Printing Ink Problems-Causes and Remedies

8/10/2019 Printing Ink Problems-Causes and Remedies

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PRINTING INK PROBLEMS: CAUSES AND REMEDIES.

Printing ink is a colloial sol!tion o" a #ig$%nt in a &%'icl% ('%r% %ac' #ig$%nt #articl% iss!rro!n% )* a "il$ o" &arnis' or &%'icl%. T'% ink s'o(s c'aract%ristics o" lio#'ilic collois. T'%

&iscosit* o" t'% ink is gr%at%r t'an t'% $%i!$ an t'%* ar% sta)l% to t'% aition o" s$all a$o!nt o"

%l%ctrol*t%.

Inks s!##li% to #rint%rs &ar* (i%l* in "or$!lation an #ro#%rti%s. T'% &ariation is n%%%)%ca!s% o" t'% (i% rang% o" s!r"ac%s )%ing #rint%+ t'% c'aract%ristics o" i""%r%nt #r%ss%s+ an t'%

&ario!s %n,!s% r%-!ir%$%nts o" #rint% o)s. T'%r% ar% inks "or g%n%ral co$$%rcial (ork t'at can)% a!st% )* t'% #rint%r to s!it a &ari%t* o" #a#%rs. T'%r% ar% also inks %sign% %s#%ciall* "or la)%l

#rinting+ #ost%rs+ $aga/in% co&%rs+ gr%%ting cars+ %cals+ "oils+ #lastics+ $%tal %corating+ or ot'%r#!r#os%s0 t'%s% inks ar% !s!all* #r%ss,r%a* an r%-!ir% littl% or no a!st$%nt )* t'% #rint%r.

R%garl%ss o" t'% s!r"ac% to )% #rint%+ inks can )% &ari% in trans#ar%nc*+ "inis'+ r!),+ sc!"",+ an

'%at,r%sistanc%+ lig't"astn%ss+ c'%$icals+ an sol&%nts.

Cons%-!%ntl*+ t'%r% ar% t'o!sans o" i""%r%nt ink "or$!lations+ %ac' "or$!lat% "or a s#%ci"ic#a#%r or s!)strat% or "or a rang% o" s!)strat%s+ an "or a s#%ci"ic s%t o" #rinting conitions an %n,

!s% r%-!ir%$%nts. T'%r% is no ink t'at is )%st "or all conitions. An ink t'at is s!it% "or a (i% rang%

o" #a#%rs an %n,!s%s (ill not )% )%st "or an* !s%. T'% #rint%r $!st (ork (it' t'% ink $ak%r too)tain t'% )%st inks

1'%n an ink $an!"act!r%r #ro!c%s ink "or a s#%ci"ic o)+ '% s'o!l 'a&% color co#*+ stock+

conitions o" #rinting+ an %n !s% r%-!ir%$%nts )%"or% "or$!lating an ink. Pro#%rl* "or$!lat% ink

s'o!l #%r"or$ t'% o) (%ll (it' $ini$!$ a$o!nt o" i""ic!lt* or (ast% o" #rinting #r%ss o#%rationti$%.

O"t%n ink is !s% o" stock ot'%r t'an t'at "or ('ic' it (as "or$!lat%+ $a* )% a i""%r%nt #r%ss+

!n%r i""%r%nt o#%rating conitions+ i""%r%nt at$os#'%ric conition or at i""%r%nt #r%ss s#%%s.

E&%n ('%n t'% ink is s#%ciall* "or$!lat% "or t'% o)+ c'ang%s $a* )% r%-!ir%. B%"or% ink c'ang%s


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' i ' i""i l i l ) " l i i

#r%ss is i""%r%nt an t'% o&%n ca#acit* is ina%-!at%+ t'% ink $!st )% $ani#!lat% to s#%% r*ing.

1'%n at$os#'%ric conitions ar% i""%r%nt+ ink $ani#!lation $a* )% n%%% to co!nt%ract t'%c'ang%.

Sol&ing ink,r%lat% #ro)l%$s. B%ca!s% o" t'% $an* &aria)l%s in&ol&% in ink$aking an

lit'ogra#'ic #rinting+ t'% (%) o""s%t #r%ss o#%rator is constantl* "ac% (it' sit!ations t'at r%-!ir%

kno(l%g%+ %2#%ri%nc%+ an !g%$%nt.

E2#%ri%nc% an !g%$%nt co$% (it' #ractic%. T'% ink$ak%r is a k%* so!rc% o" in"or$ation

('%n tro!)l%s'ooting. Us!all*+ it is ill a&is% to alt%r inks+ )%ca!s% !ni"or$it* is %ss%ntial "or t'%

!ration o" t'% #r%ssr!n. T'% co$#l%2it* o" '%ats%t ink "or$!las #r%s%nts #ot%ntial ang%r i" t'%* ar%

alt%r% i$#ro#%rl*.

T'% "ollo(ing s%ction lists t'% $ost co$$on ink #ro)l%$s+ t'%ir #ro)a)l% ca!s%s+ an r%$%i%s

to o&%rco$% or a&oi %ac' #ro)l%$. All t'% ink #ro)l%$s can )% classi"i% !n%r t'% "o!r cat%gori%s

s!c' as:

I. R'%ological #ro)l%$s

a8 Poor Tra##ing

)8 3l*ing or Misting

c8 Piling 9 caking

8 Ink )acks a(a* "ro$ t'% "o!ntain roll%r

%8 Poor )ining or c'alking

II. Pro)l%$s !% to #lat% or #a#%r s%l%ction

a8 S'o(t'ro!g' or Strik% t'ro!g'

)8 Stri##ing o" ink roll%rsc8 S%to""

8 Picking+ S#litting 9 T%aring o" #a#%r

8 Di l ti 9 1 i " l t


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g8 Dot gain+ Sl!rring or Do!)ling

I. a8. POOR TRAPPING

T'% s*$#to$s ar% #oor -!alit* o&%rla*s+ color s'a%s on o&%rla*s (ill not )% tr!%. Poor tra##ing

ink (ill s'o( !# on )lank%t i$$%iat%l* as )ack tra##ing T'%r% #ossi)l% ca!s%s to i$#ro#%rtra##ing in (%t $!lticolor #rintings ar%: a8 I$#ro#%r tack s%-!%nc% in t'% inks+ or )8 Inks ar%

i$#ro#%rl* )alanc% as to str%ngt'+ or c8 Too $!c' (at%r+ or 8 Too $!c' i$#r%ssion.

A!st tack 'ig' to lo(+ "irst to s!cc%ssi&% !nits. To a tack+ a '%a&* )ining &arnis'. To

lo(%r tack+ a r%!cing &arnis'. C'%ck (at%r an i$#r%ssion. G%n%rall*+ %ac' s!cc%%ing ink

s'o!l 'a&% slig'tl* l%ss tack t'an t'% #r%,c%ing ink in or%r to tra# #ro#%rl*. T'is is &%r*i$#ortant+ t'% $or% i$#%r&io!s t'% s!r"ac% )%ing #rint%. It is %ss%ntial in t'% #rinting o" $%tal

s'%%ts an al!$ini!$ "oil. It is o" littl% i$#ortanc% in #rinting so"t+ a)sor)%nt #a#%rs. R%!ction o"

t'% racks o" s!cc%%ing colors to t'% ang%r #oint+ an so $!st not )% o&%ron%.

