Seminar Report On
“Recent Trends in Anti-crease finishing of cotton”
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)
Textile Chemistry
Under the Guidance of
DR. A.K. PATRA Sir
Professor & Head (Textile Chemistry)
UPTTI (formerly GCTI)
Souterganj, Kanpur - 208001
(State-UP) INDIA
Submitted to:
DEPARTMENT OF TEXTILE CHEMISTRY
Uttar Pradesh Textile Technology Institute, Kanpur
24 July 2021

TABLE OF CONTENTS
CHAPTER PAGE
ACKNOWLEDGMENTS………………………………………………………………………………...……. I
ABSTRACT ....................................................................................................................................... II
INTRODUCTION.............................................................................................................................. III
THE TERM CREASE AND WRINKLES............................................................................................IV
WHY CREASE FORM ON COTTON (CELLULOSIC FABRIC)? ....................................................... V
EXPERIMENTAL..............................................................................................................................VI
MATERIALS AND METHODS.........................................................................................................VII
SYNTHESIS AND CHARACTERIZATION OF ACRYLATE COPOLYMERS ................................... VIII
CHEMICAL TREATMENTS: .............................................................................................................IX
EFFECT OF COPOLYMER TG AND MOLECULAR WEIGH ON TENSILE STRENGTH
RETENTION ..……………………………………………………………………………………………………
……X
RESULTS AND DISCUSSION: ........................................................................................................XI
EFFECT OF COPOLYMER -TG AND MOLECULAR WEIGHT ON DCRA....................................... XII
FORMALDEHYDE FREE CREASE-RESISTANT FINISHING OF COTTON FABRIC USING CITRIC
ACID. ………………………………………………………………………………………………………XIII
MATERIALS AND CHEMICALS…………………………………………………………………………. XIV
PREPARATION OF SILK FIBROIN SOLUTION………………………………………………………. XV
EFFECT OF CA/FIBROIN CONCENTRATION ON CREASE RECOVERY OF THE TREATED
FABRIC………………………………………………………………………………………………………XVI
CONCLUSION……………………………………………………………………………………………. XVIII
REFRENCES: ................................................................................................................................XIX

ACKNOWLEDGEMENT
Present inspiration and motivation have always played a key role in the success of
any venture.
I offer my profound gratitude to the management of UPTTI, Kanpur. For giving
me the opportunity to do prepare the project report. I express my sincere thanks to
Dr. G. Nalankilli, Director of Uttar Pradesh Textile Technology Institute,
Kanpur.
I pay my deep sense of gratitude to Dr. ARUN KUMAR PATRA Sir, HOD of
Textile Chemistry department and Academic HOD, UPTTI Kanpur to encourage
me to the highest peak and to provide me the opportunity to prepare the project.
I feel to acknowledge my indebtedness and deep sense of gratitude to Dr. Patra sir
whose valuable guidance and kind supervision given to me throughout the course
which shaped the present work as its show. I am immensely obliged to my friends
for their elevating inspiration, encouraging guidance and kind supervision in the
completion of my project.
Last, but not least, My Parents are also an important inspiration for me. So, with
due regards. I express my gratitude to them.
VIJAY PRAKASH
1704460060
Textile Chemistry
Uttar PradeshTextile Technology
Institute Kanpur, Uttar Pradesh

ABSTRACT
A simultaneous treatment of cotton fabric with 4,5-dihydroxy-1,3
dimethylethyleneurea and an acrylate copolymer was studied. When acrylate
copolymers with low glass transition temperatures (below – 22 degree C) and high
molecular weight (above 105) were used with the crosslinking agent, the treated
fabrics had an excellent level of creaseresistance, tensile strength, and flex-abrasion
resistance. Good durability to repeated launderings, resistance to hydrolysis, wash-
wear rating, shrink resistance, and color fastness were also obtained on the resin-
finished cottonfabrics. Apaddry-cureprocess was applied to various kinds ofcotton
fabrics using a production machine. No formaldehyde was detected during
processing or from the resin-treated fabrics thus produced.
Wrinkling effect in cellulose fiber–made fabrics has a major setbackfor their use as
apparels necessitating the use ofcrease resistance finish. Fora while, formaldehyde-
based-finished dimethyl dihydroxy ethylene urea has been used as crease resistance
finish. DMDHEU finished fabric will releases formaldehyde during its application,
that affects both user’s health and the environment. This research optimized citric
acid (CA) and silk fibroin solution as a crease resistance finishing agent. Citric acid
was identified as a non-formaldehyde-based cross-linking agent but causes
yellowing in cotton fabrics. To steer clear of this, silk fibroin solution was added
with citric acid to increase the crease resistant in avoiding yellowing of the fabric
caused by citric acid. The optimum combination of the processing parameters
obtained was 6% silk fibroin solution, 30 g/L of citric acid, and 6% sodium
dihydrogen phosphate, at a finishing bath at pH of 5.5 with curing temperature of
150°C. These optimized finishing parameters achieved a dry crease recovery angle
of 252° while obtaining an 84% tensile strength retention, 96% tearing strength
retention, and 75 WI (93%) whiteness index.

