PRESENTATION LAYOUT 1 INTRODUCTION AND BACKGROUND 2 LITERATURE REVIEW 3 METHODOLOGY 4 RESULTS AND EXPECTED FUTURE OUTCOMES Describing problem statement, goals and the background knowledge Covering the articles and work done in past on the project Practical approach towards accomplishing our goals Evaluation of results and their discussion INTRODUCTION & BACKGROUND BACKGROUND OF INDIGO • Indigo dye is an organic compound with a distinctive blue color and it is amongst the oldest dyes to be used in textile. • Popular in Mayan, Egyptian, Indian and Japanese culture. • It was given the name of indikon which means from India and then later due to its great importance it was given the name of “Blue Gold”. • Indigo Dye can be used on several materials but especially it is good for cotton, but it is also used for linen, leather, wool, and silk. SOURCES OF INDIGO The indigo dye can be naturally extracted and can also be made synthetically. 1 • • • • NATURAL SOURCES The main natural source of indigo dye was the leaves of indigofera tinctoria Before indigofera a common alternative was used in the colder subtropical locations. Several other plants contain indigo such as coffee beans and cacao but the problem is that in these plants indigo is in very low concentration. To obtain indigo from the leaves of indican, they are dipped in water and then fermented. 2 • • • CHEMICAL SOURCES The first method involved an aldol condensation’ of O-nitrobenzaldehyde with acetone followed by cyclization and oxidative dimerization to indigo. Eventually ‘Johannes pfleger’ came up with a new idea of industrial mass synthesis which involved treatment of N-phenylglycine with a molten mixture of sodium hydroxide potassium hydroxide and soda amide producing indoxyl which oxidizes to indigo. Another method involved heating of N-(2-Carboxyphenyl) glycine to 200degree Celsius with sodium hydroxide in an inert atmosphere INDIGO DYEING The general process of indigo dyeing is as follows DYEBATH PREPARATION ROPE DYEING OXIDATION OUTCOME The dye bath is prepared by adding all the required chemicals in a proper amount as well as the reducing agent. The yarns in the form of rope are dipped into the dye bath solution multiple times given the required dips. The dyed ropes are exposed to environment air for oxidation so that the dye can fix onto the fabric. The dyed ropes are dried on the drying cylinders and are then stored in drums for further processing. PROBLEM STATEMENT Reducing agent being used in the indigo dyeing is not environmentally favorable, during processing And even after being discharged as effluent is poses threat to the health of people and environment PROJECT OBJECTIVE To reduce the harmful effects of the indigo dyeing by using organic reducing agents instead of sodium hydrosulphite, as it is hazardous for the environment, without losing much of the dye quality SCOPE & SIGNIFICANCE About 6billion pair of jeans are being made every year with a significant portion of indigo dyed denim in them, by eliminating or reducing the consumption of harmful reducing agent we can reduce the effluent treatment cost as well as ensure safety for the environment. REDUCTION OF INDIGO DYE Indigo is required to be reduced to its water-soluble form (leuco-indigo) by using reducing agent, as indigo is initially in water insoluble form. Depending on the pH of the dyebath, the dye can undergo two-step ionization from the non-ionic form to mono-ionic or di-ionic form The process of reduction is to give negative charge (by adding electron) to the indigo molecule which then converts the indigo into leuco-indigo (water soluble) form. In this way the indigo is made to dissolve in water thus enabling it for the dyeing process. REDUCING AGENTS USED The reducing agent mainly used on industrial scale is sodium dithionite and in our project we will be using glucose as our organic alternative for reducing indigo. SODIUM DITHIONITE GLUCOSE SODIUM DITHIONITE What is Na2S2O4 Sodium dithionite (Na2S2O4) is a whitish to light yellow crystalline solid having a smell of Sulphur dioxide. Even tough it is widely used in the industries as reducing