Electronics Repair (sci.electronics.repair) Discussion of repairing electronic equipment. Topics include requests for assistance, where to obtain servicing information and parts, techniques for diagnosis and repair, and annecdotes about success, failures and problems.

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Default Photocopier - paper scratches on the OPC

ie the normal paper or dust slight scratches , not down to the metal drum
from loose screw or swarf. All quite normal for any OPC. Usually this is ok
but the original toner for this m/c not available, requiring second 1 only
source, supposed compatible, formulation. Very fine scratches seem to hold
the toner , ie exposed bits of latent image retain the toner in the
scratches and so deposit as fine lines on the paper. If too much toner
passed to the OPC then more and more lines appear, so only possible to
produce grey rather than black output. The ac cleaning voltage is now at
maximum of 2.5 KV but some lines are still present with a grey image rather
than black.
Anyone happen to know what needs adding to the toner to make it less sticky
or whatever ? or some other procedure. I'm assuming the narrow scratches are
physically holding the toner but thats only guessing really, decreasing the
transfer voltage of course produces a lighter image and still transfers the
lines, so not an option.
Physically cleaning the OPC or leaving the background heater on all the time
makes no difference. I'm wondering if the toner is too oily and decanting to
a tumbler with blotting paper lining would remove some of the oiliness,
before returning to the hopper. Anyone know of a test for oiliness that
gives some sort of numerical result ?

Incidently anyone know what the marking B stands for, on the preset for
adjusting the 200 to 250V dc voltage of the OPC relative to frame and what
this voltage is called ? The other presets are marked TR for transfer and AC
for the ac cleaning voltage


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Default Photocopier - paper scratches on the OPC

N_Cook wrote in message
...
ie the normal paper or dust slight scratches , not down to the metal drum
from loose screw or swarf. All quite normal for any OPC. Usually this is

ok
but the original toner for this m/c not available, requiring second 1 only
source, supposed compatible, formulation. Very fine scratches seem to hold
the toner , ie exposed bits of latent image retain the toner in the
scratches and so deposit as fine lines on the paper. If too much toner
passed to the OPC then more and more lines appear, so only possible to
produce grey rather than black output. The ac cleaning voltage is now at
maximum of 2.5 KV but some lines are still present with a grey image

rather
than black.
Anyone happen to know what needs adding to the toner to make it less

sticky
or whatever ? or some other procedure. I'm assuming the narrow scratches

are
physically holding the toner but thats only guessing really, decreasing

the
transfer voltage of course produces a lighter image and still transfers

the
lines, so not an option.
Physically cleaning the OPC or leaving the background heater on all the

time
makes no difference. I'm wondering if the toner is too oily and decanting

to
a tumbler with blotting paper lining would remove some of the oiliness,
before returning to the hopper. Anyone know of a test for oiliness that
gives some sort of numerical result ?

Incidently anyone know what the marking B stands for, on the preset for
adjusting the 200 to 250V dc voltage of the OPC relative to frame and what
this voltage is called ? The other presets are marked TR for transfer and

AC
for the ac cleaning voltage



I should have said the voltage on the centre of the revolving magnet
developer drum , not to the OPC, the retraction voltage ? The votage that
means the toner powder on the OPC that has become discharged from the
exposure light is pulled off, back to the toner supply side, leaving the
latent image.
These fine line toner deposits are adhering more than the 250V "retraction
voltage ?" will pull off but will pull off with the 7.3KV transfer voltage
to the paper.

Anyone know of a source of plain carbon black, fine ground, without silicone
oil/surfactants added , to dilute the supposed proper toner.


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Default Photocopier - paper scratches on the OPC

In that are is what looked like an afterthougt 1W resistor to ground,
marked brown black brown. Surely not if a few hundred volts there. With a
good light brought into the area I could then see it is brown black purple.
Just an ordinary looking MO resistor, enamelled ,no glass encapsulation, but
1 Gigohm.


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Default Photocopier - paper scratches on the OPC

In that are is what looked like an afterthougt 1W resistor to ground,
marked brown black brown. Surely not if a few hundred volts there. With a
good light brought into the area I could then see it is brown black

purple.
Just an ordinary looking MO resistor, enamelled ,no glass encapsulation,

but
1 Gigohm.


Wouldn't that be 100M? (10 x 10^7)


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Default Photocopier - paper scratches on the OPC

"William Sommerwerck" wrote in
:

In that are is what looked like an afterthougt 1W resistor to ground,
marked brown black brown. Surely not if a few hundred volts there.
With a good light brought into the area I could then see it is brown
black

purple.
Just an ordinary looking MO resistor, enamelled ,no glass
encapsulation,

but
1 Gigohm.


