Welcome to our presentation

Comparative Study on difference between reactive

dye and disperse dye on fabric.

Md.Azmeri Latif BegMSc. in Textile Engineering

INTRODUCTIONWe are introducing about reactive dye and disperse dye on fabric. At present reactive dye and disperse dyes is not a single word globally now it achieved vast sector in dyeing sector.

Reactive dyes are very popular and wide used in the wet processing industry of cotton in Bangladesh and Abroad because of Water soluble dyes. Make covalent bond with the fibers. A certain amount of dye is hydrolyzed during (10-60%).Dyeing is carried out in alkaline condition (ph=11.5).Huge electrolyte is necessary for dyeing with reactive dyes. Fastness (wash, light, rubbing, perspiration) properties are generally good .Easy applicable to cellulosic as well as protein fibers. (Wool & silk).   Disperse dyes is a universal dyes for polyester fabric. Disperse dyes can be used with various techniques and will readily colour synthetics such as polyester, nylon, cellulose acetate, vilene, viscose, synthetic velvets and PVC. They can also be used to colour plastic buttons and fastenings.Now a dye we are fully depended on reactive dye and disperse dyes. More than 80% use reactive dye and disperse dyes for dyeing textile goods.

Raw Material that are used in this project:

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

 Fabric Types:100% cotton fabric100% polyester fabric100% viscose fabricChip value cotton (CVC) Polyester Cotton (PC) CVC with lycra Dyes that are used in this project: Reactive dyesSunfix Turquoise Blue PGRReactive Blue 72Sunfix Blue H3RP / P3RReactive Blue 49 / 99Sunfix Yellow H5GReactive Yellow 2

Raw materials for knitted fabric (100% cotton + polyester):  Single Jersey, Heavy Jersey, Pique, Lapique, Minipique, Honey Comb, Rib, Cotton Fleece, Spandex, Haring Bone, Drop Needle, Fancy Design, Box Shaper, Box Knit. French Terry,2 thread Fleece Semi Jacquard, Jacquard, Mesh Fabric, Single Locoest, Double Locoest.

Raw materials for dyes:  Reactive dyes Disperse dyes Dyeing Chemicals Pretreatment ChemicalsCracking Agent + Detergent+ Lubricant+ Sequestering Agent+ Defoamer + Penetration Accelerant+ Peroxide stabilizer+ Peroxide Killer+ Catalase+ Core Alkali Neutralizer

Enzyme ProcessEnzyme

Dyebath Chemicals Leveling + Sequestering + Dispersing + Dye bath Sequestering +Salt  Wash Off Soaping Agent+Anti Back Staining Agent Fixer Fixing Agent Softeners Cationic Softener+ Nonionic Softener+ Silicon Softener

Characteristics of reactive dyes: Water soluble dyes.Makes covalent bonds with the fibers.A certain amount of dye is hydrolyzed during (10-60%).Dyeing is carried out in alkaline condition (ph=11.5). Huge electrolyte is necessary for dyeing with reactive dyes.Fastness (wash, light, rubbing, perspiration) properties are generally good.Easy applicable to cellulosic as well as protein fibers. (Wool & silk).Very popular and wide used in the wet processing industry in Bangladesh.Comparatively cheap is found.All kinds of shade are found.

Why reactive dyes are popular: Good washing fastness (Rating 4-5).Very good light fastness (6).Lower cost.Simple dyeing method. Good reproducibility.Low dyeing temp (below 100˚c).Ability to produce bright shade. Dye molecular compositionEasily applicable to cellulosic fiber as well as proteinAll kinds of shade are found.

 Reactive dye contains reactive group and this reactive group

makes covalent bond with fibers and becomes part of the fiber. By their nature, reactive dyes also react with water.

Dyes which reacts with the fiber is said to be “fixed” to the fiber. Dye which reacts with water is said to be “hydrolyzed.”

  

The general formula of reactive dye can be written as follows: 

D-X-Y Here, DChromophore of Dye posts.

XBridge. YFunctional group.

 D-X-Y + Fiber D-X-Y- Fiber covalent bond.

   Fixation reaction

 Cell—Ch2—OH + Dye—X Cell—CH2—O—Dye +HX

Cellulose reactive dye dyed fiber acid

X=reactive group

Hydrolysis reaction H—O—H + Dye—X Dye—OH + HX

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)

Importance factors for reactive dyeing:•Ph of the dye bath.•Temperature of dyeing•Concentration of electrolyte•The time of dyeing•Liquor ratio.

1. Ph of the dye bath.•Strong alkali is used for low reactive dyes Ph:11-12.•Medium alkali is used for medium reactive dyes Ph :10.5-11•Weak alkali is used for high reactive dyes. Ph: 10-11.