agent for indigo dyeing, but still it has some cons as well. • • • • It Produces hazardous by-products (SO42- and SO32-) in a large amount when discharged as effluent Harmful for the environment Poses health hazards on the workers working in the dyeing industries It increases effluent water treatment cost Na2S2O4 MONOSACCHARIDE GLUCOSE Monosaccharide (Glucose) All monosaccharides are reducing sugars because all monosaccharides have an aldehyde group (if they are aldoses). The glucose comes as white powder. The reasons of using glucose as a replacement for the sodium dithionite are as follows: • • • • It does not pose threat to the environment It does not pose threat to the workers that are working in the industry It is abundantly available It is economically favorable LITERATURE REVIEW ECO-FRIENDLY DYEING In the case of indigo dyeing the reducing Organic reducing agents are the most agent that is being commercially suitable option for the replacement of consumed (sodium dithionite) is sodium dithionite as they are environmentally Unfavorable. Several environmentally favorable but the experiments have been done to replace it problem in them is that they give a lot with an eco-friendly alternative which is of variations in dyeing. The redox both economically and environmentally potential for indigo needs to be lower friendly. than -700mV but the organic reducing agents are mostly unable to achieve this. REDUCTION METHODS Following are the reduction techniques used for the reduction of indigo 1 ELECTROCHEMICAL REDUCTION ENZYMATIC TECHNOLOGIES 4 2 BOKBUNJA SLUDGE FRUIT PEEL AND EXTRACTS 5 3 3-HYDROXYBUTANON ORGANICE REDUCING SUGARS 6 ELECTROCHEMICAL REDUCTION The purpose of electrochemical reduction is to minimize the consumption of chemicals and also to control the redox potential for monitoring the process. This can be done by direct election chemical reduction by radical process or it can be done on graphite electrodes, however this process requires a large amount of electrical energy and electrodes with large surface area, thus this is not economically favorable process. BOKBUNJA SLUDGE Bokbunja is a kind of wild berry, which contains large amount of sugars and phenolics. It is extracted by using Ethanol and water. It is then used in indigo dyeing as reducing agent. The utilization of the bokbunja sludge as a reducing agent was effective but only at an elevated temperature of 80 C and the maximum color yield was reached in one or two days. ENZYMATIC TECHNOLOGIES Enzymatic technologies can be used in place of standard chemical reduction and oxidation processes, it is also economical because of the reduction in the water treatment cost of effluent. The advantage of enzymatic reduction is the moderate temperature of processing and the absence of by-products. The problem with this method is the activation of enzymes which work on very specific temperatures and pH. FRUIT PEEL & EXTRACTS Several different fruits have been previously tested as reducing agents in the indigo dyeing, but the basic problem with this reducing method is the variation in results. The reduction system using such natural products and by-products is claime d to be more eco-friendlier However the basic problem with this reducing met hod is the variation and inconsistency of the material composition can cause problems in reproducing the results 3-hydroxyl Butanon In the case of using 3-hydroxyl butanon, the cotton has to be modified so it is pretreated using Dentex BC 200% to improve the dyeing quality. The observations were made which stated that as the temperature and alkalinity increases, so does the color strength values (K/S) increases. Higher the temperature the more reduce d the redox potential gets. Thus effecting the E (%) and K/S values as well Higher the concentration the better the bath exhaustion and E (%) and K/S values ORGANIC REDUCING SUGARS Reducing sugar like mono and di-saccharides can be used in indigo reduction. The reducing sugars are the most practical and economic alternative towards the Sodium dithionite, as they are environmental and economically friendly. • The reducing sugars are capable