Wouldn't that be 100M? (10 x 10^7)




yes.

--
Jim Yanik
jyanik
at
kua.net


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Default Photocopier - paper scratches on the OPC

Jim Yanik wrote in message
...
"William Sommerwerck" wrote in
:

In that are is what looked like an afterthougt 1W resistor to ground,
marked brown black brown. Surely not if a few hundred volts there.
With a good light brought into the area I could then see it is brown
black

purple.
Just an ordinary looking MO resistor, enamelled ,no glass
encapsulation,

but
1 Gigohm.


Wouldn't that be 100M? (10 x 10^7)




yes.

--
Jim Yanik
jyanik
at
kua.net


I'm not used to seing that colour combination.
Measured about 1000Meg, by comparison with a glass cased 1Gohm , with a high
voltage source, it is grey not purple on the third band on rechecking.




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Default Photocopier - paper scratches on the OPC

"N_Cook" wrote in
:

Jim Yanik wrote in message
...
"William Sommerwerck" wrote in
:

In that are is what looked like an afterthougt 1W resistor to
ground, marked brown black brown. Surely not if a few hundred
volts there. With a good light brought into the area I could then
see it is brown black
purple.
Just an ordinary looking MO resistor, enamelled ,no glass
encapsulation,
but
1 Gigohm.

Wouldn't that be 100M? (10 x 10^7)




yes.

--
Jim Yanik
jyanik
at
kua.net


I'm not used to seing that colour combination.
Measured about 1000Meg, by comparison with a glass cased 1Gohm , with
a high voltage source, it is grey not purple on the third band on
rechecking.


I'm surprised it would stay 1G for any length of time,with an enamel
coating.

maybe you could post a pic of it.I wonder who makes them?

--
Jim Yanik
jyanik
at
kua.net
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Default Photocopier - paper scratches on the OPC

Jim Yanik wrote in message
...
"N_Cook" wrote in
:

Jim Yanik wrote in message
...
"William Sommerwerck" wrote in
:

In that are is what looked like an afterthougt 1W resistor to
ground, marked brown black brown. Surely not if a few hundred
volts there. With a good light brought into the area I could then
see it is brown black
purple.
Just an ordinary looking MO resistor, enamelled ,no glass
encapsulation,
but
1 Gigohm.

Wouldn't that be 100M? (10 x 10^7)




yes.

--
Jim Yanik
jyanik
at
kua.net


I'm not used to seing that colour combination.
Measured about 1000Meg, by comparison with a glass cased 1Gohm , with
a high voltage source, it is grey not purple on the third band on
rechecking.


I'm surprised it would stay 1G for any length of time,with an enamel
coating.

maybe you could post a pic of it.I wonder who makes them?

--
Jim Yanik
jyanik
at
kua.net


Its just a light blue bodied resistor that looks like any other except for
an unusual colour code. It must be there to discharge any accumulated charge
inside the developer chamber. A resistor with a crimp eye terminal at either
end, looking a bit afterthoughtish. Whether it is 500M or 2000Meg probably
does not matter. I imagine it could be difficult to make a high resistivity
spiral of metal oxide, from my own attempts at making resistive compound for
1 meg pot tracks, very patchy resistivity

As for main thread I got into the generator circuit and temporarily upped
the retract ? voltage up to 350V , for a test. Black lines still there and I
think the image intensty was reduced as well, ie wanted charged, latent
image bits, partially retracted back to the developer, so no solution there.

Apparently, from an industrial chemist, it is possible to get fine ground
pure carbon black from chemical supply companies for some sort of filters ,
not activated charcoal. All laser and copier toner these days have silicone
oil added , perhaps to avoid the use of silicone oil bath/wicks at the
output fuser stage. Enough oil carries through to the output to keep the
paper from sticking to the supposed non-stick finish of the fuser roller or
its pressure roller.


--
Diverse Devices, Southampton, England
electronic hints and repair briefs , schematics/manuals list on
http://home.graffiti.net/diverse:graffiti.net/



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Default Photocopier - paper scratches on the OPC

N_Cook wrote:
ie the normal paper or dust slight scratches , not down to the metal drum
from loose screw or swarf. All quite normal for any OPC.


It's perfectly normal for the OPC to have mild scratches on it. As long
as it's not down to the metal. (Which will give you white lines along
the print.)

Usually this is ok
but the original toner for this m/c not available, requiring second 1 only
source, supposed compatible, formulation. Very fine scratches seem to hold
the toner , ie exposed bits of latent image retain the toner in the
scratches and so deposit as fine lines on the paper.