)8. 3L;ING or MISTING:

T'is r%s!lts "ro$ t'% ink )%ing ra(n o!t into %2c%ssi&% long string or "ila$%nts ('%n its "il$ is

s#lit )%t(%%n t'% rotating #r%ss roll%rs. 1'%n t'%s% strings )r%ak o"" at )ot' %ns !% to c%ntri"!gal

"orc%+ t'%n t'% ink is t'ro(n o!t an "loats into t'% at$os#'%r%+ t'is is $or% $ark% at 'ig'%r #r%sss#%%s. T'%r% ar% "o!r #ossi)l% ca!s%s o" ink "l*ing0

a8 Too M!c' Ink. T'% t'ick%r t'% ink "il$ on t'% #r%ss roll%rs+ t'% long%r t'% "ila$%nts "or$%

('%n it is s#lit )%t(%%n roll%rs. So$%ti$%s s!)stit!ting a strong%r color% ink an r!nning l%ss o" it

(ill sto# t'% "l*ing.

)8 Ink 3o!ntain O#%n Too 1i%. 3l*ing $a* r%s!lt i" t'% "o!ntain roll%r carri%s a t'ick ink "il$an i" t'% trans$itting $otion o" t'% ratc'%t is a s'ort on% so$%ti$%s call% s'ort rac'%t s(%%#8. In

t'is cas%+ tig't%ning t'% "o!ntain )ala% an incr%asing t'% roll%r $o&%$%nt s'o!l sto# t'% "l*ing.


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roll%r to #lat%+ #lat% to )lank%t an "inall* to t'% #rint% s!r"ac%. Ink s'o!l not #il% an*('%r% in t'%

s*st%$. Ca!s%s o" #iling ar%:

a8 Ink is too s'ort. Lack o" #ro#%r "lo( can )% !% to o&%r #ig$%ntation+ #oor (%tting o" #ig$%nt)* t'% &arnis'+ too $!c' ri%r+ gr%as% or (a2 co$#o!n too $!c' #lat% $oist!r%+ or a co$)ination

o" t'%s% "actors. To r%$%* t'is conition a a &arnis' t'at (ill l%ngt'%n t'% ink+ )!t al(a*s cons!lt

t'% ink $ak%r. In an* cas% r%!c% t'% a$#%ning (at%r to a $ini$!$.

)8 Ink #oorl* Gro!n: I" t'% ink contains !nis#%rs% #ig$%nt #articl%s+ t'%s% $a* s%#arat% "ro$

t'% &%'icl% an a'%r% to t'% roll%r+ #lat% an )lank%t s!r"ac% )!iling !# a cak%. T'%r% is no r%$%*

"or s!c' an ink %2c%#t to s%n it )ack to t'% $an!"act!r%r "or "!rt'%r grining.

c8 Coars%. 4%a&* Ink Pig$%nt: Coars% or '%a&* #ig$%nts lik% c'ro$% *%llo( an titani!$#ig$%nts r%-!ir% s#%cial "or$!lations to o&%rco$% #iling+ 'o(%&%r+ t'% ink $ak%r kno(s 'o( to

o&%rco$% s!c' #ro)l%$s (it' i""ic!lt #ig$%nts.

8 Pa#%r Coating is Moist!r% S%nsiti&%. Occasionall* a coat% #a#%r is "o!n t'at ca!s%s #iling o"

ink on t'% )lank%t o" t'% t'ir or lat%r !nit o" a $!lticolor #r%ss. E2a$,ination s'o(s a )!il !# o"#!tt* lik% $at%rial on t'% )lank%t t'at ca!s%s t'% ots to sl!r an gi&%s a $ottl% a##%aranc% to t'%

#rint. T'% ca!s% o" t'is tro!)l% is t'at t'% #a#%r coating a'%si&%+ !% to t'% $oist!r% "ro$ t'%

)lank%t+ )%gins to co$% o"" an is $a% stick*. T'is stick* coating is #ick% o"" !ring s!)s%-!%nt

o#%rations an "inall* (orks its (a* into+ t'% ink. B%ing inco$#ati)l% (it' t'% ink+ it sticks an)!ils !# on t'% )lank%t. T'is is a #a#%r $ak%r7s #ro)l%$ an t'%r% is not'ing t'at a #rint%r can o

$!c' a)o!t it %2c%#t (as' t'% )lank%ts "r%-!%ntl*.

It $a* )% $%ntion% t'at #iling or caking can )% %t%ct% )* %2a$ining t'% #rint clos%l*. 4%r%

t'% #rint s'o(s )lotc'* ar%as o!tlin% )* a t'in+ non,#rint% lin%.

8. INK BACKS A 1A; 3ROM T4E 3OUNTAIN ROLLER

Di""ic!lt* in 'oling color+ t%n%nc* to r!n lig't+ str%ak* or !n%&%n+ $a* )% !% to i$#ro#%r ink


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T'% root ca!s% is ins!""ici%nt )in%r n%%% to 'ol t'% #ig$%nt to t'% #a#%r. T'% ca!s% $a* )%

!% to too Io(a )in%r cont%nt in t'% ink or t'% ink &%'icl% $a* 'a&% too Io(a &iscosit*+ '%nc%#%n%trat%s %2c%ssi&%l* into t'% stock+ l%a&ing !n)o!n #ig$%nt on t'% s!r"ac%. T'is i""ic!lt* can )%

ca!s% )* i$#ro#%r aitions to t'% ink at t'% #r%ss+ s!c' as aition o" t'in oil or t'% (rong sol&%nt+aition o" a non #%n%trating+ 'ar )ining &arnis' can corr%ct t'is %"%ct.

T'% )%st r%$%* is #ro)a)l* t'% c'oic% o" a $or% &isco!s ink containing a )%tt%r "il$ "or$ing&%'icl%+ an #ossi)l* (a2 7or a si$ilar $at%rial to #ro!c% a 'ar $ar #roo" s!r"ac%.

I" c'alking occ!rs+ it (ill not )% notic% !ntil a"t%r t'% %2#%ct% r*ing ti$% o" t'% ink. 4o(%&%r+

t'% o) can )% !s!all* sa&% )* on% o" t(o $%t'os. i8 R!n t'% s'%%ts t'ro!g' a #r%ss !sing a )lank

#lat% a$#%n% (it' a "o!ntain sol!tion consisting o" >?,@?gra$s o" a r*ing sti$!lator co)altac%tat%8 #%r gallon o" (at%r. ii8 O&%r#rint t'% c'alking ink (it' a trans#ar%nt tint )as% or an

o&%r#rint &arnis'. T'is 7co&%rs !# t'% ink an also s!##li%s aitional ri%r.

II. a8. S4O1,T4ROUG4 or STRIKE T4ROUG4

Strik%,t'ro!g' r%s!lts ('%n t'% ink &%'icl% #%n%trat%s an stains t'% s'%%t so t'at t'% #rinting is

%asil* &isi)l% in t'% r%&%rs% si%. T'is is t'% "a!lt o" t'% ink an t'% #a#%r. S'o(,t'ro!g' is &isi)ilit*o" #rinting "ro$ t'% r%&%rs% si% !% to lack o" o#acit* o" t'% #a#%r.

In o""s%t #rinting+ strik%,t'ro!g' is rar%l* a #ro)l%$ )%ca!s% t'% ink "il$ #rint% is &%r* t'in+ it

$a* occ!r in &%r* lig't(%ig't or #oro!s stocks o" #a#%r. I" strik%,t'ro!g' o%s tak% #lac%+ it is !% toa strong #%n%trating &%'icl% in t'% ink+ s#%ciall* ark color% &%'icl% ar% #ron% to strik%,t'ro!g'. In

s!c' a cas%+ or%r an ink (it' a r%lati&%l* non,#%n%trating lig't color% &%'icl%. So$%ti$%s a

strong%r ink #rint% (it' a t'inn%r "il$ (ill %cr%as% or %li$inat% strik%,t'ro!g'. I" strik%,t'ro!g'

occ!rs+ it (ill a""%ct t'% #rinting on t'% r%&%rs% si%+ t'% ink r%c%#ti&it* on t'is si% (ill c'ang%ca!sing an i$#%r"%ct ink la*+ gi&ing a $ottl% a##%aranc%.


