Kodak plates bad from the factory?

[doc_hoovie]

Hi all, we are running Kodak Thermal Gold plates (600x889x30mm) for one of our presses, and using an older Quartz processor. For weeks on end we have been dealing with scratches that's been resulting in much time and sigs wasted on press to clean them up, or outright makeovers and all the time/cost associated with that. We've tried two different lot numbers, although the time/date stamps between the two lots is only +/- 60 minutes, so the plates were all made at relatively the same time in the factory. Out of the 4 plate sizes we run here, this is only happening on this plate size for the 1 press we have that runs it. Our plant across town is running the same plate size, same lot that one of ours is, with no scratches reported.

We have imaged these plates in both our Magnus VLF via the MCU and our Trendsetter manually, and plates imaged in both units turn up the same type scratches. So we don't believe it's happening in either of those. And we've ruled out our bender.

We had the plate territory sales manager out yesterday and he said the problem was in the processor and frankly his argument/reasons sounded weak. The processor field tech was also here yesterday, although not at the same time as the sales manager. The processor tech said the sales guy don't know what he's talking about and that the processor's good. He points to rough plate handling. We are a small department, 6 people covering 3 shifts. So not that many people here are making the plates, and at 28 years in the company, I'm the least senior--so we've all been doing this a while and know how to handle plates. We've pushed back to the pressroom, and they say nothing nefarious is going on out there, that they've even pulled plates off the rack and found scratches before they even do anything with them. The scratches seem to ebb and flow in severity, frequency and location--nothing straight inline with anything in our process (or the manufacturing process, so sayeth the sales guy). Most seem to be at an angle, and most seem to be able to clean up on press after they've hit it with their chemistry. We are trying to work with the pressroom with recording all the instances that they remedy the scratches on press and keep running. Remakes are ordered via a paper makeover ticket/database, so right now only makeovers are tracked. I know Friday I made 40 of that plate type and didn't see any scratches. Our Sunday overnight crew made 1 16 plate form and had 11 plates they had to make over for scratches--we caught those before they went out the door. We've pulled plates out of the Magnus cassette and gingerly checked them before they get imaged, taken plates out of both skids we have in house, and manually fed plates, inspecting each one beforehand, and have not once yet found any sort of pre-existing scratches or defects in the plate topping.

So after saying all of that, my question is just has anybody had experience receiving bad plates from the factory, Kodak in particular, after they've reasonably ruled out the variables in their plate making area? Getting the sales guy to fess up to sending out inferior product would be like pulling teeth. I believe their process is probably pretty tight, but who knows what could happen there to cause a bad product that could make it out the door. We believe our process is pretty tight, and are pushing back to bad plates. Everyone's pointing the finger at at someone else, we just really want to get to the bottom of it and get past this, but we're at our wit's end. Any thoughts/feedback would be greatly appreciated. Thank you!


Steve

 

[gordo]

Sounds like there's a gorilla in the monkey works.

I'd spend some time watching, and recording, your plates as they are removed from the box, placed in the CtP, processed, packed for and delivered to the pressroom, and mounted on press. Do you use a portfolio-like sleeve to contain the processed plated for transport to the press? Are slip sheets used? Does the sleeve contain any other material - like proofs, drawdowns, etc.

Usually, scratches caused during manufacture or processing are directional rather than random. There can be minute debris on the back of plates that can scratch randomly the front of the plate after processing when they're placed on top of one another without slip sheets. Also, things like staples on proofs can scratch plates when placed in portfolio-like sleeves for transport to the press.

 

[SPECMON]

Hi Doc,

I had a similar problem with my AGFA plates, drove me crazy for months then someone mentioned a gum made by Applied Chemistries called Tuff Stuff and it solved my problems completely, they give free samples to try it out, worth a shot.

 

[CSF]

Tuff Stuff is remarkable. Water soluble polymer releases immediately. No fingerprints or scratches. A great product.

 

[bcs817]

I can absolutely help you out with the Scratching issues, the Tuff Stuff Scratch Resistant Plate finisher will eliminate all handling scratches. All you do is replace your existing finisher with Applied Chemistries Tuff Stuff.

 

[SnoopDoug]

Do you have any lot numbers on site that are more drastically different in manufacturing age than the 2 you have tried? One problem with it being a manufacturing issue is your plant across town not having the same problem with the same lot number. Is this plate a different gauge than the other 3 sizes you run, or the same gauge? Are these plates larger than all the others you run? Are the scratches all over the plate or in one general area? Are there any shards or slivers of aluminium in the package when it is first opened? Are you able to pull the plates at different areas in the processor/oven to check for scratches? Any recent changes to processor? Do you have any pictures you could share with the group? Just a few thoughts.

 

[doc_hoovie]

Thank you all for your responses, I'll try to answer some questions you posed.

First off, the scratches we're catching internally before they go out the back door are all straight off the line, before even being bent, hung on the rack or leaving the department. Since it was brought up though, we use Kodak MX-1591 Prebake Solution in our processor, the last section the plates go through. And we do not gum the plates at all after they've been baked--the prebake is the last thing to be applied to the plate. We haven't used slipsheets between bent plates on the rack for well over 5 years, and scratches have never been an issue until now, and still with only this 1 plate size.

I understand that our Thermal Gold plates are not really widely used, and that they're only made 2 or 3 times a year then warehoused until sent out. All the plates here between the two plants have the same manufacture date, 2/19/18. The plates we're having the issue with is the smallest size we use, 35" length (we also use 38", 54" and 72" plates). All are the same thickness. When loading these 35" plates in the Magnus MCU, we'll lift the corner of the stack of plates, count out 20, run our fingers beneath those 20 plates to the end, then lift them off the stack and place them between the rails of the MCU cassette. Every plate has a slipsheet between plates, and this has never produced scratches before.

The line coming out of our post-bake oven has a cool-down table, then an inline Burgess bender for our 54" and 72" plates. The smaller two sizes are sent off the side of the table, down an inclined belt to a flipper that flips the plate up on it's long edge where they're 'stacked'. We remove those plates and manually feed into our 2 different sized benders. It was theorized that debris/scratches on the back of one plate could cause scratches on the image side of the plate due to the stacking or moving the plates. While that makes sense, the length of the scratches we're seeing sometimes exceeds 1", and we know 4 or 8 plates lifted together out of the flipper aren't shifting that much, if at all. And we're not finding any debris between plates.

The scratches are at random places on the plate, not always consistent. The worst plate we've kept as an example of this has about 8 different places that are scratched. It looks like it was thrown down and pushed around on the floor. But this one was right off the line, not bent or anything.

If there were something hanging down in the pre or post-bake ovens causing this, or something in the scrub socks in the developer, or brush in the wash section, we'd expect to see it across all 4 plate sizes and we're just not. That's why we're thinking it is plate manufacturing related somehow.

Some examples below.

 

[SnoopDoug]

Has the Kodak rep been able to tell you if the scratches occur before or after imaging? They should be able to look at the disturbance and tell that where you have halftone image over one of the scratched areas.
Also, not sure of your MCU configuration, but could you try changing cassettes/drawers that you are loading into? Maybe swap with another size and see if anything changes?

 

[Saulius]

Hi,

we use Kodak Electra XD plates and, as a trend, scratches occur in our process, but only due to our internal problems (plate handling by ctp operator or transportation from prepress to shop floor). During three years we have had several lots of plates with not regular emulsion layer thickness. Kodak technician got to re-calibrate ctp laser focus.