That's more likely to be due to dirt on the laser window. Give it a wipe
& a blow. A stray hair stuck in there, or in the laser window of the
cartridge will give you a line down the page.

If too much toner
passed to the OPC then more and more lines appear, so only possible to
produce grey rather than black output. The ac cleaning voltage is now at
maximum of 2.5 KV but some lines are still present with a grey image rather
than black.
Anyone happen to know what needs adding to the toner to make it less sticky
or whatever ? or some other procedure. I'm assuming the narrow scratches are
physically holding the toner but thats only guessing really, decreasing the
transfer voltage of course produces a lighter image and still transfers the
lines, so not an option.


There's nothing 'sticky' about the toner. It adheres to the drum from
electrostatic attraction only. If it's sticking to the drum when it
shouldn't be, there's something wrong with the HV, or the IR laser or
cleaning light is not wiping the charge from the drum as it should.

Physically cleaning the OPC or leaving the background heater on all the time
makes no difference. I'm wondering if the toner is too oily and decanting to
a tumbler with blotting paper lining would remove some of the oiliness,
before returning to the hopper. Anyone know of a test for oiliness that
gives some sort of numerical result ?


Dry toner is *never* 'oily'. It's micron-sized particles.

Incidently anyone know what the marking B stands for, on the preset for
adjusting the 200 to 250V dc voltage of the OPC relative to frame and what
this voltage is called ? The other presets are marked TR for transfer and AC
for the ac cleaning voltage


'B' = Bias.

--
W
. | ,. w , "Some people are alive only because
\|/ \|/ it is illegal to kill them." Perna condita delenda est
---^----^---------------------------------------------------------------
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Default Photocopier - paper scratches on the OPC

N_Cook wrote:
Jim Yanik wrote in message
...
"N_Cook" wrote in
:

Jim Yanik wrote in message
...
"William Sommerwerck" wrote in
:

In that are is what looked like an afterthougt 1W resistor to
ground, marked brown black brown. Surely not if a few hundred
volts there. With a good light brought into the area I could then
see it is brown black
purple.
Just an ordinary looking MO resistor, enamelled ,no glass
encapsulation,
but
1 Gigohm.
Wouldn't that be 100M? (10 x 10^7)



yes.

--
Jim Yanik
jyanik
at
kua.net
I'm not used to seing that colour combination.
Measured about 1000Meg, by comparison with a glass cased 1Gohm , with
a high voltage source, it is grey not purple on the third band on
rechecking.

I'm surprised it would stay 1G for any length of time,with an enamel
coating.

maybe you could post a pic of it.I wonder who makes them?

--
Jim Yanik
jyanik
at
kua.net


Its just a light blue bodied resistor that looks like any other except for
an unusual colour code. It must be there to discharge any accumulated charge
inside the developer chamber. A resistor with a crimp eye terminal at either
end, looking a bit afterthoughtish. Whether it is 500M or 2000Meg probably
does not matter. I imagine it could be difficult to make a high resistivity
spiral of metal oxide, from my own attempts at making resistive compound for
1 meg pot tracks, very patchy resistivity

As for main thread I got into the generator circuit and temporarily upped
the retract ? voltage up to 350V , for a test. Black lines still there and I
think the image intensty was reduced as well, ie wanted charged, latent
image bits, partially retracted back to the developer, so no solution there.

Apparently, from an industrial chemist, it is possible to get fine ground
pure carbon black from chemical supply companies for some sort of filters ,
not activated charcoal. All laser and copier toner these days have silicone
oil added , perhaps to avoid the use of silicone oil bath/wicks at the
output fuser stage. Enough oil carries through to the output to keep the
paper from sticking to the supposed non-stick finish of the fuser roller or
its pressure roller.


*NO!* That is NOT correct! Laser/copier toner is totally dry. The
silicon oil is applied to the fuser roller by a wiper pad, & serves to
prevent the 'cooked' toner on the paper from sticking to the fuser
roller as it exits the fuser assembly.

--
W
. | ,. w , "Some people are alive only because
\|/ \|/ it is illegal to kill them." Perna condita delenda est
---^----^---------------------------------------------------------------


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Default Photocopier - paper scratches on the OPC

Bob Larter wrote in message
...
N_Cook wrote:
ie the normal paper or dust slight scratches , not down to the metal

drum
from loose screw or swarf. All quite normal for any OPC.


It's perfectly normal for the OPC to have mild scratches on it. As long
as it's not down to the metal. (Which will give you white lines along
the print.)

