Assoc. Prof. S.Müge YÜKSELOĞLU, Ph.D. 6th INTERNATIONAL TEXTILE, CLOTHING & DESIGN CONFERENCE - Magic World of Textiles October 7th - 10th 2012, Dubrovnik, CROATIA THE USE OF DOE METHOD IN ASSESMENT OF MECHANICAL PROPERTIES OF WOOL FABRICS DYED BY ULTRASONIC ENERGY Assoc. Prof. S.Müge YÜKSELOĞLU, Ph.D. Marmara University , Faculty of Technology, Department of Textile Engineering Göztepe-34722, Istanbul ,TÜRKİYE email: myukseloglu@marmara.edu.tr

6th INTERNATIONAL TEXTILE, CLOTHING & DESIGN CONFERENCE - Magic World of Textiles October 7th - 10th 2012, Dubrovnik, CROATIA Contents 1. What is ultrasonic energy and why do we use it in textiles? 2. What is Factorial Experiment Design? 3. Interpretation of Factorial Experiment Design 4. Experimental Work 4.1 Materials and Method 4.2 Dyeing Process 4.3 Mechanical Tests and Colour Measurement Results DOE Assessment on the Tensile Properties of the Fabrics Conclusion

Woven, non-woven, knitted materials Spun and filament yarns 6th INTERNATIONAL TEXTILE, CLOTHING & DESIGN CONFERENCE - Magic World of Textiles October 7th - 10th 2012, Dubrovnik, CROATIA 1. What is ultrasonic energy and why do we use it in textiles? Textile materials Process Woven, non-woven, knitted materials Spun and filament yarns Loose fibres Machine

6th INTERNATIONAL TEXTILE, CLOTHING & DESIGN CONFERENCE - Magic World of Textiles October 7th - 10th 2012, Dubrovnik, CROATIA The ultrasonics era erose in 1917 with invention of the quartz sandwich transducer for underwater sound transmission in submarine detection, by Prof. Paul Langevin . Chemical and biological effects of ultrasonic energy were reported by Alfred Lee Loomis in 1927. Ultrasound is a cyclic sound pressure wave which spans the frequencies of roughly 18 kHz-10 MHz beyond human hearing. Three ranges of frequencies are reported for three distinct uses of ultrasound: low frequency or conventional power ultrasound (20-100 kHz), medium frequency ultrasound (300-1000 kHz) and diagnostic or high frequency ultrasound (2-10 MHz). Dolphins can hear (160kHz) ultrasound and use ultrasonic sounds in their navigational system to orient and capture prey. Implementing ultrasonic energy to textiles has commenced since the 1990’s. In these studies, ultrasonic energy was generally applied to textile dyeing and its finishing processes. Cotton materials can be bleached and stains on the surgical gowns can be easily removed with the use of ultrasonic energy. The fabrics treated with ultrasonic have shown less tenacity loss than the conventional methods.

6th INTERNATIONAL TEXTILE, CLOTHING & DESIGN CONFERENCE - Magic World of Textiles October 7th - 10th 2012, Dubrovnik, CROATIA We use it because : Ultrasonic energy allows for process acceleration and attainment of same or better results than existing techniques under less extreme conditions, i.e., lower temperature and lower chemical concentrations. For this reason, textile wet processes assisted by ultrasonic energy are of high interest for the textile industry. From this point of view, 100 % wool fabrics were studied with the use of ultrasonic energy and their mechanical properties were reported here.

6th INTERNATIONAL TEXTILE, CLOTHING & DESIGN CONFERENCE - Magic World of Textiles October 7th - 10th 2012, Dubrovnik, CROATIA 2. What is Factorial Experiment Design? The selection of an experiment design is essential during the planning of any research. Since the analysis of the experimental work is based on the use of one of the designs, it is therefore necessary to turn attention to the factorial designs before looking at any of the results and their meaning/significance. There are many types of factorial design, of which three cover most of the applications that are likely to be met.

6th INTERNATIONAL TEXTILE, CLOTHING & DESIGN CONFERENCE - Magic World of Textiles October 7th - 10th 2012, Dubrovnik, CROATIA These three designs are:- Full factorial designs which enable the main effects and all the interactions between variables to be accurately measured. They are very useful in some applications but with a large number of variables they require a large number of experiments to study the effects of the sample(s). Fractional or screening designs are used where the number of variables is as many as 15. These designs establish which variables are important and which are not. Some of the interactions are sacrificed and hence only a fraction of the design is used. The number of experiments is less for these types of designs. Central composite designs are used for the optimisation of products, processes and formulations. They are also useful when attempting to meet complex specifications.