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pH-12 lowreactivity

pH-10.5mediumreactivity

pH-11 highreactivity

East

Figure: Relation between pH & temperature of reactive dyes

Disperse dyeing

mechanism

Disperse dyeing mechanismThe four stages of the process mechanism are as follows a. Some of the dyes dissolve in the water of the dyebath.b. Molecules of dye are transferred from solution to the surface of the fibre.c. The solution in the dyebath is replenished by the dissolution of more solid materialfrom the dispersion.d. The adsorbed dye diffuses monomolecularly into the fibre.The process of transfer from the aqueous solution to the fibre is comparable with theextraction of a solute from one solvent by a second, immiscible solvent and similar laws of partition are applicable. Distribution coefficients that are related to the solubilities of the dyes in the aqueous and fibre phases can be determined for different processing temperatures, although they may be affected by the simultaneous equilibrium between the aqueous and solid phases of the dye. The rates of the first and second stages of the process mechanism are governed by these solubilities.It was established that the disperse dyeing system was truly reversible and that the results conformed to a rectilinear isotherm. Typical results show linear relationship in distribution of dye between polyester and water. It is well established that dyeing with disperse dyes .

100% Polyester, PC And CVC Polyester Part Dyeing ProcedureProcess

Load Fabrics 90X30 Detergent -.5%and Soda -1.5 % Hot

Cooling and DrainAdd A/acid To control Ph 4-4.5

40'C, Check PH 4-4.5 +Add Buffer Solution-.6%+Add Polyester Levelling-2% +Dispersing agent-1%

Raise Temp at 60‘60X10 Color Dosing

Direct Raise Temp at 80' CRaise Temp. at 130'C in 1.5 'C per minute

130X30 Light ColorRun Time (color steam) 130X45 Medium Color

130X60 Dark Color Cooling Down at 85'C in 1.5'C / Min

Shade CheckCooling Down And Rinse Drain

80X20 Reduction Cleaning –Hydrous-3% & Caustic- 3%application

100% Cotton Dyeing Procedure SOLID COLOR

PROCESS LOAD FABRICS

95X60 SCOURING (DETERGENT-.5%+ANTICREASING-.5%+STABLIZER-.6%+SEQUESTERING-.6%+NAOH-2.5%+H2O2-2.5%)

60X20 NEUTRALIZATION (A.ACID -.8%)PEROXIDE KILLER -.6%

60X20 NEUTRALIZATION (A.ACID -.6%)55X60 ENZYME- .5%

TEMPERATURE RAISE 70 C FOR DESTROYING ENZYME 40’C SEQUESTERING-.5%+ ANTICREASING-.5%+A.ACID-.6%+LEVELING-1.5%

+SALTCOLOR DOSING FOR 30 MIN

RUN TIME 20 MIN ,TEMP 50-60ADD SODA(NAOH) PROGRASIVE DOSING FOR 30 MIN

65X45-60 (DEPEND ON SHADE) COLOR STEAM SHADE CHECK

BATH DRAIN(BD)90X25 HOT WASH+(SOAP-.5%)

60X20 NORMAL WASH SHADE CHECK

60X20 NEUTRALIZATION (A.ACID -.6%)45X30 FIXING -1%

50X30 SOFTNER-.8%+A.ACID-.2% SHADE CHECK

COOLING DOWN AND RINSE DRAIN

Compares between reactive and disperse dyeing phase

500C 20' 20' 10' Semplecheek 650Cx10min

Levelling Salt 600C Dye Soda Sole

Fig: dyeing curve on different phase of reactive dyes

Figure: dyeing curve on different phase of disperse dyes

Process Load Fabrics

95X60 SCOURING (DETERGENT-.5%+ANTICREASING-.5%+STABLIZER-.6%+SEQUESTERING-.6%+NAOH-2.5%+H2O2-2.5%)

60X20 NEUTRALIZATION (A.ACID -.8%)PEROXIDE KILLER -.6%

60X20 NEUTRALIZATION (A.ACID -.6%)55X60 ENZYME- .5%

TEMPERATURE RAISE 70 c FOR DESTROYING ENZYME60X10 LEVELING-1.5%+COLOR+SALT+SEQ-.5%+ANTRICREASING-.5%

TEMPER RAISE 80X20 FOR MIGRATIONCOOLING (60 FOR 10MIN)

SODA DOSING (60 FOR 30 MIN)COLOR STEAMING(60X40)

SHADE CHECKBATH DRAIN(BD)