Usually this is ok
but the original toner for this m/c not available, requiring second 1

only
source, supposed compatible, formulation. Very fine scratches seem to

hold
the toner , ie exposed bits of latent image retain the toner in the
scratches and so deposit as fine lines on the paper.


That's more likely to be due to dirt on the laser window. Give it a wipe
& a blow. A stray hair stuck in there, or in the laser window of the
cartridge will give you a line down the page.

If too much toner
passed to the OPC then more and more lines appear, so only possible to
produce grey rather than black output. The ac cleaning voltage is now at
maximum of 2.5 KV but some lines are still present with a grey image

rather
than black.
Anyone happen to know what needs adding to the toner to make it less

sticky
or whatever ? or some other procedure. I'm assuming the narrow scratches

are
physically holding the toner but thats only guessing really, decreasing

the
transfer voltage of course produces a lighter image and still transfers

the
lines, so not an option.


There's nothing 'sticky' about the toner. It adheres to the drum from
electrostatic attraction only. If it's sticking to the drum when it
shouldn't be, there's something wrong with the HV, or the IR laser or
cleaning light is not wiping the charge from the drum as it should.

Physically cleaning the OPC or leaving the background heater on all the

time
makes no difference. I'm wondering if the toner is too oily and

decanting to
a tumbler with blotting paper lining would remove some of the oiliness,
before returning to the hopper. Anyone know of a test for oiliness that
gives some sort of numerical result ?


Dry toner is *never* 'oily'. It's micron-sized particles.

Incidently anyone know what the marking B stands for, on the preset for
adjusting the 200 to 250V dc voltage of the OPC relative to frame and

what
this voltage is called ? The other presets are marked TR for transfer

and AC
for the ac cleaning voltage


'B' = Bias.

--
W
. | ,. w , "Some people are alive only because
\|/ \|/ it is illegal to kill them." Perna condita delenda est
---^----^---------------------------------------------------------------



This is a conventional copier, not scanner/laser.
Silicone oil wick/baths at the output have not been used on photocopiers
since the days of sliding top ones, relying on silicones added (sub 1
percent) to the toner instead, not enough to appear oily to the touch but
enough to make sure paper does not stick to fuser drum or silicone rubber
pressure roller. The first one I came across to fix, was wet process toner
in paraffin carrier, 1970s vintage, paper on a roll and a vicious
guillotine.

The toner these days is mainly carbon/charcoal black but also such as
styrene ,styrene acrylic copolymer, polypropylene,metal complex dyes,
methylmethacrylate,styrene butylarylate, silicones and oleic acid


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Default Photocopier - paper scratches on the OPC

"N_Cook" wrote in
:

Jim Yanik wrote in message
...
"N_Cook" wrote in
:

Jim Yanik wrote in message
...
"William Sommerwerck" wrote in
:

In that are is what looked like an afterthougt 1W resistor to
ground, marked brown black brown. Surely not if a few hundred
volts there. With a good light brought into the area I could
then see it is brown black
purple.
Just an ordinary looking MO resistor, enamelled ,no glass
encapsulation,
but
1 Gigohm.

Wouldn't that be 100M? (10 x 10^7)




yes.

--
Jim Yanik
jyanik
at
kua.net

I'm not used to seing that colour combination.
Measured about 1000Meg, by comparison with a glass cased 1Gohm ,
with a high voltage source, it is grey not purple on the third band
on rechecking.


I'm surprised it would stay 1G for any length of time,with an enamel
coating.

maybe you could post a pic of it.I wonder who makes them?

--
Jim Yanik
jyanik
at
kua.net


Its just a light blue bodied resistor that looks like any other except
for an unusual colour code. It must be there to discharge any
accumulated charge inside the developer chamber. A resistor with a
crimp eye terminal at either end, looking a bit afterthoughtish.
Whether it is 500M or 2000Meg probably does not matter. I imagine it
could be difficult to make a high resistivity spiral of metal oxide,
from my own attempts at making resistive compound for 1 meg pot
tracks, very patchy resistivity

As for main thread I got into the generator circuit and temporarily
upped the retract ? voltage up to 350V , for a test. Black lines still
there and I think the image intensty was reduced as well, ie wanted
charged, latent image bits, partially retracted back to the developer,
so no solution there.

Apparently, from an industrial chemist, it is possible to get fine
ground pure carbon black from chemical supply companies for some sort
of filters , not activated charcoal. All laser and copier toner these
days have silicone oil added , perhaps to avoid the use of silicone
oil bath/wicks at the output fuser stage. Enough oil carries through
to the output to keep the paper from sticking to the supposed
non-stick finish of the fuser roller or its pressure roller.


