ESD Flooring: What is an ESD antistatic floor?

In some sensitive areas in industry environments like electronic assembly lines, semi conductors production, or sometimes in healthcare facilities, electrostatic discharge phenomena needs to be controlled to avoid risks of explosion or risks of damaging electronic devices.

In such cases, flooring plays a critical role to control ESD.

Product

What is ESD?

Before defining the role of an ESD floor, it is appropriate to explain what an electrostatic discharge is. The ESD phenomenon refers to the electrostatic discharge that occurs when electrical charges accumulate on the surface of a material or a human. A discharge occurs when these charges find access to the ground or another unbalanced element. Typically, the electrostatic discharge felt when one has just walked on a carpet and then grabs a doorknob.

Very often the explanation of this phenomenon is seen from the angle of discharge, but there is no discharge without charge. The observation of charging phenomena (measured in Volts) is as important as the measurement of the discharge phenomenon (measured here by resistance in Ohms).

What are the risks associated with ESD phenomena?

ESD phenomenon-related risks can be categorised into two families: those related to people protection and those related to electronic devices protection.

Firstly, people protection aims to control and avoid electrostatic discharges to prevent fires and explosions (e.g., in ATEX environments) in production conditions that present risks associated with vapours, gases, powders, and flammable liquids.

In hospital environments, controlling the ESD phenomenon is crucial to prevent potential damage to equipment (MRI, scanners, etc.), protect against possible explosion risks related to aesthetic gases (which is less and less the case nowadays), and avoid dust accumulation for maximum hygiene.

Regarding industries, a human being feels electrostatic discharges starting from 3000 Volts, but certain electronic devices (printed circuit boards, semiconductors, etc.) can be affected by powers below 100 Volts, even below 10V for very sensitive ones. This can have a direct impact on non-quality directly on the production line, but also create weaknesses and latent failures that will impact the device’s performance, or even significantly limit its lifespan. As an example, we cannot afford to send a satellite into space with a potentially defective electronic circuit board.

ESD floors, how to monitor their performance?

Before discussing flooring solutions, controlling ESD phenomena in an environment must be part of a comprehensive control plan that includes grounding of all equipment (workbenches, tools, castor chairs, etc.), grounding people (PPE, ESD shoes, ESD wristbands, gloves, etc.), ionisation of workstations, staff training, and regular audits.

Firstly, an ESD floor is only useful if operators use ESD shoes (man, ESD shoes, and floor system) or other systems that allow personnel to be grounded through the floor. Flooring being the last line of defence for eliminating and conduction of charges to the ground in an ESD system.

To measure performance, a normative reference and structured test procedures are obviously required. A company willing to set up an EPA (Electrostatic discharge Protected Area) must first choose and define the standard most suitable to its environment. There are many standards related to either applications and/or geographical areas: EN14041, IEC 61340, ANSI ESD S20.20, etc.

Two factors are measured according to ESD standards:

Charge accumulation or charge potential

In other words, the floor’s ability to more or less charge the operator moving in the area. This factor is measured in Volts. Depending on the standard used, for a floor to be ESD, the charge potential must not exceed 2000 Volts or 100 Volts.

Resistance

The floor’s ability to conduct the discharge to the ground more or less quickly, this factor is measured in Ohms. For a floor to be considered ESD, its resistance must not exceed 10^9 Ohms. Also, for the safety of operators, the resistance must not be below 5x10^4 Ohms (for 210-220V electrical installations) or 2.5x10^4 Ohms (for 110V electrical installations).

ESD and antistatic floors, making the right choice

As previously mentioned, the choice of flooring solution will first be based on the ESD standard selected and adapted to your organisation. However, the choice of flooring must also be guided by its use and installation conditions:

Subfloor conditions and installation

In the case of a new building project or renovation of an existing area, the quality of the subfloor and the ease of installation must be taken into account. This is to ensure a flooring choice that meets short and medium-term needs, as well as an installation time that shall not impact productivity in the case of installation in an occupied environment.

For example, an ESD resin for a renovation will require production to stop during installation, while ESD tiles like GTI allow installation with co-activity and thus have a very low impact on productivity.

Traffic conditions

depending on the frequency, type of traffic (pedestrian and/or mechanical), and loads, the appropriate flooring must be chosen. For example, for pedestrian traffic, the use of manual electric pallet trucks, a homogeneous 2mm ESD PVC floor will be suitable. In the case of stronger constraints, the GTI EL5 tile solution will be preferred.

Resistance to cleaning and decontamination processes

By making a list of maintenance products or chemicals related to the process, the flooring must resist according to the concentrations used. Gerflor has developed for many years patented and innovative surface treatments that meet the constraints of industrialists regarding chemical resistance, both for tile and roll solutions.

Maintenance

It is important to consider the long-term life of the flooring in terms of ease of maintenance and repairability. Vinyl solutions allow quick repairs (hot welding for small repairs such as cuts or impacts) and easy replacement of areas to be renovated without interrupting production, unlike epoxy or polyurethane resins.

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ESD and cleanroom

In controlled environments where ESD floors are a must (e.g., semiconductor manufacturing or pharmaceutical industries). The flooring must also meet additional requirements such as: control of particulate emissions according to ISO14644-1, control of biocontamination (bacteriostatic flooring), ease of decontamination, control of outgassing, etc.

Gerflor, with its cleanroom experience, offers in its flooring ranges, both in tile and roll solutions, products certified by independent laboratories (Fraunhofer Institute for example) allowing their use safely in cleanrooms.

GERFLOR experts are here to guide you in your choice of ESD, antistatic floor coverings!