antistatic bag, how does it work?

[gaara]

ola,

 

you know when you buy a piece of computer hardware, lets say a hard drive, they usualy come in that dark grey bag, to my understanding thats an antistatic bag.

 

How does it physically work. thanks my science friends from the time of no return.

[swansont]

They have a conductive layer in them, so the bag acts as a Faraday cage — the voltage inside is unaffected by charge on the surface.

 

All bets are off, though, if you grab the device and you haven't grounded yourself. The bag only protects the device as long as it's inside.