Comment by userbinator
8 hours ago
Free as in speech or beer...?
I wonder if they used static-dissipative/ESD-safe plastic, as pure polypropylene is good insulator and easily builds up a static charge. There's a reason nearly all computer cases are conductive.
Wouldn't the power supply ground all static?
Probably not guaranteed, I've often wondered why my clothes out of the dryer have a static charge when the dryer is plugged into a grounded outlet.
That had never occurred to me but is a great question. I suppose between the poor conductivity of the fabric and the paint inside the dryer, the system is very well insulated. Maybe a dryer with bare walls could be antistatic without the use of dryer sheets. But maybe that would be a fire hazard.
As the clothes get dryer they become less conductive. Even if there was a perfect path to ground, the charge wouldn't be able to get there across the material itself.
this case is conductive, precisely so the excess charge can be grounded by the power supply by being in touch/contact with the psu metallic casing.
the psu is grounded, but the static has no way of getting to ground (via psu) if the case itself is non-conductive.