Plate damage on tail

[dean112263]

We are a folding carton plant and run all Heidelberg XL-145's. Have been running Fuji plates for past 4 years (LH-PJ). Had to switch to LH-PJ2 plates (mfg. in Japan) a few months ago.
Encountering something re: the tail edge of the plates (2 images attached)

The first image was from one of our older XL-145s. This damage occurred 8/26. The second one was one of several units from a brand new XL-145 that was just installed about 3 months ago.
We already had the newer press' tail clamps checked by Heidelberg service techs (and they were adjusted). Even since the adjustment we had the shredded tail of occur only on runs over 50,000 (usually occurring between 50-70m sheets). We've had it happen on SBS and CCNB stock.

We've used the same print blankets for all of our presses (hybrid type of blanket since we print conv., some UV/Hybrid and a small amt of pure UV.

We did not encounter this problem with the LH-PJ's (manufactured in Greenwood, SC). We used the LH-PJ's for approx. 3 years prior to switch to LH-PJ2's

Haven't been able to pinpoint root cause yet.
Since it was only happening on our new press, we were thinking it's purely a mechanical / clamp issue.
But with this happening on another press also only on a >50,000 sheet run I feel it may be more of raw materials / plate issue.
Have our Fuji tech rep coming in to examine.
Has anyone else encountered this issue with LH-PJ2 plates?

Any insight anyone can provide is appreciated.

 

[SteveSuffRIT]

Have plate mfg investigate grain direction (roll milling) of the plate?

 

[Alois Senefelder]

Re- plate cracking....

Hello to all at PrintPlanet, after a long absence!

Hello Dean, "Aluminum Litho Plates are manufactured from a High-Grade Aluminum Metal" It is extremely rare for

grain direction to have an influence on plate cracking on a sheet-fed press.

Regards, Alois

See the PDF

 

[dean112263]

Checking to verify that the plates are getting punched on platesetter at the proper depth so it fits into plate cylinder registartion pins OK.
We've never had the issue with the LH-PJ plates made in the US. This has only happened on the LH-PJ2 plates (made in Japan). Will be measuring plates out to see current lot is within spec.
We've already informed press supervisors to have their operators check plates loaded onto plate cylinders to verify there's no bulging/ill fitting areas at tail of plate.
Would think it'd be fairly straightforward to diagnose. We have 4 of one type of press (Heid. XL-145), all output on 1 platesetter (Suprasetter 145).

 

[Ashok Taneja]

Hi dear
Here we have to isolate the problem 1st (is it the problem of press or is it the problem with palte(new type) as per you.

For checking
1) used old plate (lhpj- USA) and print on new xl145.
2) if you any other supplier of palte Or tell fuji suppliee to supply at least on packet for testing.

Now
On press side all 4 xl145 are equipped with auto plate. So there is no issue of over tighting.
Check the plate and blanket packing also may be some one has put more packing.
These are the few reason.

 

[dean112263]

Ashok, Thanks for the response.
Unfortunately, I don't have the old style LH-PJ plates on hand anymore. Those were gone several months ago. The LH-PJ plates were discontinued in light of LH-PJ2 plates.

You are correct that we are using autoloaders, so the overtightening issue is non-existent.
We have the packing matching the press specs. (have had luxury of a Heidelberg trainer here the past several weeks so we're following specs pretty tightly)

Appreciate your feedback.