6th INTERNATIONAL TEXTILE, CLOTHING & DESIGN CONFERENCE - Magic World of Textiles October 7th - 10th 2012, Dubrovnik, CROATIA 3. Interpretation of Factorial Experiment Design The most useful function of factorial experiment designs is their ability to detect interactions between variables. A Factor is any feature of the experimental conditions which is of interest to the experimenter. These may be quantitative or qualitative. The value of the factor is called the Level. The overall object and the first advantage of a factorial experiment design may be to get a general picture of how the response variable, which is an unknown function (y) of several variables (x1, ..., xn), is affected by the changes in different factors or in the over-all combinations of the factor levels.

6th INTERNATIONAL TEXTILE, CLOTHING & DESIGN CONFERENCE - Magic World of Textiles October 7th - 10th 2012, Dubrovnik, CROATIA The second major advantage of these designs is that even if no interactions is present, the results from a complete design make it possible to estimate the effects of the individual factors, called the Main Effects. In the case of one or two controlled variables, it is easier to think of the function in geometrical terms; with just one variable this relationship can be represented between y and x, by a curve with two or more variables, x1, x2, ..., xk, ....xn , the relation between y and x1 and x2 (or xk and xn ) can be represented by a surface whose height is equal to the response variable. These values of the response variable are called Response Surface and are often represented by a Contour Diagram. On each contour the value of the response variable is constant.

Table 1: Wool yarn properties 6th INTERNATIONAL TEXTILE, CLOTHING & DESIGN CONFERENCE - Magic World of Textiles October 7th - 10th 2012, Dubrovnik, CROATIA 4. Experimental Work 4.1. Materials and Method Wool woven fabrics made of 2/2 Z twill and weights of 158.6 g/m2 and 243.3 g/m2 , with different warp and weft densities of sirospun yarns were used in the experimental work. Table 1: Wool yarn properties Yarn type Sirospun Yarn linear density (Tex) 22X2 21 29X2 Twist (T/m) 950 650 750

Table 2: Wool woven fabric properties 6th INTERNATIONAL TEXTILE, CLOTHING & DESIGN CONFERENCE - Magic World of Textiles October 7th - 10th 2012, Dubrovnik, CROATIA Table 2: Wool woven fabric properties Fabric parameters A B Structure 2/2 Z twill Weight of fabric (g/m2) 158.6 243.3 Weft density (thread/cm) 40 32 Warp density (thread/cm) 30

6th INTERNATIONAL TEXTILE, CLOTHING & DESIGN CONFERENCE - Magic World of Textiles October 7th - 10th 2012, Dubrovnik, CROATIA Process Spinning Weaving Scouring Drying Dyeing 1g/L of nonionic scouring agent at 60:1 and at 50°C for 20 min. Room temperature Mill conditions Mill conditions BRANSON ultrasonic probe at 20 kHz

6th INTERNATIONAL TEXTILE, CLOTHING & DESIGN CONFERENCE - Magic World of Textiles October 7th - 10th 2012, Dubrovnik, CROATIA Measurement and Tests Reflectance Spectrophotometer Mechanical and Abrasion Tests Datacolor SF 600plus, D65/100 illuminant with specular component included Instron 4411 Strength Tester, clamping lenght 200 mm, testing speed 100mm/min Nu-Martindale Abrasion Tester

6th INTERNATIONAL TEXTILE, CLOTHING & DESIGN CONFERENCE - Magic World of Textiles October 7th - 10th 2012, Dubrovnik, CROATIA Table 3: Chemicals used in the dyeing method Chemicals Amount Dorolan Black MSRL (78% acidic dye concentration) 4.9 % (colour strength) Doregal PAWO (levelling agent) 0.5 % Glaubers’s salt (anhydrous) 5 % CH3COOH - CH3COONa (buffer solution) 0.5–0.15 ml Tanaterge LFN (wetting agent) 1g/L

6th INTERNATIONAL TEXTILE, CLOTHING & DESIGN CONFERENCE - Magic World of Textiles October 7th - 10th 2012, Dubrovnik, CROATIA 4.2 Dyeing Process Ultrasonic energy, was applied for wool fabrics with the BRANSON ultrasonic probe at 20 kHz. The dyeing recipes are given in Figure 1a and 1b. In this dyeing process, the woven fabric samples weighed of 3 g and the liquor ratio is 40:1. The dyeing process started at 40°C. After 10 minutes the dye is added and the temperature was maintained for 10 minutes and then raised to 80-90°C in 20 minutes and maintained dyeing 40-50 minutes to allow a good penetration of the dyes and level dyeing. Later the dye bath cooled to 40°C at a rate of 5°C/minute. After completion, the samples were taken out of the dyeing tubes and post-treated. The post-treatment of the dyed samples were made at a liquor ratio of 100:1. The samples were rinsed with cold water for 10 minutes. After rinsing the samples were left to dry under laboratory conditions. The colour co-ordinates of ultrasonic dyeing techniques of the samples were measured on the reflectance spectrophotometer (Datacolor SF 600plus) coupled to a PC under D65/100 illuminant with specular component included.

