tecnología de tintas flexografía

8/20/2019 tecnología de tintas Flexografía

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Polymer Science

Coatings and Adhesives

Technology of Printing Inks

Dr Sharif AhmedMaterials Research Lab

Dept of ChemistryJamia Milia Islamia

New Delhi- 1100 !

"01-10- 00#$

ContentsIntroductionHistorical BackgroundRaw materials and formulations for different substrates

anufacturing ProcessInk color! drying and curing characteristicsPrinting Processes

"etter#ress #rintingScreen #rinting$le%ogra#hy&ravure #rinting

$uture of #rinting ink manufacturing Industry


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Introduction

I%&s occ'py a% i%te(ral a%d )ersatile positio% i% o'r daily li)es* +'r day be(i%s o% sleepy %otewith %ewspapers a%d toiletries to brea&fast table which is replete with se)eral i%&-labelled,

pac&a(ed co%s'mer prod'cts s'ch as tea or coffee, bread, b'tter a%d the% (rad'ally mo)i%( to

o'ir wor& places schools or offices which ha)e myriad i%& lade% prod'cts be it boo&s,cale%dars, photocopies, comp'ter pri%ts, stamps or e)e% mo%ey, i%& is fo'%d e)erywhere*.e%erally, i%& is a% or(a%ic or i%or(a%ic pi(me%t or dye dissol)ed or s'spe%ded i% a sol)e%t*/owe)er, chemically, it is )iewed as a colloidal system of fi%e pi(me%t particles, colo'red or '%colo'red, dispersed i% a% a 'eo's or or(a%ic sol)e%t*

he first i%&s were reportedly fr'it or )e(etable 2'ices3 protecti)e secretio%s from cephalopodss'ch as s 'id, c'ttlefish, a%d octop's3 blood from some types of shellfish3 a%d ta%%i% from (alls,%'ts, or bar& from trees* It is belie)ed that the appeara%ce of the first ma% made i%& dates bac& to 4,!00 years i% 5(ypt, which co%sisted of a mi6t're of a%imal or )e(etable charcoal"lampblac&$ a%d (l'e 71, 8* he earliest blac& writi%( i%&s, de)eloped before !009C, were

s'spe%sio%s of carbo%, 's'ally lampblac&, i% water stabilised with a %at'ral ('m or materialsli&e e(( alb'me% 7:8* Moder% i%&s are comple6 form'latio%s* Alo%( with the pi(me%t, they alsoco%tai% some additio%al i%(redie%ts collecti)ely &%ow% as ;)ehicle; i% )aryi%( le)els* hesee6emplify p/ modifiers, h'mecta%ts to retard premat're dryi%(, polymeric resi%s to impart

bi%di%( a%d allied properties, defoamer


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i%or(a%ic pi(me%ts s'ch as chrome yellow, molybde%'m ora%(e a%d cadmi'm red with or(a%ic pi(me%ts, which offer better li(ht fast%ess a%d red'ced to6icity o't of (rowi%( health a%de%)iro%me%tal co%cer%s* Spi%el blac&, r'tile blac& a%d iro% blac& i% %early all blac& i%&s ha)

bee% replaced by carbo% blac&* I%&s also co%tai% additi)es s'ch as wa6es, l'brica%ts,s'rfacta%ts, preser)ati)es, wetti%( a%d dryi%( a(e%ts to aid pri%ti%( a%d to impart a%y desired

special characteristics* +ther i%or(a%ic materials s'ch as clays ser)e as fillers or e6te%ders,which primarily red'ces the cost of pi(me%ts, tho'(h some also impro)e i%& properties*Metallic pi(me%ts li&e al'mi%i'm powder "al'mi%i'm bro% e$ a%d copper- i%c alloy powder "(old bro% e$ are 'sed i% %o)el sil)er a%d (old i%&s* Miscella%eo's i%or(a%ic pi(me%ts pro)idel'mi%esce%t a%d pearlesce%t effects* he ma2or classes of pri%ti%( processes are litho(raphy or the offset process, fle6o(raphy, (ra)'re pri%ti%(, scree%-pri%ti%(, letterpress a%d di(ital pri%ti%(*

