CD replication is the physical production process
involving actually pressing the discs during manufacture
from a glass
master. Replicated discs are referred
to as CD ROM discs, with the 'ROM' standing for 'Read-Only
Memory' (as opposed to the CD-R where the 'R' stands for
'Recordable').
The glass master is made of a solid thick disc of glass
that has been coated by a chemical, which is burned off
with a laser. The glass master is a 'negative' of the
CD and it is then coated with a molten nickel compound
and turned into a 'stamper'. The stamper punches
tiny pits in the discs that use molten aluminium
as the reflective surface and two polycarbonate layers
sandwich the aluminium layer to help protect it.
CD replication is a very quick and cost-effective production
method for larger quantities of discs (1000 or more).
However due to the high setup costs this type of production
is not suitable for smaller production runs.
Replicated
CDs are then printed using a five colour silk screen
or offset lithographic process, resulting in a very high
quality disc.
The other main type of CD or
DVD production is referred to as CD
duplication and is suitable for smaller
production runs with quicker turnaround times. CD and
DVD duplication involves burning blank CD and DVD media
with a laser to add the file contents onto the discs. |