Introduction:
Cotton is one of the most favoured textile materials because of its superior wearing
comfort and excellent wearability. Unfortunately, cotton fabric wrinkles easily
during home laundering and causes considerable inconvenience for users. The poor
resiliency of cottonis caused by the structure of biopolymer-cellulose in fibers, as it
has hydrogen bonds as the major intermolecular interactions but is lack of
intermolecular chemical cross-linkages. Crosslinking of cellulose with
formaldehyde-based compounds, mainly dimethylol dihydroxy ethylene urea
(DMDHEU) was introduced to overcome winkles. DMDHEU has been used in
cotton finishing for prominent wrinkle resistance property since 1950s. However,
when treated cottonfabric is subjected to multiple laundering cycles, ether linkages
of DMDHEU gradually hydrolyse to become N-methylol groups. Hence, free
formaldehyde releases continuously during the entire life of the treated garment. In
1987, the U.S. Environmental Protection Agency classified formaldehydes “a
probable human carcinogen” (Environmental Protection).
Many researchers have been dedicated in finding and developing formaldehyde-free
easy-care agents or finishes for cotton fabric. Polycarboxylic acids (PCA) are non-
formaldehyde reactants that have the possibility of replacing the conventional
finishing agents. Among the various effective agents, carboxylic acids, 1,2,3,4-
butanetetracarboxylic acid (BTCA) is the most effective cross-linking agent for the
cotton fabrics (Sunder and Nalankilli 2012; Yang and Hu 2006). Even though
BTCA in the presence of sodium hypophosphite provides the same level of DP
performance and better mechanical properties as found in DMDHEU-treated cotton
fabrics, its high costis an obstaclefor mills to use it as replacement for conventional
DP reactants. Citric acid (CA) is another candidate that could replace DMDHEU.
The advantages of citric acid over others ofthe Polycarboxylic acids are its low cost,
lack of toxicity, and readily available. However, finishing based on citric acid alone
causes yellowing in cotton fabrics due to formation of unsaturated acid.
In the present study, an attempt has been made to find the optimum processing
parameters used forcitric acid and fibroin solution as a DP finish treatment on cotton
fabric to improve the appearance properties of fabrics treated with citric acid and to
minimize the associated yellowing problem.

The term Crease and Wrinkles:
Creases are a fold in a fabric introduced unintentionally. The definition of a wrinkle
is less clear, however. Some define wrinkles as three-dimensional creases, whereas
others define them as short and irregular creases. They form when fabrics undergo
double curvature, which occurs when a flat material is bent in both of its planes.
Sufficient force must be applied that the change is permanent to some degree. Some
people use the terms ‘wrinkle’ and ‘crease’ interchangeably.
Wrinkles and creases are distinct to pleats, because pleats are introduced
intentionally and over regular intervals. They are usually sharp folds, often running
lengthways to give a decorative effect.
Crease marks are marks left in a fabric once the crease has been removed and are
usually caused by mechanical damage.
Crease resistance is the ability of a material to resist, or recover from, creasing.
Crease recovery is a specific measurement of crease resistance that determines the
crease recovery angle. It is therefore a quantitative method of analysis.
Why crease form on cotton (cellulosic fabric)?
Cotton (like most plants) is made of a substance called cellulose, which contains
hydrogen - an essential ingredient in water. When this material is woven into a piece
of apparel - like a shirt - the hydrogen particles are attracted to each other and form
a bond. This gives the shirt shape and helps it to maintain its form when it's worn,
sat upon or folded - unless you get wet.
If you sweat, spend time in a humid area, spill a liquid on yourself or wash your
shirt, it wrinkles. It does this becausethe hydrogen links in the cottonreact to water,
causing the fabric to bend out of shape and form wrinkles in the cloth.
So, now that you know how wrinkles are happen, how do you prevent them? Well,
obviously, it's difficult to prevent ourselves from sweating when it's hot and
sometimes we can't avoid humid environments - so the next best thing to do is treat
the fibers with something that's waterproof to prevent the hydrogen bonds from
breaking.
Todaythis is accomplished with non-toxic, chemical treatments, leaving your cotton
clothing looking crisp and sharp all day long. This type of apparel is especially
appealing to travellers, golfers - and those of us who dislike irons.