he compositio% of pri%ti%( i%&s depe%ds o% the type of pri%ti%( process - specifically, how thei%& distrib'tio% rollers are arra%(ed i% the pri%ti%( press*

he pri%ciple of pri%ti%( ca% be ill'strated by simple pad operatio% where li 'id i%& is 'sedwhich ca% wet the pad* A r'bber type is first dipped i% the pad, it (ets wet with i%&* It is %ow

pressed a(ai%st the s'bstrate, e*(*, paper a%d its impressio% is prod'ced o% the s'bstrate* hisi%& sho'ld remai% i% li 'id form whe% i% the pad3 howe)er, it sho'ld dry fast whe% it has bee%cast o)er the s'bstrate to be pri%ted* he )ario's pri%ti%( processes differ i% the way the type isimpre(%ated with the i%&, altho'(h di(ital pri%ti%( does %ot i%)ol)e mo)able types* 5ach

process therefore dema%ds i%& that differs i% its )iscosity a%d dryi%( efficie%cy, which is possible by fi%e-t'%i%( the compositio%* 9efore st'dyi%( each process it is importa%t to (ai% a(e%eral '%dersta%di%( abo't the basic raw materials a%d processes i%)ol)ed i% pri%ti%( i%& ma%'fact're*

Historical Background

I% abo't !009C, writi%( i%&s were first ma%'fact'red i% both a%cie%t 5(ypt a%d Chi%a* hey basically co%sisted of paste of soot bo'%d with ('ms which was formed i%to rods a%d dried,them mi6ed with water immediately before 'se* Abo't :000 years later, pri%ti%( was i%)e%ted

by Chi%ese who 'sed a mi6t're of colo'red earth, soot a%d pla%t matter for pi(me%ts, a(ai%mi6ed with ('ms as a bi%der* he first pri%ti%( press with a mo)able type was first i%)e%ted byJoha%%es .'tte%ber( i% 1440* /ere, the i%& was bo'%d with either li%seed or )ar%ish materialssimilar to those 'sed for blac& i%&s today* I% 1?# , colo'red i%&s appeared followed by dryi%(a(e%ts i% %i%tee%th ce%t'ry*

oday=s pri%ti%( i%&s are composed of a pi(me%t "o%e of which is carbo% blac& similar to soot'sed i% !009C$, a bi%der "a% oil, resi% or )ar%ish$, a sol)e%t a%d )ario's additi)es s'ch asdryi%( a%d chelati%( a(e%ts* he e6act recipe for (i)e% i%& depe%ds o% the type of s'rface that itwill be pri%ti%( o% a%d the pri%ti%( method that will be 'sed* I%&s ha)e bee% desi(%ed to pri%to% a wide ra%(e of s'rfaces from metals, plastics a%d fabrics to papers* he )ario's pri%ti%(methods are all similar- i%& is applied to a plate


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Raw aterials for Printing ink formulations

he raw materials for i%& prod'ctio% are pi(me%ts, bi%ders, sol)e%ts a%d additi)es 748*@i(me%ts- colo'r the i%& a%d ma&e it opa 'eResi%s- bi%d the i%& to(ether i%to a film a%d bi%d it to the s'rface

Sol)e%ts- ma&e the i%& flow so that it ca% be tra%sferred to the pri%ti%( s'rfaceAdditi)es- alter the physical properties of the i%& to s'it differe%t sit'atio%s

Pigments' @i(me%ts are co%sidered to be the chief co%stit'e%t of i%& a%d co%trib'teabo't !0 per ce%t of its cost* A pi(me%t is esse%tially a%y partic'late solid - colo'red,

blac&, white or fl'oresce%t - that alters the appeara%ce of a% ob2ect by the selecti)eabsorptio% a%d


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Table () Common resins used in ink formulations

Acrylics Feto%es 5po6ides @oly)i%ylb'tyralAl&yds Maleics 'marics @olyamidesCell'lose deri)ati)es ormaldehydes /ydrocarbo%s Shellac

