a cell determines
which metabolic pathways occur in that cell. The study of enzymes is
called enzymology.
Enzymes are known to catalyze more than 5,000 biochemical reaction
types. Most enzymes are proteins, although a few are catalytic RNA
molecules. Enzymes' specificity comes from their unique three-
dimensional structures.

32. Structure

33. Reactive dye
Properties of reactive dye:
 Reactive dyes are anionic dyes, which are used for dyeing
cellulose, protein and polyamide fibres.
 Reactive dyes are found in power, liquid and print paste
form.
 Reactive dyes are soluble in water.
 Dyeing method of reactive dyes is easy. It requires less time
and low temperature for dyeing.
 Reactive dyes are comparatively cheap
 Reactive dyes have good perspiration fastness with rating
4-5.
 Reactive dyes have good perspiration fastness.

34. Chapter-4
Methodology

35. Working procedure:
 At first we take 220 gm grey fabric.
 Then the fabric was divided into two parts.
 One part is taken to combine desizing, scouring and bleaching bath.
 Another part is taken to desizing bath then to scouring and bleaching
bath.
 After completing these processing, we have done the absorbency test &
weight loss . Then this two kinds of sample are divided into several
parts.
 Then we dyed each 6 sample with three basic color of each two kind of
sample.
 These sample are sent to Dyesin-chem lab for measuring their color
difference along with whiteness and reflection index of undyed sample.
 Then the strength test was done.
 We evaluated the test result and make decision on the project.

36. Flow Chart:

37. Recipe(For Combined bath):
 Wetting Agent : 1 cc/L
 NaOH : 4 g/L
 Sequestering Agent : .5cc/L
 Sodium Silicate: 3 g/L
 H2O2: 8 g/L
 M:L : 1: 30
 Temperature : 70° C ±5
 Time : 40 min
 pH: 10-11

38. Curve:

39. Recipe(For individual bath):
 Wetting Agent : 1 cc/L
 Desizing Enzyme : 1cc/L
 Sequestering Agent : .5cc/L
 Acetic Acid : 1cc/L
 M:L : 1: 30
 Temperature : 60° C ±5
 Time : 40 min
 pH: 4.5-5.5

40. Curve:

41. Recipe:
 Wetting Agent : 1 cc/L
 NaoH : 3cc/L
 Sequestering Agent : 1cc/L
 Sodium Silicate : 1cc/L
 H2O2 : 4 cc/L
 M:L : 1: 30
 Temperature : 60° C ±5
 Time : 30 min

42. Curve:

43. Dyeing Recipe:
 Sample:1
 Reactive dye(Red) : 1%
 NaOH : 4 g/L
 Salt : 13 g/L
 Sequestering Agent : 1cc/L
 Wetting Agent : 1 cc/L
 M:L : 1: 50
 Temperature : 40° C ±5
 Time : 40 min

44. Dyeing Curve:

45. Chapter-5
Results and Discussion

46. Strength loss
Combined (desizing, scouring and bleaching) 14%
Individual (desizing, scouring and bleaching) 17%
Absorption test
Combined (desizing, scouring and bleaching) 40 mm
Individual (desizing, scouring and bleaching) 42 mm

47. Weight loss %
Combined (desizing, scouring and bleaching)
((205-185)/205)*100 = 9.7%
Individual (desizing, scouring and bleaching)
((210-182)/205)*100 = 13%
Whiteness %
Light source D65 10 Deg
Combined (desizing, scouring and bleaching) 50.62
Individual (desizing, scouring and bleaching) 61.33
DELTA WI 10.71

48. Color change
Color red
Result : Combine batch is more saturated more blue.
Fabric L* C* h DE*
Combined (desizing, scouring and
bleaching)
58.43 37.71 356.48
Individual (desizing, scouring and
bleaching)
58.66 36.49 357.79
Deltas -0.10 0.55 -0.55 0.78

49. Discussion
After evaluating the results of the two samples
combined desizing, scouring and bleaching and
individual desizing and scouring-bleaching the
whiteness %DELTA value is 10.71%. There for it is not
convenient for white fabric. We compared the color
change results that are DELTA 0.78, 1.16 and 1.05
which are very close to warm value .And other testing
value lies in the acceptable range.

50. Chapter- 6
Conclusion
By this project work we have learned great deal of
textile pretreatment and try to introduce a newer and
more easier process. Which is very much energy saving
and cost efficient. It will give great advantages in price
negation.
Finally we can say that a desizing, scouring and
bleaching steps can be done in a combine bath event
without cocktail enzyme for a darker shade.

51. Thank You