Reverse curl issues within the shop.

[joe stag]

Looking for some ideas and possible solutions to an issue with reverse curl on our printed sheets and lables. The problem seems to have come out of nowhere across all substrates and presses without any clear cause. Any ideas on what could be causing it and solutions on how to fix it?

 

[Cornishpastythighs]

Humidity? have you checked

 

[joe stag]

Humidity? have you checked

We are climate controlled. Usually between 47 and 55% rh.

 

[Bill Ward]

Are the sheets running through a secondary fixing unit that is possibly causing the curl? So then maybe it's an issue with the way the profile of the paper is registered? Just a guess..

 

[joe stag]

Are the sheets running through a secondary fixing unit that is possibly causing the curl? So then maybe it's an issue with the way the profile of the paper is registered? Just a guess..

Not sure what you mean by secondary fixing unit?

 

[Bill Ward]

Not sure what you mean by secondary fixing unit?

Sorry, I meant Secondary Fuser. On our machines (Canon image press 8000) the gloss papers run through a primary and secondary fuser whereas the uncoated papers only go through the primary. Sometimes we get curling issues with our uncoated papers but I can usually eliminate this with a workaround by telling the machine to run the uncoated papers through both fusers ( I have to register the uncoated paper as coated).

 

[turbotom1052]

Are we talking digital or sheetfed? If sheetfed I too would be looking first at the shops climate. You indicate that the RH is well under control. My next thing would be to be sure that the presses de curler if so equipped, was not causing the reverse call. Lastly I would be looking at proper temp management of whatever drying system you may be using.