R'bber resi%s @he%olics Isocya%ate free poly'retha%es

Solvents' hese are 'sed to &eep the i%& i% li 'id form from the period whe% it isapplied to the pri%ti%( plate or cyli%der '%til whe% it has bee% tra%sferred to the s'rfaceto be pri%ted* At this poi%t the sol)e%t separates from the i%& to allow the ima(e to drya%d bi%d to the s'rface* Some pri%ti%( processes s'ch as (ra)'re a%d fle6o(raphicre 'ire a sol)e%t that e)aporates rapidly " able $*

Table *) Printing ink solventsSolvent Boiling #oint + oC$

5thyl acetate ##Isopropa%ol G *!%-propyl acetate 101*BCyclohe6a%o%e 1!!*B9'to6yetha%ol 1#1-1#Aromatic distillates 40- ?09'tyrolacto%e G? "9oili%( poi%t at 1 torr$

/i(h boili%( poi%t " bH 40 oC -: 0 oC$ hydrocarbo%s are chose% as sol)e%ts for litho(raphic i%&sas the sol)e%ts 'sed m'st be )isco's a%d hydrophobic* Scree% pri%ti%( i%&s %eed to ha)esol)e%ts with moderately hi(h boili%( poi%ts " able :$*

Table , $ormulations of different ty#es of inks for different substrates

Contents "f'%ctio%$ Amount " w


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dryi%( oil o6idatio%$G0-: 0 oC petrole'm distillate "sol)e%t$ :*00

$le%ogra#hic ink for #olyethylene filmtita%i'm dio6ide "white pi(me%t a%d opacifier$ :!*00

alcohol sol'ble %itrocell'lose "resi%$ !*00alcohol sol'ble polyamide "resi%$ 1!*00dib'tyl phthalate "plasticiser$ 1*00

polyethyle%e wa6 "pre)e%ts dama(e 1*00to the film a(ai%st r'bbi%($amide wa6"pre)e%ts dama(e 1*00to the film a(ai%st r'bbi%($etha%ol "low b*p* sol)e%t$ :0*00%-propyl acetate "low b*p* sol)e%t$ G*00%-propa%ol "low b*p* sol)e%t$ 4*00

&ravure ink for #a#erC*I*pi(me%t red !#>1"red pi(me%t$ 10*00alcohol sol'ble %itrocell'lose "resi%$ 0*00&eto%e resi% "resi%$ 10*00dioctyl phthalate "plasticiser$ *00

polyethyle%e wa6 "pre)e%ts dama(e 1*00to the film a(ai%st r'bbi%($etha%ol "low b*p* sol)e%t$ :0*00%-propyl acetate "low b*p* sol)e%t$ 0*00etho6y propa%ol "low b*p* sol)e%t$ #*00

$or letter#resss #rinting on corrugated bo%es+water reducible red-9la%ce i6e "CI @i(me%t hite 1$ 10*00R'tile tita%i'm white "CI @i(me%t hite B$ !*00La&e red C 14*00

ar%ish !4*00Diethyle%e (lycol G*00

a6 paste !*00Ami%e 4*00

ar%ish/i(h acid )al'eMaleic resi% !0*00.lycol 40*00Ami%e 10*00Black ink+as #er British Standard for letter#ress inks .BS,/*/'(010Calci'm 49 to%er "CI @i(me%t Red !#* $ 1!*00@olyethyle%e wa6 paste :*00


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Coo&ed 'ic&-set )ehiclea : *!.loss 'ic&-set )ehicleb G*0Cobalt


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he process i%)ol)es two sta(es> "i$ )ar%ish preparatio% a%d "ii$ dispersal of pi(me%ts+i- 3arnish #re#aration' ar%ish is pri%cipally a mi6t're of sol)e%t, resi%s a%d additi)es* Ite6ists as a clear li 'id that solidifies as a thi% film, wets the pi(me%t particles a%d bi%ds the

pi(me%t to the pri%ted s'rface* here are two mai% types of )ar%ishes-oleoresi%o's a%d %o%-oleoresi%o's3 the former i%corporates a dryi%( oil s'ch as li%seed oil a%d is ma%'fact'red at