of being used as reducing agents as they have free aldehyde or ketone groups. • Glucose and Fructose are most suitable because they do not require high elevated temperature and they give good redox potential values. • Most dye baths reached the redox potential around -650 to -700 mV within 10mins and the dye bath was stable throughout the 60min experiment at 50 C. • Amongst the sugars, the fructose reached the highest negative redox potential within 5mins, and stayed stable for 60mins. METHODOLOGY OUR METHODOLOGY DYE BATH PREPARATION Dye bath is prepared with all the chemicals and auxillaries DYEING Dyeing is performed by pad-batch method on the padder machine WASHING OR AFTER DYEING PROCESS Washing is done in hot water and then cold water and then dried at room temp. Or fixing agent is applied after dyeing process. TESTING Color fastness tests are performed along with observation of CIELAB values on spectrophotometer EVALUATION 1 2 3 4 5 The results are evaluated and compared in between standard and batch CHEMICALS USED DYE REDUCING AGENTS CAUSTIC 1 2 3 SODIUM DITHIONITE NaOH (50%) 4 g/L DIRESUL INDIGO BLUE 30L 0.5 or 10 g/L OR REDUCER RDT GLUCOSE POWDER 2.2 g/L FIXING AGENTS USED 1 2 3 ACHIFIX FF-429 DIREFIX SD LIQ LAVA FIX FF DYEING PROCESS DYE BATH PREPARATION • The solution is prepared for the respective reducing agent in 100ml of bath volume. • The chemical quantity calculations are performed according to the provided recipe and the bath volume. • Now that the bath is prepared, dyeing process can begin. DYEING PROCESS PADDING PROCESS • The prepared bath is poured in between of the nip of padding rollers. • The samples are then passed through the padder machine at the set parameters. • The fabric samples are given 12 dips • Oxidation time of 2 minutes is given between each dip. • Fabric is then washed and dried at room temperature. METHODS OF PERFORMANCE OLD METHOD • Dye given some resting time led to it NEW METHOD • being hydrolyzed • No oxidation time between dips led to using hit and trial method • no depth of shade even after more dips • • 2mins of oxidation time given to fabric after every dip • Poor oxidation of samples led toward poor staining CF results Selection of process parameters by Excellent oxidation of the samples led toward great staining CF results • Denim twill fabric was tested for the Plain Weaved fabric couldn’t provide dyeing process which held up to the us with even dyeing results due to great dyeing results and even dyeing. some faults in padder METHODS OF PERFORMANCE OLD METHOD Trial Machine Type of No. of No. of No. Parameters Fabric Dye Dips Observations baths • Four trials were done in the old method of performance. • No standard was set as benchmark. • The number of dye baths were also Trial 2bar Plain 0 Cotton 2.2m/min • Trial 2bar Plain 1 Cotton 2.2m/min also used for the last trial to observe the dyeing outcomes. Very light shade Uneven poor dyeing 1 4 Very light shade Uneven poor dyeing Fabric Trial 2bar Plain 2 Cotton 2.2m/min 2 4 Slight better shade Slight better dyeing Fabric Plain weaved fabrics were used for this method, and denim fabric was 4 Fabric kept minimum to see the results, thus leading to poor dyeing outcome. 1 Trial 2bar Denim 3 Fabric 2.2m/min 1 4 Slight Better shade Uneven poor dyeing METHODS OF PERFORMANCE NEW METHOD • Several trials were ran on hit and trial basis in order to find the correct set of process parameters required for the correct way of dyeing. • The plain fabric was replaced with the denim fabric as it could withstand the Trial Machine Type of No. of No. of No. Parameters Fabric Dye Dips baths T1 T2 T3 T4 T5 T6 Plain Weave 2m/min Cotton Fabric 2bar Plain Weave 1.5m/min Cotton Fabric 2bar Plain Weave 2m/min Cotton Fabric 2bar Plain Weave 2.2m/min Cotton Fabric 2bar Denim Fabric 1 12 2bar The decided parameters gave the 2bar 1 12 darkest shade as well as even dyeing 2bar 1 12 2bar 2.2m/min Slightly better shade Uneven poor dyeing 2 12 Better shade Uneven poor dyeing 2 12 Better shade Even & better dyeing Denim Fabric 4 12 Darker shade Even & better dyeing Denim Fabric 6 12 More darker shade Even & better dyeing Denim Fabric 12 12 2.2m/min T9 Very light shade Uneven poor dyeing 2.2m/min T8 Very light shade Uneven poor dyeing 2.2m/min T7 outcome. 