Reaction Mechanism of Reactive Dyes in Bengal Hurricane Group on Cellulose

8/18/2019 Reaction Mechanism of Reactive Dyes in Bengal Hurricane Group on Cellulose

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PROJECT REPORT ON

REACTION MECHANISM OF REACTIVE DYES IN

BENGAL HURRICANE GROUP ON CELLULOSE

FIBER.

BASIS OF

BENGAL HURRICANE GROUP


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Prepared By : Mazad! Ha"a# "$e"$%r

ID: &'('''')''''*

(+,$ Ba,-$ "e""%/# &''01&'(+2

Depar,3e#, : 4e, Pr/-e""%#5 Te-$#/!/5y

E3a%!: 3azad!$a"a#6ya$//.-/3

B!/5 : 777. Te8,%!e!a9.9!/5"p/,.-/3 %"%,2

Southeast UniversityDepartment Of Textile Engineering

I/A 251252 Te!gaon Dha"a #angla$esh

%repare$ #y &

©right


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CONTENTS• Introduction

• Raw Materials• Importance of The Survey

• Reason of using Reactive dyes in major

textile industry in Bangladesh• Methods of Dyeing & rinting !otton

"oods with Reactive Dyes

• Technical De#ciency of Reactive Dyes$!auses and Remedies of TechnicalDe#ciency

•!onclusion


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'hapter 1A("no)le$gement

Project Work is an academic function of the Pabna Textile Engineering College. Our teacher *$+ A,$ul*annan Princi!al Pabna Textile Engineering College ga"e us an o!!ortunit# to choose !referablemills for Project Work. $ chose #engal -urri(ane Dyeing . printing pvt+0 t$+ jo#full# %ith thesu!er"ision of *ithun #is)as &sst. 'anager(!roduction).

*uring the Project %ith #engal -urri(ane Dyeing . printing pvt+0 t$+ $ %orked in all thede!artments related %ith *#es and Chemicals. +eside these $ learned about *#e ,ualit# Control andStorage S#stem!rinting -arments Store $n"entor# /nishing s!eciall# d#eing.

Our dee!est a!!reciation goes to *ithun #is)as &sst. 'anager(!roduction)*#eing #engal -urri(aneDyeing . printing pvt+0 t$. to gi"e us the o!!ortunit# to ha"e !roject %ork at #E3A-U44I'A 34OU%.

$ %ould like to thank Engr. 'd. $1bal 'ahamud (2ead of the 3actor#) -' *#eing #engal -urri(aneDyeing . printing pvt+0 t$. for hel!ing to kno% about the all as!ects of #E3A -U44I'A34OU%.

$ %ould also like to thank Tare Ahme$(*e!ut# 'anager)*$+An)arulIslam(*e!ut# 'anager) 'd. &rif 4abbani Talukdar(*e!ut# 'anager)*#eing #engal -urri(ane Dyeing

. printing pvt+0 t$. for hel!ing to kno% about the all as!ects of #E3A -U44I'A 34OU%.

Our gratitude also goes to all the em!lo#ees of #E3A -U44I'A 34OU% for their sincere co5o!eration su!!ort and "aluable ad"ice %hich the# ha"e !ro"ided us during the t%o months oftraining.

6astl# $ ex!ress m# gratitude to our su!er"ising teacher the name that should be mentioned /rst Shi,Shan"ar 'ha"ra,orty 2ead of the *e!t. Wet Processing Technolog# for his "aluable direction su!er"ision.

2o%e"er $ ha"e !re!ared m# $ndustrial &ttachment o"ercoming all the di7culties also the shortage oftime. 2ere $ %ould like to !resent the re!ort.

