Question:  How should ESD jackets be laundered?

ESD jackets come in many shapes and colors, not to mention fabrics, so it can be very difficult to choose the right jacket for your application.  Now you have tried all the samples, haggled with salesmen, and have placed your first order, how do you care for your ESD jackets to ensure long life?

Answer: Wash in cool or cold water (90°F maximum) with any commercially available liquid detergent. Do not bleach. Hang dry or tumble dry on low heat. The carbon-suffused mono-filament nylon is sensitive to heat and should not be ex-posed to laundering heat in excess of 120°F or more.

The Four Rules Of ESD Control

Follow these simple rules of ESD control and you will never be shocked (yes, we went there) by static damage.

1^st Rule of ESD:  Ground everything you can.

If you can attached a ground cord to it, do it.  Grounding conductive materials sends any charge buildup to ground where it is neutralized.

2^nd Rule of ESD:  Avoid Insulators whenever you possibly can!

Insulators cannot be grounded and a potentially dangerous charge can build up fast.  Remove everything you can made out of insulating materials, like plastics and Styrofoam.

3^rd Rule of ESD: Use Dissipative materials whenever possible and ground them.

Get yourself a dissipative ESD Mat!  Dissipative materials allow a charge to flow slowly and controlled to ground.  Anything more conductive or more insulative is a problem.

4^th Rule of ESD: Use an ionizer on any insulators and ungrounded conductors that can’t be remove.

Ionizers blow air full of positively and negatively charged ions that neutralize static on contact.  They are the only way to control static on insulative materials.

Covering your work surface with ESD material is a basic step in ESD prevention. With a proper ESD worksurface, static is safely removed from items placed on the surface. There are several types materials used, but the most common is 2 layer ESD rubber. ESD rubber is constructed with a rugged dissipative top layer and a conductive black bottom layer. For ESD purposes, materials are classified by their resistance to the movement of electricity. The dissipative top surface allows charges to drain from its surface in a controlled manner, sending it to the bottom conductive layer. The conductive bottom layer has a low electrical resistance and quickly sends the charge to ground via a ground cord that includes a current limiting resistor for safety. The top layer is also extremely durable, offering excellent resistance to hot solders, soldering irons and most solvents.

Transforming Technologies has the most cost effective ESD rubber available.  The MT4500 series is a smooth rubber surface in light blue, royal blue, gray and green.  The MT-Textured series ESD rubber matting is made of 100% co-extruded rubber with a textured surface in light blue, royal blue and gray.

Contact Transforming Technologies for your work surface ESD rubber needs.

For ESD control purposes, materials are classified by how quickly electricity moves through the material. The speed is referred to as the “resistance” of the material i.e.  how strongly the material resists charge movement.

The speed is measured in Ohms and is typically displayed in powers of 10 (example 10^3). The lower the number, the more conductive the material and may be considered “Antistatic”.

The following ranges and definitions are found in ESD Association or EIA standards publications:

Conductive materials: With a low electrical resistance, electrons flow easily across the surface or through the bulk of these materials. Charges go to ground or to another conductive object that the material contacts or comes close to. Conductive materials have a surface resistivity less than 1 x 10^5 Ω/sq or a volume resistivity less than 1 x 10^4 Ω-cm.  Conductive materials are classified “Antistatic”.

Dissipative materials: For these materials, the charges flow through the material slowly and in a somewhat more controlled manner than with conductive materials. Dissipative materials have a surface resistivity equal to or greater than 1 x 10^5 Ω/sq but less than 1 x 10^12 Ω/sq or a volume resistivity equal to or greater than 1 x 10^4 Ω-cm but less than 1 x 10^11 Ω-cm.2.  Dissipative materials are classified “Antistatic” and are considered to be the ideal range for ESD materials.

Insulative materials: Insulative materials prevent or limit the flow of electrons across their surface or through their volume. Insulative materials have a high electrical resistance and are difficult to ground. Static charges remain in place on these materials for a very long time. Insulative materials are defined as those having a surface resistivity of at least 1 x 10^12 Ω/sq or a volume resistivity of at least 1 x 10^11 Ω-cm.  Insulative materials are not classified as “Antistatic”.

Anti-Static: Is a term used to describe materials that prevent the buildup of static electricity. Both conductive and dissipative materials are classified as Antistatic.  Insulative materials are not.

How to Measure Surface Resistivity
The SRM200 Surface Resistance Meter is an easy to use tester for measuring surface resistivity. This SRM200 uses parallel electrodes on the back of the meter to accurately measure RTT, RTG, or resistivity for periodic verification, factory audits or test lab evaluation of a product.

