15 Jun

Conductive, Dissipative, or Anti-Static Flooring?

Conductive, Dissipative, or Anti-Static Flooring

You’re hard at work at your latest assignment. Your boss wants you to put together a complete plan for creating a large-scale electrostatic protection area (EPA) for a client who will be assembling various sensitive electronics and they want to avoid any risk of losing their investment due to electrostatic discharge (ESD).

You’ve selected the grounding cables, the workstations, the custom cut matting, containers and furniture, all designed to minimize or eliminate the slightest chance of ESD damage. But a curious thing happens when you research the proper flooring.

A simple Internet search for ESD flooring yields numerous options, more than you expect and you start to notice they all fall under 3 categories.  In an instant, you’re faced with a decision, just like the game show, “Let’s Make a Deal.”

Suddenly, Monty Hall (or Wayne Brady, the current host!) is staring at you, asking do you want to choose door number one, number two, or number three: conductive, dissipative, or anti-static? The clock is ticking… How do you decide?

Door #1

For starters, let’s eliminate one of your options. Much like the ‘ZONKS’ of the game show, ‘anti-static’ is a worthless term in your ESD vocabulary.  By strict definition, anti-static refers to a material that resists generating a charge.  At one time it did designate a level of resistance, but was so overused and misunderstood, the term was removed from the ANSI/ESD standards.

So likewise, eliminate the term ‘anti-static’ from your discussion.

Deciding between the other two doors requires a closer look at the specific needs of the area for which the flooring is intended.

We’ve talked in another article about Ohms (Ω) and how they are the unit of measurement for resistance to electrical current.

Door #2

Because of the size and scope of most areas where it is necessary, the most common form of ESD flooring is referred to as ‘Static Conductive.’ Conductive flooring is at the low end of the electrical resistance scale.

Conductive carpeting may even be laced with carbon lines or metallic yarn fibers to encourage the flow of electricity. Because of the low electrical resistance, electrons flow easily across and through the surface, and can be grounded safely and quickly. This carpeting or vinyl tile is laid down with a conductive adhesive and grounded through the use of conductive tape or copper strips that run to a common ground.

This type of flooring is also generally a little more cost-effective than a dissipative solution.

Door #3

On the higher end of the resistance scale falls ‘Static Dissipative’ flooring. The higher resistance of these materials keeps the electrical charge more under control as it slowly flows over the surface and into a ground. Dissipative flooring is much more common in shared office environments where everyday shoes are more common, as opposed to a location where every element, from furniture to footwear, is controlled.

In our example above, the client will be assembling sensitive electronics like circuit boards and such in a large-scale environment. In this instance, a vinyl tile, or a poured epoxy flooring with conductive properties would most likely be the best option.

In an office setting where a company has their own IT department that fixes and assembles computers within the same facility, a dissipative, static resilient tiled floor would be a better fit.

But the fact is, these are very simplified examples of the myriad of variables that you can encounter when selecting the proper ESD controlled flooring. Your best option is to talk to an expert.

We’d love to be the experts you can count on for your full service, seamless ESD solutions. For more information or advice on your specific ESD flooring needs – or any other ESD questions, contact us today.

18 May

Conductive vs. Dissipative Materials

Conductivee Vs Dissipative

In the mid-1820’s, Georg Ohm, a self-taught mathematician and physicist, began doing experiments in the newly discovered field of electromagnetism. Hoping to advance his stalled career, he used the work of Hans Christian Ørsted as a jumping off point, discovering an inverse mathematical relationship between current and resistance.

Georg Simon Ohm

Georg Simon Ohm

Unfortunately, in an effort to make his theories more understandable to non-mathematicians, he managed to alienate the scientific community and his groundbreaking work went unrecognized for almost 15 years.

Today, he’s remembered by the law that bears his name and its legacy, the standardized unit by which we measure electrical resistance – the Ohm (Ω).

Electrical Resistance: The Water in Pipe Analogy

To put it simply, what Ohm had discovered, but failed to adequately communicate, is that electricity acts like water in a pipe. In this analogy, resistance tells us how wide or narrow the “pipe” transmitting the electricity is.