•


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&!!lication of reacti"e d#es inmajor textile industries in

+angladesh


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major textile industries in

+angladesh

h


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Cha!ter8:Project &bstract

•

The use of reacti"e for *#ed !roducts has dramaticall# increased o"er the last ;


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'hapter 7 IT4ODU'TIO

• With the e"aluation of the %et !rocessing industries the use of the reacti"e d#esin the most of the industries increases da# b# da#. &s a result to com!lete the!roject it is has become a !art to discus about the e"aluation or gro%th of the%et !rocessing industries in +angladesh. No% the number of the %et !rocessingindustries and /nishing industries in +angladesh is 189 %hich are totall# ex!ortoriented according to the sur"e# of the BTMA %hich has been !ro"ided intotheir %e address.

• +ut the interesting matter is that %ith the gro%th of the textile %et !rocessingmills the number of the em!lo#ee is not increasing. This is because of to reducethe cost and increase the 1ualit# the moderni>ation of the machine is alsoincreasing %hich reduce the number of %orker in %et !rocessing industries. +ut%hat is the actual number of the %orker in %et !rocessing industries has notbeen found due to the lack of !ro!er sur"e# in this sector.

• Our pro!e(t )or" )as estimate$ as&• A%%I'ATIO O: 4EA'TI;E DTIE I #A3ADES- .

DE:I'IE'< O: 4EA'TI;E D


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The o,!e(ts of pro!e(t 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.


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'hapter 5

4A? *ATE4IAS

• 4a% material is auni1ue substance in

an# !roduction orientedtextile industr#. $t notonl# !la#s a "ital rolein case of continuous!roduction for high

1ualit# fabric but also itis related to the !ro/tof the industr#.

Types of ra) material

• The basic ra%materials used in %et

!rocessing industriesare8

• 3abric

• *#estu=s

• Chemicals

auxiliaries.

•


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ames . sour(e

3abric8*i=erent t#!es of fabric treated in #engal -urri(ane 3roup pvt

t$. d#eing section are namel#

$yeing se(tion• Single ?erse#

• Single jerse# %ith 6#craattachment

• Single ?erse# %ith slub

• *ouble ?erse#

• Polo !i1ue

• +ack !i1ue

• 4ib 3abric

• 3lat back 4ib

• $nterlock

$yeing se(tion• $nterlock %ith 6#cra

• Pi1ue

• 6acost

• 6acost 6#cra

• 3leece

• Ter# 3leece

• Wa@e

• 'elange

3ib d d


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3ibres d#ed8

By reactive dyes thefollowing fibres can bedyed successfully:

1)otton! rayon! flax andother cellulosic fibres.")#olyamide and wool

fibres.

$)%il& and acetate fibres

't covers a wide range ofcolor spectrum andincludes shades varying

from bright to heavydar& li&e!a. (iolet

b. Bluec. reen

d. *ede. Blac& f. +ellow

g.,tc.


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Trade namesSome trade names of this d#e are mentioned8

Trade name -anufacturer ountry

#rocion '..' .K

iba cron iba %wit/erland

*ema/ol 0oechst ermany

evafix Bayer ermany

*eactone eigy %wit/erland

#rima/in B2%3 ermany

4rimarine %ando/ %wit/erland


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Po!ularit# of reacti"e d#e8

*eactive are mostly used for dyeing cellulosic fibres. 2t past cellulosic fibreswere dyed with direct and vat dyes! but after the introduction of reactivedyes there utility has become limited. *eactive dyes are superior to directdye in the following aspects:

i) 2bility to procedure bright shades of wide range.

ii) 0igh leveling 5uality.iii) ood washing fastness.iv) ood light fastness.

2nd it is superior to vat dyes in the following aspects:i) %imple dyeing method therefore one stage dyeing.ii) ow temperature dyeing 6below 1777)

iii) ower cost! i.e. cheaper.

2gain its dyeing process is fast and gives brighter shades than metalli/ed a/odyes. 3or the above reasons reactive dyes are more popular.