EXPERIMENTAL
MATERIALS AND METHODS:
Fabrics:
The fabrics were a 100% cotton poplin, a 100% cotton sateen of 129 g/m2, and a
polyester/cotton(65/35) blend broad weave of 143 g/m2. The poplin was used unless
otherwise specified. The fabrics were singed, desized, scoured, and mercerized on a
productionmachine. Various kinds of fabrics were also used for testing in the large-
scale production process.
Synthesis and Characterization of Acrylate Copolymers:
Acrylate copolymers were prepared by emulsion polymerization. The various Tg of
the copolymers, determined by differential scanning calorimetry, were - 54°C, -
22°C, and 26°C, respectively.
Number average molecular weight (M) of the copolymers was determined by gel
permeation chromatography. The calibration curve was constructed from the peaks
in the elution pattern of polymethyl methacrylate of known molecular weights. Most
copolymers applied to cotton fabrics were M = 105. One copolymer of lower
molecular weight, M = 1 0~, and Tg of - 54°C was also prepared and applied.
Chemical Treatments:
The fabrics were immersed in an emulsion solution containing acrylate copolymer,
DHDMEU, and zinc fluoroborate. Optimum concentration of catalyst was
determined by a screening study. A copolymer formulation containing 4,5-
dihydroxyethyleneurea (DHEU) and magnesium chloride hexahydrate with 2-
amino-2-methyl-1-propanol was also used for the experiment on the effect of pH on
dry creaserecovery angles (DCRA). Forcomparison, a conventional resin-treatment
was performed using 4,5-dihydroxy-1,3-dimethylol ethylene urea (DMDHEU) of
low formaldehyde type crosslinking agent. Magnesium chloride hexahydrate was
used as the catalyst of DMDHEU. The fabrics were padded to 70% wet pick-up,
dried for 3.5 min at I 20°C, and then cured for 3.5 min at 150°C.

Chemistry
The crosslinking agents that result in the permanent-press finish are often derivatives
of urea. Popular crosslinkers include DMDHEU (dimethylol
dihydroxyethyleneurea) and DMEU (dimethylol ethylene urea).
Test Methods
Physical tests of the fabrics were carried out at 65% RH and 20°C by standard test
procedures. DCRAand wet crease recovery angles (WCRA) were determined using
the same procedure as described in a previous report. Tear strength was measured
by ASTM D 1424-63 (Elmendorf) method. Wash-wear rating was determined by
AATCC 88B-1975 (IIIC). Shrinkage resistance was determined by AATCC 88B-
1975 (IIIC) with drying at 130°C for 30 s in a flat-bed press under pressure of 60
pounds/inch’. Flex-abrasion resistance tests were performed by JIS L 1004-1978 A
Stiffness of the fabrics was measured by Handle- O-Meter and presented as the sum
of values in warp and filling directions on both sides of fabrics.
Color Fastness
The tests of dryand wet crocking were performed by the AATCC 8-1969 procedure.
Results and Discussion
EFFECT OF COPOLYMERTg AND MOLECULAR WEIGH ON TENSILE
STRENGTHRETENTION
Relationships between the retention index of the tensile strength and DCRA values
after resin treatment are shown in Figure 3. As expected from the crease recovery
properties, the fabrics treated with the copolymer systems exhibit higher values for
the retention index of tensile strength than the fabrics treated without copolymer.

Straight lines with similar slopes are observed for the different systems employed.
At a given DCRA value, the tensile strength of the treated fabrics increases as the
Tg of the copolymer decreases. However, the strength retention is lowered as the
molecular weight of the copolymer decreases to about 104. Therefore, the film-
forming property of polymer is important in enhancing tensile strength retention.
Disadvantage:
 Yellowness
 Weight loose
 Dryness
 Reduction in tear strength
 Reduction in durability
FIGURE 4. Scanning electron micrograph of the
cotton fibers on the surface of the fabric treated with
the systemincluding 10% DHDMEU and 1.6%
copolymer having T. of -54°C and molecular weight
of n,, 105.
FIGURE 3. Effects off, and molecular weight of the
copolymer on the retention of tensile-strength.e
copolymer on
the retention of tensile-strength.

