UV white color problem

[india286@hotmail.com]

i been printing Metalised mono cartons and have 2 color press.
We started with white color and everthing is ok as soon as we reached the final printing i mean C+M 2nd pass and then Y+B 3 rd pass the white color printed 1st becomes dirty and yellowish what is the solution

 

[jaed]

do you have any close up pictures of the problem?

 

[saso777]

It can be a lot of things,check and clean rollers and if you can send picture.

 

[india286@hotmail.com]

it became dirty and yellowish only after when it gone 3-4 pass under UV curing system
whether i print other colors or not doesnt matter only if i pass it 3 times under UV curing system it become dirty and turned yellowish

 

[Komory]

probably painted in the third run, goes to white .Sorry for inglish.What kind of ink you use?

 

[india286@hotmail.com]

arets UV inks

 

[Data]

If there is no signs of the white stripping from the substrate it sounds more like you wasnt using enough damp thus its tinting from the latter passes

 

[india286@hotmail.com]

If there is no signs of the white stripping from the substrate it sounds more like you wasnt using enough damp thus its tinting from the latter passes

enough damp??? means i use lesser ink while printing and should increase the supply of the ink to the sheet.???
and no stripping is there we base coat the sheet 1st and then printing with uv inks

 

[eng reda]

white color curing need special lamps
are you have this lamps or not?

 

[india286@hotmail.com]

what kinda special lamps???
its got cured with ordinary UV curing lamps
if anything special then let me know

 

[Data]

I mean you might need more damp on the later colours. Dirty and yellowing white suggests your colours are scumming

 

[Andy-zhang]

Maybe it is the problem of ink. you can change other brand of ink.
MSN: dennispaul@live.cn & Skype: andyzhang0415
website: www.zyprinter.com & www.zytech86.com

 

[Drew812]

Do a test put the white through the press 3 times before you put the other colors on to see if it's getting dirty, to see if the other colors are really the problem and not just getting toasted from 3 passes under the lights.

 

[Drew812]

We use a Toyo plastics white that works great on paper and plastic, and i put the same (make ready) through the press about 7 time and still looks white.

 

[india286@hotmail.com]

you mean to say there is no need of UV drying it works great on paper and plastic without requiring UV drying??
sukesh