WELCOME to MY WELCOME to MY PRESENTATIONPRESENTATION

Md.Azmeri Latif BegMd.Azmeri Latif BegMSc.in Textile Engineering(DIU)MSc.in Textile Engineering(DIU)

Textile

Chapter-1

General Introduction

Characteristics of reactive dyes:

1. Water soluble dyes.2. Makes covalent bonds with the fibers.3. A certain amount of dye is hydrolyzed during (10-60%).4. Dyeing is carried out in alkaline condition (ph=11.5). 5. Huge electrolyte is necessary for dyeing with reactive dyes.6. Fastness (wash, light, rubbing, perspiration) properties are

generally good.7. Easy applicable to cellulosic as well as protein fibers. (Wool &

silk).8. Very popular and wide used in the wet processing industry in

Bangladesh.9. Comparatively cheap is found.10. All kinds of shade are found.11. Dyeing method is easy.

Broad Objectives:  Hot brand reactive dyeing and its application

system on cotton goods in exhaust method.

 

Objectives:    Comparison of the color appearance of cotton

fabrics dyed using hot brand reactive dyes at different temperature.

  Describe exhaust dyeing method on cotton

goods.

 

Comparison of different fastness properties e.g. washing fastness between standard temperature and different temperature of dyeing.

 

Hot brand reactive dye is one of the types of reactive dyes.These types of reactive dyes have lower reactivity towards cotton.

High dyeing temperature is required and normally dyeing is carried out at the temperature between 90-95c, these types of dyes also requires strong alkaline medium and NAOH is used to bring the PH at 10.5-11.

 

Chapter-2

Literature Review

Types Exhaust dyeing temperature(0c

)

Alkali recommended

High reactivity(cold brand)

25-40 Weak Alkali(NaHCO3)

Medium reactivity(Warm brand)

40-60 Mild Alkali(Na2CO3)

Low Reactivity(hot brand)

60-95 Strong Alkali(NaOH)

Hot brand reactive dyes:

Hot brand reactive dye is one of the types of reactive dyes. These types of reactive dyes have lower reactivity towards cotton. High dyeing temperature is required and normally dyeing is carried out at the temperature between 900-950c, these types of dyes also requires strong alkaline medium and NAOH is used to bring the PH at 10.5-11.

Example includes: Monochlorotriazine(MCT) Dichloroquinaxoline(DQT) and Trichloro pyrimidine reactive dyesTrichloro pyrimidine reactive dyes

Chapter-3

Material & Methods

Dyeing of Cotton Fabric with Reactive dye:

Recipe:

•Anionic detergent :1 g/L•Nonionic detergent :.5 g/L•Sequestering agent :1 g/L•Hyhrogenperoxide : 3g/L•NaOH :3 g/L•Enzyme

Procedure:•At first Anionic detergent, Nonionic detergent, Sequestering agent,Hydrogen peroxide, NaOH are taken in a bath in 40 tem. For 10 minutes.•Temperature is increased slowly. Normally 2-3 degree per min•After that tem. Is kept is kept in 95-110 for 30 min.•Temperature is decreased slowly.•Enzyme is added in 80•After 10 min. passing acetic acid is added.•After 10 min. passing, cooling and draining is completed.•Fabric are kept for 10 min. in a bath.•Fabrics are washed by overflowing process.•Finally fabrics are prepared for dyeing.

Sunfix Turquoise Blue PGR Reactive Blue 72

Sunfix Blue H3RP / P3R Reactive Blue 49 / 99

Sunfix Yellow H5G Reactive Yellow 2

Raw Material that are used in this project:

2. Fabric 3. Dye stuff 4. Chemical and auxiliaries

Fabric Types:100% cotton fabric Single jersey with lycra.Dyes that are used in this project:

Lab Dyeing Machine: Dye-Master (Glycerin bath)Origin: IndiaCapacity: 24 pots

Chapter-4

Result & Discussion

Method of dyeing: In this project Exhaust dyeing method is used for dyed of cotton goods by sunfix hot brand reactive dyes.