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c8. SETO33

Also r%"%rr% to as o""s%t !s!all* in lit'o #rinting. T'is i""ic!lt* s'o(s !# in t'% trans"%r o" ink"ro$ t'% #rint% si% to t'% !n%r si% in t'% %li&%r* #il% or r%(in+ roll. It can also ca!s% t'% s'%%ts

to stick tog%t'%r an int%r"%r% (it' "%%ing in t'% s%con #rinting. So$%ti$%s it can ca!s% #icking or

r!#t!r% o" t'% stock ('%n t'% ri% s'%%ts ar% s%#arat%. T'%s% $a* )% !% to s%&%ral ca!s%s:

Ink Not A!st% To t'% Stock: T'% Ink $!st al(a*s s%t on t'% s'%%t )%"or% it is contact% )* t'%"ollo(ing s'%%t in t'% %li&%r* #il%. To o t'is+ its )o* an #%n%trating -!alit* $!st )% #ro#%rl*

a!st% to t'% s$oot'n%ss an a)sor)%nc* o" t'% stock. !ick%st inks ar% "or$!lat% to a&ois%to"". T'%* ar% )%st s!it% "or !s% on coat% #a#%rs an )oars.

Anti o""s%t co$#o!n ar% %""%cti&% i" !s% #ro#%rl*. T'%* s#%% !# s%tting o" t'% ink+ s'ort%ningit. T'os% t'at contain (a2 "or$ a #rot%cti&% "il$ on t'% s!r"ac% o" t'% ink. I" too $!c' is !s%+ t'is

can #r%&%nt tra##ing o" s!cc%%ing colors. T'% (a2 "il$ can conta$inat% t'% )acks o" "ollo(ing

s'%%ts (it'o!t )%ing &isi)l%. T'%n+ on #rinting t'% r%&%rs% si%+ t'% ink $a* not tak% #ro#%rl*+r%s!lting in a $ottl%. Anti o""s%t co$#o!n t'at contain $agn%sia #r%&%nt s%to"" )* s'ort%ning t'%

ink+ )!t t'%* t%n to !ll t'% "inis' o" t'% ri% ink an r%!c% its r!),r%sistanc%.Cornstarc' an starc' co$#o!ns r%!c% s%to"" )* slig'tl* ro!g'%ning t'% s!r"ac% o" t'% ink

"il$. T'is %la*s inti$at% contact (it' t'% "ollo(ing s'%%ts an allo(s $or% ti$% "or t'% ink to s%t.T'% ro!g'n%ss r%!c%s t'% ink7s r!) r%sistanc%. Us% a $ini$!$ o" starc'0 a)o!t to < gra$s #%r

#o!n o" ink+ too $!c' (ill ca!s% (at%r logging an %la* ink r*ing.

R!nning Too M!c' Ink: T'% t'ick%r t'% ink "il$ a##li% to #a#%r or #a#%r)oar+ t'% long%r (ill

)% its s%tting ti$% an gr%at%r t'% c'anc%s o" s%to"". T'% t'inn%r ink "il$s #rint% )* o""s%t ar% a

%ci% a&antag% o&%r l%tt%r#r%ss #rinting in t'is r%s#%ct. B!t %&%n (it' o""s%t #rinting+ too $!c'ink can ca!s% s%to""+ s#%ciall* ('%r% on% ink o&%r#rints anot'%r.

A #rint%r $a* r!n too $!c' ink "or t(o r%asons:


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Piling S'%%ts Too 4ig'. S%to"" $a* occ!r in #rinting '%a&* non,a)sor)%nt #a#%rs+ #a#%r)oars+

%calco$ania #a#%rs+ #lastics an "oils. 4%r% t'% lack o" a)sor)%nc* o" t'% stock #r%&%nts s%tting o"t'% ink )* #%n%tration. S%tting can tak% #lac% %it'%r !% to t'% sol&%nt or )* t'i2otro#*. 4%r% t'%

s'%%ts s'o!l not )% #il% too 'ig' on t'% %li&%r* #lat"or$+ )!t $!st )% rack% in li"ts+ to r*. T'%n!$)%r o" s'%%ts #%r li"t $!st )% "o!n )* o)s%r&ation.

Ro!g' 4anling o" Print% S'%%ts: Print% s'%%ts i" 'anl% car%l%ssl* can ca!s% s%to"". Ro!g''anling co!l )% arring+ !$#ing t'% #il% '%a&il* inst%a o" la*ing it g%ntl*+ carting o&%r ro!g'

"loors %tc. Car%"!l 'anling is t'% #r%&%ntion.

Printing 1it' Gloss Inks: Gloss inks ar% "or$!lat% to r* (it' a $ini$!$ o" #%n%tration. T'%

t'ick%r t'% ink "il$+ 'ig'%r t'% gloss. 4%nc% gloss inks ar% $or% #ron% to s%to"" t'an ot'%r t*#%s o"inks. T'% )%st #r%&%nti&% "or s%to"" is anti o""s%t s#ra*. A s$all a$o!nt is all t'at is n%%%. An

%2c%ss (ill ca!s% scratc'ing an also gi&% a #oor r!) an sc!"" r%sistanc% to t'% ri% ink "il$. Too

$!c' s#ra* (ill ca!s% #oor tra##ing o" s!)s%-!%nt colors+ an it can also #il% on t'% )lank%tsn%c%ssitating "r%-!%nt (as',!#s. I" #ossi)l%+ a&oi gloss inks !s%+ inst%a con&%ntional or -!icks%t

inks an o)tains t'% %sir% gloss (it' s#irit &arnis'+ lac-!%r or an o&%r#rint gloss &arnis'.

Static El%ctricit*: Un%r &%r* r* conitions !ring col (%at'%r ('%n t'% #rint roo$ is not

'!$ii"i% static %l%ctricit* can ca!s% s%to"". D!ring t'% #assag% o" t'% #a#%r t'ro!g' t'% #r%ss it can

ac-!ir% static %l%ctricit*. Orinaril* t'is c'arg% is -!ickl* issi#at% )* t'% "il$ o" $oist!r% t'%#a#%r r%c%i&%s "ro$ t'% )lank%t. B!t i" t'% r%lati&% '!$iit* is &%r* lo( t'% c'arg% r%$ains on t'%

s'%%ts an ca!s%s t'%$ to )% strongl* attract% to t'% %li&%r* #il%. T'% air c!s'ion is -!ickl*s-!%%/% o!t+ r%s!lting in an ink "il$+ ('ic' o%s not r* -!ickl* t'!s ca!sing s%to"".

Air,conitioning or at '%at '!$ii"ication o" t'% #rint roo$ at$os#'%r% is t'% )%st #r%&%ntion "or

static tro!)l%. I" t'is is not #ossi)l% t'%n a static %li$inat% or+ #ro#%rl* $o!nt% on t'% #r%ss $a*

#r%&%nt s%to"" ca!s% )* static.