1.5bar 2.2m/min minor errors of the padder machine. • Observations Very dark shade Even & better dyeing Denim Fabric 12 12 Very dark shade Even & better dyeing DISTRIBUTION OF DYED SAMPLES Trial Samples Sodium Dithionite Samples Glucose Samples Fixer Samples T1 S1 G1 F1 (Achifix FF-429) T2 S2 G2 F2 (Direfix SD Liq) T3 S3 G3 F3 (Lava Fix FF) T4 S4 G4 T5 S5 G5 T6 S6 G6 T7 S7 G7 T8 S8 G8 T9 S9 G9 S10 G10 G11 PERFORMED TESTS 1 2 2.1 2.2 COLOR STRENGTH (K/S) COLOR FASTNESS WASHING CROCKING RESULTS & DISCUSSION TESTING RESULTS • Four trials of dyeing were done with previous methods while a total of 33 trials were done with the new method including 9 trial samples, 10 sodium dithionite samples, 11 glucose samples and 3 fixer samples. • The samples were evaluated on the basis of their color strength (K/S) values and their color fastness results. • The results of standard benchmark sample was compared with all other batch samples. • All the samples were dyed from the same recipe and procedure as mentioned earlier. OLD METHOD COLOR FASTNESS RESULTS TRIAL 0 TRIAL 1 COLOR FASTNESS TO CROCKING COLOR FASTNESS TO CROCKING STANDARD BATCH1 DRY 4-5 4-5 WET 3-4 4-5 STANDARD BATCH1 DRY 3-4 3-4 WET 2-3 2-3 COLOR FASTNESS TO WASHING (SHADE CHANGE) COLOR FASTNESS TO WASHING (SHADE CHANGE) SHADE CHANGE 4 3-4 4-5 4 3-4 COLOR FASTNESS TO WASHING (STAINING) COLOR FASTNESS TO WASHING (STAINING) STAINING SHADE CHANGE 4 STAINING 4-5 3-4 OLD METHOD COLOR FASTNESS RESULTS TRIAL 2 TRIAL 3 COLOR FASTNESS TO CROCKING COLOR FASTNESS TO CROCKING STANDARD BATCH1 DRY 2-3 2-3 WET 2-3 2-3 STANDARD BATCH1 DRY 4-5 4-5 WET 3-4 4 COLOR FASTNESS TO WASHING (SHADE CHANGE) COLOR FASTNESS TO WASHING (SHADE CHANGE) SHADE CHANGE 4 4 5 4 4-5 COLOR FASTNESS TO WASHING (STAINING) COLOR FASTNESS TO WASHING (STAINING) STAINING SHADE CHANGE 3 STAINING 5 4-5 COLOR STRENGTH RESULTS (K/S) SODIUM DITHIONITE Sample Name K/S GLUCOSE FIXING AGENTS Sample Name K/S Sample Name K/S S1 19.49 (Standard Sample) Standard Sample 19.49 19.49 S2 16.3 G1 16.83 Standard Sample S3 14.59 G2 16.7 G3 16.5 G4 12.6 S4 16.8 S5 17.9 G5 17.06 S6 16.8 G6 13.7 S7 16.8 G7 14.3 S8 14.49 G8 15.1 G9 14.03 S9 16.4 G10 14.07 S10 18.3 G11 13.34 16.43 F1 Achifix FF-429 16.43 F2 Direfix SD LIQ F3 Lava Fix FF 16.93 COLOR FASTNESS RESULTS SODIUM DITHIONITE SAMPLES COLOR FASTNESS TO CROCKING S1 S2 S3 S4 S5 S6 S7 S8 S9 S10 Dry 3-4 3-4 3-4 3-4 3 3-4 3-4 3-4 3-4 3-4 Wet 3-4 3 3 3 3 2-3 2-3 3 2-3 2-3 COLOR FASTNESS TO WASHING (SHADE CHANGE) Shade Change 5 4-5 4-5 4-5 4-5 4 4-5 4-5 4-5 4-5 COLOR FASTNESS TO WASHING (STAINING) Staining 5 4-5 4-5 4-5 4-5 4-5 5 5 5 5 COLOR FASTNESS RESULTS GLUCOSE SAMPLES COLOR FASTNESS TO CROCKING Std G1 G2 G3 G4 G5 G6 G7 G8 G9 G10 G11 Dry 3-4 3-4 3-4 4 3 3 3-4 3-4 3-4 3-4 3-4 3 Wet 3-4 2-3 2 2 2-3 2 3 3 2-3 3 3 2-3 COLOR FASTNESS TO WASHING (SHADE CHANGE) Shade Change 5 4 4-5 3-4 4 3-4 3-4 4 4 4 3-4 3 4-5 4-5 COLOR FASTNESS TO WASHING (STAINING) Staining 5 5 5 4-5 4-5 4-5 4-5 4-5 4-5 4-5 COLOR FASTNESS RESULTS FIXING SAMPLES COLOR FASTNESS TO CROCKING Standard F1 (ACHIFIX) F2 (DIREFIX) F3 (LAVAFIX) Dry 3-4 3-4 4 3-4 Wet 3-4 3-4 3-4 3-4 COLOR FASTNESS TO WASHING (SHADE CHANGE) Shade Change 5 4-5 4-5 4-5 COLOR FASTNESS TO WASHING (STAINING) Staining 5 5 5 5 Columns Lay WORK out CONCLUSION & FUTURE • We can conclude that, the possibility of replacement of reducing sugars with sodium dithionite is quite high. • The values for color strength and color fastness of the dyed sample are all dependent on the combined outcome of the process control parameter. • The different fixers improved the color fastness results of the glucose samples. • For this project, glucose was the main focus, and it was observed that the amount of glucose consumed for dyeing is almost 20times than the amount of sodium dithionite used. • For future, more reducing sugars can be researched such as Fructose and Galactose. Even the combination of the reducing agents can be used in order to reduce the consum ption of sodium dithionite. Thank you!