X3 Wool fabric weight (g/m2) 6th INTERNATIONAL TEXTILE, CLOTHING & DESIGN CONFERENCE - Magic World of Textiles October 7th - 10th 2012, Dubrovnik, CROATIA Figure 1: Dyeing diagrams Table 4: Parameters of the dyeing process X1 Temperature (oC) X2 Time (min) X3 Wool fabric weight (g/m2) Level 1 80 158.6 Level 2 90 243.3

6th INTERNATIONAL TEXTILE, CLOTHING & DESIGN CONFERENCE - Magic World of Textiles October 7th - 10th 2012, Dubrovnik, CROATIA 4.3 Mechanical Tests and Colour Measurement Tensile strength and elongation of the fabrics were determined on the Instron 4411 Strength Tester under the standard atmosphere conditions. Clamping length was 200 mm and testing speed was chosen 100 mm/min. The abrasion tests were also carried out under the standard atmosphere conditions on the Nu-Martindale Abrasion Tester; the ultrasonically dyed wool fabrics were abraded at the cycles of 2500, 5000, 7500 and 10000.

Dyeing Condition of Ultrasonic Energy 6th INTERNATIONAL TEXTILE, CLOTHING & DESIGN CONFERENCE - Magic World of Textiles October 7th - 10th 2012, Dubrovnik, CROATIA Results Table 5: Dyeing conditions and the CIELab values of acidic dyed wool fabrics Fabric Dyeing Condition of Ultrasonic Energy L* a* b* C * h X Y Z x y ΔE* A 80oC,80min 17.64 1.28 -2.13 2.49 300.94 2.37 2.44 2.92 0.30 0.31 0.887 80oC,90min 14.76 1.06 -1.44 1.79 306.37 1.81 1.86 2.17 0.631 90oC,80min 14.19 0.82 -0.73 1.10 318.63 1.70 1.76 1.97 0.828 90oC,90min 14.25 0.83 -0.99 1.29 310.18 1.96 0.32 0.583 B 18.10 1.27 -2.35 2.67 298.47 2.47 2.54 3.07 4.446 15.80 1.24 -2.06 2.40 301.12 2.01 2.06 3.748 14.20 -1.88 300.31 1.72 1.77 2.11 0.692 12.98 0.96 -1.47 303.21 1.51 1.56 1.82 0.967

6th INTERNATIONAL TEXTILE, CLOTHING & DESIGN CONFERENCE - Magic World of Textiles October 7th - 10th 2012, Dubrovnik, CROATIA The more accepted ΔE* values (ΔE* < 1) were obtained for the lighter fabric (Fabric A) in all the dyeing process where dyeing conditions chosen. However, the heaviest fabric B has only shown a good ΔE* values at both dyeing durations (80 min and 90 min) at the temperature of 90 oC (see Table 5). It can be said that effects of dyeing temperature and fabric type are much more important than the dyeing time of wool fabrics when dyed with the use of ultrasonic energy. The lower the ΔE* value is the best and therefore it can be stated that for the Fabric A the ideal dyeing process is 90 oC and 90 min and on the other hand for the Fabric B the best dyeing condition with the ultrasonic probe is 90 oC and 80 min.

6th INTERNATIONAL TEXTILE, CLOTHING & DESIGN CONFERENCE - Magic World of Textiles October 7th - 10th 2012, Dubrovnik, CROATIA Table 6: Breaking strength and elongation of the dyed wool fabrics Fabric Dyeing Condition of Ultrasonic Energy Breaking Strength (Warp direction) (kN) (Weft direction) (kN) Elongation (Warp direction) (%) Elongation (Weft direction) Un-dyed fabric - 0.276 0.181 27.81 26.03 80oC,80min 0.232 0.238 29.41 28.43 A 80oC,90min 0.262 0.227 39.79 19.76 90oC,80min 0.243 0.240 35.94 30.81 90oC,90min 0.253 0.256 34.06 20.86 0.548 42.86 38.66 0.605 0.284 50.04 35.75 B 0.617 0.298 53.13 34.21 0.637 0.306 55.97 40.51 0.500 0.295 67.38 35.64

6th INTERNATIONAL TEXTILE, CLOTHING & DESIGN CONFERENCE - Magic World of Textiles October 7th - 10th 2012, Dubrovnik, CROATIA Table 7: Fabric weights (g) after abrasion Fabric Dyeing Condition Rubs 2500 5000 7500 10000 A Un-dyed fabric weight 0.218 80oC, 80min 0.214 0.209 0.210 0.203 80oC,90min 0.211 0.215 90oC,80min 0.213 90oC,90min 0.219 0.217 0.212 B 0.345 80oC,80min 0.343 0.342 0.341 0.337 0.336 0.339 0.338 0.360 0.361 0.356 0.358 0.353 In general, it was observed that dyed wool fabrics have not shown a significant weight loss after the abrasion tests. However it was interestingly noticed that the heavy fabric (B coded) has slightly gained in weight when was abraded after dyeing carried out at 90 oC in both dyeing times.