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NH (bridging part)

C

C C

N

Cl

N

N-N N-

- NH

Hetreocyclic ring

The general structure of reactive dye is: D-B--! "

Che#ical structure of reactive dyes

Here$

D% dye part or chro#ogen (color producing part)

Dyes #ay be direct$ acid$ disperse$ pre#etallised dye etc"

B % bridging part"

Bridging part #ay be &NH- group or &N'- group"

% reactive group bearing part"

!% reactive group"


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Classi/cation of reacti"e d#es8

*eactive dyes may be classified in various ways as below:

1) 8n the basis of reactive group:a) 0alogen 6commonly chlorine) derivatives of nitrogen containing

heterocycle! li&e $ types9• Tria/ine group• #yridimine group•

uinoxaline dyes ,xample:Tria/ine derivatives: procion! cibacron.

#yridimine derivatives: reactoneuinoxaline derivatives: levafix.

b)2ctivated vinyl compound:• (inyl sulphone• (inyl acrylamide• (inyl sulphonamide.

,xample: (inyl sulphone: rema/ol (inyl acrylamide: prima/ine

(inyl sulphonamide: levafix.


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Classi/cation of reacti"e d#es8") 8n the basis of reactivity:

a) ower reactive dye:

0ere ph is maintained 1"91".; by using


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The rea(tive rate of some (ompoun$s arementione$ ,elo)&

C*+ND ,T'+CT+' '.CT/0 '.T

1ater H-H 2"3

/so-propanol CH4-CHH-CH4 3"5thanol CH

4-CH

6-H 5"7

ethanol H-CH6-H 26"4

lucose C8H

26

8 9"9

,o fro# the above table it is obvious that secondary hydroyl group is the beast reactive ;hile

pri#ary one is the #ost reactive"


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4yeing mechanism of reactive dye:

The dyeing mechanism of material with reactive dye ta&es place in $ stages:91.,xhaustion of dye in presence of electrolyte or dye absorption.".3ixation under the influence of al&ali.$.wash9off the unfixed dye from material surface.•


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4yeing mechanism of reactive dye:

". 3ixation:

3ixation of dye means the reaction of reactive group ofdye with terminal 80 or9


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al


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2pplication method of reactive dyes varies significantly with type of dyes! shade

re5uired! and available e5uipments in the mill. These are $ application procedures

available:

1. 4iscontinuous method99onventional method9,xhaust or constant temperature method90igh temperature method

90ot critical method. ". otinuous method9 9#ad9steam method

9#ad dry method 9 #ad thermofix method

$. %emi continuous method9

9 #ad roll method9 #ad jig method9 #ad batch method.


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Stripping of reactive dye:

2"*artial stripping:

*artial stripping is obtained by treating the dyed fabric ;ith dilute acetic

acid or for#ic acid" Here te#perature is raised to 53-233>C and treat#ent

is continued until shade is re#oved by desired a#ount" .fter that a

through ;ashing is necessary to re#ove the product of hydrolysis" The

a#ount of acid used is as belo;: -lacial acetic acid : 9-23 parts

1ith ;ater :2333 parts

r

?or#ic acid :6"9 to 23 parts

1ith ;ater :2333 partsTe#perature : 53 - 233>C

Ti#e : until desired shade is obtained"


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2+ :ull stripping& 3or com!lete stri!!ing the goods are /rst treated %ith

sodium h#drosul!hite (h#drose) at boil then %ashed o=and bleached %ith AB sodium h#!ochlorite (NaOCl) atroom tem!erature. This is carried out for :< min.

The recipe is as belo;: -

Na-hypochlorite : 2@ at roo#

te#perature

Na-hydrosulpite: at boil"

Ti#e : 43 #in D-'-Cl = H-H D-'-H

= H-Cl•Hydrolysis of activated vinyl co#pound containing dye$

D-?-CH6-CH

6-,

4H = H-H D-?- CH

6-CH

6-H = H

6,

7

?or preventing hydrolysis the follo;ing precautions are ta


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'mportant factors for dyeing cellulosic fibre with

cold brand reactive dye in batching process: The im!ortant factors are as follo%s8A) !2 of the d#e bath8

