International Journal of Engineering & Technology IJET-IJENS Vol: 12 No: 01 5

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1 International Journal of Engineering & Technology IJET-IJENS Vol: 12 No: 01 5 Advantages of Prewashed 100 % cotton knit fabric over Scoured Bleached fabric in deep color Reactive dyeing process. Asma Begum Ahsanullah University of Science and Engineering Department of Textile Engineering Love Road, Tejgaon Industrial Area Dhaka Abstract : Natural fibre like cotton contains oils, fats, waxes, minerals, leafy matter and motes as impurities and natural color, all are removed by scouring and bleaching process from cotton knit fabric which reduces fabric qualities and other properties. So it is possible to achieve similar or better results from deep color Reactive dyeing of prewashed fabric to dyeing of Scoured bleached fabric. Prewash is done with Oleic acid based wetting agent which is biodegradable, low foaming, lubricant with leveling, dispersing and emulsifying properties. Examinations have shown higher values of color fastness to wash, similar rubbing fastness, higher color strength as well as reduction in weight loss, better strength and softness of fabric can be achieved from prewashed dyed fabric. Key Words: Prewash, Burst strength, Bending length, Wash fastness to color, Rubbing. INTRODUCTION Cotton fibres mainly consist of cellulose (94%), small amounts of other compounds like Protein (1.3%0,Ash(1.2%),Wax (0.6%0, Sugar (0.3%), Pigments (Traces) and others (2.6%).Cotton fabrics are affected by strong acid and boiled in a dilute solution of an alkali like caustic soda, in the presence of air, the cotton turns yellow and lose strength slightly. Scouring process removes water insoluble materials such as oils, fats, and waxes from the cotton fabric. Oils and Fats are removed by Saponification with hot Sodium Hydroxide solution. Unsaponifiable materials such as waxes and dirt are removed by Emulsification. Depending on the amount of impurities and the reaction and wash conditions, the loss in weight of the raw cotton material due to boil off can reach up to seven percent or even higher in case of high impurity cotton. Cotton, like all natural fibres, has some natural coloring matter, which confers a yellowish brown color to the fibre. The purpose of bleaching is to remove this coloring material and to confer a white appearance to the fibre. Hydrogen peroxide is the most useable bleaching agent. It is a

2 International Journal of Engineering & Technology IJET-IJENS Vol: 12 No: 01 6 corrosive, oxidizing agent which may cause combustion when allowed to dry out on oxidizable organic matter. Decomposition is accelerated by metal contamination and accompanied by the liberation of heat and oxygen, which will support combustion and explosions in confined spaces. The material is an irritant to the skin and mucous membrance and dangerous to the eyes. Hydrogen peroxide is a weak acid and ionizes in water to form a hydrogen ion and a perhydroxyl ion. The perhydroxyl ion is the active bleaching agent. Hydrogen peroxide can also decompose.this reaction is catalyzed by metal ions. This reaction is not desired in bleaching because it is an ineffective use of hydrogen peroxide and causes fibre damage. At P H 10.2 to 10.7 is optimum for controlled bleaching. Sodium hydroxide is used to obtain the proper P H. There are risks to get the below problems in Scouring and bleaching process: 1. Harsh handle 2. Yellowing the goods 3. Fibre degradation or reduction in fibre strength 4. Pinholes, broken yarns, tears 5. Resist spots 6. Loss in voluminous character of the material 7. Decrease in the elasticity of the materials 8. Low sewability of the materials 9. Weight loss Above problems can overcome using oleic acid based product (Humectol C, Clariant) for cotton washing instead of scouring bleaching. Oleic acid is a mono unsaturated, straight chain C18 fatty acid (double bond in between C9 and C10). It occurs in almost all natural fats. Most oleic acid is obtained from animal tallow or vegetable oils. It is a yellow to red oily liquid with lard like odour and darkens on exposure to air. It is immiscible with water but miscible with alcohol, ether and other organic solvents. It is a solvent for oils, fatty acids and oil soluble compounds. The fatty acid is obtained from fats by hydrolysis followed by steam distillation and separation by crystallization or solvent extraction. Filtration from the press cake gives the oleic acid triethanolamine soap, which is an emulsifier for mineral oil. After esterifying and sulphonating, wetting agents and leveling agents can be made from oleic acid. Humectol C liquid high concentrate is a yellow brown liquid, preparation based on oleic acid, anionic, dilutable with water in any proportion which is bio-degradable, low foaming wetting agent and lubricant with leveling, dispersing and emulsifying properties.