6th INTERNATIONAL TEXTILE, CLOTHING & DESIGN CONFERENCE - Magic World of Textiles October 7th - 10th 2012, Dubrovnik, CROATIA 6. DOE Assessment on the Tensile Properties of the Fabrics Total of 8 wool fabrics were dyed with the use of ultrasonic energy at 2 different temperatures and 2 different times, and later their breaking strength and elongation in warp direction were analysed by using MINITAB statistical software programme. The analysis of variance is given below in Table 8.

6th INTERNATIONAL TEXTILE, CLOTHING & DESIGN CONFERENCE - Magic World of Textiles October 7th - 10th 2012, Dubrovnik, CROATIA Table 8: ANOVA analysis for breaking strength and elongation Source DF SS MS F P Breaking strength in warp direction Temperature (oC) 1 9,25 0,35 0,584 Time 9,37 0,36 0,582 Fabric weight (g/m2) 2436,02 93,04 0,001 Error 4 104,73 26,18 Total 7 2559,37 Elongation 55,02 2,07 0,224 Time (min) 66,13 2,49 0,190 953,10 35,85 0,004 106,33 26,58 1180,57 It could be seen that the most important parameters affecting the fabric's breaking strength and elongation in warp direction is fabric weight. The p values corresponding to the F values show that the F values for these two parameters are significant. The R2 for breaking strength and elongation are 96% and 91% respectively.

6th INTERNATIONAL TEXTILE, CLOTHING & DESIGN CONFERENCE - Magic World of Textiles October 7th - 10th 2012, Dubrovnik, CROATIA (b) Figure 2: Main effects plot- Data means for breaking strength and elongation in warp direction It can be said that as the fabric weight increases the breaking strength and elongation of the fabric increases as well. With the increase in both dyeing temperature and time, a slight increase on the elongation can be seen in main effects plot. However, temperature and time has no effect on the breaking strength of the dyed wool fabrics.

6th INTERNATIONAL TEXTILE, CLOTHING & DESIGN CONFERENCE - Magic World of Textiles October 7th - 10th 2012, Dubrovnik, CROATIA (a) (b) Figure 3: Interaction plot between variables - Data means for breaking strength and elongation in warp direction The interactions between the variables of breaking strength and elongation are similar to each other with a little change. There was no distinct correlation between temperature and fabric weight in both breaking strength and elongation. Similar tendency has occurred between time and fabric weight in both breaking strength and elongation. But there is a strong correlation between temperature and time in breaking strength of the wool fabrics. It was also observed that as the fabric gets heavier breaking strength increases and the lower temperature and lower time is slightly gives better breaking strength than the higher parameters. However, the higher temperature and higher times are presented better elongation values on the heaviest wool fabrics.

Figure 4: Contour plots for the wool fabric weight of 243,3 g/m2 6th INTERNATIONAL TEXTILE, CLOTHING & DESIGN CONFERENCE - Magic World of Textiles October 7th - 10th 2012, Dubrovnik, CROATIA Figure 4: Contour plots for the wool fabric weight of 243,3 g/m2

6th INTERNATIONAL TEXTILE, CLOTHING & DESIGN CONFERENCE - Magic World of Textiles October 7th - 10th 2012, Dubrovnik, CROATIA 7. Conclusion 100% Wool fabrics were successfully dyed with reducing time and temperature by using of ultrasonic energy. It can be concluded that the best condition for dyeing wool woven fabrics are 90 oC and 80-90 min depending on the fabric weight 159 and 243 g/m2. The dyed fabrics were tested for breaking strength and elongation properties in both warp and weft directions, however in this study DOE technique was only applied to the warp direction. From the design, it was seen that fabric weights have a significant effect on the tensile strength in warp direction rather than the time and temperature. It could be also said that time-temperature interaction has an effect on the breaking strength of the dyed wool fabrics.

6th INTERNATIONAL TEXTILE, CLOTHING & DESIGN CONFERENCE - Magic World of Textiles October 7th - 10th 2012, Dubrovnik, CROATIA Thank you . Assoc.Prof. S. Müge YÜKSELOĞLU, Ph.D. Marmara University , Faculty of Technology, Department of Textile Engineering Göztepe-34722, Istanbul ,TÜRKİYE Phone: +(90) (216) 336 57 70 / ext:104 Fax: +(90) (216) 337 89 87 email: myukseloglu@marmara.edu.tr