Primary Exhaustion PhaseExhaustion of dye from the dye bath to the cellulose during Primary Exhaustion phase is governed by the following three physical processes and the phenomenon of substantivityAdsorptionDiffusion, Absorption/ Exhaustion/Migration

Secondary Exhaustion

The observations and inferences in the above deliberations related to primary exhaustion in a Reactive exhaust dyeing process are incomplete without the final fixation. When Alkali is added, the cellulose ionizes to form Cell-O- and H+ (Cell O– Na+) and starts forming covalent bonds with the reactive functional groups of the dye Chromophore. When more and more of dye anions are covalently bond, the distribution coefficient shifts to fiber phase effecting further exhaustion due to deficiency of dye anions in the cellulose phase and dye bath concentration starts depleting further. The degree of alkalinity in terms of pH plays a major role in shifting the fixation of dye to its hydrolysis reacting with water. Any exhaustion during this stage if it is hydrolyzed dye it would be far more undesirable In a reactive dye system therefore, primary exhaustion alone does not govern the efficiency of dyeing. The degree of secondary exhaustion also would influence the efficiency.

During the secondary exhaustion when alkalie is added, there is a second reaction that also sets in motion in parallel ( i.e. the hydrolysis of the Reactive dye with water) in competition to the fixation of the dye that is the primary aim. The dye anion is equally facilitated to react with OH of water to form the hydrolyzed dye in which state the dye is as good as a direct dye with all its ‘undesirable’ characteristics.

It is the reactive group in the dye, pH and temperature that influence the hydrolysis of dye in preference to reacting with cellulose. It becomes critical that the hydrolysis is curbed to maximize efficiency. The relationship between temperature and reactivity is that higher temperatures require lower alkalinity; to optimize on hydrolysis. They can be broadly grouped under ‘High’ ‘Medium’ and ‘Low’ categories requiring 40º C. 60 º C and 80º.C respectively - levels of pH 12.5 for High (cold dyeing), 11.5 for Medium (Warm) and 10 - 11.0 for Low (Hot Dyeing) for the reaction to proceed more favorably towards the substrate.

Migration phaseSince fiber surface area is a factor in diffusion process, the exhaustion would proceed to locations where relatively more surface area is presented like in the amorphous areas and less densely packed crystalline areas in that order in the cellulose and therefore the dye concentration within the cellulose substrate would not be uniform/even. Such a situation would result in uneven build up of the dye both in hue and intensity.

In a trichromatic mixture the situation could be worse. The process of Migration of the exhausted dye depends on the molecular size of the dye its spatial profile (Steric) and the solubilizing groups present. The other external factors would relate to temperature, machinery used and the package profiles and densities (in case of package dyeings). 

Raising the temperature would provide the required thermal energy; but cannot be increased arbitrarily due to limitations discussed under ‘Temperature’. Both exhaustion and migrations can be maximized /improved by better mechanical agitations that would facilitate intimate surface area contact of the cellulose with dye liquor and by improved flow designs that facilitate better liquor exchange at the fiber liquor inter-phase. Migration phase should precede the fixation phase as once the reactive dye forms a covalent bond with Cell O- it is anchored strongly and cannot be shifted.

Discussion

Above all of experiment we found that, migration method is better than ISO method. Because ISO method show low Color fastness, light fastness etc. Migration method need more time than ISO method. ISO method gives unfixed dye. So create problem during dyeing. On the other way, Migration method show better result during dyeing.

Chapter-5

Conclusion

CONCLUSION:During the work phase on the project, several fields were identified which are not clarified on the topic. So we have to assume some matters to proceed on our work that are clearly recognized later on relevant section. Moreover there is also unavailable information that we have worked with. In most instances the unavailable information was nonexistent obtaining t would require detailed research efforts, which is impossible to us due to lack of facilities, lack of time and lack of professionalism. In other instances information was available, but the database was insufficient to establish reliable and representative estimates. The areas of effective shade matching recommended for additional study are:Develop information of properties of dyestuffs-- Most of the information available on physical/ chemical dyestuffs properties are general and does not describe properties of specific large volume dyestuffs currently in use.Characterize the size capacity and dye usage of textile dyeing operations.Develop data on Worker Exposure to dyestuffs- although little data is included in the report but it requires more detailed study and attention.Balance lab dyeing condition with production- for successful application of comport predicted recipe ,it is essential that the dyeing conditions and material must be identical in calibration experiment as well as in production plant .Widen the database with different dyestuffs and methods, Fiber, Fabric types- much information is available on the report is based on only two dyes brands of same types one method one type of fiber one fabric types. Database requires all dye brands that are commercially used from different dyestuffs manufacturer following their guidelines and all dye classes available in the industry and also all types of fiber and substrate.

Above all discussion we can say that, it has great effect of hot brand reactive dye on cotton fabric with exhaustion method. Migration method is more acceptable for proper color fixation in a dyeing process. Another way when we followed ISO method has create a lot of problem such as wash fastness variation rubbing fastness variation, uneven dyeing etc. If we want to get perfect dyeing than we must maintain migration method.

THE END

THANKS TO EVERY BODY