--
Diverse Devices, Southampton, England
electronic hints and repair briefs , schematics/manuals list on
http://home.graffiti.net/diverse:graffiti.net/





toner is a wax compound.waxes are also lubricants.

--
Jim Yanik
jyanik
at
kua.net
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Default Photocopier - paper scratches on the OPC

On 6/13/2009 5:42 AM Jim Yanik spake thus:

toner is a wax compound.waxes are also lubricants.


That's not my understanding: from what I've read, toner is basically a
mixture of pigment (carbon black or equivalent) and plastic (styrene)
that melts onto the printed substrate (paper).

Maybe you're thinking of phase-change/sublimation printing (e.g.,
Xerox/Tektronix Phaser), which does use wax as the carrier.


--
Found--the gene that causes belief in genetic determinism
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David Nebenzahl wrote in message
.com...
On 6/13/2009 5:42 AM Jim Yanik spake thus:

toner is a wax compound.waxes are also lubricants.


That's not my understanding: from what I've read, toner is basically a
mixture of pigment (carbon black or equivalent) and plastic (styrene)
that melts onto the printed substrate (paper).

Maybe you're thinking of phase-change/sublimation printing (e.g.,
Xerox/Tektronix Phaser), which does use wax as the carrier.


--
Found--the gene that causes belief in genetic determinism



I would agree with that summary but add that there are surfactants added to
assist in even distribution of the toner over the OPC, otherwise the coarse
distribution of the iron filings transfer process would be rather patchy.


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Default Photocopier - paper scratches on the OPC

"N_Cook" wrote in
:

David Nebenzahl wrote in message
.com...
On 6/13/2009 5:42 AM Jim Yanik spake thus:

toner is a wax compound.waxes are also lubricants.


That's not my understanding: from what I've read, toner is basically
a mixture of pigment (carbon black or equivalent) and plastic
(styrene) that melts onto the printed substrate (paper).

Maybe you're thinking of phase-change/sublimation printing (e.g.,
Xerox/Tektronix Phaser), which does use wax as the carrier.


Heh.I worked for TEK for 21.5 years.
their thermal wax process is a sort of wax-jet deposition thru a printhead.
I've had pretty good looks at TEK's printer mechanics.

just feel the toner that's fused onto the paper;it feels waxy.
Googling showed several references to wax for copier toner.



--
Found--the gene that causes belief in genetic determinism



I would agree with that summary but add that there are surfactants
added to assist in even distribution of the toner over the OPC,
otherwise the coarse distribution of the iron filings transfer process
would be rather patchy.


Isn't it done by electrostatics?

--
Jim Yanik
jyanik
at
kua.net


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David Nebenzahl wrote:
On 6/13/2009 5:42 AM Jim Yanik spake thus:

toner is a wax compound.waxes are also lubricants.


That's not my understanding: from what I've read, toner is basically a
mixture of pigment (carbon black or equivalent) and plastic (styrene)
that melts onto the printed substrate (paper).


Correct.

Maybe you're thinking of phase-change/sublimation printing (e.g.,
Xerox/Tektronix Phaser), which does use wax as the carrier.


That'd be my guess too.

--
W
. | ,. w , "Some people are alive only because
\|/ \|/ it is illegal to kill them." Perna condita delenda est
---^----^---------------------------------------------------------------
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Default Photocopier - paper scratches on the OPC

Jim Yanik wrote in message
...
"N_Cook" wrote in
:

David Nebenzahl wrote in message
.com...
On 6/13/2009 5:42 AM Jim Yanik spake thus:

toner is a wax compound.waxes are also lubricants.

That's not my understanding: from what I've read, toner is basically
a mixture of pigment (carbon black or equivalent) and plastic
(styrene) that melts onto the printed substrate (paper).

Maybe you're thinking of phase-change/sublimation printing (e.g.,
Xerox/Tektronix Phaser), which does use wax as the carrier.


Heh.I worked for TEK for 21.5 years.
their thermal wax process is a sort of wax-jet deposition thru a

printhead.
I've had pretty good looks at TEK's printer mechanics.

just feel the toner that's fused onto the paper;it feels waxy.
Googling showed several references to wax for copier toner.



--
Found--the gene that causes belief in genetic determinism



I would agree with that summary but add that there are surfactants
added to assist in even distribution of the toner over the OPC,
otherwise the coarse distribution of the iron filings transfer process
would be rather patchy.


Isn't it done by electrostatics?

