by Record-changer »
Tue Dec 01, 2015 9:24 am
It has always been done the same way since the mid 78 days.
First they use a record lathes to cut a lacquer master of an entire side. A second master is made for the other side.
Then they electroplate nickel onto the lacquer master to produce a metal master. This has ridges instead of grooves.
Then they electroplate (using release agents) a metal "mother" onto the metal master. It has grooves. A master can make many mothers.
Then they repeatedly electroplate onto the mother to make as many stampers as they need. The stamper has ridges.
The mother can make any number of stampers.
If only a few copies are needed, they use the metal master as the stamper.
A stamper is usually good to make somewhere between 500 and 2500 records, depending on the quality they want to maintain.
The above are the expensive parts. But this has to be done only once for the life of production for that record..
Now to pressing the records:
The stampers for each side of the record are placed in the two halves of the record press.
The pressing cycle is:
- The press is heated with steam flowing through channels behind the stampers.
- Biscuits of vinyl are placed on the bottom stamper.
- When the vinyl melts, the halves of the stamp0er are brought together to mold the record.
- Cold water flows through the channels to cool the record.
- The stamper opens and a worke3r removes the record and puts in biscuits for the nest record.
- Another worker trims the extra flash plastic from the rim of the record with a tool the diameter of the recoird.
- Another worker puts the record into an inner sleeve.
- Another worker puts the record into an outer sleeve.
- A machine shrink-wraps the outer sleeve.
A counter counts the number of records the stamper has made, so they know when to change it.
Obviously, it costs less per record if more records are made, because the mastering process needs to be done only once..