PROJECT REPORT ON

REACTION MECHANISM OF REACTIVE DYES IN BENGAL HURRICANE GROUP ON CELLULOSE

FIBER.BASIS OF

BENGAL HURRICANE GROUP

Prepared By : Mazadul Hasan sheshirID: 201000040000813th Batch (session 2009-2013)Department : Wet Processing Technology Email: mazadulhasan@yahoo.comBlog : www. Textilelab.blogspot.com (visit)

Southeast University Department Of Textile Engineering

I/A 251,252 Tejgaon Dhaka Bangladesh

Prepared By :

©right

CONTENTS• Introduction• Raw Materials• Importance of The Survey• Reason of using Reactive dyes in major textile

industry in Bangladesh• Methods of Dyeing & Printing Cotton Goods

with Reactive Dyes• Technical Deficiency of Reactive Dyes, Causes

and Remedies of Technical Deficiency• Conclusion

Chapter 1Acknowledgement

Project Work is an academic function of the Pabna Textile Engineering College. Our teacher Md. Abdul Mannan, Principal, Pabna Textile Engineering College, gave us an opportunity to choose preferable mills for Project Work. I chose Bengal Hurricane Dyeing & printing (pvt.) Ltd. joyfully with the supervision of Mithun Biswas, Asst. Manager(production).

During the Project with Bengal Hurricane Dyeing & printing (pvt.) Ltd. I worked in all the departments related with Dyes and Chemicals. Beside these, I learned about Dye Quality Control and Storage System,printing, Garments, Store & Inventory , finishing & specially dyeing.

Our deepest appreciation goes to Mithun Biswas, Asst. Manager(production)Dyeing, Bengal Hurricane Dyeing & printing (pvt.) Ltd. to give us the opportunity to have project work at BENGAL HURRICAN GROUP.

I would like to thank Engr. Md. Iqbal Mahamud (Head of the Factory), GM, Dyeing, Bengal Hurricane Dyeing & printing

(pvt.) Ltd. for helping to know about the all aspects of BENGAL HURRICAN GROUP. I would also like to thank Tareq Ahmed(Deputy Manager),Md.AnwarulIslam(Deputy Manager), Md. Arif Rabbani Talukdar(Deputy Manager),Dyeing, Bengal Hurricane Dyeing & printing (pvt.)

Ltd. for helping to know about the all aspects of BENGAL HURRICAN GROUP. Our gratitude also goes to all the employees of BENGAL HURRICAN GROUP for their sincere co-operation, support and

valuable advice which they have provided us during the two months of training. Lastly I express my gratitude to our supervising teacher, the name that should be mentioned first, Shib Shankar

Chakraborty, Head of the Dept. Wet Processing Technology for his valuable direction & supervision. However, I have prepared my Industrial Attachment overcoming all the difficulties & also the shortage of time. Here I

would like to present the report.

•

Chapter:2Application of reactive dyes in major

textile industries in Bangladesh

Application of Reactive dyes in major textile industries in Bangladesh

Chapter:3Project Abstract

•

The use of reactive for Dyed products has dramatically increased over the last 50 years. Reactive dyes are now used to produce multiple products. Reactive coloring components are inert into materials which are adhered to the base substrate by the application of soda ash which act as fixing agent.

The main goal of our project is to provide information about the reason of using reactive dyestuff in

major textile industry in Bangladesh, different methods using in our industry for cotton dyeing with reactive dyes, technical deficiency of reactive dyes during dyeing & causes and remedies of deficiency of reactive dyes.

During reactive dyeing there is a rule of using different amount of soda ash with fixed amount of salt &

auxiliaries. In case of dyeing of cotton with reactive dyes alkali pH should be correctly maintained as during dyeing more electrolytes required for exhaustion and alkali for fixation.

However the rubbing fastness and hand feel properties of dyed fabric depends on the amount of soda

ash. When we use fewer amounts of soda ash then hand feel is good but rubbing fastness is not good. And when we use more amounts of soda ash then rubbing fastness is good but hand feel is not good.

Chapter 4 INTRODUCTION

• With the evaluation of the wet processing industries the use of the reactive dyes in the most of the industries increases day by day. As a result to complete the project it is has become a part to discus about the evaluation or growth of the wet processing industries in Bangladesh. Now the number of the wet processing industries and finishing industries in Bangladesh is 193 which are totally export oriented according to the survey of the BTMA which has been provided into their we address.

• But the interesting matter is that with the growth of the textile wet processing mills the number of the employee is not increasing. This is because of to reduce the cost and increase the quality the modernization of the machine is also increasing which reduce the number of worker in wet processing industries. But what is the actual number of the worker in wet processing industries has not been found due to the lack of proper survey in this sector.

• Our project work was estimated as:• APPLICATION OF REACTIVE DYES IN MAJOR TEXTILE IN BANGLADESH & DEFICIENCY OF REACTIVE

DYE:• The project work is interesting as well as lengthy but we must admit that we had to really work

hard and it helps us a great deal to know about whole procedure of reactive dyeing on dyed fabric. Though reactive dyeing products exhibit intrinsic characteristics which make them suitable for multiple products application but reactive dye has it main problem with hydrolysis while dyeing as a result wastage of the reactive dye increase and it become difficult to match the proper

The objects of project are:

Knowing the source of textile raw materials of wet

processing and cost.

To mention the reasons of using reactive dyes in major

textile industry.

To study on the application of reactive dyes

To learn about the technical deficiency of reactive dyeing.

To study the causes and remedy of deficiency of reactive

dyeing.