When two items touch each other, they create an electrostatic charge – one item is positively charged, and one negatively charged. When the items are separated, it creates a triboelectric effect – a buildup of potential energy which can result in an electrostatic discharge (ESD).

In our quest to prevent ESD, which can be damaging and potentially catastrophic to sensitive electronics and circuitry, there are several approaches that vary, depending on the situation.

To illustrate those, we go back to Ohm’s electrical “pipe.”

At the narrowest end of the pipe, we have insulative materials – wood, carpeting, plexiglass. Insulative materials prevent or severely limit the flow of electrons across their surface.

While it may seem that this is the highest and best protection, the opposite is actually true. Because insulative materials are self-contained, they do not ground – meaning the potential energy continues to build up without going anywhere, until it comes into contact with another object, at which point, the new item is bombarded with the electrostatic discharge.

At the widest end of the pipe, we find the conductive materials – copper, steel, water. Conductive materials offer almost no resistance to electrostatic discharge. The electrical charge moves quickly through the materials – too quickly, which can lead to significant problems, as well as safety hazards.

In between these two extremes are the two materials most often used for ESD storage containers, matting and flooring: static conductive and static dissipative.

Towards the wider end of our metaphorical pipe, we find static conductive materials. Because of the low electrical resistance, electrons flow easily across the surface, and can be grounded safely. Typically, static conductive materials are most often used for ESD flooring.

Towards the narrower end of the pipe we find static dissipative materials. The higher resistance of these materials keeps the electrical charge more under control as it slowly flows over the surface and into a ground. Static dissipative materials are much more commonly used for ESD prevention and can be found in table top mats, ESD shoes and some flooring.

For storage containers – boxes, bins & totes – both conductive and dissipative materials can be used, depending on individual needs. Just keep in mind that dissipative materials have a higher resistance than conductive materials.

For more information, or an even more technical discussion of the properties of ESD materials, contact us today.  We would love to be your full service, seamless ESD solution provider.

05 Dec

The difference between Low Static and Static Dissipative

Q: What is the difference between Low static 3.5kv carpeting and static dissipative carpeting? When used on walls is 3.5kv carpeting ok in electronic equipment rooms?

A: When people refer to 3.5 kV carpeting I believe they are referring to the threshold voltage that people can feel as a nuisance static shock. We deal primarily with manufacture, test, assembly, and application environments where the end-user is protecting expensive electronic components, explosives, assemblies, etc. and the threshold for their needs is down to 100 volts and less.

I believe the 3.5 kV carpeting is considered to be somewhat antistatic (resists or has reduced tribocharging abilities) and is treated topically with some temporary chemical. These types of carpet do not satisfy our needs to provide long-term solutions for the commercial, industrial, and even consumer electronics industry.

I’d like to find out more about what you’re using the carpet for. Are you using it on the walls to deaden noise or create some special environment for audio design? If you need some kind of ESD protection, can you find out what your voltage threshold is- or what is the highest acceptable voltage that your environment can tolerate?

We offer ESD carpet in broadloom form and in tile form in both static conductive (typically around 2.5e04 or 25,000 ohms to 1e06 or 1 Meg Ohm) and static dissipative (1E06 – 1E09 ohm). As the resistance increases, the generated charge dissipates less rapidly to the point that a charge potential exists somewhere in the system and an ESD event occurs. This ESD event may occur without the end user knowing, but it may damage or destroy sensitive devices. Having a textile with a resistance in the static conductive range will discharge this charge potential more rapidly and work to prevent a charge from getting too high in the first place. Different textiles tribocharge at different rates and increase to different potentials, depending which textiles are making contact with and separating from them. Many carpets perform fairly well compared to other textiles in a humid environment. The humid environment may knock the created voltage down from 10’s of thousands of volts to thousands or hundreds of volts, but not low enough to prevent ESD Sensitive Devices from getting damaged or destroyed.

I hope I’ve touched on some of your questions but need to know more about your current application to help you better.