The o!timum !2 for /xing cold brand reacti"e d#es on cotton and "iscose ra#onde!ends on indi"idual d#es the tem!erature and time of d#eing. !2 decreases %ithincreasing tem!erature and time of d#eing. 3or most of the d#es the o!timum !2 isA


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'mportant factors for dyeing cellulosic fibre with

cold brand reactive dye in batching process:

) Electrol#te concentration8Since reacti"e d#es ha"e lo% a7nit# for cellulose exhausting the d#e bath b#adding common salt or -lauberFs salt !rior to /xation can increase the/xation. The amount of salt re1uired !roducing ade1uate exhaustiondecreases %ith decreasing li1uor ratio. Thus for !ale shade on cotton and"iscose ra#on A; and A< gGl of common salt used. The 1uantities ma# beincreased to :< and 9< to :< gGl for medium and dee! shades on these/bres.

;) Time of d#eing8-enerall# the d#e ma# be added in t%o !ortions. The salt ma# also be addedin t%o lots. The exhaustion takes !lace in 9< to :< min. There is generall# noad"antage in extending the !eriod be#ond :< min. The alkali is then addedand the d#eing continued for :< to H< min. The de!th of shade and reacti"it#

of the d#e decide the time of d#eing. 3or dee!er shades larger times arere1uired. D) 6i1uor ratio8

With decreased li1uor ratio both exhaustion and /xation take !lace toincreased exert. 2o%e"er the rate of /xation of most of the d#es is notsigni/cantl# a=ected. &s the li1uor ratio is decreased the e=ecti"eness of

increasing salt addition also decreases. 2ence lo%er amount of salt aresu7cient to get o!timum exhaustion.


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Why low affinity reactive dyes are preferred for dyeing?

• 'f the reactivity of the dye is increased considerably! the rate of reaction with the fibreincreases. There fore! the dyeing can be carried out in a short time. 0owever in this case the

rate of dye also increases! leading to deactivation of a part of the dye. This results inwastage of the dye. 'f on the other hand the reactivity of the dye is decreased! the extent ofhydrolysis can be reduced considerably. 0owever this results in the slower rate of reactionwith the fibre also. The ultimate object of dyeing is to react as much of the dye ass possiblewith the fibre and minimi/e the hydrolysis of the dye. This is achieved in practice in twostages. The dyeing is first started from the a5ueous medium under neutral conditions whenthe dye does not react either with the fibre or with water. Then gluber salt or common salt isadded to exhaust the dye onto the fibre as much as possible. 'n this respect! this stage ofdyeing 6exhaustion) resembles the dyeing of direct dyes on cotton. Then the second step 6thatof fixation or reaction with the fibre) is carried out by adding the al&ali 6usually used sodaash). %ince the exhausted dye is already on the fibre! it is more li&ely that the exhausted dyereacts with the fibre in preference to water. 0owever the dye present in the dye bath 6whichcontains a substantial amount of the reactive dye) can now react with water since it is underal&aline condition. 't is already stated that the hydroly/ed dye cannot further react with thefibre but dye to the affinity forcesC it is absorbed by the fibre and is retained in it. 4uring the

subse5uent washing or soaping the substantivity held hydroly/ed dye gets stripped into thetreatment of the dyeing with boiling soap or detergent solution removes almost all hydroly/eddye. 0owever if the affinity is very low! exhaustion of the dye bath prior to fixation cannot beachieved substantially. This results in a larger amount of the reactive dye remaining in thedye bath and getting hydroly/ed when al&ali is added subse5uently. 'f the dye has highaffinity for cellulose li&e a direct dye! it becomes difficult to remove the hydroly/ed dye fromthe 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.0ence in actual practice low affinity dyes are selected for converting in to reactive dyes.

Dyestuffs:


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Dye Brand name Origin/source

REACTIVE

DE

Be/active Be/ema ! %wit/erland

iba iba ! %wit/erland

4ychufix 0ubei 0walle dyestuff 'nd.co.