Chapter 5

RAW MATERIALS

• Raw material is a unique substance in any production oriented textile industry. It not only plays a vital role in case of continuous production & for high quality fabric but also it is related to the profit of the industry.

Types of raw material

• The basic raw materials used in wet processing industries are:

• Fabric• Dyestuffs• Chemicals & auxiliaries.

•

Names & source

Fabric:Different types of fabric treated in Bengal Hurricane Group pvt Ltd. dyeing section are

namely

dyeing section• Single Jersey• Single jersey with Lycra

attachment• Single Jersey with slub • Double Jersey• Polo pique • Back pique• Rib Fabric • Flat back Rib

• Interlock

dyeing section• Interlock with Lycra• Pique• Lacost• Lacost Lycra• Fleece • Tery Fleece• Waffle

• Melange

Fibres dyed:

By reactive dyes the following fibres can be dyed successfully:

1) Cotton, rayon, flax and other cellulosic fibres.

2) Polyamide and wool fibres.

3)Silk and acetate fibres

It covers a wide range of color spectrum and includes shades varying from bright to heavy dark like, a. Violet b. Blue c. Green d. Rede. Blackf. Yellow

g.Etc.

Trade namesSome trade names of this dye are mentioned:

Trade name Manufacturer Country

Procion I.C.I U.K

Ciba cron Ciba Switzerland

Remazol Hoechst Germany

Levafix Bayer Germany

Reactone Geigy Switzerland

Primazin BASF Germany

Drimarine Sandoz Switzerland

Popularity of reactive dye:Reactive are mostly used for dyeing cellulosic fibres. At past cellulosic fibres

were dyed with direct and vat dyes, but after the introduction of reactive dyes there utility has become limited. Reactive dyes are superior to direct dye in the following aspects:

i) Ability to procedure bright shades of wide range.ii) High leveling quality.iii) Good washing fastness.iv) Good light fastness.

And it is superior to vat dyes in the following aspects:i) Simple dyeing method therefore one stage dyeing.ii) Low temperature dyeing (below 1000C)iii) Lower cost, i.e. cheaper.

Again its dyeing process is fast and gives brighter shades than metallized azo dyes. For the above reasons reactive dyes are more popular.

NH (bridging part)

C

C C

N

Cl

N

N-N N-

- NH

Hetreocyclic ring

The general structure of reactive dye is: D-B-G-X.

Chemical structure of reactive dyes

Here, D= dye part or chromogen (color producing part) Dyes may be direct, acid, disperse, premetallised dye etc. B = bridging part. Bridging part may be –NH- group or –NR- group. G = reactive group bearing part. X= reactive group.

Classification of reactive dyes:Reactive dyes may be classified in various ways as below:

1) On the basis of reactive group:a) Halogen (commonly chlorine) derivatives of nitrogen containing

heterocycle, like 3 types-• Triazine group• Pyridimine group• Quinoxaline dyes Example: Triazine derivatives: procion, cibacron. Pyridimine derivatives: reactone Quinoxaline derivatives: levafix.

b)Activated vinyl compound:• Vinyl sulphone • Vinyl acrylamide • Vinyl sulphonamide.

Example: Vinyl sulphone: remazol Vinyl acrylamide: primazine Vinyl sulphonamide: levafix.

Classification of reactive dyes:2) On the basis of reactivity:

a) Lower reactive dye: Here ph is maintained 12-12.5 by using NaOH in bath.

b) Medium reactive dye: here pH is maintained 11-12 by using Na2CO3 in dye bath.

c) Higher reactive dye: here pH is maintained 10-11 by using NaHCO3 in dye bath.

3) On the basis of dyeing temperature:a) Cold brand:

These types of dyes contain reactive group of high reactivity. So dyeing can be done in lower temperature i.e. 320-600C.

For example: PROCION M, LIVAFIX E.b) Medium brand:

This type of dyes contains reactive groups of moderate reactivity. So dyeing is done in higher temperature than that of cold brand dyes i.e. in between 600-710C temperatures.

For example, Remazol, Livafix are medium brand dyes. c) Hot brand:

This type of dye contains reactive groups of least reactivity. So high temperature is required for dyeing i.e. 720-930 C temperature is required for dyeing.

For example PRICION H, CIBACRON are hot brand dyes.

The reactive rate of some compounds are mentioned below:

COMPOUND STRUCTURE REACTIVE RATE Water H-OH 1.0Iso-propanol CH3-CHOH-CH3 0.7

Ethanol CH3-CH2-OH 7.4

Methanol H-CH2-OH 12.3

Glucose C6H12O6 5.5

So from the above table it is obvious that secondary hydroxyl group is the beast reactive while primary one is the most reactive.

Dyeing mechanism of reactive dye: The dyeing mechanism of material with reactive dye takes place in 3 stages:-1.Exhaustion of dye in presence of electrolyte or dye absorption.2.Fixation under the influence of alkali.3.wash-off the unfixed dye from material surface.•Now they are mentioned below:

1.Dye absorption:

When fibre is immersed in dye liquor, an electrolyte is added to assist the exhaustion

of dye. Here NaCl is used as the electrolyte. This electrolyte neutralize the negative

charge formed in the fibre surface and puts extra energy to increase dye absorption. So

when the textile material is introduces to dye liquor the dye is exhausted on to the

fibre.