3 International Journal of Engineering & Technology IJET-IJENS Vol: 12 No: 01 7 If raw cotton materials are washed with only Oleic acid based product can be get below advantages: 1. Soft fabric 2. Minimum strength loss 3. Minimum weight loss 4. Less amount of dyes used 5. Less chemicals used 6. Less softener used 7. Short time 8. Easy process 9. Increase production 10. Better fastness SAMPLE PREPARATION For this experiment 100 % cotton, 175 GSM, Single Jersey knit fabrics were pretreated according to Prewashing recipe and Scouring bleaching recipe and after that Black, Brown and Red shades were dyed on both prewashed fabrics and Scoured bleached fabrics with reactive dyes. After pretreated, weight loss and CIE whiteness were studied. After dyeing Burst strength, Bending length, Wash fastness to color, Rubbing fastness tests had done. EXPERIMENTAL PART Throughout this study, the following materials were used. Fabrics : 100 % cotton knit single jersey, 170 GSM Chemicals & Dyes : Oleic acid based wetting agent (Humectol C liquid high conc,clariant), Wetting and detergent (Imerol PCLF, Clariant), Sequestering agent Sirrix 2UD, Clariant ), Stabilizer ( Stabilizer SOF, Clariant ), Sodium Hydroxide, Hydrogen Peroxide 50 %, Acetic acid, Peroxide killer ( Bactisol ARL, Clariant ), Glauber s salt, Soda ash, Washing off agent ( Ladipur SP, Clariant ), Reactive dyes ( Drimaren yellow CL 2R, Drimaren Red CL 5B, Drimaren Blue HF RL, Drimaren Black CL S, Clariant ). Prewashing recipe: Grey cotton was washed with 0.50 gm/l Humectol C liquid high concentration at 98 ᵒ c for 40 min and washed and Black, brown, red shades were dyed on this fabric.

4 International Journal of Engineering & Technology IJET-IJENS Vol: 12 No: 01 8 Scouring and bleaching recipe: Treated the fabric with 1.00 g/l Imerol PCLF, 1.00 g/l Sirrix 2UD, 0.80 g/l Stabilizer SOF, 2.50 g/l Sodium Hydroxide, 2.50 g/l Hydrogen peroxide 50 % at 98 ᵒ c for 60 min, after hot wash, neutral the fabric and treated with 0.20 g/l Bactosol ARL at 40 ᵒ c for 10 min, wash. Dyeing: Both type of pretreated fabrics are dyed the below recipes. Black colour recipe : 5 % Drimaren Black CL S, 80 g/l Glauber s salt, 20 g/l Soda ash, Isothermal 60 ᵒ c method Brown color recipe : 2.00 % Drimaren Yellow CL-2R, 0.80 % Drimaren Red CL 5B, 0.50 % Drimaren Blue HF RL, 80 g/l Glauber s salt, 20 g/l Soda ash, Isothermal 60ᵒ c method. Red color recipe : 0.60 g/l Drimaren Yellow CL- 2R, 2.00 % Drimaren Red CL 5B, 0.20 g/l Drimaren Blue HF RL, 80 g/l Glauber s salt, 20 g/l Soda ash, Isothermal 60 ᵒ c. After dyeing cold wash, neutral and soaping had done and normal dried the fabrics. DATA ANALYSIS Weight loss: Weight loss of prewashed fabric is 4 % and Scoured bleached fabric is 6 %. CIE Whiteness Index, D65, 10 Deg : Prewashed fabric is 9.01 and Scoured and bleached is Burst Strength Test: Table 1 Prewashed dyed fabric Shade Name Time in second Burst strength kpa Average kpa Black Brown Red Table 2 Scoured bleached dyed fabric Shade Name Time in second Burst strength kpa Average kpa Black Brown Red From above two tables it is clearly studied that prewashed fabrics are stronger than scoured bleached fabrics.

5 International Journal of Engineering & Technology IJET-IJENS Vol: 12 No: 01 9 Bending Test: (BS3356 BS 9073 Part 7 and ASTM D 1388 ) Shirley Stiffness Tester m/c Bending length is a property of a fabric related to stiffness. It is the length of the fabric that will bend on its own weight to a definite extend. A high value of bending length corresponds to a stiff fabric and vice versa. Table 3 Prewashed dyed fabrics, wales direction Shade Name Ends Bending length in cm Face UP Face Down Average In cm Black 1st nd Brown 1st nd Red 1st nd Table 4 Prewashed dyed fabrics, courses direction Shade Name Ends Bending length in cm Face UP Face Down Average In cm Black 1st nd Brown 1st nd Red 1st st

6 International Journal of Engineering & Technology IJET-IJENS Vol: 12 No: Table 5 Scoured bleached fabrics, wales direction Shade Name Ends Bending length in cm Face UP Face Down Average In cm Black 1st nd Brown 1st nd Red 1st nd Table 6 Scoured bleached fabrics, courses direction Shade Name Ends Bending length in cm Face UP Face Down Average In cm Black 1st nd Brown 1st nd Red 1st nd From above 3, 4, 5 and 6 tables we studied that prewashed fabrics are softer than scoured bleached fabrics due to bending lengths are less in both directions of prewashed fabrics than scoured bleached fabrics. Table 7 Wash fastness to color (ISO105CO6C2S Method) Prewashed dyed fabric Shade Name Shade Change Staining on Multi fibre N CT CO PA PES PAC WO Black Brown Red