m'ch hi(her temperat'res a%d '%der )i(oro's co%ditio%s tha% the latter*+a- 4leoresinous varnish manufacture > his process occ'rs i% closed &ettles where the oila%d sol)e%t are heated to allow for rapid sol'tio%i%( or tra%sesterificatio% at thetemperat'res ra%(i%( from 1 0 oC- B0oC for afew mi%'tes to se)eral ho'rs* he rate of temperat're cha%(e, ma6im'm temperat'res attai%ed a%d coo&i%( times ha)e to be closelymo%itored* he whole set-'p is e 'ipped with a co%de%sor to pre)e%t the loss of sol)e%t3%itro(e% atmosphere is mai%tai%ed to e6cl'de the atmospheric o6y(e%, which may ca'se

polymeri atio% of dryi%( oil*+b- 5on2oleoresinous varnish manufacture > hese are simple resi% sol'tio%s that do %otre 'ire hi(h temperat'res d'ri%( ma%'fact're* he process 's'ally i%)ol)es brea&i%( 'p theresi% particles a%d dissol)i%( them i% a sol)e%t i% either a ca)itatio% or a rotor


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+b- Bead ill > It pri%cipally co%sists of beads filled cyli%drical chamber s'rro'%ded bywater 2ac&et for cooli%( p'rposes* he si e of the beads depe%ds 'po% the )iscosity a%drheolo(y of the fi%al prod'ct, i*e*, the type of i%& re 'ired* or hi(h 'ality low )iscosityi%&, e*(*, (ra)'re, typical bead si e may ra%(e from 1- mm3 for medi'm )iscosity paste or scree% i%& the bead si e may ra%(e 'pto 4 mm* hese beads are 's'ally made of irco%i'm

o6ide, (lass or stai%less steel* A drawbac& 's'ally faced by the ma%'fact're d'ri%( thisoperatio% is that certai% beads may ca'se discolo'ratio% of i%&3 th's, it is )ery importa%t totest a partic'lar type of i%& with differe%t beads before (ri%di%( for the selectio% of appropriate type of bead-i%& combi%atio%*

I% this type of dispersal operatio%, i%& has to be p'mped i%to the chamber a%d the beads"char(e$ are set i% motio% by a series of spi%%i%( discs or pi%s* he beads i% motio% brea& 'por (ri%d the pi(me%t cl'mps a%d pro)ide e)e% dispersal of i%&* he dispersed i%& is the%sie)ed o't off the chamber3 the beads remai% behi%d a%d may be re'sed*+c- Cavitation mi%ers > hese are co%sidered to be )ery efficie%t i% dispersal of pi(me%tss'ch as tita%i'm dio6ide* /owe)er, i% a hi(hly )isco's i%& system, these may be i%s'fficie%t

a%d a% additio%al sweeper blade is re 'ired*

Ink Colour! 6rying and curing characteristics

Colour' he tech%olo(y of pri%ti%( i%& colo'r is based o% the o'%(-/elmholt theory of three colo'r )isio% which implies that white li(ht is composed of li(ht from a co%ti%'o'sspectr'm of wa)ele%(ths, h'ma%s percei)e o%ly three broad ba%ds of this li(ht, bl'e, (ree%a%d red li(ht3 a%y other colo'r of li(ht is bor%e by a% appropriate combi%atio% of these three

primary colo'rs=* S'btracti)e colo'rs= are prod'ced by s'btracti%(= o%e of these three primary colo'rs from white li(ht, e*(*, red a%d bl'e li(ht to(ether prod'ce* When white light strikes an object, some of the light is absorbed and the remainder is reflected. The colour that we perceive as the colour of the object is the colour of the reflected light.

I% pri%ti%( i%&s, fo'r differe%t colo'rs of i%& are employed> cya%, ma(e%ta, yellow a%d blac&* All other colo'rs ca% be formed by o)erpri%ti%(= these i%&s, e*(*, red is prod'ced byo)erpri%ti%( yellow a%d ma(e%ta, as the yellow absorbs the bl'e li(ht "beca'se yellow is theemissio% of red a%d (ree% li(ht$ a%d ma(e%ta absorbs the (ree% li(ht, lea)i%( behi%d p'rered li(ht* Cya%, ma(e%ta a%d yellow add to(ether to (i)e brow% colo'r 's'ally*I% co%2'(ated systems "o%e co%sisti%( of alter%ate si%(le a%d do'ble bo%ds i% which Oelectro%s are delocalised$, the colo'r is d'e to li(ht e%er(y absorbed by the O electro%s* heyare characteri ed by a ba%d (ap, the e%er(y of which falls i% the )isible re(io% "the electro%sof the seco%d electro% pair of the do'ble bo%d$*