Dyeing mechanism of reactive dye:

2. Fixation: Fixation of dye means the reaction of reactive group of

dye with terminal –OH or-NH2 group of fibre and thus forming strong covalent bond with the fibre and thus forming strong covalent bond with the fibre. This is an important phase, which is controlled by maintaining proper pH by adding alkali. The alkali used for this purpose depends on brand of dye and dyeing temperature. Here generally caustic soda, soda ash or NaHCO3 is used as alkali depending upon reactivity of dye. They create proper pH in dye bath and do as the dye-fixing agent. The reaction takes place in this stage is shown below:

alkali

pH10-12.5 1. D-SO2-CH2-CH2-OSO3Na + OH-Cell D-SO2-CH2-CH2-O-Cell + NaHSO3

Alkali

2. D-SO2-CH2-CH2-OSO3Na + OH-Wool D-SO2-CH2-CH2-O-Wool + NaHSO3

3.

3.

alkali

pH10-12.5

3. Wash-off:

As the dyeing is completed, a good wash must be applied to the material to remove extra and unfixed dyes from material surface. This is necessary for level dyeing and good wash-fastness. It is done by a series of hot wash, cold wash and soap solution wash.

Application method of reactive dyes varies significantly with type of dyes, shade required, and available equipments in the mill. These are 3 application procedures

available:

1. Discontinuous method--Conventional method-Exhaust or constant temperature method-High temperature method-Hot critical method. 2. Cotinuous method-

-Pad-steam method -Pad dry method - Pad thermofix method

3. Semi continuous method-- Pad roll method- Pad jig method- Pad batch method.

Stripping of reactive dye:

1.Partial stripping: Partial stripping is obtained by treating the dyed fabric with dilute acetic acid or formic acid. Here temperature is raised to 70-100°C and treatment is continued until shade is removed by desired amount. After that a through washing is necessary to remove the product of hydrolysis. The amount of acid used is as below: -Glacial acetic acid : 5-10 partsWith water :1000 partsOrFormic acid :2.5 to 10 partsWith water :1000 partsTemperature : 70 - 100°CTime : until desired shade is obtained.

2. Full stripping: For complete stripping the goods are first treated with sodium hydrosulphite (hydrose) at boil then washed off and bleached with 1% sodium hypochlorite (NaOCl) at room temperature. This is carried out for 30 min. The recipe is as below: -

Na-hypochlorite : 1% at room temperature

Na-hydrosulpite: at boil.Time : 30 min

D-R-Cl + H-OH D-R-OH + H-Cl

•Hydrolysis of activated vinyl compound containing dye,

D-F-CH2-CH2-OSO3H + H-OH D-F- CH2-CH2-OH + H2SO4

For preventing hydrolysis the following precautions are taken—1.As hydrolysis increases with increasing temperature during dissolving and

application temperature should not be more than 40°C.1.Dye and alkali solution are prepared separately and mixed just before using.2.Dye and alkali should not be kept for long time after mixing.

Important factors for dyeing cellulosic fibre with cold brand reactive dye in batching process:

The important factors are as follows:1) pH of the dye bath:

The optimum pH for fixing cold brand reactive dyes on cotton and viscose rayon depends on individual dyes, the temperature and time of dyeing. pH decreases with increasing temperature and time of dyeing. For most of the dyes the optimum pH is 10.8 to 11 at 20o to 25oC. Soda ash has been the best alkali for dyeing at 30oC for cotton, mercerized cotton and linen. Increased fixation (due to higher temperature) and increased dye bath stability and better reproducibility are the advantages of soda ash as the fixing agent.

For viscose rayon the optimum pH is 10.3 at 20o to 25oC. 2) Amount of alkali:

The amount of alkali used for fixing depends on the depth of shade dyed and the liquor ratio employed.Some quantities of alkali required for fixing the reactive dyes are given table 28.

3) Dyeing temperature:

Since increase in temperature affects the rate of physical and chemical processes involved in dyeing, it is important in dyeing reactive dyes also. The affinity of the dye for the fibre decreases with increases in temperature and at the same time the rate of hydrolysis of the dye increases and adversely affects the fixation of color yield. However the rate of diffusion of the dye in the fibre increases with increased temperature. At temperatures lower than 20oc, the rate of fixation is very low. Hence for most of the dyes a temperature of 20o to 25oC is the recommended temperature while for some other dyeing at 50o to 60oC with sodium bicarbonate as the alkali gives maximum color value.

Important factors for dyeing cellulosic fibre with cold brand reactive dye in batching process:

4) Electrolyte concentration:Since reactive dyes have low affinity for cellulose exhausting the dye bath by adding common salt or Glauber’s salt prior to fixation can increase the fixation. The amount of salt required producing adequate exhaustion decreases with decreasing liquor ratio. Thus for pale shade on cotton and viscose rayon 15 and 10 g/l of common salt used. The quantities may be increased to 30 and 20 to 30 g/l for medium and deep shades on these fibres.

5) Time of dyeing:

Generally the dye may be added in two portions. The salt may also be added in two lots. The exhaustion takes place in 20 to 30 min. There is generally no advantage in extending the period beyond 30 min. The alkali is then added and the dyeing continued for 30 to 90 min. The depth of shade and reactivity of the dye decide the time of dyeing. For deeper shades larger times are required.

6) Liquor ratio:

With decreased liquor ratio, both exhaustion and fixation take place to increased exert. However the rate of fixation of most of the dyes is not significantly affected. As the liquor ratio is decreased, the effectiveness of increasing salt addition also decreases. Hence lower amount of salt are sufficient to get optimum exhaustion.

