Static electricity grounding

[Gauss2k]

Hello!

I have to ground several stocking silos made of 100% polypropylene fabric (the silos are filled with polystyrene beads). It doesn't contain any grounding wires included within the fabric. The silos are about 4x6x10 feets and their frame is made of metal pipes.

I am not familiar with static electricity and I wonder how much wires (connected to the ground) I should add on the silo's surface to remove most of its charges since I don't think that grounding only the frame will be enough.

And what kind of grounding rod should I use? (depth, size, etc) And what about the size of the gounding wire?

Thanks
Gauss2k

 

[busbar]

Some discussion at thread238-46951

 

[IRstuff]

Grounding to what end?

The polystyrene beads will still carry charges, even in a fully metallic silo.

You'd almost be better off running a high humidity and snuff the charge that way.

TTFN

 

[Gauss2k]

You're absolutely right. But we must eliminate as much static electricity as we can.

It would be technically quite hard to raise the humidity level so I will consider it only as a last resort.

If we put a grounded metal grid through which the beads would pass, do you think it'd help?

Thanks
Gauss2k

 

[analogkid2digitalman]

Have you thought of static eliminators (ionizers)using forced air. Ideal for plastics that can't conduct to ground.

For example, see:

http://www.exair.com/product_info/product_info_page.htm

 

[IRstuff]

The ionizer approach is probably better than a humidifier, but both might not be a bad idea.

It's otherwise not possible to remove the static, since just the flow motion of the beads will generate frictional static. And since the beads are non conductive, grids would not bleed off all the charge

TTFN

 

[aviat]

You can also look into anti-static agents. They are used in jet fuel and works by making it more conductive and hence able to bleed off charges better.

http://www.specialchem4polymers.com/tc/Antistatic-Agents/index.aspx?id=2701

http://www.ce-mag.com/archive/2001/janfeb/mrstatic.html