presentation on mercerization parameters

WELCOMEto

the Project presentation on

Determination of the effects of Mercerization parameters on moisture regain, brightness &

strength of cotton fabrics.

Acknowledgement

First of all, we would like to thank the almighty ALLAH for enabling us to complete the project work successfully.

We would like to express our thanks to our project supervising teacher A.S.M. Atiquzzaman, Assistant Professor & co-supervising teacher Mohammad Mahbubul Alam, Assistant Professor. A special thanks to our Department head, Professor Dr. Mustafizur rahman sir.

Finally we would like to thank all of our teachers of the Department of Textile Technology.

Introduction

In textile wet processing , mercerization is done for cotton goods either as pretreatment process for dyed materials or as finishing process for white goods. In this project work, mercerization was done as a finishing process for white cotton woven fabrics and observed its impact on brightness, moisture absorbency and strength. Here, some major mercerization parameters like temperature, alkali concentration and tension were varied, which play the vital role during mercerization. After mercerization, the brightness, strength and moisture absorbency of the samples were measured and the results were evaluated in context to the variables.

Objectives

To know the influences of mercerization parameters on mercerization effects.

To observe the different physical & chemical changes of cotton fabric after mercerization.

To determine the effect of tension, temperature and alkali conc. on moisture regain, strength, and brightness of cotton fabric.

To analyze the different results, compare them graphically & find out some relations among them.

THEORETICAL PART

Structure of cotton fibre

Chemical composition of cotton

Component Main location Relative amount (%)

Cellulose Secondary wall 86.8

Oils, waxes Cuticle 0.7

Pectin Primary wall 1.0

Carbohydrates Primary wall 0.5

Proteins Lumen 1.2

Salts Lumen 1.0

Water 6.8

Other 2.0

Important physical properties of cotton

Tensile strength : 2800-8400kg/cm2

Elongation at break : 5-10 % Moisture regain : 8.5% Luster : Natural luster Elastic Properties : Relatively inelastic, rigid fibre Specific gravity : 1.54

Mercerization

Mercerization is the process of subjecting a vegetable fiber to the action of a fairly concentrated solution of a strong base so as to produce great swelling with resultant changes in fine structure, dimensions, morphology and mechanical properties. Usually cotton goods are treated with 15-25% w/v caustic soda solution (55-65oTw) at a temperature of 15-25oC during mercerization.

Chemicals used in mercerization:•Sodium hydroxide•Mercerizing wetting agent

Major changes occur in mercerization

Lengthwise shrinkage and swelling axially Increase adsorption of dyestuffs and chemicals Breaks the hydrogen bonds and weak Vander Waals forces Increase the tensile strength Decrease the extension at break Increase luster and smoothness of fiber

Factors affecting mercerization

Caustic soda concentration Temperature Tension Time of treatment Washing condition Rate of drying Construction of yarn

EXPERIMENTAL PART

Machines & instruments

Wooden Band:

Tensile tester Oven Spectrophotometer

Fig: Circular Band Fig: Fabric attached with band

Raw materials

Fabric specification : Fiber type : Cotton Weave : Plain Fabric construction : 60×60/110×70 GSM : 75 Chemical specifications

Sodium hydroxide: Purity : 98 %( Lab standard) Physical form : solid flakes

Mercerizing oil: Name : Nanowet MRO Chemical composition : Sulphated alcohol

Mercerization

Sample preparation

Sample size (12 inch x 12 inch)

Mercerization liquor

NaOH : 13% /18% /25%

Mercerizing oil : 4 g/l

Water : 650ml

Time : 1 min

Temp : 10oC/ 17oC/ 27oC

Mercerization parameters

No Concentration Temperature Tension

1 13% 10oC With tension

17oC With tension

27oC With tension

Without tension


17oC With tension

27oC With tension

Without tension


17oC With tension

27oC With tension

Without tension

Mercerization parameters which we varied during our experiment are given below:

Testing procedure

The following tests were done:Determination of moisture regain %Determination of Brightness valuesMeasurement of Tensile strength

RESULT & DISCUSSION

Effects of NaOH conc. on moisture regain

Concentration of NaOH (%)

Moisture regain (%)

0* 6.66

13 7.02

18 7.46

25 8.47

*unmercerized

Dependence of moisture regain (%) on Conc. of NaOH

0 13 18 250123456789

6.667.02 7.46

8.47

conc. of NaOH(%)

mo

istu

re r

eg

ain

(%

)

Comment :From the above graph, we found that moisture regain increases with the increase of concentration of NaOH.

Effects of NaOH conc. on moisture regain

Effects of temperature on tensile strength

For 13% NaOH conc.

Temperature

Tensile strength (N)

Warp Weft

10oc 456.98 232.36

17oc 451.03 226.32

27oc 448.28 219.55


Dependence of tensile strength on temperature

10 17 27442

444

446

448

450

452

454

456

458

456.979999999999

451.03

448.28

temperature (oc)

ten

sile

str

eng

th(N

)

10 17 27210

215

220

225

230

235

232.36

226.32

219.55

temperature (oc)

ten

sile

str

eng

th(N

)

A) Warp B) Weft


For 18% NaOH conc.

TemperatureTensile strength (N)

Warp Weft

10oC 478.31 237.57

17oC 473.09 231.02

27oC 461.55 227.63


Dependence of tensile strength on temp. (for 18% NaOH conc.)

10 17 27440

445

450

455

460

465

470

475

480

485

478.31

473.09

461.55

Temperature(oc)

ten

sile

str

eng

th(N

)

10 17 27222

224

226

228

230

232

234

236

238

240

237.57

231.02

227.63

temperature (oC)

ten

sile

str

eng

th(N

)

A) Warp B) Weft


For 25% NaOH conc.

Temperature

Tensile strength (N)

Warp Weft

10oc 520.32 255.14

17oc 495.12 246.4

27oc 467.31 240.25

Dependence of tensile strength on temperature

10 17 27440

450

460

470

480

490

500

510

520

530

520.32

495.12

467.31

temperature (oC)

ten

sile

str

eng

th(N

)

10 17 27230

235

240

245

250

255

260

255.14

246.4

240.25

temperature (oC)

ten

sile

str

eng

th(N

)

Comment From the above graphs, we can say that the tensile strength decreases at both warp and weft direction with the increase of temperature within same NaOH concentration (13%/18%/25%).

A) Warp B) Weft


Effect of NaOH conc. on tensile strength

13 18 25430

450

470

490

510

530

456.979999999999

478.31

520.32

451.03

473.09

495.12

448.28

461.55

467.31

conc. of NaOH(%)

ten

sile

str

eng

th(N

)

13 18 25200

210

220

230

240

250

260

232.36

237.57

255.14

226.32

231.02

246.4

219.55

227.63

240.25

10

17

27

conc. of NaOH(%)

ten

sile

str

eng

th(N

)

CommentFrom the above graphs, we can say that the tensile strength increases at both warp and weft direction with the increase of concentration of NaOH within same temperature (10 oC/17oC /27oC)

A) Warp B) Weft

Effects of tension on tensile strength

For warp Conc. of NaOH (%) Tensile strength(N)

With tension Without tension

13 448.28 441.6

18 461.55 460.27

25 467.31 465.4

13 18 25420

430

440

450

460

470

480

490

500

448.28

461.55467.31

441.6

460.27465.4

with tension

without tension

conc. of NaOH(%)

ten

sile

str

en

gth

(N)

For weft

Effects of tension on tensile strength

Conc. of NaOH (%) Tensile strength(N)With tension Without tension

13 219.55 21518 227.63 221.2725 240.25 226.33

13 18 25200

210

220

230

240

250

260

219.55

227.63

240.25

215221.27

226.33with tension

without tension

conc. of NaOH(%)

ten

sile

str

eng

th(N

)

CommentFrom the above graphs, we found that mercerization with tension shows greater tensile strength, both warp & weft, than mercerization without tension .