Results and Discussion:
EFFECT OF COPOLYMER-Tg AND MOLECULAR WEIGHT ON DCRA
The effects of Tg and molecular weight of the copolymers on DCRA at various
concentrations of DHDMEU. The DCRA values of the resin-treated fabrics are
remarkably increased by simultaneous treatment with copolymers and DHDMEU.
The Tg of the copolymer is an important factor controlling the value of DCRA. The
fabrics treated with the copolymer system with the lowest Tg examined show
particularly high DCRA values. When Tg of the copolymers is decreased, DCRA
values are greatly increased, and this tendency is more propounced with an increase
in the DHDMEU concentration. When the DCRA values obtained from the
simultaneous treatment are compared to those from treatment without the
copolymer, it is clear that the marked improvement of fabric property is attributable
to the concerted action of the copolymer and the crosslinking agent.

Formaldehyde free crease-resistant finishing of cotton fabric using
citric acid.
Materials and methods:
Materials and chemicals
Full bleached 100% plain weave cotton fabric (100%), having the following
structural characteristics, was used: 20s Ne count yarn end per inch; 54 Picks per
inch; and fabric mass per unit area with 150 g/m2 fabric was sourced fromBahir Dar
Textile Share Factory, Bahir Dar, Ethiopia. Bombyx mori silk cocoonwas obtained
in raw form Wereta Agriculture College, Bahir Dar, Ethiopia. Fibroin solution was
used as a DP finish. Ethanol (absolute GR for analysis) was obtained from M/s
Merck (Darmstadt, Germany). CA, calcium chloride, and hydrochloric acid are of
laboratory grade. Deionized water was used in all experiments.
Methods:
To optimize the process parameters, fabric samples (40 cm × 125 cm) were
impregnated with solution containing different concentrations ofCA (10, 20, 30, and
40 g/L), fibroin solution (2%, 4%, 6%, and 8%), and sodium dihydrogen phosphate
(NaH2PO4; 5%, 6%, 7%, and 8%) on a three-bowel padding mangle using 80% wet
pickup (2 dip 2 dip). The padded fabric samples after padding were dried at 100°C
for 5 min and then the curing process was carried out at 140°C, 150°C, 160°C, and
170°C for 2 min in each process in a laboratory curing unit (Ernst Benz, Model
KTF/M).
The cured fabric sample was treated with soap solution (sodium lauryl sulfate 2 g/L)
for 5 min in a laboratory jigger and finally rinsed for 10 min at room temperature
and then dried under ambient conditions.
The effects of concentration ofCA, fibroin solution, catalyst, and curing temperature
on the fabric properties were investigated separately. Forthe optimum conditioning
of ease care finishing crease recovery angle, tensile strength, tear strength and
whiteness has been tested.
Preparation of silk fibroin solution
Raw silk fibers were degummed thrice with 0.5% (w/w) NaHCO3 solution at boiling
temperature for 60 min and then washed with distilled water. Degummed silk was
dissolved in a ternary solvent system of calcium chloride, ethyl alcohol, and water

(1:2:8 in molar ratio) at 80°C for 6 h. After dialysis with Himedia tubular dialysis
membrane-50 in distilled water for 3 days, pure silk fibroin solution was filtered.
The aqueous silk fibroin solution was hydrolyzed in hydrochloric acid at 70°C for
150 min and then neutralized with sodium hydroxide.
Application methods of the finishing
The fabric was padded with a bath containing cross-linking agent (CA), fibroin
solution, acid liberating catalyst, sequestering agents, and wetting agent. Fabric was
dried at 100°C and cured at 140°C, 150°C, 160°C, and 170°C for 2 min followed by
washing to remove free formaldehyde and residual catalyst.
Measurement of crease recovery
The crease recovery of the fabrics was tested using the Shirley crease recovery tester
and the value reported in this instrument was CRA according to AATCC TM 66-
2017 method.
Measurement of tensile strength
Instron machine was used to analyse the tensile strength of the samples, which was
measured by the ravelled strip (20 cm × 5 cm) method. The tensile strength of fabric
was tested as per ASTM D-5035 method.
Measurement of tearing strength
The tearing strength of the fabric samples was determined by the Elmendorf tearing
tester in accordance with ASTM Test Method D 1424-96. A template was used to
cut fabric strips of 100 ± 2 mm length and 63 ± 0.15 mm width. The tearing strength
was then calculated by the following formula:
Tearing strength (g) = Scale reading × 64.
Warp-way and weft-way strips were tested for each sample, and 10 readings were
taken in each sample.
Measurement of abrasion
The abrasion of the fabrics was measured by the Martindale abrasion tester and the
weight loss of untreated and finished fabric as per ASTM D-4966 method was
measured. The grades of abrasion were obtained by comparison with the standard
specimens.

