HEIDELBERG PRINTMASTER QM46-2 - problem with marking plates going on machine

[inkyplate]

Hi There,

Can anybody offer some advice. We have a Printmaster QM46-2.
Recently when putting plates onto Printing Unit 2 ( the head nearest the feed end of the machine ), we have been getting an in ink band at the top of the plate running the full width of the plate and about 2 to 3 inches in depth. It’s a problem as it can come to contaminate lighter inks on the other printing unit.

Please see attached pic showing problem outlined in orange


We are using metal plates.

The Machine is about 12 years old and has done 11 Million impressions.

the 3 inking form rollers are all quite new – about 6 months old

We have done ink stripe tests to the plate from the 3 inking form rollers and the damping roller - and each is perfect. Printing and damping is great and no complaints from the print minder.

We can put the plates manually ok, and we DON’T get the marks.

Does anybody know how to rectify this>?


Thanks in Advance.

 

[jef]

plate

Could the plate be loose?

 

[inkyplate]

Hi Jef, thanks for your reply. Plate seems pretty tight on the cylinder, and print is perfect to so I assumed it was ok, is there a way to change how loose or tight the plate get clamped.

 

[jef]

plate

you can drop the tail edge clamp all the way to the cylinder. It still looks like a loose plate with the band on the front edge of the plate.