05 Dec

Copper Tape and an Epoxy Floor

Q: How do we do the copper mesh earthing in case of an Epoxy Floor?

A: That’s a nice question. You first want to profile your structurally sound and moisture acceptable (3-maybe up to 5 lbs or less of water per 1000 square feet in a 24 hour period per ASTM E-1907-97 & ASTM F-1869-98), then I’d apply my anchor coat and let that cure. Then I’d install the copper tape after all prep work was done and before you are ready to apply the ground plane coat and/or the ESD coat. If you have more than one ESD coat, that’s fine. But the copper grid has to make contact or be electrically conductive to the final ESD coating. If you’d like to connect the copper grid to the earthing, 3rd wire ground, or a grounding rod, that’s fine. Just make sure your flooring is properly bonded to a path to ground and be sure that all grounding sources are less than 1 Ω AC per ANSI/ESD S6.1-2005

05 Dec

Size and thickness of copper foil when installing ESD Flooring

Q: What is the recommended size of the copper grid while installing the ESD Flooring and what should be the thickness of the copper foil?

A: Copper tape comes in varying widths and typically comes in 108’ runs. Our Copper tape has an adhesive backing to it that enables you to run it the length of the ESD floor. There is a spec for how thick the copper is and how thick the adhesive is in mils, but what is most critical is how conductive the tape is across its length and from top side to adhesive side. It’s pretty conductive stuff. We’ve found it to be less than 0.025 Ω in the field using a 4 lead resistance meter. The scientists have more precise data, but that it measures less than 0.1 Ω from earth is what is necessary. You can select between ½ “, 1”, 2”, and 3”, 6”, and 12”. The ½” tape is sufficient for most applications, but I prefer the 2” type.

05 Dec

Copper Mesh Grid with two and three layer flooring

Q: Some ESD material suppliers claim that Copper Mesh Grid is not required in case of two layer flooring. Is it correct and if so, why only in case of three layer?

A: This question may be off topic. It sounds like you are talking about ESD flooring, not bench or floor matting. If that’s the case, some manufacturers of esd flooring make a conductive backed tile or sheet good. This backing may be so conductive and along with a conductive esd adhesive, they claim that you don’t have to lay down an expensive copper grid. That’s fine. But if I’m installing the floor, I’ll use copper (or aluminum if requested) tape and run a standard grid the length of the room (along the x-axis) and cross it up (y-axis) so as to ground the floor at least once every 2500 square feet or a couple of times per room minimum. I’ve found that this helps prevent hot spots from tile to tile or gives more consistent RTT (Resistance Top-to-Top or Point to Point). One roll of copper tape would enable me to ground a room that was 60’ x 40’ without a problem. If I have more tape to use, I’ll use it. A liberal amount of copper tape and ESD adhesive is provided free of charge with the purchase and installation of an ESD floor from Ground Zero Electrostatics, Inc.

Copper mesh grid just doesn’t apply to 2 layer or 3 layer mats. They use ground cords. One per every 10 feet, I believe.