•

Why low affinity reactive dyes are preferred for dyeing?• If the reactivity of the dye is increased considerably, the rate of reaction with the fibre

increases. There fore, the dyeing can be carried out in a short time. However in this case the rate of dye also increases, leading to deactivation of a part of the dye. This results in wastage of the dye. If on the other hand the reactivity of the dye is decreased, the extent of hydrolysis can be reduced considerably. However this results in the slower rate of reaction with the fibre also. The ultimate object of dyeing is to react as much of the dye ass possible with the fibre and minimize the hydrolysis of the dye. This is achieved in practice in two stages. The dyeing is first started from the aqueous medium under neutral conditions when the dye does not react either with the fibre or with water. Then gluber salt or common salt is added to exhaust the dye onto the fibre as much as possible. In this respect, this stage of dyeing (exhaustion) resembles the dyeing of direct dyes on cotton. Then the second step (that of fixation or reaction with the fibre) is carried out by adding the alkali (usually used soda ash). Since the exhausted dye is already on the fibre, it is more likely that the exhausted dye reacts with the fibre in preference to water. However the dye present in the dye bath (which contains a substantial amount of the reactive dye) can now react with water since it is under alkaline condition. It is already stated that the hydrolyzed dye cannot further react with the fibre but dye to the affinity forces; it is absorbed by the fibre and is retained in it. During the subsequent washing or soaping the substantivity held hydrolyzed dye gets stripped into the treatment of the dyeing with boiling soap or detergent solution removes almost all hydrolyzed dye. However if the affinity is very low, exhaustion of the dye bath prior to fixation cannot be achieved substantially. This results in a larger amount of the reactive dye remaining in the dye bath and getting hydrolyzed when alkali is added subsequently. If the dye has high affinity for cellulose like a direct dye, it becomes difficult to remove the hydrolyzed dye from the dyeing since it is also absorbed by and retained in the fibre by fairly strong affinity forces, through not as strong ass the covalent bond formed between the dye and the fibre. Hence in actual practice low affinity dyes are selected for converting in to reactive dyes.

Dye Brand name Origin/source

REACTIVE DYE

Bezactive Bezema , Switzerland

Ciba Ciba , Switzerland

Dychufix Hubei Hwalle dyestuff Ind.co.

Kemafix Jaychem,India

Levafix Dystar , Germany

Procion Dystar, Germany

Jackazol India

Kemazol Jaychem,India

Remazol Dyestar , Germany

Solazol Solarfine , Taiwan

Solacion Solarfine , Taiwan

Dyestuffs:

Brand name Type SourceNovolube Jet Anti creasing agent Techna,ItalyBluton BVB1 Violet tone brightener CHT,GermanyCibacel DBC Sequestering agent Ciba,India.Cibafix ECO Fixing agent Ciba ,Switz.Cibafluid C Anticreasing agent Ciba ,Switz.SandocleanPCLF Detergent Clarient,GermanyPermacol FA Stabilizer Techna,ItalyNovostone CR Enzyme Techna,ItalyCotton white T Redder tone brightener CHT,GermanyCyclanon E Fixing agent BASF,GermanyCyclanon ECO Reduction cleaning agent BASF,GermanyJinlev RLF349 Dispersing agent Geigy,TaiwanEulysin S pH buffer in PET dyeing BASF,GermanyFelosan NOF Detergent CHT,GermanyUvitex EBF Whitening agent Ciba ,Switz.Jinlev CL-225 Levelling agent for reactive dye Geigy,TaiwanOxalic caid Iron remover -Palegal FA-8 Levelling agent for disperse dye BASF,GermanyRespumit BU Antifoaming agent BASF,GermanyPermacol SQ Sequestering agent Techna,ItalyNa thiosulphate Peroxide killer -Uniperol O Washing agent for PET dyeing BASF,GermanyUvitex EVF PET brightener Ciba, Switz.Uvitex 2B Yellow tone brightener Ciba ,Switz.Mollan129 Soapinging agent Rota,dystarAcetic acid pH controller -Reduction HCS Reduction cleaning agent Geigy,TaiwanMollan130 Sequestering agent Rota,dystarBluton 2B Whitening agent Ciba,India

Chemicals:

• Remark• The list is for the time of our industrial attachment. It

varies according to the availability of the material & their price.

• The price has not been supplied to us due to their secrecy act.

• The annual requirement was not available & is a record of the procurement department.

Chapter 6

IMPORTANCE OF THE SURVEY The main goal of our project is to provide information about the reason of using

reactive dyestuff in major textile industry in Bangladesh, different methods using in our industry for cotton dyeing with reactive dyes, technical deficiency of reactive dyes during dyeing & causes and remedies of deficiency of reactive dyes.

As these topics are very sensitive for dyeing industries, it is very much important to

make a survey. It will be very helpful not only for our studying period but also for our future career.

This survey also has these importances: 1. To mention the reason of using reactive dyes in major textile industry.2. To study on the application of reactive dyes.3. To learn about the technical deficiency of reactive dyeing.4. To study the causes and remedy of deficiency of reactive dyeing.

Chapter 7Reason of using Reactive Dyes in Major Textile Industries in Bangladesh

Maximum textile industries in Bangladesh are based on cotton knit fabric and reactive dyes are easily applicable to cellulose fibres.

Other associated reason as follows: 1. Reactive dyes are soluble in water.

2. They have very good light fastness with rating about 6. 3. The dyes have very stable electron arrangement and can protect the degrading effect of ultra-violet ray. 4. Textile materials dyed with reactive dyes have very good wash fastness with rating about 4-5 due to strong covalent bonds formed between fibre polymer and reactive group of dye.