Kemafix Daychem!'ndia

evafix 4ystar ! ermany#rocion 4ystar! ermany

Dac&a/ol 'ndia

Kema/ol Daychem!'ndia

*ema/ol 4yestar ! ermany

%ola/ol %olarfine ! Taiwan

%olacion %olarfine ! Taiwan

Dyestuffs:

C$e3%-a!":


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Brand name Type %ource


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• 4emar" • The list is for the time of our industrial

attachment. $t "aries according to the

a"ailabilit# of the material their !rice.• The !rice has not been su!!lied to us due to

their secrec# act.

• The annual re1uirement %as not a"ailable

is a record of the !rocurement de!artment.


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C!apter "

I#$ORTA%CE O& T'E S(RVE

The main goal of our !roject is to !ro"ide information about the reasonof using reacti"e d#estu= in major textile industr# in +angladeshdi=erent methods using in our industr# for cotton d#eing %ithreacti"e d#es technical de/cienc# of reacti"e d#es during d#eing causes and remedies of de/cienc# of reacti"e d#es.

&s these to!ics are "er# sensiti"e for d#eing industries it is "er# much

im!ortant to make a sur"e#. $t %ill be "er# hel!ful not onl# for ourstud#ing !eriod but also for our future career.

This sur"e# also has these im!ortances8

A. To mention the reason of using reacti"e d#es in major textile industr#.9. To stud# on the a!!lication of reacti"e d#es.:. To learn about the technical de/cienc# of reacti"e d#eing.. To stud# the causes and remed# of de/cienc# of reacti"e d#eing.

C!apter )


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C!apter )Reason of using Reactive Dyes in #a*or Te+ti,e Industries in Bang,ades!

'aximum textile industries in +angladesh are based on cotton knit fabric and reacti"e d#es are easil# a!!licable

to cellulose /bres.

Other asso(iate$ reason as follo)s&

A. 4eacti"e d#es are soluble in %ater.

9. The# ha"e "er# good light fastness %ith rating about D.

:. The d#es ha"e "er# stable electron arrangement and can !rotect the degrading e=ect of ultra5"iolet ra#. . Textile materials d#ed %ith reacti"e d#es ha"e "er# good %ash fastness %ith rating about 5; due to strongco"alent bonds formed bet%een /bre !ol#mer and reacti"e grou! of d#e.

;. 4eacti"e d#es gi"e brighter shades and ha"e moderate rubbing fastness. D. *#eing method of reacti"e d#e is eas#. $t re1uires less time and lo% tem!erature for d#eing.

I. 4eacti"e d#es are com!arati"el# chea!. . 3ixation occurs in alkaline condition.

H. 4eacti"e d#es ha"e good !ers!iration fastness %ith rating 5;. A


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C!apter -

#et!ods of Dyeing Cotton .oods it! Reactive Dyes

$roperties:

1. 2nionic in nature.". %oluble in water.

$. 3orm strong covalent bond

E. Better wet G light fastness.

;. 0ave better substantivity.

=. 4yeing is carried out at al&aline condition.

Inf,uencing factors:1. #0

". Temperature.

$. onc. of electrolyte.

E. Time.

;. i5uor ratio.

REACTIVE DYE :

'eactive dye react ;ith the fibres #ainly react ;ith cellulose fibres e"g" cotton$ ute$ bast fibres$

viscose$ fla" /t can be applied to protein fibres e"g" ;ool sil


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REACTIVE DEI%. &OR SE%SITIVE S'ADE AT "0oC

83#in at 83C$

23#in at 73-93C$

Dye%#5: .nticreasing .gent ("9 gFl)

Geveling .gent (2 gFl)

." .cid ( "6 gFl)

Dyes (.ccording to ,hade @)

" ,alt (.ccording to ,hade @) ,oda .sh (.ccording to ,hade @)

Ne,ra!%za,%/# Dye%#52:

." .cid (2 gFl)

S/ap%#5:

,oaping .gent ("9 gFl)

Dye%#5 -re: ,euestering .gent Color Dosing 833C 93#in

Geveling .gent Ginear (43#in) 933C 23#in

Bath drain

493C 63#in 43#in 23#in 23#in 49 3C Cold*H =Hardness Chec< ,alt (29#in) 2 gFl ,oda 'est ,oda ;as

(43#in) (83#in)

Pr/-e"" ",ep":


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2OT +4&N* 4E&CT$JE *KE$N-8*KE$N- &T H9oC8

83#in at I3C$ *H % .boveI

(.l;ays)

23#in at 73-

93C$

63#in at 53-

I3C$

29#in at

73C$

63#in at

73C$

Pr/-e"" ",ep":

Dye%#5: .nticreasing .gent ("9 gFl)

Geveling .gent (2 gFl)

." .cid ( "6 gFl)

Dyes (.ccording to ,hade @)

" ,alt (.ccording to ,hade @)

,oda .sh (.ccording to ,hade @)

Ne,ra!%za,%/# Dye%#52:

." .cid (2 gFl)

S/ap%#5:

,oaping .gent ("9 gFl)

F%8%#5 ; S/


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Dyeing curve:,euestering .gent Color Dosing 83 3C 93#in

Geveling .gent Ginear (43#in) 933C 23#in

Bath Drain

493C 63#in 43#in 23#in 23#in 49 3C Cold ;ash

*H =Hardness Chec< ,alt (29#in) 2 gFl ,oda 'est ,oda

(43#in) (83#in)

N.B: T$e ,e3pera,re %#-rea"e a, ,$e 5rade ('C=3%# 9e-a"e

%,>" a# %3p/r,a#, 3a,,er ,/ a/%d ,$e "$ade ar%a,%/# %# dye%#5


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DA4@ 'OO4 D


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4yeing procedure for dar& shade

3elosan NO3GWetting agent L on 2;:NEGStabili>er (29O9) L


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4yeing #rocedure for Ahite

Q3elosan NO3G%etting agent on 2;:NE GStabili>er


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4yeing procedure for ightI-edium %hade

Q

NOTE& During #lea(hing )e maintain gra$ian to risetemperature from FBo 1B5o' as 1+5o/min an$ (ooling

3elosan NO3GWetting agent on 2;:NE GStabili>er (29O9)


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4yeing procedure for %ID ight I -edium olor

Q3elosan NO3G Wetting agent L on 2;:NE G29O9 Stabili>er L


42/61

g y g p ! g

3elosan NO3G%etting agent on 2;:NE Gstabili>er (29O9)


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Samp,e 1Dyeing2

CO3OR RECI$E SA#$3E

B2K %2T28 +,8A $*%L1.=E@M

%2T28 *,4 $B% L8.@1"M %2T28 B2K


44/61

Samp,e 1Dyeing2

CO3OR RECI$E SA#$3E

2%%' B, %2T28 +,8A $*%L7.71$M%2T28 *,4 $B% L8.7==M%2T28 B, %,T* L7.="M

84 *%T %2T28 +,8A $*%L$.1EM%2T28 B, BB L8.77EM%2T28 B, BB L7.E7M

('89,T %2T28 *,4 $*% L7.=;M%2T28 *,4 $B% L8.EFMB. B, (A L1.E7M

T*'%0 ,IB B, *%# L".1M*I- T. B, L7.=M

'0T +,8A %,T2. +,8A $B%L7.7EFM

*-. +,8A $ L7.7?=M


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#rinting of cotton fabric with reactive dyes 6bloc& and screen

printing method)! combination shade.

'ntroduction:+# the term textile !rinting %e mean the locali>ed a!!lication of d#es or

!igment and chemical b# an# method %hich can !roduce !articulare=ect of color on the fabric according to the design. $n this !ractical%e !rint cotton fabric %ith cold brand reacti"e d#es in block andscreen5!rinting methods in combination method.

