Static in FRP
Static in FRP
(OP)
We manufacture FRP over the road tankers and customer has a question about static charge and how to dissipate during loading or unloading. There is a carbon fiber conductive layer but not sure how to address this problem in a practical manner.
Thanks for the help.
Thanks for the help.





RE: Static in FRP
The common feature to both methods, is that the conductive layer is bonded to the filler neck, and to ground,( earth.) so that any charge is dissipated as it builds.
B.E.
RE: Static in FRP
RE: Static in FRP
Charge separation develops due to fluid molecules separating from surfaces in pipes and tanks. But charged fluid molecules are attacted to grounded surfaces. So the amount of charge is a balance between charge creation and charge dissipation. Without grounded surfaces in the tank, the tank becomes a big capacitor. Grounded surfaces on the outside of the tank will significantly increase capacitance.
Simply having a grounded pipe dipping into the fluid will improve static dissipation.
RE: Static in FRP
If I read your cross section correctly. The carbon layer is in the outermost skin of the tank. You can use that as your conductive layer. A grid of stainless steel or bronze mesh with a contact pin welded to it, bedded down tight to the carbon fiber and covered with resin will give you a means of connecting a ground cable.
With that balsa core there, you would need to connect the inner and outer skins with a conductive layer at some point or you will be making a capacitor inside the tank.
I hope this helps.
B.E.
RE: Static in FRP
thanks again
RE: Static in FRP
OK I misread your layup section. Your existing carbon veil is inside the tank next to the liquid.I was thinking of a second layer of carbon to get a conductive layer next to the liquid.You already have the conductive layer where it is needed.Now you just need a conductive path from that layer out of the tank and to ground.
If you have an area where there is no balsa core, like an inspection hole, then a few layers of carbon cloth or veil and or resin loaded with carbon black, in that area, will get you a conductive path to the outside of the tank where you can fit a grounding clamp or strap.
B.E.