7 International Journal of Engineering & Technology IJET-IJENS Vol: 12 No: Table 8 Wash fastness to color test: (ISO105CO6C2S) Scoured bleached dyed fabrics Shade Name Shade Change Staining on multi fibre N CT CO PA PES PAC WO Black Brown Red Table 9 Rubbing Fastness test: (ISO / AATCC ), Grey scale to staining Prewashed dyed fabrics Shade name Rubbing GS Value GS Rating Black Dry Wet Brown Dry Wet Red Dry Wet Table 10 Rubbing Fastness test: (ISO / AATCC ), Grey scale to staining Scoured bleached dyed fabrics Shade Name Rubbing GS Value GS Rating Black Dry Wet Brown Dry Wet Red Dry Wet

8 International Journal of Engineering & Technology IJET-IJENS Vol: 12 No: From tables 7, 8, 9 & 10 we can say that dyeing with reactive dyes on Prewashed & Scoured bleached fabrics completed properly that means fixation of reactive dyes on both fabrics are done fully. Table 11 Color Strength data: (Spectro photometric) Prewashed Standard Scoured bleached Batch Strength % Standard Strength % Batch CMCDE DL Da Db Dc MI Black Black Brown Brown Red Red From above table it is observed that scoured bleached batch fabrics are lighter than prewashed standard fabrics. RESULTS Figure 01 Burst Strength Black Brown Red Prewashed kpa Sc.-bleached kpa

9 International Journal of Engineering & Technology IJET-IJENS Vol: 12 No: In this figure, it is clearly observed that prewashed fabrics are stronger than scoured bleached fabrics. Figure 02 Bending Length, in cm Black Brown Red In this figure it is clearly seen that prewashed fabrics are softer to scoured bleached fabrics. Figure 03 Wash fastness to color (ISO105CO6C2S Method) Prewashed dyed fabric Black Brown Red N CT CO PA PES PAC WO

10 International Journal of Engineering & Technology IJET-IJENS Vol: 12 No: Figure 04 Wash fastness to color( ISO105CO6C2S Method ) Scoured bleached dyed fabric Black Brown Red N CT CO PA PES PAC WO From Figure 3 & 5 it is clearly understood that both fabrics are dyed properly with reactive dyes for deep colors. Figure 05 Color Strength Standard, Prewash Batch, Sc.- bleached 75 Black Brown Red

11 International Journal of Engineering & Technology IJET-IJENS Vol: 12 No: In this column chart, it is clearly studied that prewashed fabrics need less dye-stuffs compared to scoured bleached fabrics to match any shade. CONCLUSION In this study, grey cottons were prewashed with oleic acid based product and same time same fabrics were scoured and bleached with related recipe and after treated Burst strength were studied, it was observed that the strength of prewashed fabrics are higher than scoured bleached fabrics. In this experiment, bending length, wash fastness to color, rubbing fastness and color strength were observed and it was found that wash fastness to color and rubbing fastness data are similar, that means both fabrics were dyed properly. In this study also it was found that color strength values of prewashed fabrics are higher than scoured and bleached fabrics, it means that prewashed fabrics need less dye stuffs to match any shade.there are further scope to dye many different shades with different percentages on prewashed fabrics. In bulk production, deep color dyeing required more time than light color dyeing. Prewashed fabrics required less time to dye deep color compared to scoured bleached fabrics. So easily it is possible to deliver more productions with prewashed fabrics. In case of prewashed fabrics required less softener in finishing stage due to they are already soft. In the other hand, scoured bleached fabrics required high amount of softener due to they are stiff. So it is suggested that same experiment can be done for medium shades. REFERENCES: [1] Dr. V. A. Shenai, Technology of Textile Processing, Chemistry of organic textile chemicals. P [2] Dr. Charles Tomasino, Chemistry & Technology of Fabric Preparation & Finishing. [3] Dr. V. A. Shenai, Technology of Textile Processing, volume III, Technology of Bleaching and Mercerizing P.82, p [4] Dr. V.A. Shenai, Technology of Textile Processing, volume I, Textile Fibres P [5] Textile Progress Published by Taylor & Francies,2006, volume 35 no.4, Subcription No p [6] Dr. V. A. Shenai, Technology of Textile Processing, Volume II, Chemistry of Dyes and Principles of Dyeing. P [7] J.E.Booth,B.Sc.F.T.L, Principles of Textile Testing. p [8] B P Saville [8] Physical testing of Textiles. P ,p [9] Clariant literature ( Dyes & Chemicals ).

Dyeing of Cotton Fabric with Basic Dye in Conventional Method and Pretreated with Cationic Polyacrylamide

SEU Journal of Science and Engineering, Vol. 10, No. 2, December 2016 ISSN: 1999-1630 Dyeing of Cotton Fabric with Basic Dye in Conventional Method and Pretreated with Cationic Polyacrylamide Syed Atiqur