--
Jim Yanik
jyanik
at
kua.net



The rotating magnets + iron filings bring the toner close to the OPC and
then the electrostatic voltage on the OPC, set up by the corona wire, pulls
the toner across the gap. Then there should be an even charge distribution,
but although very fine ground, it is finite size and the surfactants can
help to allow easier flow.
This maybe the key to the problem . What is the charge distribution over a
semiconductor surface that instead of being perfectly smooth, has very fine
scratches around it ? Maybe it is possible to reduce the corona voltage.
Previously mistyped as 7.3KV, actually 8.3KV, I've not looked into that
area, separate HV board somewhere, just measured the voltage at the corona
housing .


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I found the neat little Murata corona generator, marked 4.55KV, 0.3mA . I
don't know what the o/p voltage should be
Corona measured as 8.7KV so something not right there, plenty of room to
drop the corona voltage. Not got to the point of monitoring the lines to it
yet nor tried the preset yet, lines to it are 2 grounds, supply, control,
and one marked REM , any ideas what that one means ?


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Default Photocopier - paper scratches on the OPC

N_Cook wrote:
Jim Yanik wrote in message
...
"N_Cook" wrote in
:

David Nebenzahl wrote in message
.com...
On 6/13/2009 5:42 AM Jim Yanik spake thus:

toner is a wax compound.waxes are also lubricants.
That's not my understanding: from what I've read, toner is basically
a mixture of pigment (carbon black or equivalent) and plastic
(styrene) that melts onto the printed substrate (paper).

Maybe you're thinking of phase-change/sublimation printing (e.g.,
Xerox/Tektronix Phaser), which does use wax as the carrier.

Heh.I worked for TEK for 21.5 years.
their thermal wax process is a sort of wax-jet deposition thru a

printhead.
I've had pretty good looks at TEK's printer mechanics.

just feel the toner that's fused onto the paper;it feels waxy.
Googling showed several references to wax for copier toner.


--
Found--the gene that causes belief in genetic determinism

I would agree with that summary but add that there are surfactants
added to assist in even distribution of the toner over the OPC,
otherwise the coarse distribution of the iron filings transfer process
would be rather patchy.

Isn't it done by electrostatics?

--
Jim Yanik
jyanik
at
kua.net



The rotating magnets + iron filings bring the toner close to the OPC


Modern laser printers & copiers use monocomponent toner, which has the
magnetic material in each toner particle. You're thinking of older
systems, which used a separate magnetic 'developer' powder to carry the
toner to the drum.



--
W
. | ,. w , "Some people are alive only because
\|/ \|/ it is illegal to kill them." Perna condita delenda est
---^----^---------------------------------------------------------------
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Default Photocopier - paper scratches on the OPC

On 6/14/2009 7:49 PM Bob Larter spake thus:

N_Cook wrote:

The rotating magnets + iron filings bring the toner close to the OPC


Modern laser printers & copiers use monocomponent toner, which has the
magnetic material in each toner particle. You're thinking of older
systems, which used a separate magnetic 'developer' powder to carry the
toner to the drum.


Reminds me of the old Kodak* copier I had when I owned a print shop; the
previous owner had bought it for something ridiculous like less than
$1000. The thing was a behemoth, and required lots of maintenance, but
when it was running it would whip out good copies all day long and not
even breathe hard.

I remember having to replace various parts of the "developer" system in
it. Very old school.


* Actually Kodak/Heidelberg, during their short partnership in imaging
systems.


--
Found--the gene that causes belief in genetic determinism


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Default Photocopier - paper scratches on the OPC

The ps voltage was a bit high but not enough to push the corona voltage from
5.55KV to over 8KV. The preset only varied it a few hundred volts. Put a
dropper in line and its now 5.8KV and working , subjectively, just as
before - lines on the paper image. But these lines are no longer "burned"
onto the OCD. Previously if you removed the corona housing and wire, then
the lines still emerged onto the paper for a number of runs because of a
build up on the OCD, that failed to clean off with AC and wiper blade.
Now if you remove the corona the next output is plain white so the cleaning
process can now cope with it.
I tried changing the corona housing to a spare one but the lines are in
exactly the same place. It is difficult convincing myself that the toner
lies in fine lines on the OCD as there is no obvious repeat, coincident with
the lines on the paper. There are hundreds of such fine lines with nothing
making the most persistently tranferrd ones stand out.
If the following makes no difference I will try the earlier OCD that worked
fine but the original owner managed to scratch numerous deep lines axial to
the drum so produced heavy black lines obscuring the image. If the lines
stay in the same position then it will be a total mystery as I've cleaned
,twice now, all surfaces near the OCD path. I should have said these
present lines are so fine they are just intrusive rather than blocking
information.