8. PICKING+ SPLITTING AND TEARING O3 PAPER


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(%ak%ns t'% #a#%r7s s!r"ac%+ t'%n #icking (ill tak% #lac% on s!cc%%ing !nits. B%ar in $in t'at on

"o!r an "i&% color (ork0 $oist!r% is c!$!lati&% on t'% #a#%r+ '%nc% #icking incr%as%s (it' %ac'#rinting. R!nning a $ini$!$ o" #lat% $oist!r% an #rinting (it' $ini$!$ o" #r%ss!r% ar% t'% onl*

$%ans o" co$)ating #icking on $!lticolor (ork. Un"ort!nat%l* in s!c' cas%s t'%r% is no t%st ot'%rt'an act!al #rinting. A ro!g' inication (o!l )% to r!) t'% #a#%r s!r"ac% (it' a $oist!r% "ing%r. I"t'% "i)r%s ar% li"t% or t'% #a#%r s!r"ac% r!#t!r%+ t'%n t'% #a#%r is lik%l* to gi&% tro!)l%.

8 Ink B%gins To Dr* On T'% Pr%ss. An ink (it' a s!ita)l% initial tack can start to r* on t'%

#r%ss roll%rs+ an )* t'% ti$% it r%ac'%s t'% #a#%r it can ca!s% #icking. T'%r% $a* )% t'r%% sol!tions

to s!c' a #ro)l%$.

i8 A a littl% ?? &arnis' to t'% ink to r%!c% its initial tack.

ii8 A a littl% anti o2iant or slo( r* co$#o!ns+ cons!lt t'% ink $ak%r.

iii8 L%t t'% ink $ak%r #r%#ar% a "r%s' )atc' o". ink (it' l%ss ri%r. In t'% cas% o" -!ick,s%t an

'%at,s%t inks+ r*ing on t'% roll%rs can )% !% to %it'%r sol&%nt a)sor#tion )* t'% roll%r co$#osition

roll%rs (it' lo( a)sor)%nc* s'o!l )% !s%. B!t %&%n t'%n tro!)l% still #%rsists. Tro!)l% occ!rs$ainl* in starting t'% r!n !% to incr%as% in tack ('il% t'% ink stans on t'% roll%rs !ring $ak%,

r%a*. Onc% t'% r!n 'as start% an t'% ink "%% an "lo( %sta)lis'% t'%n t'%r% $a* not )% a

#icking.

To #r%&%nt tro!)l% !ring start,!#s (it' -!icks%t an '%at,s%t inks+ t'% "ollo(ing $a* )%ao#t%:

i8 Us% a s#%cial start !# ink+ ('ic' 'as t'% %sir% color )!t no &olatil% sol&%nt0

ii8 I" t'% co$#osition roll%rs ar% n%( or 'a&% )%%n staning r* "or so$% l%ngt' o" ti$%+ sat!rat%

t'%$ (it' an ink sol&%nt s!c' as '%at,s%t oil )%"or% inking t'%$ !#. T'is #r%&%nts t'%$ "ro$ #icking

!# sol&%nt "ro$ t'% ink.

iii8 So"t%n t'% ink on t'% roll%rs at t'% start to co!nt%ract t'% sti""%ning %""%ct !% to loss o"sol&%nt )* %&a#oration !ring $ak% r%a*. Onc% t'% r!n 'as start% an t'% ink "lo( %sta)lis'%+

t'%n t'% r%g!lar ink s'o!l ca!s% no tro!)l%.


9/21

T'% non i$ag% ar%as o" a #lat% ark%n or t!rn *%llo( or gr%%n. T'is is ca!s% )* t'% "or$ation o"

a %#osit o" $%tallic l%a or an insol!)l% l%a co$#o!n on t'% #lat% !% to t'% #r%s%nc% o" a (at%r,sol!)l% l%a salt in t'% a$#%ning (at%r.

L%tt%r#r%ss #ast% ri%rs contain l%a ac%tat%+ ('ic' is &%r* (at%r,sol!)l%+ t'is #ast% is !s% in

o""s%t inks an t'% l%a ac%tat% issol&%s in t'% a$#%ning (at%r. T'is sol!)l% l%a ac%tat% -!ickl*

r%acts (it' t'% #lat% s!r"ac%+ ('ic' is $a% o" /inc t'!s "or$ing /inc ac%tat%+ an $%tallic l%a is#r%ci#itat% as a )lack %#osit.

Lit'o #ast% ri%rs t'% l%a salt is oil sol!)l% )!t i" t'% "o!ntain sol!tion is s!""ici%ntl* aci+ t'%

l%a is con&%rt% into aci #'os#'at%+ ('ic' is so$%('at+ (at%r,sol!)l%. T'% %""%ct on t'% #lat% can

t'%n &ar* %#%ning on t'% conitions. T'% #lat% $a* t!rn )lack+ gra*+ *%llo( or gr%%n. Blackinicat%s $%tallic l%a+ gra* inicat%s l%a #'os#'at% gr%%n or *%llo( %#osit inicat%s l%a

c'ro$at%+ ('ic' is !% to t'% "o!ntain sol!tion+ ('ic' $a* contain c'ro$ic aci or a )ic'ro$at%.

Plat% iscoloration can )% #r%&%nt% )*:

a8 Us% o" a lit'o #ast% ri%r0 )8 Us% co)alt ri%r0 c8 A&oi %2c%ssi&% -!antit* o" ri%r in inks0an 8 k%%# t'% #4 o" t'% "o!ntain sol!tion a)o&% =..

T'% #lat% #%r"or$anc% $a* &ar* (i%l* %#%ning on #r%ss conition+ t*#%s o" stock to )%

#rint%+ 'o( (%ll t'% #lat% is $a% an t'% car% t'at is gi&%n to it. I" t'% #lat% i$ag% s'o(s (%ar&%r* -!ickl* t'% ca!s% $a* )% on% o" t'% "ollo(ing:

Too M!c' Plat% To Blank%t Pr%ss!r%: S#%ciall* (it' /inc an al!$ini!$ #lat%s+ )lank%t "riction(ill ca!s% (%ar+ gr%at%r t'% #r%ss!r% gr%at%r t'% (%ar.

3o!ntain sol!tion too aciic: Strong aci "o!ntain sol!tions (ill r%act (it' /inc an al!$ini!$+

"latt%ning t'% #lat% grain+ %stro*ing t'% ink r%c%#ti&it* o" t'% i$ag% ar%as an ca!s% )lining.

A)rasi&% Pig$%nt In T'% Ink: I" t'% ink #ig$%nt is coars% or contains !nis#%rs% agglo$%rat%s+

it (ill act as an a)rasi&% an gra!all* (%ar a(a* t'% colloi+ lac-!%r+ co##%r or ('at%&%rconstit!t%s t'% )as% o" t'% #lat%7s #rinting i$ag%. T'% r%s!lt is t'at t'% #lat% go%s )lin. B!t gritt*

#ig$%nts ar% 'arl* %&%r !s% t'%s% a*s )* t'% ink $ak%r.


10/21

Ink Too So"t. I" an ink is not tack* %no!g' at #r%ss s#%% Ho #!ll o!t s'ar# an #rint cl%an

'al"ton%s an lin%s+ t'% (ork (ill gra!all* t'ick%n. T'% ink s-!as'%s an "orc%s t'% $oist!r% a(a*"ro$ t'% $argins o" t'% #rinting i$ag%+ %&%nt!all* a'%ring an #r%&%nting a$#%ning rig't !# to

t'% %g%s o" t'% i$ag%. T'% "irst %&i%nc% o" t'is (ill )% t'% loss o" 'al"ton%s s'ao( %tail.

T'% onl* r%$%* is to sti""%n t'% ink an incr%as% its tack )* aing I to o!nc%s o" )o* g!$ or

(at%r r%sistant &arnis' #%r #o!n o" ink. I" t'is (%ak%ns t'% ink too $!c'+ tr* anot'%r tacki%r ink. I"t'is ca!s% #icking o" #a#%r+ t'%r% is no r%$%* %2c%#t to (as' !# an %tc' t'% #lat% or g%t a $or%

#ick,r%sistant #a#%r.

