Fuser And Media Handling - Xerox 3001 Service Manual

Fuser and Media Handling
There are three major components involved in
the fusing process: the fuser heat roll, the
pressure plate, and the fabric guide.
The media guide plate creates a gradual
entrance for the media into the fuser area.
The guide plate creates a larger area of
pressure at the entrance t o the fuser which
prevents wrinkles (in paper and the *Tracing
Paper). If there i s uneven pressure or friction
at the pressure point, a wrinkle will occur in
the area of the least amount of pressure. For
this reason, the guide plate must be flat.
Removal of the pressure plate removes the
pressure point and generally allows *Tracing
Paper t o be transported through the fuser, but
it will become damaged, usually wrinkled.
Bond paper will almost always wrinkle
without the pressure plate.
If the media is too damp or the fuser
temperature is too high, the rapid escape of
moisture causes the media t o shrink very
rapidly. This overcomes the force of the
pressure plate and allows wrinkles t o develop.
Film is an entirely different material. Film
doesn't absorb moisture, but it does shrink
when heat is applied t o i t which, in some cases,
can cause a wrinkle deletion.
The fabric guide holds the media against the
heat roll. The media must slip on the fabric
guide as the heat roll drives the media
through the fuser. If there is excessive friction
between the fabric guide and the back side of
the copy media, distortion of the media will
occur. This distortion is transmitted back into
the transfer area which causes the smears,
deletions and smudges, and copy quality
defects if the media doesn't stall first. No copy
i s made t o show the copy quality defect.
If the media, especially the *Tracing Paper,
stops at the entrance t o the fuser, this is
caused by excessive friction from the fabric
guide at the pressure plate. Any contaminant
that is released from the media changes the
friction properties of the fabric guide.
Fuser oil is used t o prevent drag between the
fuser heat roll and the fabric guide when there
is no media present; it also prevents fuser
offsetting of the toner from the media t o the
heat roll. Silicone oil is used because it can
provide the lubrication needed. It is also odor-
free, can withstand high temperature without
changing the lubricating properties, and
evaporates with time so that the copy is free of
oil.
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Fuser and Media Handling