Effects of temperature and NaOH conc. on brightness values

*The brightness value of unmercerized sample was 63.65

TemperatureBrightness values at different conc. of NaOH (%)

13% 18% 25%10oC 70.22 71.24 72.4617oC 68.85 70.21 71.3127oC 67.09 68.72 70.67

Dependence of brightness on temperature (for 13% concentration)

10 17 2765.5

66

66.5

67

67.5

68

68.5

69

69.5

70

70.570.22

68.85

67.09

Temperature (oC)

bri

gh

tnes

s

Effects of temperature and NaOH conc. on brightness values Dependence of brightness on temperature

10 17 2767

67.5

68

68.5

69

69.5

70

70.5

71

71.571.24

70.21

68.72

temperature (oC)

bri

gh

tnes

s

10 17 2769.5

70

70.5

71

71.5

72

72.5

73

72.46

71.31

70.67

temperature (oc)

bri

gh

tnes

s

A)For 18% conc. B)For 25% conc. Comment

From the above graphs, we found that the brightness value decreases with the increase of temperature within same NaOH concentration (13%/18%/25%).

Effects of NaOH conc. on brightness values

Dependence of Brightness on conc. of NaOH (%)

13 18 256566676869707172737475

70.22

71.2472.46

68.85

70.21

71.31

67.09

68.72

70.67

10

17

27

conc. of NaOH(%)

Bri

gh

tne

ss

Comment From the above graph, we can say that the brightness value increases with the increase of concentration of NaOH within same temperature (10 oC/17 oC/27 oC).

Effects of tension on brightness value

Conc. of NaOH (%) Brightness valueWith tension Without tension

13 67.09 65.6418 68.72 67.825 70.67 69.28

Dependence of brightness on concentration of NaOH (%)

13 18 256566676869707172737475

67.09

68.72

70.67

65.64

67.8

69.28

with tension

without tension

conc. of NaOH(%)

Bri

gh

tnes

s

CommentFrom the graph, we found that mercerization with tension shows greater brightness values than mercerization without tension.

Limitations

There are few limitations in this project. Such as:

There was no tensioning device to control the fabric tension precisely over the whole process.

We could not do enough tests due to lack of same construction fabric. Uniformity of the strength of the supplied fabric was not good. We found

strength variation in different parts of the fabric. We could not maintain standard atmospheric condition. We were not able to maintain the mercerizing temperature perfectly. Fabric properties & construction were not well known. We were not able to control the liquor pickup of fabric. We were not able to determine the oven dry weight accurately.

Suggestions

This project could have been better if we had a tensioning device & moisture testing oven. More number of tests would give us more accurate results. Fabric of known properties like construction, strength, count and TPI for both warp and weft may help for better evaluation of the results. Standard atmospheric condition & liquor pick up control must be ensured for accurate result. Similar project work can be done for further investigation on the effects of mercerization parameters on dye absorbency and the brightness after dyeing.

Conclusion

In this project, we have learned about mercerization & its effect. We found effect of mercerization parameters variation over its performance. We have also learned about important cotton properties & there change after mercerization. We have learned about a project presentation, writing sequence, team work. This will enrich our analytical ability. All these will be very helpful for our knowledge; will increase our experience, skill & above all our future industrial job life.

THANK YOU

Alkali concentration(Tw) Lustre value

0 2620 2825 4445 7052 76

Alkali concentration , 0Tw

Tensile strength,gm

25 247

35 287

45 288

52 302

Temperature (oC) Lustre

7.5 76

17.0 71

25.0 57

35.0 40

Temperature,oC Tensile strength , gm

7 302

17 276

30 253

presentation on mercerization parameters

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