Ink 6%'icl% Is too aci: I" t'% ink &%'icl% contains too $!c' o" "att* aci it can %stro* t'%

%s%nsiti/ing "il$ on t'% non,i$ag% ar%as o" t'% #lat%. So$%ti$%s a "att* aci lik% ol%ic or a

co$#o!n o" it is a%+ in an att%$#t to co!nt%ract )lining o" a #lat% loss o" ink r%c%#ti&it* in t'%#lat%7s i$ag% ar%a8. T'is s'o!l )% on% (it' gr%at car% so as not to o&%ro it. Us!all* a)o!t 'al" an

o!nc% to a #o!n o" ink is lik%l* to ca!s% sc!$$ing.

Too M!c' Ink. R!nning too $!c' ink 'as t'% sa$% %""%ct as r!nning it too so"t. I" s-!as'% t'%#lat% i$ag% t%ns to t'ick%n t'% (ork. T'% r%$%* is to !s% a strong%r ink an r!n l%ss o" it.

Ink Pig$%nt Is Coars%: T'is can act as an a)rasi&% an (%ar t'% %s%nsiti/ing "il$ o"" t'% #lat%7s

non,i$ag% ar%as+ ca!sing sc!$. T'% r%$%* is to !s% anot'%r (%ll,gro!n an (%ll,is#%rs% ink+

Too M!c' Plat% To Blank%t Pr%ss!r%: Too $!c' #r%ss!r% ca!s%s t'% ink to s-!as' an "ill in !stt'% sa$% as i" t'% ink is too so"t or too $!c' ink is r!n. Also+ t'% )lank%t scr!)s t'%n on,I$ag% ar%as

o" t'% #lat%+ (%aring o"" t'% %s%nsiti/ing "il$+ t'is is %&i%nc% )* 'ori/ontal sc!$ str%aks. T'%

r%$%* is to k%%# #lat% to )lank%t #r%ss!r% at a $ini$!$.

I$#ro#%r Roll%r S%ttings: Plat% (%ar an sc!$$ing can r%s!lt i" %it'%r t'% "or$ roll%rs ora$#%ning roll%rs ar% s%t too clos% to t'% #lat%. T'% r%s!lt is t'% sa$% as a)o&%+ #lat% to )lank%t

#r%ss!r%.

1or$ Or irt* Da$#%ning Roll%rs: 1'%n t'% cotton,a$#%ning roll%r co&%rs (%ar,o""+ t'% )as%

"a)ric )%co$%s a)rasi&% an (%ars t'% #lat%. Also i" t'% a$#%n%rs ar% not s!""ici%ntl* cl%an ancontain ri% ink t'is #r%s%nts !ni"or$ a$#%ning an can ca!s% #lat% (%ar T'% )%st r%$%* is to


11/21

T'is is 'o( a li-!i is con&%rt% into a soli. 3or t'is r%action to #roc%%+ t'% t'r%%,ar$% $ol%c!l%s

"o!n in ink &arnis'% n%% o2*g%n. O2*g%n "ro$ t'% air r%acts %2tr%$%l* slo(l* (it' t'% &arnis'.To s#%% !# t'% c'%$ical r%action+ ri%rs ar% a%: salts o" l%a+ co)alt an $angan%s%+ ('%n t'%

o2*g%n is carri% )* t'%s% ri%rs t'% r%action tak%s #lac% ra#il*. I" t'% rig't a$o!nt o" ri%r is#r%s%nt+ t'% inks s'o!l r* in a##ro2i$at%l* "o!r 'o!rs. 3ro$ a #!r%l* #'*sical &i%(#oint+ t'%r*ing o" -!icks%t inks can )% look% at as a gra!al incr%as% in &iscosit*.

T'% %""%cti&%n%ss o" t'% ri%r is r%!c% )* aci an )* %2c%ss $oist!r%. T'% %""%ct is

s*n%rgistic+ i.%. t'% %""%ct o" %2c%ss $oist!r% tog%t'%r (it' %2c%ss aci is "ar (ors% t'an t'% s!$ o"

t'% t(o %""%cts alon%. Sinc% so"t inks t%n to %$!lsi"* (at%r $or% r%ail* t'an tack* inks+ r%!cingt'% inks 'as t'% aitional !n"a&ora)l% %""%ct o" r%taring r*ing.

Dr*ing )%co$%s &%r* slo( ('%n t'% "o!ntain sol!tion 'as an aciit* o" #4 an t'% r%lati&%'!$iit* o" t'% roo$ is F. On% $!st also not%+ t'% #oint o"t%n o&%rlook% is t'at ('%n "o!ntain

sol!tion is trans"%rr% to #a#%r an %&a#orat%s+ t'% #4 on t'% s!r"ac% o" t'% #a#%r go%s o(n an t'%r%lati&% '!$iit* ris%s. So i" t'% "o!ntain sol!tion 'as an original #4 o"


12/21


13/21

c'ill% roll%rs can #ro&i% at% to t'% #rint%r t'at (ill allo( 'i$ to $ak% #ro#%r corr%ctions. At t'is

stag% it )%co$%s $or% con&%ni%nt an l%ss %2#%nsi&% "or 'i$ to "%%l t'% (%) (it' 'is 'ans an%t%r$in% i" it is #ro#%rl* c'ill%. In s#it% o" #ro#%r c'illing+ i" t'% r%sin 'as too Io(a $%lting #oint+

t'%8 ink "il$ (ill r%$ain tack* %&%n t'o!g' all t'% sol&%nt 'as %&a#orat%. T'is is kno(n as a"t%rtack. 3or s!cc%ss"!l r%s!lts t'% $%lting #oint o" t'% r%sin an a"t%r cooling o" t'% #rint% (%) $!st)% #ro#%rl* )alanc% "or t'% #r%ss s#%%. 4%r% onc% again+ t'% onl* control t'% #rint%r 'as is to lo(%r

t'% t%$#%rat!r% o" t'% c'ill roll%rs an i" t'is o%s not '%l#+ t'%n t'% ink $!st #r% r%"or$!lat%.

So$% r%sins r%l%as% t'%ir sol&%nts "ast%r t'an ot'%rs. 1%) inks ('ic' contain r%sins s'o!l

r%l%as% t'%ir sol&%nts -!ickl* so as not to r%$ain tack*. S%l%ction o" s!c' r%sins is t'% sol%r%s#onsi)ilit* o" t'% ink $ak%r.

1it' "l%2o an gra&!r% inks+ sol&%nt co$#osition is t'% #ri$ar* ca!s% o" r*ing i""ic!lti%s. I"t'% inks r* too ra#il*+ t'%* $a* r* on t'% #r%ss roll%rs. Aition o" a 'ig' )oiling sol&%nt (ill

ca!s% t'% ink to r* $or% slo(l*. I" t'% inks r* too slo(l*+ t'%n t'%* $a* not r* on t'% (%).

I" a $i2% sol&%nt is !s% to #r%#ar% t'% inks an $or% o" t'% on% co$#on%nt 'as %&a#orat% 'asto )% a% to co$#%nsat% "or t'% loss. T'% sol&%nt to )% !s% $!st )% t'% on% r%co$$%n% )* t'%

ink $ak%r. So$% #rint%rs #r%"%r to a t'% $i2% sol&%nt+ )%ca!s% t'%r% is no si$#l% (a* to

%t%r$in% t'% -!antit* o" %ac' co$#on%nt to a to )ring t'% sol&%nt $i2t!r% )ack to its original

co$#osition.