5. Reactive dyes give brighter shades and have moderate rubbing fastness. 6. Dyeing method of reactive dye is easy. It requires less time and low temperature for dyeing. 7. Reactive dyes are comparatively cheap. 8. Fixation occurs in alkaline condition. 9. Reactive dyes have good perspiration fastness with rating 4-5. 10. It has a wide range of shade

Chapter 8Methods of Dyeing Cotton Goods with Reactive Dyes

Properties:

1. Anionic in nature.

2. Soluble in water.

3. Form strong covalent bond

4. Better wet & light fastness.

5. Have better substantivity.

6. Dyeing is carried out at alkaline condition.

Influencing factors:

1. PH

2. Temperature.

3. Conc. of electrolyte.

4. Time.

5. Liquor ratio.

REACTIVE DYE :Reactive dye react with the fibres mainly react with cellulose fibres e.g. cotton, jute, bast fibres,

viscose, flax. It can be applied to protein fibres e.g. wool & silk. Reactive dye contains reactive group and this reactive group makes covalent bonds with the fibres and becomes the part of the fibre.

The general formula of reactive dye as follows:D-X-YHere D->Chromophore of dye post X->Bridge Y->Functional groupD-X-Y + Fibre ->D-X-Y-Fibre Covalent bondReactive dyes water solubleD-F + Cell-OH ->Dye-F-O-cellD-F + H-OH ->Dye-F-OH Hydrolysis

REACTIVE DYEING FOR SENSITIVE SHADE AT 60oC

60min at 60OC,

10min at 40-50OC,

Dyeing: Anticreasing Agent (.5 g/l) Leveling Agent (1 g/l) A. Acid ( .2 g/l) Dyes (According to Shade %) G. Salt (According to Shade %)

Soda Ash (According to Shade %)

Neutralization (Dyeing): A. Acid (1 g/l)

Soaping: Soaping Agent (.5 g/l)Dyeing curve: Sequestering Agent Color Dosing 60 0C 50min

Leveling Agent Linear (30min) 500C 10min

Bath drain350C 20min 30min 10min 10min 35 0C ColdPH +Hardness Check Salt (15min) 1 g/l Soda Rest Soda wash (30min) (60min)

 HOT BRAND REACTIVE DYEING:

DYEING AT 92oC:

60min at 80OC, PH = Above8 (Always)

10min at 40-50OC,

20min at 70-80OC,

15min at 40OC,

20min at 40OC,

Process steps:Dyeing: Anticreasing Agent (.5 g/l) Leveling Agent (1 g/l) A. Acid ( .2 g/l) Dyes (According to Shade %) G. Salt (According to Shade %)

Soda Ash (According to Shade %)

Neutralization (Dyeing): A. Acid (1 g/l)

Soaping: Soaping Agent (.5 g/l)

Fixing & Softening: Fixing Agent (.5 g/l)

A. Acid (.5 g/l) Softener (1.5 g/l)

Bath

Drain

Dyeing curve: 800C 40min

Sequestering Agent Color Dosing 600C 50min

Leveling Agent Linear (30min) 500C 10min Bath Drain

350C 20min 30min 10min 10min 35 0C Cold washPH +Hardness Check Salt (15min) 1 g/l Soda Rest Soda (30min) (60min)

N.B: The temperature increase at the grade 10C/min because it’s an important matter to avoid the shade variation in dyeing

DARK COLOR DYEING WITH REACTIVE DYE AT 600CDyeing:

  

Anticreasing Agent (1.5 g/l) Leveling Agent (1 g/l) A. Acid (.2 g/l) Dyes (According to Shade %) G. Salt (According to Shade %) Soda Ash (According to Shade %)60min at 60OC,

Neutralization (Dyeing): A. Acid (1 g/l)10min at 40-50OC,  

Soaping: Soaping Agent (.5 g/l)20min at 70-80OC,

Fixing & Softening: Fixing Agent (.5 g/l)15min at 40OC, 15min at 40OC,

A. Acid (.5 g/l) Softener (1.5 g/l)20min at 40OC,

Bath Drain

60min at 60OC,

10min at 40-50OC,

20min at 70-80OC,

20min at 40OC,

15min at 40OC,

Dyeing procedure for dark shadeFelosan NOF/Wetting agent = 0.5g/lKappazon H53NEU/Stabilizer (H2O2) = 0.5 g/lAnticreasing agent = 1.0 g/l [Only for S/J]

↓ 60oC x 5'Caustic → 2 g/l

↓ 60oC x 15'Hydrogen peroxide → 2.5 g/l [Dosing 10']

↓ (60oC - 80oc)Temperature rise up to 105oC ↓ 30'Acetic acid → 1.0 g/lH2O2 killer → 0.5 g/l

↓ 60oC x 10'Acetic acid → 0.8 g/l (To control pH = 4.5-5.5)Enzyme → 1.5 g/l

↓ 55oC x 45' - 60'Kappaquest FE / Sequestering Agent → 0.35 g/l

↓ 90oC x 5'Sarabid LDR → 0.5 g/l (leveling agent)

↓ 60oC x 5'Gluber Salt (Runtime → 10')

↓ 60oC x 10'

↓Dye stuff 

↓ 60oC x 35' Runtime 20'Soda ash

↓ 60oC x 40' Runtime 60'Bath drop after shade matching ↓ Hot rinse

↓ 60oC x 10'Soaping

↓ 80o - 95oC x 10'Cold rinse

↓ 45oC x 10'Neutralize (Acetic acid = 0.5 g/l)

