Heidelberg CD102 - Print Shrinkage

[herbert]

Hi All

We are currently printing 55 x 90 cards 110up on a B1 Sheets, then rotary diecut. The issue is all the cards have Terms and conditions on the reverse (text close to the trim), the customer has found cards towards the Tail edge of the sheet, the T&C's are too close to the trim compared to the cards to the middle / grip edge.

Initially I thought the dispro on the forme was incorrect, but after outputting a CAD drawing and overlaying the Sheet, I found from the start of the sheet to the tail edge the print had actually started to shrink gradually final ending about 1mm on the Tail end row of cards.

Ive check all measurements on the CAD drawing and its spot on (692mm tick to tick), the plates are fine (692,, tick to tick), but the print is 691mm.

How can this be, ive heard of paper stretch, but Paper shrinkage !!

Spec:
UV inks, sheetwork, 400gsm B1 stock 4col both sides - Heidelberg CD102 5 / 1


Any help would be great

Regards

Dan

 

[dabob]

Are you printing this on the same 4/c press? If so how is the front side length??? - other than that . . and its been a long time since I've been on a press but you can change the length (around the cylinder) by changing the packing take some out of your blanket and add it to your plate . . or the other way around - like I said its been a long time since I've had to deal with this issue

 

[herbert]

Are you printing this on the same 4/c press? If so how is the front side length??? - other than that . . and its been a long time since I've been on a press but you can change the length (around the cylinder) by changing the packing take some out of your blanket and add it to your plate . . or the other way around - like I said its been a long time since I've had to deal with this issue

Yeah, someone said that today, but one of the press guys said you shouldnt pack out your plates, one to think about

 

[herbert]

The Jobs has been printed on the same press, Front side (Grip) looks fine...the shrinkage starts at around the middle of the B1 Sheet

 

[sivakumar]

I too face the same problem when i print 6 colour job on my KBA105 5 colour machine. We print 4 colour on 170 gsm paper, then try to print 2 spot colours. there is size shrinkage in 4colour, causing registration problem.

We did try to keep the paper in room temperature for 1 day, checked all blanket, packing, blanket tightening, alchohol, ph, etc, etc. still the problem remains same. I too look forward for solution to this problem.

 

[Alois Senefelder]

Print Length

Print Length

Hello all


I suggest you read the PDFs I have posted, re print length


Thread: Print Length Issues page 2


Link - http://printplanet.com/forums/sheetfed-web-offset-discussion/17469-printlength-issues-constantly


Regards Alois

 

[SHELBY]

Lets not reinvent the wheel ,If you want to shorten the image add some packing under your plate!

 

[Alois Senefelder]

Crucial Step !

Crucial Step !

Hello Shelby,


Pray do - tell us the next crucial step to take after adding packing under the plate !!



Regards, Alois

 

[SHELBY]

ummmmmmmm take a hit and up see if it DA fits

 

[SHELBY]

not as wise as you old guys, iv only been doing this for umm 27 years now

 

[SHELBY]

I have no need for pdfs sorry its all in my head sorry no disrespect! just call it like it is!

 

[Alois Senefelder]

Magic !

Magic !

Hello again Shelby,


Being a Stone Age Man, Now I am intrigued by a head full of Magic!


Regards, Alois

 

[Prime12]

If your running UV inks can assume that you are using lamps to cure. Due to the heat from the lamp and the curing process it cause some shrinkage towards the tail and sides of the sheet. Try to use as little power on your lamps as possible to cure the inks. Might not make a difference some stocks just do not have the pulp to hold shape.