& d#e %hich is ca!able of reacting chemicall# %ith a substrate to

form a co"alent d#e substrate linkage is kno%n as reacti"e d#e. Thed#e contains a reacti"e grou! and this reacti"e grou! makes co"alentbond %ith the /bre !ol#mer and act as an integral !art of /bre.4eacti"e d#es forms co"alent bond %ith /bre !ol#mer and thus attachitself %ith /bre. $t is no% a da# mostl# used for d#eing and !rinting ofcotton #arn and fabric. $t is a cationic d#e. Cold brand reacti"e d#esha"e higher reacti"it#.

#lo(" printing metho$ is the ol$est printing metho$+ It is use$mostly in sarees han$"er(hiefs et(+ in this printing metho$)e use ,lo("s of $ierent $esigns.

$n screen !rinting a "er# little screen made b# glass /bre is used. There are man# t#!es of screen5!rinting but %e ha"e done in ourex!eriment %as hand screen5!rinting. 2and screen5!rinting is mostl#

used for sarees to A5AD colors in on !attern can be !roduced at atime.

Style of printing&


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Style of printing& *irect st#le.

*etho$ of printing& +lock and screen5!rinting method.

Sam!le8

One !iece of s1uare si>e bleached scoured cotton fabric (small) and One!iece of s1uare si>e bleached scoured cotton fabric(bigger)

Combination color8

Total *#es L A.gm

+lue L


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Pre!aration of thickener8

1)1= gm of starch and "77cc water are ta&en in bowl.

")0eat is applied and solution is stirred

continuously until a thic& viscose solution isobtained.

$)By continuous stirring and boiling a specificviscosity is obtained.

E)The heat application is stopped otherwiseviscosity falls down. %o temperature ismaintained strictly.

P ti f i ti t


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Pre!aration of !rinting !aste8

1) 2t first we ta&e re5uired amount of dyestuffs in a bath.") Then little amount of water is added into the bath for

mixing these dyes. 2nd start stirring for mixing thethree types of dye.

$) Then re5uired amount of urea is added into the dye bath.E) 2fter then re5uired amount of thic&ener is added;) Then continuous stirring is done for few minutes for

mixing all the ingredients of print paste.

=) 2fter mixing finally re5uired amount of al&ali is addedto the dye bath and mix them with the help of stirring.•

P i ti


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Printing !rocess8

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

printing table.

")The printing paste is put on the tray box.$)The bloc& is selected and it is touched with print paste.

E)Then bloc& is pressed upon the sample fabric.;)2fter pressing the bloc& on the sample fabric the

bloc& is put off from the fabric.=)3inally we get the printed fabric of re5uired dyes.•

S i ti th d


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Screen%printing method

1) The fabric is placed on the printing table of flat screen9 printing machine. The table is made of soft by layingon it.

") Then the screen is placed on the sample fabric.

$) The printing paste is ta&en on the screen perforation.E) Thus we can find the printed fabric with a smoothwooden stri&e the paste is spread over the screen withslight pressure.

;) %o that the dye particles can penetrate through the

screen perforation.=) Thus we get printed fabric.•

&ft t t t


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&fter treatment8

• The printed fabric is steamed for ;917 minutes

in a cottages steamer at 17;791177 and

washed with cold water for removing unfixed

dye and exhausted thic&ener and then dried.


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onclusion

#rinting of cotton fabric with reactive dyes hasexcellent build up property and maximumfixation. %hade is also bright. By this

experiment we have ac5uire &nowledge about process of printing cotton fibres with cold brand reactive dyes in combination shade. Theshade of printed fabric is moderately good! as

we re5uired. %pecial than&s to our teacher andhis assistants for grate cooperation.