Whiteness index (WI) property
Whiteness of the bleached fabrics was determined with reflectance value using i5
Macbeth visible spectrophotometer. Whiteness values were measured at four
different places in the samples and their average was used for the analysis of results.
The WI of fabrics was analysed as per ASTM DE 313-67 standard.
Results and discussion
Effect of CA/fibroin concentration on crease recovery of the treated fabric
The concentration of cross-linking agent has significant effect on the dry crease
recovery angle (DCRA) of crease resistance finishing of treated fabric than that of
untreated fabric (bleached fabric).
When the concentration of CA varies as 10, 20, 30, and 40 g/L, the percentage in
DCRA of the treated fabric also increases. As shown in Figure 1(a), the percent
increase was recorded as 58.6%, 65.5%, 73.8%, and 84.8% for the CA concentration
of 10, 20, 30, and 40 g/L, respectively. Figure 1(b) shows the influence of CA with
fibroin solution and without fibroin solution effect on CRA. With the same
concentration of CA, the fibroin solution-treated fabric has more DCRA than that of
untreated fabric.
The results show that the CA-treated fabric showed more crease resistance angle
increase as the concentration of the cross-linking agent increased. Figure 1(a) shows
that as the concentration of CA increased, the percent in DCRA also increased
significantly.
Effect of catalyst concentration on crease recovery of the treated fabric
To investigate the effect of catalyst concentration on crease recovery of the treated
fabric, the concentration of catalyst varied from 5%, 6%, 7%, and 8%, keeping the
other variables constant.

Figure 1. (a) % DCRA increases as a function of citric acid concentration. (b)
Effect of CA concentration on crease recovery of the treated fabric.

Figure 2. DCRA increase as a function of catalyst concentration.
As shown in Figure 2, the DCRA of treated fabric increased as concentration of the
catalyst increased. However, the CRA of the fabric increased up to 6% as
concentration of catalyst increases. After this concentration, the increment of CRA
was not significant.
The percent increase in DCRA of the treated fabric as compared to untreated bleach
fabric was 58%, 74%, 79%, and 79% for the catalyst concentrations of 5%, 6%, 7%,
and 8%, respectively.
Conclusion:
Treatment with PCA is a viable and effective method to impart DP properties to
cottonfabrics. The effect ofthe finishing variables, CA, fibroin solution and catalyst
amounts, and curing temperature were investigated. The CA/fibroin treatments to
the cotton fabric significantly improve its CRA, tensile strength, tearing strength,
and abrasion resistance compared with DMDHEU-treated cottonfabric. The results
showed that CA/fibroin is a very effective cross-linking agent to the DP finishing of
cottonfabrics. Cottonfabrics treated with both CA and fibroin solution show higher
DCRA values than samples treated with CA alone, at the same curing temperature.

Figure 12. Results of tensile strength retention of cottonfabric treated with 30 g/L,
6% fibroin, 6% catalyst and cured at 150°C for 2 min.
It was also found that the addition of fibroin and catalyst to CA in the right
proportions leads to the almost complete retention of the mechanical properties
originally present in untreated cotton, which severely reduced with the traditional
treatment. The use of fibroin as additive with CA for the crease-resistant finishing
of cotton fabrics increased the crease resistance of cotton and avoided fabric
yellowing caused by CA as a finishing agent for cotton fabric.
The optimized finishing parameters were given up to 252°C of DCRA and were
obtained with 84%, 96%, 75 WI (93%) tensile strength retention, tearing strength
retention, and reserved WI, respectively. The optimum combination of the
processingparameters to obtain this result was 6% fibroin, 30 g/L ofCA, 6% sodium
dihydrogen phosphate, at a pH 5.5 finishing bath and a curing temperature of 150°C.

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