Can bare concrete be utilized as an anti-static floor finish, for ESD control?
Bare unsealed concrete exhibits antistatic (and dissipative or conductive) tendencies, depending on the volume of moisture vapor permeating through it. The higher the moisture content, the higher the conductivity. Due to variable moisture levels, concrete has very unpredictable conductivity. Concrete floors cannot be designated to be ESD Flooring, due to this uncertainty of electrical resistance. The conductivity is subject to changing environmental and geological conditions, which will not allow for certification as an ESD floor. Another disadvantage of bare unsealed concrete, compared top an esd floor finish, is that potential high conductivity usually means a damp and often dusty building, with a floor that is difficult to clean and maintain.
Note: ANSI/ESD S 20-20 2007 requires a system resistance of < 35M ohms from a person, through the footwear and the anti static floor, and then to earth ground. Discharge or dissipation is directly related to conductivity and not antistatic properties. Calling a floor “antistatic” only means that floor will not contribute to tribocharging. It does not mean that it will also act as a ground.
What is the difference between static dissipative flooring, & static conductive flooring?
In general, dissipative or conductive refers to conductivity range (resistance to ground) for anti static flooring using in electronics environments, versus explosion proof environments. However, these terms are not appropriate for a complete specification, for static control flooring. ESD control flooring specifications should be based on both its propensity to tribocharge people, and its electrical resistance to ground. Terms such as dissipative and conductive, do incorporate these necessary properties. Engineers must verify the following properties, for evaluating ESD floors for its ability to control static:
1) The esd floor coating will not generate > 100V when someone walks on it;
2) The sum total system resistance of the: person+footwear+walking surface to ground, is < 3.5 x 107 or 35 meg-ohms (35 million ohms).
Should I use an anti static coating, or a conductive floor coating?
The word antistatic does not designate some special electrical resistance range. Antistatic merely refers to a material’s propensity to charge other materials during contact and separation. You should look at antistatic properties as part of an ESD control program, that includes resistance to ground and tribocharge performance at low relative humidity conditions.
How are ESD epoxy floor coatings made conductive?
ESD floor coating manufacturers utilize different methods for making the coatings conductive, including: fiber technology, conductive aggregate additives, carbon and graphite particulate blending and sometimes a combination of several in the same coating.
How long do conductive properties last?
Conductive properties should last for the life of the product. However some “dissipative” vinyl products require regular recoating with antistatic floor finish in order to maintain acceptable electrical properties. Some ESD carpets require periodic applications of a topical antistat treatment.
All of EP Floors Corp electrostatic flooring maintain conductive properties for the life of the product, even as they wear. No maintenance is required to maintain it’s electrical properties. They are “built into” the floor.
Make sure you read the fine print of competitor’s products !
Can a conductive floor become a “live wire”?
If the ESD flooring has a resistance to ground > 25,000 ohms the floor can be used in manufacturing and industrial applications. Most standards recognize the 25,000 ohm number as a safe lower parameter, in case 110 volts “shorted” to the floor.
How does relative RH affect the performance of an ESD floor?
Static charges buildup faster, when the RH (relative humidity) is low. Static charge capacity also increases on surfaces when the air is dry. This can be a problem for antistatic flooring such as carpet and vinyl. However, resistance to ground does not vary with humidity for our epoxy esd floor coating, and our polyurethane esd floors.
Can your new floor be installed over an existing floor?
This usually requires an analysis of site conditions, including detailed photos and/or site inspection. Generally speaking, a new epoxy or polyurethane ESD floor coating system can be installed over an old esd floor coating, as long as the old floor coating(s) is well adhered. For existing vinyl floors, it must be structurally intact, and bond testing must be performed, with further analysis required.
Do I need to worry about moisture protection w/ ESD floor systems?
Moisture emission through concrete slabs can cause problems with all types of seamless and vinyl flooring. Most manufacturers recommend that levels do not exceed 3 pounds of moisture (per 1000 square feet per 24 hour period). This may cause serious problems, such as delamination, blisters/bubbling, cracking, and staining. High moisture can also lead to the development of bacteria and molds, which, in addition to causing foul odors, contribute to sick building syndrome. Testing the concrete floor for water vapor emissions is easy, low cost, and can prevent headaches and expense in the future. READ MORE…