↓ 45oC x 10'Fixing

↓ 40oC x 15'Softening ↓ Unload

Dyeing Procedure for White

↓ Felosan NOF/wetting agent → 0.5 g/l Kappazon H53NEU /Stabilizer → 0.5 g/l Anticreasing agent → 1.0 g/l [Only for S/J] Caustic → 3 g/l

↓ 60oC x 15'Hydrogen peroxide → 10.0 g/l

↓ 60oC x 10'Syno white 4BK/Optical brightener (60o →

80oC) ↓ 105o x 60'

Acetic acid → 1.0 g/l ↓ NT x 10'

Acetic acid → 0.8 g/l [To Control PH- 4.5 - 5.5]

Enzyme → 1.5 g/l ↓ 55oC x 45' - 60'

Sequestering agent →

0.5 g/l

↓ 90oC x 5'

Acetic acid → 0.35 g/l

Softener → 1.5 g/l

↓ 40oC x 10'

N. Hot

↓

Unload

Dyeing procedure for Light/Medium Shade ↓

NOTE: - During Bleaching we maintain gradian to rise temperature from 80o - 105oC as  1.5o/min and cooling from 105oC - 80oC as 2o/min. For S/J or low GSM. Fabric. 

Felosan NOF/Wetting agent → 0.5 g/lKappazon H53NEU /Stabilizer (H2O2) → 0.5 g/l Anticreasing → 1.0 g/l [Only for S/J]

↓ 60oC x 5'Caustic → 2 g/l

↓ 60oC x 15'Hydrogen peroxide → 2.5 g/l

↓ (60o - 80oC)Temperature rise up to 105oC

↓ 30'Acetic acid → 1 g/lH2O2 Killer → 0.5 g/l

↓ 60oC x 10' Acetic acid → 0.8 g/l [To Control PH- 4.5 - 5.5]Enzyme → 1.5 g/l

↓ 55oC x 45'Sequestering agent / Kappaquest FE → 0.35 g/l

↓ 90oC x 5' Sarabid LDR → 0.5 g/l (leveling agent)• ↓

Anticreasing agent → 0.5 g/l [ For S/J] ↓ 60o x 5'

Dye stuff ↓ 60oC x 35' → Runtime → 20'

Glauber Salt ↓ 60o x 10' → Runtime → 20'

Soda ash ↓ 60o x 40' → Runtime → 60'

Bath drop after shade matching ↓Hot rinse

↓ 60o x 10'Soaping

↓ 80o - 90oC x 10' Cold rinse

↓ 45o x 10' Neutralize

↓ 45o x 10'Softening ↓Unload

Dyeing procedure for S/J Light / Medium Color

↓Felosan NOF/ Wetting agent = 0.5 g/lKappazon H53NEU /H2O2 Stabilizer = 0.5 g/lAnticreasing agent = 1.0 g/l

↓ 60o x 5'Caustic = 2 g/l

↓ 60oC x 15' [Dossing]Hydrogen peroxide (H2O2) = 2.5 g/l

↓ (60o - 80oC)Temp rise up to 105oC & Run - 30' ↓ Acetic acid = 1.0 g/lH2O2 killer / Kappaquest FE = 0.5 g/l

↓ 60oC x 10'Acetic acid = 0.8 g/l [To control PH - 4.5 - 5.5')Enzyme = 1.5 g/l

↓ 55oC x 45' - 60'Sequestering agent = 0.35 g/l

↓ 90oC x 5'Sarabid LDR /Levelling agent = 0.5 g/lAnticreasing - 0.5 g/l• ↓

60o x 5' Dye stuff

↓ 60o x 35' - Run time - 20'Glauber Salt

↓ Dosing - 60o x 10' - run time - 20'Soda ash

↓ 60 x 40'Bath drop after shade matching ↓

Hot rinse - 10' x 60oC

↓ Soaping ↓ 80o - 90oC x 10'

Neutralization / Acetic acid ↓ 45oC x 10

Cold rinse - 45o x 10' ↓

Softening ↓ Unload

Migration Dyeing procedure for dark, medium & light shade

Felosan NOF/wetting agent → 0.5 g/lKappazon H53NEU /stabilizer (H2O2) → 0.5 g/lAnticreasing → 1.0 g/l [Only for S/J]

↓ 60oC x 5'Caustic → 2 g/l

↓ 60oC x 15'Hydrogen peroxide → 2.5 g/l

↓ (60oC - 80oC)Temperature rise up to 105oC

↓ 105oC x 30'Acetic acid → 1.0 g/lKappaquest FE /H2O2 killer → 0.5 g/l

↓ 60oC x 10'Acetic acid → 0.8 g/l [To control PH = 4.5 - 5.5']Enzyme → 1.5 g/l

↓ 55oC x 45' - 60'Sequestering agent → 0.35

↓ 90oC x 5' Sarabid LDR → 0.5 g/lAnticreasing agent → 0.5 g/l [for S/J] ↓

Dye stuff ↓ 60oC x 35' → Run time - 20'

↓ Glauber Salt [Run time 10']

↓ 60o x10'Temperature rise up to 80oC [ Run time→ 20']

↓ 80oC x 20'cooling to 60oC ↓

soda ash ↓ 60oC x 40' → Run time → 60'

Bath drop after shade matching ↓

Hot rinse ↓ 60o x 10'

Soaping ↓ 80oC - 95oC x 10'

Cold rinse ↓ 40o x 10'

Neutralize ↓ 45 o x 10'

Fixing [ For medium & dark shade] ↓ 40 o x 10'

