Uncoated 20# Bond Wavy after digital printing

jpfulton248

Well-known member
Offset sheets come off of the press perfectly flat. Digital sheets do come off of our digital printers very wavy. We struggle with our offline bookletmaker when he paper is wavy. Our high speed digital (Xerox D125) seems to be the worse culprit. I suspect the high heat required for high speed, is drying out the paper. We keep a humidifier running throughout the day but we are in a dry climate and the humidity is probably at or below 20RH in our press room in the fall/winter/early-spring.

Has anyone else experienced these problems? What have you done? We are getting close to "buy-mode" again on one of our printers. Have digital laser printers gotten better in the last 10 years? I know nothing about inkjet... would that potentially be a fix?
 

MacDaddy

Well-known member
Yes the have newer toners allowing for lower heat. But wavvy sounds funny I assume you have the setting for the correct paper weight and type? Try lowering it, check if toner is fused ok to sheet that might help. To have some curl up or down might be standard on 20# but you should be able to adjust the curl in you setting and balance that out. If you have a de-curler on board.
 

jpfulton248

Well-known member
I'm going to post a pic of my "wavy paper" as soon as I have a stack printed. Just took a pic of a stack of offset. It really isn't curl (though we deal with that as well). Paper settings are indeed correct in the fiery/printer. No problem with fusing/quality. One other consideration (perhaps irrelevant but worth mentioning)... we print on 11x17 and then cut down to 8.5x11. So the printer path and the bookletmaker path are perpendicular to one another from the perspective of the sheet of paper.
 

Stickman42

Well-known member
If the issue is happening across multiple digital printers, I would suspect the paper. Try a different brand maybe?
 

crajos

Active member
Is it wavy with the grain or perpendicular to it? Running 11x17, your paper should be grain long. If it's wavy with the grain, that makes me think it's definitely a paper issue. If it's wavy perpendicular to the grain (across the short width of the sheet), then it could be the press. Easiest way to troubleshoot is to try another paper in the same size/weight - sometimes that's all it takes.

Regarding a new digital press - yes they have absolutely improved. Worth taking a look.
 

ColorMonkey

Well-known member
So I'm assuming the reams are wrapped. Is the paper after being removed from its wrapper sitting for any length of time before running? Also have you tried LEF as well as SEF as well as both seam side up as well as seam side down. Those are some things I might check to see effects.

Is this something that possibly is due to a bad lot of paper. In other words this is something you run a lot of and always have this problem or possibly you just received a bad lot.
 

azehnali

Well-known member
the D125 never those that
well at least hasn't in over 50 million impressions
I would have your tech check the fuser
 

Bill Ward

Member
We have that same issue from time to time and the techs seem to think it's a humidity issue (we are also in a dry climate), not just in terms of how the digital press is handling the paper but in how the paper is affected by the lack of humidity as it sits in the distribution center at over 5000'. Trying a different brand might help.
 

Ynot_UK

Well-known member
It can be a combination of the wrong relative humidity and the stock. Our RH sits around the 33% mark at this time of year, so below KM's "Q Zone" of 40 to 60% but within the "B Zone".

With one particular substrate, Navigator 100GSM uncoated white, the output develops a wavy characteristic during the half hour after printing. Leaving it a metre in front of one of the night storage heaters until the next day... perfectly flat again.
 

wildox

New member
Did you ever find a solution? We have the same problem with lynx uncoated cover. Its mainly an issue in the winter months.
 

Alois Senefelder

Well-known member
Gentlemen,

A constant refrain from Digital Printers is 1) Problems with Wavy Paper.

You all have a poor understanding of Paper Problems and Papermaking, I'm posting

a PDF which I hope you will find of interest and value.

Regards, Alois
 

Attachments

  • How Temperature # 1101.pdf
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De-Inking

Avanti
Sustainable Printing Goes Far Beyond Using FSC Certified or Recycled Paper
This informative paper on deinking: demand, principles, problems and solutions also explains why printing technologies are not all equally compatible with paper recycling systems; and why just a small fraction of printed material in the paper can cause difficulties.
Link To White Paper

   
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