KBA Genius Ink Set-Off (plastic substrate)

[plasticpro]

One of our clients is running into an ink set-off issue printing on our PVC sheets.
Small "picks" of ink are pulling off and transferring onto the sheet placed on top of it. The offsetting is occurring in one particular line running perpendicular with the longer dimension of the sheet. Any thoughts on the dynamics of offsetting (in one recurring spot of the sheet) on a KBA Genius would be appreciated.

 

[RichardK]

Is this in the direction of sheet travel through the press? Is the press kitted with UV dryers? Is the press kitted with antisetoff spray? If so check lamps are OK, check spray powder is free running and that nozzles are not blocked.

Oh and welcome to the forum.

 

[plasticpro]

Sorry, I used the wrong word. The set-off occurs in a pattern or line parallel to the color bar. The person I'm working with is a very experienced plastic printer but only with the Genius for about a year. Maybe the lamps are something to look closer at. I can't see any mechanical oil or coating on the sheet that is interfering with the ink laydown. The ink is adhering but it's being pulled off.

 

[RichardK]

So it's a UV press then? Is the affected area running in the direction of sheet travel or at right angles to it?

 

[plasticpro]

Yes,it is a UV press and the affected area is at a right angle to the sheet travel direction

 

[RichardK]

Have you tried turning the sheets over. This should determine whether its a press or substrate issue. ie if the problem shifts position then you know the press is fine...if the not then you need to ensure there's nothing that can cast any kind of shadow in front of the lamp as the sheet passes thru.

Is the sheet touch dry art the delivery...even in the affected area?

 

[RichardK]

Although I haven't had very much experience with plastics I do know that the material itself can have 'faults' particularly in the way the surface allows ink to 'key' to it. If all the preceding suggestions don't show any positive result you may have to call your supplier in.

 

[RichardK]

OK if the issue is at right angles to the direction of sheet travel it really rules out the lamps. My gut tells me its a material issue. Call your supplier and see if they're a techie who can help.

 

[jonprintz]

Plasticpro,
I've not seen this problem on the Genius in our shop. It would be a good idea to check the lamp hours but I don't think that is the issue. Is your customer having this problem with other stocks?

 

[eyeneuh]

Sorry to hijack the thread,
Jon, can you please send me your email address, I am a genius owner and need to ask another owner a question.
michael@hueneye.com
thanks
m.

 

[mountaindew]

Hello All, I just joined this forum.

Plasticpro, will it be ok for you to post or email me the picture ? I think i had this kind of problem too in the past but my printer fixed it.

pcia@multicard-indonesia.com

 

[plasticpro]

Would love to but the sheets were sent off to my factory for analysis.

 

[big deano]

priming the plastics should help also the inks could be a problem.is it only one colour or all?