6rying and curing' After its applicatio% o)er the s'bstrate to be pri%ted, the i%& '%der(oesdryi%( or c'ri%( phe%ome%a i%)ol)i%( a series of cross li%&i%( a%d polymeri atio% reactio%sthat res'lt i% film formatio% th's bi%di%( the i%& to the pri%ted s'bstrate* I%& dryi%( or c'ri%( may occ'r by a%y o%e or by s'itable combi%atio% of the followi%( processes*"i$ 7va#oration - Some i%&s dry or c're by the e)aporatio% of the sol)e%t* .e%erally,)olatile sol)e%ts e*(*, methylated spirits are 'sed* /owe)er, sol)e%ts with boili%( poi%ts


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abo)e 1 0 oC may also be 'sed s'ch as i% scree% pri%ti%( i%&s to pre)e%t the i%& from dryi%(d'ri%( applicatio%*"ii$ Penetration > or poro's s'rfaces, pri%ti%( i%&s are desi(%ed so that the sol)e%t

pe%etrates i%to the b'l& of the pri%ti%( s'rface a%d the dry i%& is left o% the s'rface*"iii$ 4%idation' I% case of i%&s where dryi%( oil is 'sed as sol)e%t, c'ri%( occ'rs by the

reactio% of atmospheric o6y(e% with '%sat'ratio% of oil*"i)$ Radiation curing' i%)ol)es a series of polymeri atio% reactio%s which are i%sti(ated'%der the i%fl'e%ce of radiatio%s e*(*, P , falli%( o% pri%ted s'bstrate* his process isco%sidered as a (ree%= c'ri%( ro'te i%)ol)i%( lesser e%er(y a%d time*")$ Preci#itation > his process is applicable to a% i%& system that is o%ly spari%(ly misciblei% water* /ere, e6cess water "'s'ally i% the form of steam$ is added to the i%& system* hes'dde% i%crease i% dil'e%t co%ce%tratio% ca'ses the sol'bility of the resi% to decrease sharplya%d the resi% precipitates o%to the pri%ted s'rface3 the e6cess water precipitates off*

Printing Processes

+i-"etter#ress #rinting2 Also &%ow% as typo(raphic pri%ti%(, si%ce 1: th ce%t'ry, it is o%e of the oldest pri%ti%( tech%i 'es i% practice* It is a commercial pri%ti%( tech%i 'e where ma%ycopies of a% ima(e are prod'ced by repeated, direct impressio% of a% i%&ed, raised s'rfacea(ai%st sheets or a co%ti%'o's roll of paper* /ere, the ima(e or pri%ti%( areas are raisedabo)e the %o%-pri%ti%( areas3 the process i%)ol)es pri%ti%( ima(es by the Qrelief type

pri%ti%( plates* Rollers are lade% with i%& a%d they pass it to a separate i%& bed3 a fresh filmis pic&ed here for the followi%( sheet of paper* A sheet of paper is pressed o%to a type,sw'%( bac& a(ai% a%d fi%ally remo)ed* A %ew sheet or roll of paper is a(ai% i%serted at this

place* wo types of letterpress pri%ti%( machi%es are there- lat bed cyli%der Machi%es a%dRotary letterpress pri%ti%( machi%es*"a$ $lat2bed cylinder - a% i%&i%( roller a%d a% i%& fo'%tai% s'pply i%& to the plate cyli%der*

he plate is loc&ed to a hori o%tal or )ertical bed, which passes o)er the i%&i%( roller a%dthe% a(ai%st the s'bstrate* As the s'bstrate mo)es from the feed stac& to the deli)ery stac&, it

passes aro'%d a% impressio% cyli%der* I% other words, a si%(le re)ol'tio% of the cyli%der mo)es o)er the bed while i% a )ertical positio% so that both the bed holdi%( the s'bstrate a%dcyli%der mo)e 'p a%d dow% i% a reciprocati%( motio%* 5ither o%e or two-color impressio%sca% be pri%ted by lat-bed cyli%der presses, which operate i% a ma%%er similar to the plate%