Softening ↓ Unload

Sample (Dyeing)

COLOR RECIPE SAMPLE

BLACK SATAZOL YELLOW 3RS=1.649%SATAZOL RED 3BS =O.912% SATAZOL BLACK NNT=8.47%

RED KIRA.YELLOW HB=1.4%KIRA. RED HB =2.0%KIRA. RED SP2B=6.64%

MERUN KIRA.YELLOW HB=0.47%KIRA. RED HB =3.8%KIRA. BLUE HB =0.86%

DK-BLUE KIRA.YELLOW RR=0.188%KIRA. RED RR =0.29%KIRA. BLUE RR =1.26%

PINK SETA. RED 3BS =0.078%SOLA.RED SP2B=0.02%

DK- TURGISH SATAZOL YELLOW 3RS=0.385%SATAZOL RED 3BS =O.049% SATAZOL BLUE BB=1.64%

Sample (Dyeing)

COLOR RECIPE SAMPLE

CLASSIC BLUE SATAZOL YELLOW 3RS=0.013%SATAZOL RED 3BS =O.066%SATAZOL BLUE SETR =0.62%

GOLD RUST SATAZOL YELLOW 3RS=3.14%SATAZOL BLUE BB =O.004%SATAZOL BLUE BB =0.40%

VIO-LET SATAZOL RED 3RS =0.65%SATAZOL RED 3BS =O.48%BZ. BLUE VW =1.40%

TURGISH E/B BLUE RSPL =2.1%R/M T. BLUE G =0.6%

LIGHT YELLOW SETA. YELLOW 3BS=0.048%RM. YELLOW 3GL =0.076%

NATURAL BEZ.YELLOW SLF=0.154%BEZ.RED SLF =0.05%BEZ.BLUE SLF =0.132%

DEEP LILAC E/B. YELLOW-4GL=0.008%RED 3BSN =1.1%BE. BLUE VRN =1.14%

Printing of cotton fabric with reactive dyes (block and screen printing method), combination shade.

Introduction:By the term textile printing we mean the localized application of dyes or pigment and

chemical by any method, which can produce particular effect of color on the fabric according to the design. In this practical we print cotton fabric with cold brand reactive dyes in block and screen-printing methods in combination method.

A dye, which is capable of reacting chemically with a substrate to form a covalent dye substrate linkage, is known as reactive dye. The dye contains a reactive group and this reactive group makes covalent bond with the fibre polymer and act as an integral part of fibre. Reactive dyes forms covalent bond with fibre polymer and thus attach itself with fibre. It is now a day mostly used for dyeing and printing of cotton yarn and fabric. It is a cationic dye. Cold brand reactive dyes have higher reactivity.

 Block printing method is the oldest printing method.  It is used mostly in sarees, handkerchiefs etc. in this printing method we use blocks of different designs.

In screen printing a very little screen made by glass fibre is used. There are many types of screen-printing, but we have done in our experiment was hand screen-printing. Hand screen-printing is mostly used for sarees to 14-16 colors in on pattern can be produced at a time.

Style of printing: Direct style. Method of printing: Block and screen-printing method. Sample: One piece of square size bleached, scoured cotton fabric (small) and One piece of square size

bleached, scoured cotton fabric(bigger) Combination color:Total Dyes = 1.8gmBlue = 0.6gmRed = 0.6gmYellow = 0.6gm Recipe:Dye: Total Dyes = 1.8gmCIBA CRON RED = 0.6gmCIBA CRON BLUE = 0.6gmCIBA CRON YELLOW = 0.6gm Urea = 8gmThickener = 70gmAlkali = 8gmAdditional water = as required.

Preparation of thickener:

1)16 gm of starch and 200cc water are taken in bowl.

2)Heat is applied and solution is stirred continuously until a thick viscose solution is obtained.

3)By continuous stirring and boiling a specific viscosity is obtained.

4)The heat application is stopped otherwise viscosity falls down. So temperature is maintained strictly.

Preparation of printing paste:

1) At first we take required amount of dyestuffs in a bath.2) Then little amount of water is added into the bath for

mixing these dyes. And start stirring for mixing the three types of dye.

3) Then required amount of urea is added into the dye bath.

4) After then required amount of thickener is added 5) Then continuous stirring is done for few minutes for

mixing all the ingredients of print paste.6) After mixing finally required amount of alkali is added

to the dye bath and mix them with the help of stirring.•

Printing process:

• Block printing method:1)The fabric, which will be printed, is placed on the

printing table.2)The printing paste is put on the tray box. 3)The block is selected and it is touched with print

paste.4)Then block is pressed upon the sample fabric.5)After pressing the block on the sample fabric the

block is put off from the fabric.6)Finally we get the printed fabric of required dyes.•

Screen-printing method:

1) The fabric is placed on the printing table of flat screen-printing machine. The table is made of soft by laying on it.

2) Then the screen is placed on the sample fabric.3) The printing paste is taken on the screen perforation.4) Thus we can find the printed fabric with a smooth

wooden strike the paste is spread over the screen with slight pressure.

5) So that the dye particles can penetrate through the screen perforation.

6) Thus we get printed fabric.•

After treatment:

• The printed fabric is steamed for 5-10 minutes in a cottages steamer at 1050-1100C and washed with cold water for removing unfixed dye and exhausted thickener and then dried.

Conclusion

Printing of cotton fabric with reactive dyes has excellent build up property and maximum fixation. Shade is also bright. By this experiment we have acquire knowledge about process of printing cotton fibres with cold brand reactive dyes in combination shade. The shade of printed fabric is moderately good, as we required. Special thanks to our teacher and his assistants for grate cooperation.

