Fingerprints on Plates

[Holsinger60]

So, we use Fuji Superia LH-PJ plates here. About every 3 months or so, the production floor comes up complaining about their plates inking up fingerprints all over the place. I've tried to recreate the problem by having everyone on my shift slam their hands all over the plates pre and post imaging/processing. No joy.

I was just curious if others have had similar issues and if they found what the cause was. Really don't want my plate department to have to wear gloves all the time. And they don't either. TIA

[Possum]

We use Fuji plates of a different ilk, but I've never had that happen here. I handle them as little as possible, and with the slip sheet on. Of course, the pressmen are another matter.

The only things I can think of is that somebody handling the unfinished plates had something on their hands, or their body chemistry is such that acids on their skin actually affect the plate coating. See if more frequent hand washing makes a difference, although I'm sure that suggestion will be taken up enthusiastically. 

[David]

Are these hand loaded into the platesetter or are you using an auto-loader?

If these are hand loaded, someone is touching them all over when they load them in, nothing to do but stop touching the plates, only handle them by the edges. We had some issues (another brand of plates) that we had a similar issue, turned out 1 platemaker had extremely oily hands, he had to end up wearing gloves.

If it is an auto-loader, then they must be coming from the factory like that.

Have you sent out a plate that has not been touched by humans to see if they finger print as well?

[JohnO]

Everyone has to wear gloves when handling plates at our shop. It's a safety thing as well as plate edges are quite sharp and many of the plates sizes are quite large.

[scottrsimons]

Same plates here, but no problems. I have seen fingerprints on the back side of plates after it's been processed, but no problems, as we only touch them around the edges, and we have an auto-loader.

[Holsinger60]

No auto-loader here. Hand loaded into platesetter. I've never been able to narrow it down to a certain individual either. Seems to be mostly on plates where after they've processed we have to cut down on a manual cutter. A lot of folks will steady it by pushing down on it. Maybe I should require gloves when doing that process and see if it clears up any.

Thank you all for your suggestions and advice. I certainly appreciate it.

[Farabomb]

Ran those plates for years. Depending on the mood of the pressman I would get some complaints of fingerprints. Sine I was the only one doing everything, I know where I handle the plates and anytime they would show up, it was nowhere near the edges where I grab them.

I've seen some prints but they were in the platebend and gripper so it wasn't a major issue. Since it's handfed I'd have the loaders only use the edges and see how that works.

[Tracy]

Line everyone up for fingerprinting!!  :laugh:

I use fuji and I always grab a plate by the edges, when it comes out of the imagesetter it is super sensitive.
I always slip sheet too.

[wonderings]

Seems very peculiar to have finger prints all over the plate as they really do not need to be handled all that much and certainly not in the centre of the plate or where the image will be. Like others I take plates by the sides and once imaged I put one of the slip sheets that comes with the plates between it.

[Joe]

When I make plates I usually leave blood on them.

[Possum]

During your long prepress career, you've probably left blood in a lot of places. 

[Joe]

Not nearly enough!

[AaronH]

Unless something got on the plate and an operator is trying to brush it off, I can't see a reason to touch the plate center, or anywhere outside of the first couple inches. I try to minimize plate touching as well and usually end up getting cut, though usually not bleeding. I'm short though and the big 40" plates are hard to manage.

[Joe]

Our biggest plate is 57" x 49.5" and they are a bitch to handle.

[StudioMonkey]

No auto-loader here. Hand loaded into platesetter. I've never been able to narrow it down to a certain individual either. Seems to be mostly on plates where after they've processed we have to cut down on a manual cutter. A lot of folks will steady it by pushing down on it. Maybe I should require gloves when doing that process and see if it clears up any.

Thank you all for your suggestions and advice. I certainly appreciate it.

You've got fingerprints - it should be easy to identify whose they are with a loupe.