press a%d pri%t stoc& as lar(e as 4 i%ches by !B i%ches* hese presses operate )ery slowlywith a% ho'rly prod'ctio% rate of %ot more tha% !,000 impressio%s* or this reaso%, m'ch of the pri%ti%( i%itially do%e by this type of press is %ow bei%( carried o't by rotary letterpressor litho(raphy*"b$Rotary "etter#ress Printing2 re 'ires c'r)ed ima(e carryi%( plates* he most pop'lar types of plates 'sed are stereotype, electrotype, a%d molded plastic or r'bber* hese presses'se heat-set i%&s a%d are e 'ipped with dryers, 's'ally the hi(h-)elocity hot air type, whe%

pri%ti%( o% coated papers* hese are of two types- sheet-fed a%d web-fed* he 'se of theformer has bee% decli%ed while the latter presses are the most pop'lar type of letterpress

pri%ti%(* hey are 'sed primarily for pri%ti%( %ewspapers* hese presses are desi(%ed to pri%t both sides of the web sim'lta%eo'sly* ypically, they ca% pri%t 'p to fo'r pa(es acrossthe web3 howe)er, some of the %ew presses ca% pri%t 'p to si6 pa(es across a ?0-i%ch web*


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Rotary letterpress is also 'sed for lo%(-r'% commercial, pac&a(i%(, boo&, a%d ma(a i%e pri%ti%(* Depe%di%( o% the si e a%d ima(e eleme%ts i% the pri%ti%(, Letterpress pri%ti%(machi%es e6ert )ariable amo'%t of press're o% the s'bstrate* o e%s're that the impressio%

press're is 2'st desirable close mo%itori%( sho'ld be accomplished a%d certai% ad2'stme%tsm'st be made thro'(ho't the machi%e r'%* Ma2or chemicals 'sed i% letterpress pri%ti%( are

)ery similar to those 'sed i% litho(raphy* hey i%cl'de film de)elopers a%d fi6ers, i%&s, a%d bla%&et a%d roller washes* Application: Letter @ress pri%ti%( is 'sed i% commercial operatio% a%d specialty operatio%si%cl'di%( impri%ti%(, stampi%(, die c'tti%(, %'mberi%( a%d others* Applicatio%s of this typeof pri%ti%( i%cl'de b'si%ess cards, compa%y letterhead, proofs, billheads, forms, posters,embossi%(, hot leaf stampi%( a%d others*+ii-Screen Printing - his tech%i 'e, which (ai%ed pop'larity d'ri%( the irst orld ar for ma&i%( ba%%ers a%d pri%ti%( fla(s ca% be traced bac& to the be(i%%i%( of the 1?th ce%t'ry*

he pri%ti%( tech%i 'e creates a sharp-ed(ed ima(e 'si%( a poro's fabric a%d a ste%cil* hescree%, a piece of poro's, fi%ely wo)e% fabric i%cl'di%( sil&, polyester or %ylo% is stretchedo)er a woode% or al'mi%'m frame, is placed o% top of a piece of paper or fabric* Areas of

the scree% are bloc&ed off with a %o%-permeable material "a ste%cil$* I%& is placed o% top of the scree%, a%d it is f'rther spread e)e%ly across the scree% with a r'bber blade* he i%& passes thro'(h the ope% spaces i% the scree% o%to the paper or fabric below3 the scree% isthe% lifted off a%d ca% be re-'sed after clea%i%(* or m'ltiple colo'r scree% pri%ti%( o% thesame s'rface, the i%& is allowed to dry a%d the% the e%tire process is repeated with a%other scree% a%d differe%t color of i%&*