•

C!apter 4


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C!apter 4Tec!nica, Deficiency of Reactive Dyes5 CA(SES A%D T'EIR

RE#EDIES

•

• 0ydrolysis is the main problem in dyeing with

*eactive dyes. 8nly =7 to ?7 percent dyes are

absorbed in *eactive dyeing. There are also

many causes of technical deficiency of

reactive dye. Those are described below:

'ydro,ysis of reactive dyes:

+ d l< li diti ti d t ith th t i l h d l f


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+nder al


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&actors !ic! affect t!e !ydro,ysis of t!e reactive dye:

67 Sa,t concentration:

Ahen the cellulosic textile material is sin& into water it convert into negetive charge or anionic

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

the dye molecules. To overcome the problem we use electrolite material li&e salt. 't hepls to netrali/e the

negetive ion over the textile material and helps the reactive dye ion to fix on the surface of the materail. 2s a

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

87p':

if the p0 of the medium increase hydrolysis of the reactive dye also increase. This is for! reactive dye

ionised more in al&aline medium and as a result it react with hydroxyl group of the water. 97Temperature:

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

7Su;stantivity:

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


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&actors !ic! affect t!e !ydro,ysis of t!e reactive dye:

-y$rolysis of )ater&

2#drol#sis of the %ater is also a causeof the technical de/cienc# of the reacti"e d#e.

4emi$ies of the hy$rolysis of the rea(tive $yes& The highest absor!tion of the reacti"e

d#e is about Ie the more lose of thereacti"e d#e %e should maintain !ro!er li1uor ratio!ro!er time and tem!erature. E"en the !2 of the

emdium is also an im!ortant factor to a"oid themore %astage of the reacti"e d#e


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&au,ts and t!eir remedies for t!e tec!nica, deficiency of reactive dyes:

• There creates man# !roblems and defects in d#ed fabrics %hen d#eing %ith 4eacti"ed#es due to technical de/cienc#. Some defects ma# be remedied b# some !rocess.

Those are described belo%8• • Defe(t& 'olors are not fast to )ashing A,rasionG Staining in the fa,ri( )hen

transporting from pla(e to the other )ater mar"s on the fa,ri(

4eme$y 8 Wash the fabric %ith soa! and soda ash at right tem!erature. &ddingse1uestering agent %ill #ield good results. Treating %ith &mmonia %ill also gi"e goodresults.

Defe(ts in the fa,ri( $ue to %rinting ee$ to ta"e out full (olor

4eme$y& Treat the d#ed fabric %ith Sodium 2#drosul!hite %ith ;5A< gm Sodium2#drosul!hite at I; deg C for :


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:aults an$ their reme$ies for the te(hni(al$eH(ien(y of rea(tive $yes&

• Defe(t& #lee$ing in (olors $uring )ashing a,rasion

4eme$y& +oil the fabric %ith caustic Treat the fabric %ith 2#drogen Peroxide ( ;5A< g!l D


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C!apter 60

Conc,usion Ob"iousl# the !roject %ork %e ha"e discussed has man# other arguments

but as far as %e belie"e the !resented "ie% to a large extent is onethat has a !redominant role in our textile sector es!eciall# inREACTIVE DYEING thus has the abilit# to inuence our thoughts.

REACTIVE DYEING is trul# an im!ortant d#eing !henomenon forcellulose materials ranks as the major contribution to the!rogression of an# textile d#eing industr#. *#eing !arameters ha"e agreat inuence on reacti"e d#eing %hich ha"e described in m# re!ort.$t %as reall# an im!ortant subject also inno"ati"e one. $ ha"e triedm# best to ex!ress the to!ics !ro!erl#.

The !roject %ork has gi"en us a s!ecial interest has been arranged as a!resentation of the a!!lication reacti"e d#es in cotton d#eing. $ thinkan#one can research in future about this to!ic %hich %ill enrich ourtextile kno%ledge.

&n# absolute conclusion is im!ossible but %aiting the !ros cons $Fmcertain that m# !osition is a tenable one.


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Reaction Mechanism of Reactive Dyes in Bengal Hurricane Group on Cellulose

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