double-sided printing with laser printers

[Wolfgang Jeltsch]

Hello,

I want to do double-sided printing with a laser printer which doesn't
directly support duplex printing. I once thought that it is okay to just
print on one side and feed the printer with the same sheet of paper again
to print on the other side.

But recently I was told that during printing on the back side of the paper
the toner already present on the front side could get liquid again during
the heating process so that it dirties parts of the printer. Is this
correct? If yes, does this problem apply only to certain laser printers?

Thanks for your help.

Best wishes,
Wolfgang

 

[jbuch]

Hello,

I want to do double-sided printing with a laser printer which doesn't
directly support duplex printing. I once thought that it is okay to just
print on one side and feed the printer with the same sheet of paper again
to print on the other side.

But recently I was told that during printing on the back side of the paper
the toner already present on the front side could get liquid again during
the heating process so that it dirties parts of the printer. Is this
correct? If yes, does this problem apply only to certain laser printers?

Thanks for your help.

Best wishes,
Wolfgang

You got some bad information.

Consumer laserjet printers which do double sided printing feed the paper
into a loop like circuit that first prints on one side, and then on the
other.

So, the doublesided printers sold automatically just feed the paper back
in for printing on the back side.

In fact, for many printers, the special machinery is called a "Duplexer"
and it is sometimes sold separately as an upgrade which the user can
install, often now by just pushing it into place.

I suggest that you decline to accept information from your "source".

I have had duplexing laserjet printers in my business for over six
years. Your "Source" may not own one, and may not ever have seen one.

You can look at the insides of a lot of laserjet printers at
http://www.printerworks.com

It is probably a good indea to find a better "source".

Jim

 

[Lukasz Spychalski]

It is probably a good indea to find a better "source".

Sorry, but I definitely cannot agree with you. You are writing about
duplex or duplex-ready printers, but Wolfgang asked for simplex ones.


Wolfgang: yes, it's posible, that melted toner sticks to pressure roller
located in the fusing unit. In single-sided pinters the pressure roller
normally doesn't touch the printed side of paper and therefore doesn't
need a special anti-stick coating. I've seen a lot of dirty rollers
causing dirty printouts and (what's much worse) rollers wrapped in paper
which usually devastates the fuser unit due to increased roller
diameter.

So if you want to reliably "duplex-by-hand" using simplex laser printer,
you have to make sure, that pressure roller is not made of bare silicone
rubber, but is coated instead. I'm pretty sure there are such models on
the market, although I can't tell you which one has coated pressure roller.

 

[Wolfgang Jeltsch]

Sorry, but I definitely cannot agree with you. You are writing about
duplex or duplex-ready printers, but Wolfgang asked for simplex ones.


Wolfgang: yes, it's posible, that melted toner sticks to pressure roller
located in the fusing unit. In single-sided pinters the pressure roller
normally doesn't touch the printed side of paper and therefore doesn't
need a special anti-stick coating. I've seen a lot of dirty rollers
causing dirty printouts and (what's much worse) rollers wrapped in paper
which usually devastates the fuser unit due to increased roller
diameter.

So if you want to reliably "duplex-by-hand" using simplex laser printer,
you have to make sure, that pressure roller is not made of bare silicone
rubber, but is coated instead. I'm pretty sure there are such models on
the market, although I can't tell you which one has coated pressure
roller.

Hello,

thanks for your information.

Well, if your printer can be made a duplex printer by attaching a duplex
unit to it then "duplex-by-hand" should work in case you don't have such a
unit because the printer must have coated pressure rollers, right?

Best wishes,
Wolfgang

 

[Wolfgang Jeltsch]

[...]

So if you want to reliably "duplex-by-hand" using simplex laser printer,
you have to make sure, that pressure roller is not made of bare silicone
rubber, but is coated instead. I'm pretty sure there are such models on
the market, although I can't tell you which one has coated pressure
roller.

Does anyone on this forum know about *low-cost* printers which have coated
pressure rollers?

Best wishes,
Wolfgang

 

[Ryadia]

Hello,

I want to do double-sided printing with a laser printer which doesn't
directly support duplex printing. I once thought that it is okay to just
print on one side and feed the printer with the same sheet of paper again
to print on the other side.

But recently I was told that during printing on the back side of the paper
the toner already present on the front side could get liquid again during
the heating process so that it dirties parts of the printer. Is this
correct? If yes, does this problem apply only to certain laser printers?

Thanks for your help.

Best wishes,
Wolfgang

Some brands of colour laser printers do damage the ink/paper on the second
pass. Primarily earlier model Xerox 'digital' printers. The specs of the
printer should be your guide. If duplex printing is an option, you can
safely re-feed the paper upside down to print on the back. Minolta printers
are quite happy doing this as are most HP colour lasers. As I said, check
the specs.

DOug

 

[Lukasz Spychalski]

Well, if your printer can be made a duplex printer by attaching a duplex
unit to it then "duplex-by-hand" should work in case you don't have such a
unit because the printer must have coated pressure rollers, right?

Right. The only remaining issue is the feeder. In duplex printers a sheet
of paper is fed from tray only once, and then printed sequentially on
both sides. In "duplex-by-hand" printing process you have to load the
paper two times. Sheets which are already printed on one side, curled,
loaded with static electricity and dried in high temperature sometimes
don't want to feed properly.

 

[John]

I do duplex printing on my lj5n
I use fineprint.

 

[John]

Hello,

I want to do double-sided printing with a laser printer which doesn't
directly support duplex printing. I once thought that it is okay to just
print on one side and feed the printer with the same sheet of paper again
to print on the other side.

But recently I was told that during printing on the back side of the paper
the toner already present on the front side could get liquid again during
the heating process so that it dirties parts of the printer. Is this
correct? If yes, does this problem apply only to certain laser printers?

yes this is a problem

 

[Alan]

Hello,

I want to do double-sided printing with a laser printer which doesn't
directly support duplex printing. I once thought that it is okay to just
print on one side and feed the printer with the same sheet of paper again
to print on the other side.

But recently I was told that during printing on the back side of the paper
the toner already present on the front side could get liquid again during
the heating process so that it dirties parts of the printer. Is this
correct? If yes, does this problem apply only to certain laser printers?

I can testify from personal experience that melting toner is not a
problem with HP II, HP III, HP IIIP, HP4 or HP4ML printers.

On occasion I've duplexed 100 + page runs (print odd pages, restack,
print even) -- however, jams are more frequent, you need to keep an
eye on it.

 

[MikeD]

I can testify from personal experience that melting toner is not a
problem with HP II, HP III, HP IIIP, HP4 or HP4ML printers.

I can add the HPLJ 5L to that list. I've done a lot of double sided printing
with no problem other than an occasional small streak of toner on the top of
the second side of the page. According to other 5L users this is common.

Mike