90X25 HOT WASH+(SOAP-.5%)60X20 NORMAL WASH

Shade Check 60X20 NEUTRALIZATION (A.ACID -.6%)

45X30 FIXING -1%50X30 SOFTNER-.8%+A.ACID-.2%

Shade Check Cooling Down And Rinse Drain

100% COTTON DYEING PROCEDURE SOLID COLOR TURQUOISE MIGRATION PROCESS

100% COTTON FLUORESCENT DYEING PROCEDURE OPTICAL WHITE/FLUORESCENT WHITENERS

Process Load Fabrics

95X60 SCOURING ( DETERGENT-.5%+ANTICREASING-.5%+STABLIZER-.6%+SEQUESTERING-.6%+NAOH-2.5%+H2O2-2.5%)

60X20 NEUTRALIZATION (A.ACID -.8%)PEROXIDE KILLER -.6%

60X20 NEUTRALIZATION (A.ACID -.6%)80X45 SYNO WHITE(OBA) 4BK -.3%

Shade Check55X60 ENZYME- .5%

TEMPERATURE RAISE 70 c FOR DESTROYING ENZYME50X30 SOFTNER-.8%+A.ACID-.2%

Shade Check Cooling Down And Rinse Drain

100% Cotton Dyeing Procedure OFF WHITE OR EGRET

Process Load Fabrics

SCOURING DETERGENT-.5%

95X45 ANTICREASING-.8%STABLIZER-.5%

SEQUESTERING-.6%NAOH-3%H2O2-7%

Shade Check60X20 NEUTRALIZATION (A.ACID -.8%)

PEROXIDE KILLER -.6%60X20 NEUTRALIZATION (A.ACID -.6%)

55X60 ENZYME- .5%TEMPERATURE RAISE 70 c FOR DESTROYING ENZYME

50X30 SOFTNER-.8%+A.ACID-.2% Shade Check

Cooling Down And Rinse Drain

Hydrolysis of Reactive dyesReactive dye contains reactive group and this reactive group makes covalent bond with fibers and becomes part of the fiber. By their nature, reactive dyes also react with water. Dyes which reacts with the fiber is said to be “fixed” to the fiber. Dye which reacts with water is said to be “hydrolyzed.”  

 Hydrolysis reaction

H—O—H + Dye—X Dye—OH + HX 

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 dyeing) and 10 - 11.0 for Low (Hot Dyeing) for the reaction to proceed more favorably towards the substrate.

Difference between reactive dye and disperse dye on fabric.We know that reactive and disperse fully different dyes due to their properties, molecular size, application, water absorbency, solubility.

0

20

40

60

80

100

120

140

reactivity low HTHP medium reactivity carrier method

reactive

disperse

Figure: temp. Effect between reactive and disperse

Temperature

Application

reactive

disperse

acid dyes

others dyes

Figure: Application of total dyeing

Absorbency by Fibre:

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100

pH-3 pH-4.5-5.5 pH-9 11.5

Reactve

Figure: Absorbency % by reactive dye due to pH.

0

20

40

60

80

100

pH-3 pH-4.5-5.5 pH-9 pH-12

disperse

pH of dyebath

Generally, in the commercial dyeing of polyester fibres with disperse dyes, dyeing is carried out within the pH range 5.5 to 6.5. Strongly alkaline or acidic conditions, such as higher than pH 9 and lower than pH 4, induce hydrolysis of the fibre as well as decomposition of azo disperse dyes .In the case of high temperature dyeing, this degradation of polyester fibre and dye is accelerated

SOME TECHNICAL TERMS OF DYEINGExhaustion: The proportion of dye or other substrate taken by a substrate(material) at any stage of the process to the of the amount originally available.

Fixation: The proportion of dye or other substrate is fixed by a substrate(material) after final wash.

Disruption: When dye stuff comes to the outer surface of the fabric, that is called disruption.

Adsorption: Deposition of dyes on the surface of the fiber.Absorption: Penetration of dyes inside the fiber.

Stripping: To remove color from substrate and make color less is called stripping Sodium thio sulphate (hydrous)Na2S2O4 is used .generally it react with fiber & produce two colorless amino substitute compound (R1-NH2+NH2-R2)one is remove from fiber but another is remain so fiber have not 100% colorless.

Topping: After stripping dyeing is done i.e topping.Addition: Without stripping extra dyes are add in dye bath to match the required shade is called addition.(always avoid addition because it gives uneven shade)

Dosing: There are 3 type of dosing.

Linear dosing: Dosing rate is same due to time.

Progressive dosing: Dosing rate gradually increase due to time.

Digressive dosing: Dosing rate gradually decrease due to time.

Time

Do

zin

g R

ate

THANKS TO ALL