Application: Scree%-pri%ti%( tech%i 'e fi%ds )ersatile applicatio%s 'sed i% differe%ti%d'stries, from clothi%( to prod'ct labels, fabric labels to circ'it board pri%ti%( a%d othersd'e to its compatibility with a )ariety of materials, i%cl'di%( te6tiles, ceramics, metal, wood,

paper, (lass, a%d plastic*+iii- $le%ogra#hy Printing Process' idely 'sed to pri%t pac&a(i%( materials, this

tech%i 'e is 'sed to pri%t o% a %'mber of materials a%d prod'cts i%cl'di%(corr'(ated bo6es, foldi%( carto%s, m'lti-wall sac&s, paper sac&s, plastic ba(s made'p of )ario's materials s'ch as plastic, paper a%d others* he pri%ti%( plates arefle6ible a%d made of r'bber or plastic* he i%&ed plates with a sli(htly raised ima(eare rotated o% a cyli%der, which tra%sfers the ima(e to the s'bstrate* hesemachi%es i%)ol)e simple operatio% a%d easy adaptatio% for the 'se of water-basedi%&s a%d prod'ce hi(h 'ality, fi%er a%d clear impressio%s o% differe%t s'bstrates*

hese machi%es are pop'larly 'sed for pri%ti%( o% materials i%cl'di%( plastic, paper, foils,acetate films, which is (e%erally carried o't by the 'se of r'bber


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adhesi)e labels, adhesi)e tapes, e%)elopes, %ewspapers, plastic ba(s a%d food a%d ca%dywrappers*

ypes of le6o(raphic @ri%ti%( Machi%e> "a$ Stac& ype Machi%e"b$ Ce%tral Impressio% Cyli%der "CIC$ Machi%e"c$ I%-Li%e Machi%e

"d$ Newspaper P%it Machi%e+iv- &ravure Printing @rocess is 'sed for lo%( r'% pri%ti%( with sharper, fi%e a%d clear ima(es* he (e%eral operatio% i%)ol)es ima(e preparatio%, cyli%der preparatio%, pri%ti%( a%dfi%ishi%(* It is a form of i%ta(lio pri%ti%(* he ima(e is formed o% a depressed or s'%&e%s'rface* he ima(e area co%sists of ho%eycomb shaped cells that are etched or e%(ra)ed i%toa copper cyli%der* As the cyli%der rotates i% a% i%& pa% "bath of i%&$, a%y e6tra i%& is wipedoff the cyli%der with the help of a steel doctor blade* As the s'bstrate passes betwee% the

plate cyli%der a%d the impressio% cyli%der, i%& is directly tra%sferred to the s'bstrate a%dima(e is formed*

Applications i%cl'de pri%ti%( ma(a i%es, (reeti%( cards, (ift-wraps, labels, fle6ible pac&a(i%(, carto%s a%d others*

Rotogravure Printing Machi%es operate at )ery hi(h speeds a%d are 'sed by a %'mber of i%d'stries for pri%ti%( ma(a i%es, ad)ertisi%( pri%t materials, cards etc for pri%ti%( 2ob thatare lo%( r'%%i%( i% %at're a%d re 'ire sharper a%d fi%er pri%ts ima(es o% differe%tmaterials i%cl'di%( @5 , @ C, @5 a%d paper* hese machi%es employ t'rret type '%wi%der a%d rewi%der3 a'tomatic splici%( a%d web dischar(i%( ca% also be do%e* o e%ha%ce thedryi%( performa%ce a%d mi%imi e pri%ti%( defects, these machi%es are e 'ipped with hi(hspeed dryi%( systems*

Applications > .reeti%( Cards, ma(a i%es, ad)ertisi%( materials i%cl'di%( broch'res,catalo(s, fle6ible pac&a(i%(, self-adhesi)e labels

$uture of the Printing ink anufacturing Industry

he e%)iro%me%tal a%d health problems ca'sed by the i%&s Co%tai%i%( )olatile or(a%iccompo'%ds " +Cs$ call for %ew sol'tio%s i% pri%ti%( chemistry a%d tech%olo(y *+%e of theapproaches may be hot melt* It refers to i%&, which is solid at ambie%t temperat're a%dli 'id at the time of pri%ti%(* S'ch i%&s co%tai% %o +Cs to be trapped i% the i%& film or to

prod'ce +Cs* I% 1??0s, the 5'ropea% ech%ical Committee for @ri%ti%( I%&s of C5@5" European Technical Committee for printing inks and Artists Color anufacturers !ndustr" $

