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DETAILED EXAMPLE OF FLEXIBLE MANUFACTURING

SYSTEMS - CD/ DVD MANUFACTURE

V. Ryan 2007

 

The music is then transferred on to a MASTER CD which will eventually be used to manufacture thousands of CDs. At this stage the master CD is made of two layers - glass and a photoresist layer. The laser burns pits into the surface of the photoresist and this is how the music is stored on the disc.

 

A nickel layer is added to protect the delicate glass with its music burnt into the surface. Nickel is a metal and cannot be damaged easily.
This is the MASTER CD-ROM and it will be used to press the music into other blank CDs.

The CD you buy in the shops is mainly made of polycarbonate (plastic). Before music can be stamped into its surface, the blank CD is made by injecting hot plastic into a mould, at very high pressure. When the mould opens the blank CD is removed automatically and then a new blank is made. Computers monitor the temperature of the plastic and the pressure.

 
 

The MASTER CD is now used to stamp the music into the surface of the blank plastic CD. An automatic stamping machine is used for this process. It is computer controlled so that just the right amount of pressure is used to press the master CD into the blank plastic CD. The plastic CD is then moved onto the next process.

 
 

The plastic CD is then given an aluminium layer. Without this the laser beam in the CD player would shine straight through the plastic CD. The aluminium reflects the light from the laser making it possible for the CD player to change the reflected light into music.

 
 

Lacquer is then sprayed on the surface of the CD. This helps protect it from scratches and damage. The lacquer can withstand most scratches although with effort it can be damaged to such an extent that the CD will not play.

A screen printer is then used to apply all the colour - pictures and text - to the final surface of the CD. Ink is used as this gives a good finish and it is permanent. Click here for basics on screen printing.

 
 
     
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