I dont know if you noticed...but with the increased speed of laser printers, they tend to curl the paper more than before. I have been trying to find an automatic DUPLEX laser that wont curl them up real bad...especially bad when duplexing.

I tried a brother printer and it was pretty bad..not professional quality. Can you believe I am still using an HP laser from 10 years ago (doesnt do duplex though). Even though its slow, its still better than anything I can find from a paper curling standpoint. So weird...technology is supposed to get better, not worse.

Hi hozer2k, the reason that newer laser printers can curl paper more is that the fusing/fixing rollers need to operate at a higher temperature, toner requires an amount of energy to melt it into the paper... the faster the paper speed the higher temperature needed in the fusing rollers.

Curl occurs because one fusing roller is solid and the other is made of sponge like silicon rubber.
Many modern papers are deliberately 'built' to curl one way (look for instructions or little arrows on the edges of the packet), this is so the machine tries to curl the paper one way and the paper wants to curl the other hopefully resulting in a fairly flat end product, of course installing the paper 'upsidedown' results in excessive curl.
This is done so the paper is flatter, resulting in less jams, on the second pass (duplexing).

Paper that is suffering from dampness will increase the likelyhood it will curl. If the paper is damp, as it goes through the fusing section the heat causes the moisture to turn into steam, softening the paper and allowing it to curl more before it dries out due to the heat. That's the reason most paper will come in a plasticised wrapper i.e. to provide it with a protective environment for storage.

In low usage situations, storing the paper in a drier area helps a lot, airing cupboards are great in the home environment as are boiler rooms... but don't let the paper get too dry because that can create problems too...


Pete
P.S. Next weeks lesson is Scoroton Grids...

I love how even the most obscure stuff ((like why does laser printer paper curl, why is the sky blue, how do hard drives work), there is always someone on SPCR who knows and can explain it...Pete, i take it you are in the biz?

Guilty as charged...



Pete
P.S. That was the abridged/carefull you don't look too geeky version.....

I'm afraid the damage has already been done...

I had absolutely no idea that paper was actually "built" to curl one way or another. Does it apply with cheap copier paper (which I guess gets used quite a lot in lasers), or just the more expensive stuff?

Hi Nick, it's not an 'expense' item... any cost of paper may or may not have it.

Paper has been like this for 15-20 years now... (No I'm not that old... er... my older brother told me about it... yeah, that's it... )

The thing is finding the arrow (if it even has one), on some brands it's stupidly small and many people will miss it or not be able to see it for what it is... Think 4mm X 4mm bright yellow indistinct blob/arrow on bright blue packing and not perfect sight.....

And just because it's got an arrow... don't think it can be trusted to be pointing in the right direction... many a time I have had to say to customers "Yeah, I know the arrow is pointing that way but if we put the paper in upsidedown there's less curl look!!!"

As for the copier/laser point, as far as I know, nobody manufactures non-digital (analogue) copiers anymore. Copiers have been laser/LED printers with a built in scanner for some years now.

Whatever you do make sure the packet says copier/laser paper on it. Don't use anything for inkjet/bubblejet etc machines. I've seen some pretty horrible messes in copiers, quite often destroying the fusing rollers, particularly the stuff used to create image to transfer onto t-shirts.

If you use paper that's designed to curl, the wrong way... and it's sufficiently damp, the paper can come out and roll itself into a tube of about 25mm diameter
Needless to say it doesn't then doubleside very well



Common conversations I've had over the years:

"It's your paper causing the problem."
"You said that last time!!"
"And this time, as last time, when we put fresh paper from a fresh pack in the problem goes."
"Whys that then?"
"Because this time, as last time, the papers damp."
"You always blame it on the paper!"
"Yes, and when we change the paper, the problem goes doesn't it!!!"

[pause]..........[/pause]

"What's wrong with the copier then?..."

-----------

(On arrival)
"The last three engineers have blamed it on the paper!"
"Does the problem go when you put fresh paper in?"
"Yes..... but the problem comes back after a couple of days!!!"



Now that everyone has fallen asleep... I'll sign off
Pete

Thanks for that response...some of that I knew, some I did not. Learn something everyday. Soooo...that being said, is there a good duplexing printer that wont have so much of an issue?

I dont care much about speed, I would rather have the quality. I tried a couple out, but no luck....I did try a couple different stock sizes and new vs old paper (but not the directional part though I admit). All of my results consistently found that the 10 yr old printer did a much better job than my new ones.