duplexer causes curl

[holytech]

I think...
Just put a duplexer on my HP 4100TN.
Works and prints but the paper comes out curled.
I have the fuser mode set to plain and am using plain 20lb paper.
The paper is not curling when not put through the duplexer.
Would the fan in the duplexer not running do this... it seems to run.
Any ideas would be appreciated.
Thanks

[Big Al]

There are some paper type settings in the firmware that you can experiment with. We have a 4100 that had problems with card stock (post cards) and this was the fix for that issue. Try some diffierent paper stock? Is this a new problem? The fuser has two thermostats to keep the temperature within a close tolerance.

A temporary fix would be to manually duplex but that is also labor intensive. I know because I do a lot of it at home.

If the curling is not excessive and the duplexer is not jamming you can try putting the paper on a flat surface with something flat and heavy like a big book and let the paper cool and straighten out some.

Let us know what you find.

Al

[printerguy]

Paper will curl if it is too damp.

Try opening up a new ream of paper and see if the curling lessens.
If not, try a good quality 20 pound paper like Hammermill.

I am pretty sure that the better quality papers will resist absorbing water in the air.
I have been at this game for 25 years.

The curl is caused by the moisture in the paper being heated and sucked out of it when it goes through the fusing assembly.

If my advice works, try taking the paper out of the tray at night and putting it in a sealed Tupperware container.

Humid air will seek out the dryest thing in the office overnight.

Jim