Many of us often refer to toner as dry ink. The truth is that toner has nothing to do
with ink (a pigmented liquid) at all.
Toner, in reality, is a powder that is plastic-based and negatively
charged. The blackness of copier toner
comes from pigments blended into the plastic particles while being
manufactured.
In a copier, the toner stored inside a cartridge is stuck on
larger, positively charged beads. As
toner-coated beads are made to roll over the drum, the toner particles are more
attracted by the positively charged ions on the unexposed areas on the drum's
surface than the weakly charged beads.
Later, the same particles are attracted even more towards the
electro-statically charged paper. The
plastic in the toner lets the user keep it from jumping ship once he/she has
finally got it on the paper. Now all
that is needed is to apply heat to the toner.
Once the temperature rises, the plastic particles melt and fuse the
pigment to the paper.
The fuser adds the finishing touches, to lend permanency to
the toner image on a sheet of paper. It
has to perform two jobs. First, it has
to melt and press the toner image into the paper. Second, it has to stop the melted toner
and/or the paper from sticking to the fuser.
In order to perform these tasks, quartz tube lamps and
Teflon-coated rollers are required.
First, the sheet of paper is sent between two of the rollers. Following it, the rollers are gently pressed
down on the page to embed the toner in the paper fiber.
In the meantime, the lamps are on inside the rollers,
producing sufficient heat to melt the toner.
The toner, however, does not melt onto the rollers. How? The Teflon coating on the rollers
prevents the toner and paper from sticking to them, just as the non-stick
coating that prevents your favorite omelet from becoming glued to the bottom of
your frying pan.