p'blished a ('ideli%e paper o% health a%d safety* Si%ce the% e%er(y c'ri%( prod'cts ha)e(ai%ed si(%ifica%t (rowth both i% coati%(s a%d pri%ti%( tech%i 'es* he ma2or e%er(y c'ri%(

processes are 'sed> P a%d 59 "Pltra )iolet lamps a%d 5lectro% 9eam$* 5%er(y c'ri%(tech%olo(y is importa%t i% the prod'ctio% of all types of pri%ti%( applicatio%s where fastdryi%(, d'rability a%d hi(h (loss fi%ish ma&e them s'stai%able for immediate 'se, e*(* carto%

pri%ti%( ood a%d pharmace'tical pac&a(i%(, labels plastic s'bstit'tes a%d metaldecoratio%* A%other de)elopme%t area of imme%se i%terests De)elopme%t of water based Psystems* ater is ideally s'ited to red'ce the )iscosity of i%& systems* /owe)er, the mai%

problem with water P system is that it is i%e)itable to remo)e water completely before Pc'ri%(* ater based fle6 i%&s are bei%( 'sed i% Napla% pri%ti%( i%&s 7N@I8* N@Is werei%itially form'lated 'si%( petrole'm-based materials* /owe)er, they left a% offe%si)e odor


13/13

o% pri%ted s'bstrates* Some pri%ters 'sed (lycol "water washable i%&s$ to o)er come thedrawbac&s * he 'ltimate sol'tio% was the 'se of water based fle6 i%&s, which apart from

bei%( odor freeha%d se)eral other ad)a%ta(es* Risi%( petrochemical crisis a%de%)iro%me%tal co%cer%s draw atte%tio% to )e(etable oil based i%&s* Altho'(h )e(etable oilsha)e bee% 'sed i% i%&s for ma%y years, the first soy bea% oil based i%& were de)eloped i%

1?G! a%d were mar&eted i% 1?G#*Soy i%&s %ow ma&e 'p at least o%e third of the colored%ewspaper i%&* Soy i%& co%tai%s less +C, less alcohol a%d ca% be washed 'p witho'tsol)e%t* heir disad)a%ta(es i%cl'de their hi(h cost compared to co%)e%tio%al li%& as well astheir disposal* or the prese%t, P a%d 59 c'red i%& tech%olo(y co%ti%'es to de)elop*5fforts are bei%( directed towards the 'se of water-based i%&s* Fey 'ses prese%tly remai% i%the de)elopme%t of )e(etable oil co%tai%i%( i%&s 'si%( P a%d 59 c're tech%olo(ies i% theworld of pri%ti%( i%&s* e are desti%es to e6pertise ma%y i%d'stry i%%o)atio%s i% this field i%the %e6t few years with almost '%limited possibilities

References1* @ri%ti%( meets Litho> Soft approaches to hi(h resol'tio% patter%i%(> 9*Michel, A*9er%ard, A*9itesh,

5*Dalamache, M*.eissla, D*J'%chery, J*@*Re%a't, /*Rothi er, /*Schimdt, @*Schmidt, R*St't , /* olfi% I9M Jo'r%al of Research De)elopme%t ol 4!, No*, G, 001

* Chemical 5%(i%eeri%( News, he Newsma(a i%e of the Chemical orld +%li%e No)ember1B,1??G, ol'me #B, N'mber 4B, C5N5AR #B 4B 1-!B, ISSN 000?- :4#

:* Joy * F'%2app', Essa"s in ink chemistr" * New or&> No)a Scie%ce @'blishers, 0014* Firth-+thmer, 5%cyclopaedia of Chemical ech%olo(y ": rd 5ditio%$, *1: ":#4-:?#$ *1? "110-

1#!$, iley So%s, New or&, 1?G1

Suggested Readings'• L*M*Larse%, I%d'strial @ri%ti%( I%&s, New or&, Rei%hold @'blishi%( Compa%y, 1?B• he @ri%ti%( I%& Ma%'al "!th 5ditio%$, R*/*Leech a%d R*J*@ierce "eds$ Lo%do%> 9l'epri%t, 1??:• Chemical tech%olo(y i% pri%ti%m( a%d ima(i%( systems J*A*.* Dra&e "ed$ Cambrid(e>RSC, 1??:• www*p%eac*or(

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