T'% ink $ak%r s'o!l not !s% r%sins an )in%rs t'at ar% to!c'* i.%. %asil* t'ro(n o!t o"

sol!tions )* s$all c'ang%s in sol&%nt co$#osition. As t'% sol&%nt in t'% ink "o!ntain %&a#orat%s+ t'%

ink #ig$%nt )%co$%s conc%ntrat% an t'is is on% o" t'% "%( ca!s%s o" ink color &ariation in gra&!r%an "l%2ogra#'*. Cons%-!%ntl*+ t'% #rint%r $!st car%"!ll* ins#%ct t'% ink "o!ntain+ r%#lacing t'%

sol&%nt as r%-!ir%.

SUMMAR;: In concl!sion+ clos% coo#%ration )%t(%%n t'% #rint%r an t'% ink s!##li%r is &ital in

s%c!ring inks t'at (ill r* #ro#%rl*. Inks $!st )% "or$!lat% "or t'% o) to )% #rint% ('%n%&%r#ossi)l%+ an a!st$%nts i" n%%% s'o!l )% #%r"or$% )* t'% ink $ak%r. Ink r*ing #ro)l%$s ar%

costl*. Sa&ing a "%( #aisa on t'% #ric% o" t'% ink is "oolis' %cono$*+ )%ca!s% cost o" t'% ink !s!all*

r%#r%s%nts a s$all "raction o" t'% total cost o" t'% "inis'% o)


14/21

)8 Alkali S%nsiti&% Pig$%nts: Pa#%r coatings &ar* "ro$ slig'tl* aci to "airl* alkalin%. T'% #4 o"

aci #a#%rs ar% g%n%rall* . to >.? an t'os% o" alkali #a#%rs ar% @.? to ?.?. I" an alkali s%nsiti&%color is #rint% on an alkali coat% #a#%r+ it $a* a##%ar all rig't at "irst )!t t'% color )%gins to "a%

(it'in a "%( a*s an )%gins to s'o( a $ark% c'ang% o&%r t'% (%%ks. Tints $a* los% color ('il%"!ll str%ngt' #rints $a* 'arl* s'o( an* c'ang%+ )!t onc% t'% "aing starts t'%r% is 'arl* an* (a*o" r%storing t'% original color.

Iron )l!%s an c'ro$% gr%%ns s'o( a $ark% c'ang% ('%n #rint% on coat% stocks. 1'%n !sing

s!c' #ig$%nts c'%ck t'% #4 o" t'% coat% #a#%r coating o" t'% #a#%r8. Most organic #ig$%nts ar%

!na""%ct% )* t'% alkali in t'% #a#%r coatings.

c8. CR;STALIATION O3 INK ON DR;ING:

1'%n a o) r%-!ir%s t(o or $or% #rintings (it' t'% ink r*ing in )%t(%%n+ t'% ri% ink

so$%ti$%s "ails to tra# t'% s!cc%%ing ink #ro#%rl*+ t'is is )%li%&% to )% !% to t'% non,r*ing oil or

(a2 in t'% ink co$ing o!t or "loating to its s!r"ac% !ring r*ing+ ca!sing it to r%#%l t'% "ollo(ingink.

Cr*stalli/ation can r%s!lt "ro$ r!nning too $!c' ink too $!c' gr%as% or (a2 co$#o!n in t'%ink or "or allo(ing t'% ink to r* too long an ca!sing t'% ink "il$ to 'ar%n a##r%cia)l* )%"or%

o&%r,#rinting it. Too $!c' co)alt or $angan%s% ri%rs can ca!s% it )%ca!s% t'%s% ri%rs ca!s% ra#is!r"ac% r*ing. 1'%n a o) r%-!ir%s t(o or $or% #rintings+ t'% "irst ink to )% #rint% s'o!l )% $a%

(it'o!t gr%as% or (a2 in t'%ir "or$!las an no %2c%ss ri%r. At t'is stag% a #ast% ri%r s'o!l )% !s%

or a )ar% $ini$!$ o" co)alt ri%r !s%. S!cc%%ing #rints s'o!l )% $a% as soon as t'% ink 'asri% s!""ici%ntl* to #%r$it 'anling o" t'% s'%%ts.

I" an ink 'as cr*stalli/%+ t'%n an o&%r,#rint co$#o!n a% to t'% s!cc%%ing I ink to $ak% ittra#. 4%r% t'% o&%r,#rint% color $a* not a'%r% (%ll %&%n t'o!g' t'% #rint $a* look all rig't0

a'%sion can )% i$#ro&% )* '%ating. Us!all* s!c' #rint% s'%%ts ar% ri% in an o&%n. Us% o" too$!c' s#ra* #o(%r on t'% "irst #rinting can also ca!s% cr*stalli/ation


15/21

T'is i""ic!lt* is associat% (it' )ot' s%to"" an #oor r*ing. T'% ca!s% an r%$%i%s $%ntion%

a)o&% !n%r t'%s% '%aings o"t%n a##l* to #r%&%ntion o" sticking.

I6. a8. 3ILL IN or PLUS UP or SPECKING O3 4AL3TONES:

3illing in is a conition ('%r% a 'al"ton% starts o!t #rinting (%ll+ )!t gra!all* t'ick%ns !ring

t'% r!n. It is "irst notic% in t'% s'ao( ton%s ('ic' )%co$%s %ns%r an t'%n los%s %tail. It $a* )%

!% to:

a8 Poorl* D%s%nsiti/% Printing Plat%s. 1'%n t'% #lat% is not (%ll %s%nsiti/%+ t'% ar%as 'ar%stto a$#%n ar% t'os% at t'% %g%s o" t'% #rinting i$ag%. T'% i$ag% t'%r%"or% t%ns to s#r%a an

t'ick%n. T'% ar%as "irst a""%ct% ar% 'al"ton% s'ao(s+ ('ic' "ill in an los% %tail. R!nning $or%

(at%r to k%%# t'%$ o#%n r%s!lts in sno"lakin%ss an loss o" color or %nsit* A strong or sti"" ink $a*'%l# "it o%s not #ick or t%ar t'% #a#%r. 1%t (as'ing or %tc'ing t'% #lat% $a* '%l#+ )!t t'% )%st

r%$%* is a )%tt%r #lat%.

)8 R!nning Too M!c' or Too So"t an Ink. At %ac' #oint o" trans"%r+ t'% ink "il$ is !n%r #r%ss!r%

('ic' $ak%s it t%n to s-!as' or s#r%a on 7lin%s or 'al"ton%s. T'is is $or% $ark% ('%n #rinting on

'ar+ non,a)sor)%nt #a#%rs. T'% t'ick%r t'% ink "il$ or so"t%r t'% ink+ gr%at%r (ill )% t'% %"%ct.E&%nt!all* t'is %stro*s t'% #lat%7s %s%nsiti/ation at t'% %g%s o" t'% i$ag%+ so t'at t'% t'ick%ning

contin!all* incr%as%s. To #r%&%nt t'is+ t'% ink s'o!l )% r!n as sti"" an s#ar% as #ossi)l%.

c8 R!nning ink Too Tack* on So"t or Lint* Pa#%r. Uncoat% #a#%rs ar% so$%ti$%s lint*. Tack*inks #ick !# t'is lint an t'ro( it )ack on to t'% #lat% an ink roll%rs+ ('ic' )%co$% "o!l%. T'%

onl* r%co!rs% is to r%!c% t'% tack o"+ t'% ink+ )!t t'is can r%!c% t'% -!alit* o" t'% #rint i" carri%

too "ar.

