Re: How and what is toner for copiers made of?

Question:

"How and what is toner for copiers made of ?"

"I have learned that not all toners are the same. For instance one make of
toner will not work on another make of machine or even in the same range of
machines there are differences. I was told that it has something to do with
the way it is made during manufacture ?"

This is not my field of expertise but I know a little bit about how
electro-photography works and it may be enough to answer the question

Answer:

As is the case with most systems, each component is designed with other
parts of the system in mind.  The designer will start with performance
requirements dictated by the customers' needs. Whatever results are needed,
all parts of the system will need to work together.  Let's briefly remind
ourselves about electro-photography and how the  toner needs to behave.

The image of the object to be copied, for example a document or photograph,
is projected onto a photo-conductive surface which has been given a uniform
electric charge.  Where light falls in the surface the charge can leak away
leaving a "latent image" of charge on the surface.  The surface is then
treated with toner.  This is either dispersed in a non-conducting liquid or
is a powder.  Most photocopiers use powders.  The particles of toner are
charged and are attracted to the oppositely charged latent image.  The
image made up of toner is then transferred onto the paper and heated above
its melting point.  It flows into the paper and on cooling becomes solid
again.

If the image quality needs to be high or the speed of operation needs to be
very fast, the machines and materials will be designed appropriately.
Toner for colour photocopiers consists of  a pigment, usually solid organic
dyes, and  a polymeric binder, for example a polyester or styrene acrylate.
The purpose of the binder is to hold the pigment in place in the final
image.  It also provides gloss to the image areas.  In Black toners using
carbon, the binder prevents the charge leaking away from the charged toner
particles.   If the quality needs to be high the toner needs to be made
from very small particles,  for sharpness and graininess,  and it would
need to contain pigments with  good colour characteristics.

The way the machines work also dictates what other characteristics the
toner needs to have.  It has to be charged up and this can done in a number
of ways.  It has to retain the charge until it is fused.  Each machine type
will have different toner handling systems and anticipated operational
conditions.  The pigments and the polymer binders influence the ease of
charging and the stability of the charge on the toner particles.  The
melting point of the toner is a good example of the interaction of the
equipment and the toner.  It would be no good using a toner with a high
melting-point in a machine which didn't provide enough heat.

I found a web site with some information about manufacturing methods. http://www.zeon.co.jp/en
glish/new/f/f-tec13.html
This article "Polymerized Toner: Its Feature and Future" describes a method
of producing smaller more evenly sized particles than the normal type in
which
pigment is mixed with molten polymer.  The cooled mixture is broken into
small particles by a milling process.  The newer method involves producing
a homogenised emulsion of monomer containing the pigment and then
polymerising the monomer to produce the toner.  The resulting imaging
improvements are indicated.  Another article on the site "tec-7"  or
"Preparation of the Polymerized Toner" shows pictures of the polymerized
and milled toners showing the more spherical, smaller particles in the new
type of toner.