•

Chapter 9Technical Deficiency of Reactive Dyes, CAUSES AND THEIR

REMEDIES

•

• Hydrolysis is the main problem in dyeing with

Reactive dyes. Only 60 to 70 percent dyes are

absorbed in Reactive dyeing. There are also

many causes of technical deficiency of

reactive dye. Those are described below:

Hydrolysis of reactive dyes:

Under alkaline condition, reactive dyes react with the terminal hydroxyl group of cellulose. But if the solution of the dye is kept for long time, it’s concentration drops. Then the dye react with the hydroxyl group of water .The reaction of dye with water is called Hydrolysis of reactive dyes.

Factors which affect the hydrolysis of the reactive dye:

1. Salt concentration:

When the cellulosic textile material is sink into water it convert into negetive charge or anionic

charge. But the reactive dye is also convert into anionic charge. So the surface of the cellulosic material repel

the dye molecules. To overcome the problem we use electrolite material like salt. It hepls to netralize the

negetive ion over the textile material and helps the reactive dye ion to fix on the surface of the materail. As a

result If we increase the concentration of the salt hydrolysis of the reactive dye will decrease.

2.pH:

if the pH of the medium increase hydrolysis of the reactive dye also increase. This is for, reactive dye

ionised more in alkaline medium and as a result it react with hydroxyl group of the water.

3.Temperature:

With the increase of temperature hydrolysis of the reactive dye increases.

4.Substantivity:

With the increase of the substantivity hydrolysis of the reactive dye increase.

5.Reactive group of the reactive dye:

Hydrolysis of the reactive dye depends on which group does it bears. Vinyl sulphone dye hydrolyize

more than the Triazinyl group.

Factors which affect the hydrolysis of the reactive dye:

Hydrolysis of water: Hydrolysis of the water is also a cause of

the technical deficiency of the reactive dye. Remidies of the hydrolysis of the reactive dyes: The highest absorption of the reactive dye is

about 70%. To minnimize the more lose of the reactive dye we should maintain proper liquor ratio, proper time and temperature. Even the pH of the emdium is also an important factor to avoid the more wastage of the reactive dye

Faults and their remedies for the technical deficiency of reactive dyes:

• There creates many problems and defects in dyed fabrics when dyeing with Reactive dyes due to technical deficiency. Some defects may be remedied by some process. Those are described below:

• • Defect: Colors are not fast to washing, Abrasion; Staining in the fabric when transporting from

place to the other, water marks on the fabric

Remedy : Wash the fabric with soap and soda ash at right temperature. Adding sequestering agent will yield good results. Treating with Ammonia will also give good results.

Defects in the fabric due to Printing- Need to take out full color

Remedy: Treat the dyed fabric with Sodium Hydrosulphite with 5-10 gm Sodium Hydrosulphite at 75 deg C for 30-45 minutes. Add 5-7 gms Caustic Soda for even removal of colors. The color becomes light yellow or brown after removal. Wash it thoroughly with soap.

The color can also be removed by solution of Sodium Hypochlorite. Treat the fabric with a sodium hypochlorite solution ( 3-5 gms Chlorine) for 20-30 minutes. Keep the pH between 9-10. The fabric is treated with Acetic acid after removal of color to remove chlorine and to neutralize the fabric.

The fabric can be re-dyed after removal of color

Faults and their remedies for the technical deficiency of reactive dyes:

• Defect: Bleeding in colors during washing, abrasion

Remedy: Boil the fabric with caustic, Treat the fabric with Hydrogen Peroxide ( 5-10 gpl, 60-70 deg C) to make the color fast.

Defect: The fabric has been dyed in darker shade, uneven dyeing

Remedy: To take out color from the fabric treat it with caustic for 45-60 min at 70 deg C. Thereafter treat the fabric with 10-20 gpl Acetic Acid for 40-60 min at 80-85 deg C.

Defect: Uneven dyeing, marks of water, marks of colors

Remedy: Wash the fabric in soap and re-dye in a darker shade

Defect : The fabric has become stiff and rough after dyeing

Remedy: Finish after adding right softener

Defect: Color staining of fabric, uneven dyeing

Remedy: Re-dye the fabric in darker shade.

Defect: Color staining in fabrics of darker shade, uneven dyeing.

Remedy: Dye the fabric in Sulphur black.• Caution: Please treat a small length fabric to check the effectiveness and any harmful effects before commencing a full treatment.• • Defect: Color staining of fabric, uneven dyeing

Remedy: Re-dye the fabric in darker shade.

Defect: Color staining in fabrics of darker shade, uneven dyeing.

Remedy: Dye the fabric in Sulphur black.

Chapter 10

Conclusion Obviously the project work we have discussed has many other arguments but as far as

we believe the presented view to a large extent is one that has a predominant role in our textile sector especially in REACTIVE DYEING & thus has the ability to influence our thoughts.

REACTIVE DYEING is truly an important dyeing phenomenon for cellulose materials &

ranks as the major contribution to the progression of any textile dyeing industry. Dyeing parameters have a great influence on reactive dyeing which have described in my report. It was really an important subject & also innovative one. I have tried my best to express the topics properly.

The project work has given us a special interest & has been arranged as a presentation

of the application reactive dyes in cotton dyeing. I think anyone can research in future about this topic which will enrich our textile knowledge.

Any absolute conclusion is impossible but waiting the pros & cons I’m certain that my

position is a tenable one.

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