8 T'% Ink is #oorl* Gro!n. I" t'% ink is #oorl* gro!n+ it contains #ig$%nt agglo$%rat%s+('ic' $a* )% a)rasi&%. T'is ca!s%s t'% #lat% to (%ar gra!all*+ ca!s%s ots an lin%s to t'ick%n. Inks

can )% t%st% "or "in%n%ss o" grin )* $%ans o" a 4%g$an Ga!g%.


16/21

o)lit%rat% t'% %sign )%"or% it contacts t'% "or$+ a s%con ti$%. T'is can a##%ar ('%n t'% ink 'as

$or% a""init* "or $%tal t'an "or t'% "or$ roll%rs.

T'% aition o" a long+ stick* &arnis' $a* '%l# to #r%&%nt t'is co$#l%t% trans"%r. A tig't s%ttingo" t'% "or$ roll%rs to ca!s% a slig't sli##ag% o" t'% roll%r )l!rs t'% %sign an $ak%s it l%ss a##ar%nt.

G'osting is $ost #r%&al%nt on #r%ss%s (it' r%lati&%l* "%( "ro$ roll%rs. O)&io!sl*+ t'% aition o"

anot'%r "or$ roll%r can '%l# o)lit%rat% g'osts. Us% o" "or$ roll%rs o" i""%r%nt ia$%t%rs also '%l##r%&%nt t'is tro!)l%.

G'osting is $or% tro!)l%so$% in soli tints t'an in "!ll str%ngt' solis+ !s!all* )%ca!s% t'% ink is

r!n s#ar%. It is (ors% (it' trans#ar%nt t'an (it' o#a-!% colors. It can )% r%!c% )* aing No.

&arnis' to gi&% t'% ink )%tt%r istri)!tion -!aliti%s+ r!nning $or% o" a l%ss strong color% ink+ orc'anging to an o#a-!% ink. E2c%ssi&% a$#%ning (at%r also aggra&at%s g'osting an s'o!l )%

a&oi%.

STREAKS ar% !s!all* ca!s% )* $%c'anical i""ic!lti%s on t'% #r%ss. Crack% or slig'tl*

a$ag% roll%rs can ca!s% str%aks. In rotogra&!r% #rinting+ str%aks $a* )% !% to %"%cti&% octor)la% or to scratc'%s on t'% c*lin%r. In so$% cas%s+ acc!$!lation o" ri% ink or ot'%r #articl%s

!n%r t'% octor )la% int%r"%r%s (it' #ro#%r (i#ing an can )% t'% ca!s% o" str%aks.

c8. MOTTLED PRINT AND POOR LA;

Mottling is notic% $ainl* in solis an ark 'al"ton%s It is a s#ott* a##%aranc% !% to &ariation

in %it'%r ink %nsit* or "inis'. T'% "ollo(ing ar% t'% $ost lik%l* ca!s%s:

a8 Ink Too So"t or S'ort. Mottling can )% r%!c% or %li$inat% )*7 aing )o* g!$ or (at%r

r%sistant &arnis' #ro&i% it l%ngt'%ns t'% ink an incr%as%s tack. In so$% cas%s a gr%as% or (a2co$#o!n or cornstarc' $a* i$#ro&% t'% la*.

)8 Non Ink R%c%#ti&% Stocks. S$oot'+ 'ar !ncoat% #a#%rs an &arnis'% gra% coat% #a#%rst )l T i i k l t' t' i k ' l ) t i l


17/21

%8 R!nning Too M!c' Ink. R!nning too $!c' ink on 'ar+ #oor ink r%c%#ti&% #a#%rs can ca!s%

$ottling. I" t'% %nsit* or color cannot )% o)tain% (it'o!t %2c%ssi&% ink+ t'%n a strong%r ink s'o!l)% !s%.

"8 Too M!c' Pr%ss!r%: Too $!c' )ack c*lin%r #r%ss!r% t%ns 7to s-!as' t'% ink "il$. It "orc%st'% ink o"" t'% 'ig' s#ots o" t'% #a#%r s!r"ac% into t'% lo( s#ots gi&ing t'% l%tt%r a t'ick%r ink "il$.Pr%ss!r% s'o!l )% k%#t to a $ini$!$ sti""%ning t'% ink $a* '%l# r%sist s-!as'.

'8 Too $!c' Da$#%ning 1at%r. Too $!c' $oist!r% on t'% #lat% ca!s%s %2c%ssi&% $oist!r% #ick

!# )* t'% ink. T'is r%!c%s t'% ink7s tack so t'at it s-!as'%s $or% r%ail*. Also $oist!r% glo)!l%s ont'% s!r"ac% o" t'% ink "il$ !ring i$#r%ssion $oist%n s#ots on t'% s!r"ac% o" t'% #a#%r+ ('ic' t'%n

r%%cts t'% ink. T'is #ro!c%s ('it%, s#ots in solis+ ('ic' ar% $in!t% an gi&% a sno( "lak*

a##%aranc%.

8. O33 COLOUR or PRINT IS O33 S4ADE

T'% ink color is o"" s'a% ('%n it "ails to $atc' t'% #roo". T'is can onl* )% !g% acc!rat%l*

a"t%r t'% ink 'as ri%.

a8 I$#ro#%r Matc'. T'% #rint% color $a* )% cl%an )!t t'% s'a% or t'% str%ngt' $a* )% (rong+

t'is is $or% lik%l* !% to a #oor $atc'. T'is co!l 'a&% )%%n ca!s% )* t'% $atc'%r )%ing "!rnis'%an ina%-!at% co#*+ on ('ic' t'% original color 'a c'ang% or t'% (rong stock on ('ic' to c'%ck

'is $atc'. Anot'%r #ossi)ilit* $a* )% i$#ro#%r lig'ting conitions.

In all s!c' cas%s a r%$atc' is r%-!ir%. B!t in all cas%s t'% color o" t'% ink can )% corr%ct% )*

aing a ton%r o" t'% #ro#%r '!%+ or an %2t%n%r+ or )* %it'%r incr%asing or %cr%asing t'% ink "%%.B%"or% "ining t'% ink g!ilt*+ t'% #r%ss$an $!st c'%ck t'% t'ickn%ss o" 'is ink "il$ )%ca!s% t'% color

&ari%s (it' t'% ink "il$ t'ickn%ss.

)8 Pr%ss is Dirt*. I" t'% color a##%ars irt*+ t'%n t'% #r%ss $a* not 'a&% )%%n co$#l%t%l* (as'%

or it $a* still carr* irt* a$#%ning roll%rs. To c'%ck t'is $ak% a ra(o(n o" t'% ink "ro$ t'% canan anot'%r "ro$ t'% ink o" t'% #r%ss roll%rs.


18/21

T'is can )% %asil* isting!is'% "ro$ a )l%% )* t'% "act t'at it consists o" $*ria o" "in% ots

t'at can )% cl%arl* s%%n !n%r a $agni"*ing glass. A s'ort ink is $or% %asil* %$!lsi"i% t'an a sti""+tack* ink. It (ill )r%ak o(n $or% %asil* i" r!n at lo( s#%%s t'an at 'ig' s#%%s. S'ort an 'ig'l*

#ig$%nt% inks t%n to )r%ak o(n an %$!lsi"* $or% %asil* t'an long+ l%ss conc%ntrat% inks.

