> OK, so now I'm wondering. How much does it cost to buy 1 Kg of plastic?

The cost of the plastic itself is almost zero compared to the other costs 
involved (like the tooling cost, cost of running the machine, paying workers 
to keep an eye on the machine, shipping the product etc).

> And how much does it cost to tool up and turn that plastic into something 
> useful? (E.g., the casing for some sort of electronic device.)

A typical hard-tool for a simple plastic part (eg the front cover of your CD 
drive or half of a simple keyboard shell) will cost of the order of 10-40k 
pounds.  That tool will last for perhaps 200k uses until the metal is worn 
away enough that any further parts produced are considered not good enough. 
So a supplier would give you a price of like 10p per part if you were 
ordering large enough quantities.

The exact cost of the tooling usually depends on how many details there are 
in the design, someone has to design and make the tool, so the more details 
there are the more expensive.

> Also... I have a keyboard sat next to me. It seems very heavy. Is the 
> *entire* thing plastic? Or is there a metal chasis inside?

Not sure, maybe in the old days if you had a big heavy keyboard it would 
have one, but I guess with recent cheaper designs they realised that 
actually there is no reason to put a metal chassis in there (it's not like a 
keyboard needs to be that strong in normal use!).

Tools to make metal parts are usually more expensive, because they are more 
complex.  They often need to bend and cut the sheet metal in several steps 
to quite accurate tolerances.

Post a reply to this message