Going back to my original thinking, as this all started about coincident
with forced change of toner supplier. I made up a test batch of some of the
toner mixed about 2 :3 of charcoal sieved down to 75 microns, the thinking
is it would dilurte an excess of oil/styrene. It takes a while for this to
work through the feed system but so far the ratio of blackness of wanted
image to tram lines has improved, I think. I can get hold of styrene and
have plenty of silicone oil but how do you mix 98 percent sieved charcoal
with 2 percent or so of liquids without clumping? At this rate I may as well
try formulating my own toner . My set of old brass lab sieves go down to 75
micron, any ideas for a source of mesh of order 30 or 40 micron?


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Default Photocopier - paper scratches on the OPC

N_Cook wrote:
The ps voltage was a bit high but not enough to push the corona voltage from
5.55KV to over 8KV. The preset only varied it a few hundred volts. Put a
dropper in line and its now 5.8KV and working , subjectively, just as
before - lines on the paper image. But these lines are no longer "burned"
onto the OCD. Previously if you removed the corona housing and wire, then
the lines still emerged onto the paper for a number of runs because of a
build up on the OCD, that failed to clean off with AC and wiper blade.
Now if you remove the corona the next output is plain white so the cleaning
process can now cope with it.
I tried changing the corona housing to a spare one but the lines are in
exactly the same place. It is difficult convincing myself that the toner
lies in fine lines on the OCD as there is no obvious repeat, coincident with
the lines on the paper. There are hundreds of such fine lines with nothing
making the most persistently tranferrd ones stand out.
If the following makes no difference I will try the earlier OCD that worked
fine but the original owner managed to scratch numerous deep lines axial to
the drum so produced heavy black lines obscuring the image. If the lines
stay in the same position then it will be a total mystery as I've cleaned
,twice now, all surfaces near the OCD path. I should have said these
present lines are so fine they are just intrusive rather than blocking
information.

Going back to my original thinking, as this all started about coincident
with forced change of toner supplier. I made up a test batch of some of the
toner mixed about 2 :3 of charcoal sieved down to 75 microns, the thinking
is it would dilurte an excess of oil/styrene. It takes a while for this to
work through the feed system but so far the ratio of blackness of wanted
image to tram lines has improved, I think. I can get hold of styrene and
have plenty of silicone oil but how do you mix 98 percent sieved charcoal
with 2 percent or so of liquids without clumping? At this rate I may as well
try formulating my own toner . My set of old brass lab sieves go down to 75
micron, any ideas for a source of mesh of order 30 or 40 micron?


Jesus. You're sure trying to do this the hard way!

Have you cleaned the laser module window, & tried swapping out the
cartridge?

--
W
. | ,. w , "Some people are alive only because
\|/ \|/ it is illegal to kill them." Perna condita delenda est
---^----^---------------------------------------------------------------
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Default Photocopier - paper scratches on the OPC

Bob Larter wrote in message
...
N_Cook wrote:
The ps voltage was a bit high but not enough to push the corona voltage

from
5.55KV to over 8KV. The preset only varied it a few hundred volts. Put a
dropper in line and its now 5.8KV and working , subjectively, just as
before - lines on the paper image. But these lines are no longer

"burned"
onto the OCD. Previously if you removed the corona housing and wire,

then
the lines still emerged onto the paper for a number of runs because of a
build up on the OCD, that failed to clean off with AC and wiper blade.
Now if you remove the corona the next output is plain white so the

cleaning
process can now cope with it.
I tried changing the corona housing to a spare one but the lines are in
exactly the same place. It is difficult convincing myself that the toner
lies in fine lines on the OCD as there is no obvious repeat, coincident

with
the lines on the paper. There are hundreds of such fine lines with

nothing
making the most persistently tranferrd ones stand out.
If the following makes no difference I will try the earlier OCD that

worked
fine but the original owner managed to scratch numerous deep lines axial

to
the drum so produced heavy black lines obscuring the image. If the lines
stay in the same position then it will be a total mystery as I've

cleaned
,twice now, all surfaces near the OCD path. I should have said these
present lines are so fine they are just intrusive rather than blocking
information.

Going back to my original thinking, as this all started about coincident
with forced change of toner supplier. I made up a test batch of some of

the
toner mixed about 2 :3 of charcoal sieved down to 75 microns, the

thinking
is it would dilurte an excess of oil/styrene. It takes a while for this

to
work through the feed system but so far the ratio of blackness of wanted
image to tram lines has improved, I think. I can get hold of styrene and
have plenty of silicone oil but how do you mix 98 percent sieved

charcoal
with 2 percent or so of liquids without clumping? At this rate I may as

well
try formulating my own toner . My set of old brass lab sieves go down to

75
micron, any ideas for a source of mesh of order 30 or 40 micron?