S%nsiti/ation o" t'% Plat%7s Non,Printing Ar%as: So$% #a#%r coatings contain (at%r sol!)l%

#rot%in $at%rials t'at ar% slo(l* trans"%rr% to t'% #lat%7s non,#rinting I ar%as. T'is $at%rial "inall*)!ils !# on t'% s!r"ac% o" t'% #lat% an "or$s a #artiall* r%c%#ti&% s!r"ac% "or ink "il$s. 1'%n t'%

tint "irst "or$s it can )% %asil* (as'% o"" t'% #lat%+ )!t i" allo(% to r%$ain it %&%nt!all* )%co$%s a

sc!$ ('ic' can onl* )% r%$o&% )* (%t (as'ing an r%,%tc'ing t'% #lat%. I" #rinting is r%s!$% ont'% sa$% #a#%r+ t'% tint (ill again gra!all* r%t!rn.

I" tint o" t'is t*#% "irst a##%ars+ it co!l )% %asil* o&%rco$% )* !sing a i""%r%nt #a#%r an oinga(a* %ntir%l* (it' t'% original #a#%r. L%tt%r#r%ss coat% #a#%rs o not 'a&% t'is tinting #ot%ntial+ )!t

-!it% a "%( &ari%t* o" lit'o #a#%rs coat%8 'a t'is tinting %"%ct. Coat% #a#%rs t'at can ca!s% t'ist*#% o" tinting can )% %asil* i%nti"i% )* t'% "ollo(ing t%st.

C!t a ? 2 ? c$. s-. o" t'% #a#%r i# it in t'% "o!ntain sol!tion an s-!%%g%% it on to t'% non,

#rinting ar%a o" t'% #lat%. A"t%r a $in!t%+ r%$o&% t'% #a#%r an #roc%% to #rint. I" t'% #a#%r is at

"a!lt+ a soli or a tint (ill -!ickl* a##%ar in t'% ar% a contact% )* it an (ill contin!% to o so "or

-!it% a n!$)%r o" i$#r%ssions.R%si!al Plat% Coating: I" t'% )ic'ro$at% s!r"ac% coating 'as not )%%n co$#l%t%l* r%$o&%

"ro$ t'% non#rinting ar%as o" t'% #lat%+ tinting can occ!r. It (ill look lik% an %$!lsi"ication tint+ )!t

it (ill )% s#ott* an not !ni"or$ o&%r all t'% ('it% ar%as. It can )% %asil* r%$o&% "ro$ t'% #lat%(it' a g!$ s#ong%+ )!t co$%s )ack &%r* -!ickl* onc% t'% #rinting is r%s!$%.

T'%r% is 'arl* $!c' on% can o to o&%rco$% t'is tro!)l%+ "or )%st r%s!lts+ r%si!al #lat% coating

$!st )% r%$o&% co$#l%t%l* in #lat% $aking.

"8. COUNTER ETC4ING IN MULTI COLOUR PRINTING:

T'i i " " i ' l l i l I l '


19/21

Sl!r is ca!s% )* sli##ag% )%t(%%n t'% o""s%t )lank%t an #a#%r !ring t'% i$#r%ssion. It is

o)s%r&% ('il% #rinting a coat% stock+ rar%l* on an !ncoat% #a#%r. It can )% %asil* r%cogni/%('%n: a8 it ca!s%s 'al"ton% s'ao(s to "ill in an los% %tail+ ('il% 'ig'lig'ts7 ar% !na""%ct% )8 t'%

)ack %g%s o" solis ar% "ring% inst%a o" )%ing s'ar#. 1'%n sl!r occ!rs it is "irst notic% as an

incr%as% in ton% &al!%s in t'% ark%r 'al"ton%s an is &%r* o"t%n con"!s% (it' ot s-!as' orsc!$$ing. A $agni"*ing l%ns is n%c%ssar* to i%nti"* sl!r. Do!)ling is i""%r%nt "ro$ sl!rring as it

occ!rs in an* ir%ction i.%.+ not !niir%ctional as in sl!rring.

T'% c'i%" ca!s% o" sl!r is too $!c' )ack c*lin%r #r%ss!r%. On s$oot' coat% #a#%rs t'% ink canact as a l!)ricant an #%r$it sli##ag% ca!sing sl!r ('%r% t'%r% is %no!g' ink co&%rag%. B!t ('%r%

t'%r% is littl% ink co&%rag% as in 'ig'lig'ts+ t'% )lank%t cannot sli# an t'% ots #rint s'ar#+ on!ncoat% #a#%rs+ t'% s!r"ac% is !s!all* ro!g' to #r%&%nt sli##ag% %&%n ('%n #rinting solis.

To #r%&%nt sl!r+ a $ini$!$ o" ink s'o!l )% r!n. T'% $or% t'% ink+ gr%at%r t'% l!)ricating %""%ct

an gr%at%r t'% t%n%nc* to sl!r.

T'% s*$#to$s o" ot gain ar% ots !n%r $agni"ication 'a&% incr%as% t'%ir si/% 9 'al"ton%

ar%as "ill. T'% #ro)a)l% ca!s%s ar% ink too so"t+ ink #iling on )lank%t+ i$#ro#%rl* s%t roll%rs+ i$#ro#%r#acking on )lank%ts 9 i$#ro#%rl* $a% #lat%.

R%$%i%s: A long &arnis' to sto# ink #iling. C'%ck roll%r #r%ss!r%s an )lank%t #acking.


20/21

In some cases special printing aids or an ink fountain additives are suggested (Table 1A summarises ink problems which may be solvedusing ink additives, but the pressman should be aware of optional solutions).

Table 1A, ommon problems with ink and the recommended solutions.

00 8 44 220 221 230 280

PILING, POOR TRANSFERIncrease Tack,Increase length

XX

X

CHALKING or POWDERINGImprove hold out

X

X

X X

DRYING SLOW; POORGLOSS Increase

drier,Polymerising extender X X

X X X

EMULSIFYING (TINTING)Waterproof

X

FLYING, MISTINGShorten length

X

X

PICKING, LINTING,TAIL CURL,HICKIES

educe tack X

X

X

SET OFF IN DELIVERYInduce !uick set

X

SCUFFING SCRATCHINGIncrease "ax and drier,#se hard

surface drier

X X

MOTTLED SOLIDSImprove leveling

X

TRAPPING POORLY#se nonglossing drier, $d%ust

tack #se "ax free additiveXX

XX X

X

X XXX

XX


21/21

An Ink Additive should not be considered !a magic potion! but only as an immediate, possible remedy. "rior to using any ink additive, be sure to read thelabel and any technical information available on the additive you are planning to use.

&& Tack educer$n excellent transparent litho varnish, free flo"ing "ith excellent uniformity' It is an outstanding extender'

( Ink Gloss$ concentrated plastic glossing resin for all inks that produces a very high gloss' It creates a scratchproof finish and helps speed drying'

)) Print *leen+ixes "ith ink to create an immediate set on the sheet -though not on the press. to prevent offset' Great for use on coated stocks' It isrecommended reducer for all varnishes'

//& Three Way 0rier$ li1uid drier that mixes easier than paste driers "ith all inks to give controlled overall drying' 2xcellent top and 3ottom drying 1ualities' It "illnot discolour the most delicate inks'

//4 Li1uid 5o3alt 0rier$ standard 67 co3alt naphthenate drier' It sets ink easily and rapidly' This traditional surface drier forms a hard glossy finish on the printedsurface'

/8& Ink 5onditionerWax free multi purpose ink additive for all inks' Instant tack releaser' Promotes drying "ithout hindering trapping' It maintains color 1ualityand produces smoother solids' 2liminates hickey pro3lems'

/89 Ink :ardener;ormulated to assist drying and improve scuff resistance of printing inks "hen used on hard surfaced papers and 3oards'

/(& $1uacheck$ glossy plastic resin 3inder' It prevents emulsification of inks and is very useful in multi colour "ork' Gives sharper cleaner prints' +aintainscolor 1uality'

Documents

Printing Ink Problems-Causes and Remedies