I've been reading this thread with some interest.
There are a number of things which can cause inkjet head clogs. Also,
some of the causes for loss of ink on paper are not actually clogs.
I have worked with many Epson printers over the years, and I also have
helped thousands of people with clogging problems. I won't imply that I
know every nuance of Epson printers, but I have a pretty good
understanding of what causes problems with ink reaching the paper, and
some of the fixes.
Causes of actual ink clogs are numerous, and include:
Type of ink used.
Epson itself makes a wide variety of ink types. They break down to
basically two formulations, dye based and pigmented based, but within
those broader categories are many variations. Beyond that, there are
dozens if not hundreds of third party products in both dye and pigmented
formulations. Some formulations don't mix well. Some are poorly
formulated and end up too heavy bodied or dry too rapidly. Some have
contaminants or use pigment grains that are too large. Some have
pigments which clump. Some people fail to shake their pigmented ink
cartridges prior to installation, which helps to distribute the pigment
back into the ink carriers.
Epson inks use glycols in them which are heavy bodied and slow
evaporating chemicals which help to keep the ink heads from drying on
their surface. Some 3rd party inks may not have adequate amounts of
glycols.
The largest cause of actual clogs is when the ink under the head dries
or accumulates. Epson printers have ink wipers which are supposed to
remove the excess ink that develops under the head, but the wiper itself
gets contaminated over time, and isn't efficient as a result. Slowly,
ink solids begin to build up and clog the nozzles.
Pigmented inks are more vulnerable to buildup, since the ink has more
solids in it.
Other problems that can occur are if the cleaning station doesn't seal
the head on shut down. This can occur because the parts are not up to
tolerance when put together at the factory, or someone turns the printer
off via a power bar rather than the on/off switch on the printer. Again,
ink build up can cause the seal to be incomplete or distorted.
Yes, lower humidity tends to cause the inks to dry more rapidly, and
this build up under the head is more likely then. As also mentioned, a
dusty environment, paper dust, animal hair, etc can all add to problems.
If the cleaning station gets clogged up with old ink, it can reduce the
efficiency of the cleaning cycles. making clogs harder to resolve. On
some older printers, there is a valve that is supposed to move within
the cleaning station to open and close an air access. If this remains
open the heads will dry when on the cleaning station platform.
Not all "clogs" are clogs. The cause can be a dried out ink cartridge
which has too dense inks to move, there can be air bubbles within the
cartridge leading to intermittent printing, especially on refilled
cartridges. If there is an air vent on the cartridge, and it is
clogged, ink starvation can occur, where no air is supplied to replace
the ink used, causing pseudo clogs especially during heavy ink yield images.
The reason there are such contradictory experiences with inkjet printers
is because there are so many environmental variables, and variation at
manufacture.
Most inkjet printers with permanent heads will require some cleaning
maintenance at some point in their lives. Most of the fixes are
relatively easy and inexpensive to accomplish. As someone mentioned the
use of a ammoniated window cleaner can resolve many clogs. It is not
always necessary to remove the cartridges to do that, and in some cases
you can reuse cartridges you might have removed.
If anyone would like a free copy of my Epson Cleaning Manual, which
explains how to resolve most clogging and many other problems that may
show up, just email me using the address this message originated from (I
do not respond to public newsgroup request for the manual, sorry).
Art