Jesus. You're sure trying to do this the hard way!

Have you cleaned the laser module window, & tried swapping out the
cartridge?

--
W
. | ,. w , "Some people are alive only because
\|/ \|/ it is illegal to kill them." Perna condita delenda est
---^----^---------------------------------------------------------------




This is conventional copier with document glass and toner hopper feed. The
same problem must apply to cartridge/laser systems for when the original
specified cartridges are no longer available and supposed replacement
equivalents are not equivalent. Its just that the process (whatever it is)
is otherwise going on , unseen , inside the cartridge.


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Default Photocopier - paper scratches on the OPC

I tried the original OCD with the deep scratch lines axial to the drum and
there is not the slightest hint of any of the thousands of paper scratch
lines on the original, coming through to the paper, just the deep
imperfections coming through. That is old OCD with the current toner
produces a good black image with no tramlines.
I'm wondering if too high a volts/mm in the active layer, from the corona
wire being too high a voltage can cause damage. Somehow in conjunction with
very fine scratches , give a concentrated charge distribution and very
locally damage the germanium or cadmium sulphide or whatever the active
layer is. With the problem OCD outside the machine I gave it a very close
inspection and I can still not see any correlation between the paper scratch
lines that cause tramline output and any of the thousands oif other possible
ones.

It is a continuum thing. If more toner is allowed through then more and more
tramlines appear. I could understand it if some bits of hair conducted
straight from corona to OCD to cause a few permanently affected rings but
not this situation.


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Default Photocopier - paper scratches on the OPC

N_Cook wrote:
Bob Larter wrote in message
...
N_Cook wrote:
The ps voltage was a bit high but not enough to push the corona voltage

from
5.55KV to over 8KV. The preset only varied it a few hundred volts. Put a
dropper in line and its now 5.8KV and working , subjectively, just as
before - lines on the paper image. But these lines are no longer

"burned"
onto the OCD. Previously if you removed the corona housing and wire,

then
the lines still emerged onto the paper for a number of runs because of a
build up on the OCD, that failed to clean off with AC and wiper blade.
Now if you remove the corona the next output is plain white so the

cleaning
process can now cope with it.
I tried changing the corona housing to a spare one but the lines are in
exactly the same place. It is difficult convincing myself that the toner
lies in fine lines on the OCD as there is no obvious repeat, coincident

with
the lines on the paper. There are hundreds of such fine lines with

nothing
making the most persistently tranferrd ones stand out.
If the following makes no difference I will try the earlier OCD that

worked
fine but the original owner managed to scratch numerous deep lines axial

to
the drum so produced heavy black lines obscuring the image. If the lines
stay in the same position then it will be a total mystery as I've

cleaned
,twice now, all surfaces near the OCD path. I should have said these
present lines are so fine they are just intrusive rather than blocking
information.

Going back to my original thinking, as this all started about coincident
with forced change of toner supplier. I made up a test batch of some of

the
toner mixed about 2 :3 of charcoal sieved down to 75 microns, the

thinking
is it would dilurte an excess of oil/styrene. It takes a while for this

to
work through the feed system but so far the ratio of blackness of wanted
image to tram lines has improved, I think. I can get hold of styrene and
have plenty of silicone oil but how do you mix 98 percent sieved

charcoal
with 2 percent or so of liquids without clumping? At this rate I may as

well
try formulating my own toner . My set of old brass lab sieves go down to

75
micron, any ideas for a source of mesh of order 30 or 40 micron?

Jesus. You're sure trying to do this the hard way!

Have you cleaned the laser module window, & tried swapping out the
cartridge?

--
W
. | ,. w , "Some people are alive only because
\|/ \|/ it is illegal to kill them." Perna condita delenda est
---^----^---------------------------------------------------------------




This is conventional copier with document glass and toner hopper feed. The
same problem must apply to cartridge/laser systems for when the original
specified cartridges are no longer available and supposed replacement
equivalents are not equivalent. Its just that the process (whatever it is)
is otherwise going on , unseen , inside the cartridge.


Sorry, I had some sort of brainfart & was thinking that you were talking
about a laser, not a copier. You should clean all the mirrors in the
optical path, & look for stray hairs or other debris. Your problem is
incredibly unlikely to be related to the composition of your toner.

--
W
. | ,. w , "Some people are alive only because
\|/ \|/ it is illegal to kill them." Perna condita delenda est
---^----^---------------------------------------------------------------
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