This meter is designed to be used in all facets of material production including engineering, maintenance, quality control, incoming inspection, manufacturing, research, or sales departments for the testing of anti-static mats, floor finishes, paints, wrist straps, smocks, footwear, bags and containers.

The SRM200 meets periodic test requirements per Compliance Verification ESD TR53 and conforms to ANSI/EOS/ESD (S4.1, S7.1, S12.1, S2.1).

Transforming Technologies provides comprehensive knowledge of electrostatic issues, effective solution-oriented products and outstanding, friendly service. 

Because customer needs periodically include requirements for consultation, training, auditing or verification, we offer  Professional ESD Services, in cooperation with LBL Scientific.

Services Include:

Please contact us for more information on our professional services and insure that your static control program is as effective and efficient as possible.

Here at Transforming Technologies, we routinely receive phone calls and emails this time of year asking us how to prevent statics shocks around the home. While we love to help people when we can, the solutions and products we provide are geared more for manufacturing and the electronics fields.  This is why I was very excited to read the popular blog Lifehacker explain common ways to eliminate static shocks in the home.

“One of the easiest ways to avoid static shock is to pay attention to what you’re wearing and what kind of fabrics make up the furniture in your house. For example, Electrostatics.net notes that rubber-soled shoes are great insulators, and will build up a lot of static in your body when combined with a wool or nylon carpet. Instead, try walking around in leather soled shoes, or cotton socks instead of wool socks. Leather soled shoes are also great for grocery shopping, since shopping carts can often cause lots of static electricity.

Similarly, wool sweaters are common offenders, especially in the dry winter (when you usually wear them). If you sit in a chair made out of the right fabric, you’ll build up quite a bit of static. Again, cotton is going to be much more friendly, so try wearing cotton clothes when you want to avoid nasty shocks. Certain furniture covers or antistatic sprays can help alleviate this problem, too.

You may have also noticed that often, when you get out of your car, you get a shock when you touch the door. You might have even heard that touching the door frame as you get out of the car can help, and that’s true. Make sure you start holding the metal frame before you get out of the car, and you keep touching it until you’re out of the seat completely. If you forget to do this, you can also touch the car door with your keys. Since the electricity will discharge through them, you won’t feel a shock”

Read the full article for more tips on avoiding static shocks in the dry air of the winter months.

An ESD Workstation is a work area with materials and equipment that limit electrostatic voltages and ESD (electrostatic discharge) or more commonly referred to as Static.

The first step in protecting a workstation is to ground all components of the work area (work surfaces, people, equipment, etc.) to the same electrical ground point called the “common point ground.”

While it is recommended to take every precaution available to control static, not all the ESD steps below may be necessary for basic ESD protection. Your workstation may not require all these items. Call Transforming Technologies for help designing your ESD workstation

ESD Protection Steps

1. ESD Table Mat

A work surface that removes static from conductive items placed on it. Commonly made from durable materials such as rubber, vinyl or laminate. A 10mm grounding snap should be installed in the mat or every 10 ft if it is long.

2. Wrist Band and Coil Cord Set

Safely grounds a person working at a workstation.  It is worn around the wrist and is connected to ground through a long coiled cord and the common point ground.

3. Common Point Ground

Used for grounding ESD mats and provide a path-to-ground for the person wearing wrist straps.  It attaches to the ESD worksurface via the 10mm grounding snap.

4. ESD Floor Mat

ESD floor mats remove static charges from conductive items placed on it. ESD footwear such as a Heel Grounder must be worn to remove static from the person standing on the mat. It is best used for mobile personnel that cannot be tethered to one location by a wrist strap.   A grounding snap should be installed in the mat or every 10 ft if it is long.

5. ESD Floor Mat Ground Cord

Used for grounding the floor mat by providing a path-to-ground for an ESD floor mat.  Connects to the mat via a grounding snap.

6. ESD Heel Grounders

Worn on each shoe to connect a walking or standing person to ground.

7. Constant Monitors

These electronic devices continuously monitor the path to ground of a wrist strap, work surface and other grounded components on a workstation.  Eliminates the need to test wrist bands and protects against ground failures.

8. ESD Jackets

Provide shielding from static charges on your clothing. A “Hip-to-Cuff” grounding system ensures proper grounding without requiring wristbands being worn that can inhibit your movement.

9. ESD Equipment Testers

ESD wrist strap and heel grounders, like any equipment used every day, can wear. Ensure these items are in proper working order with ESD Equipment testers.

10. ESD Air Ionizers

Materials, called insulators, cannot be grounded by typical means.  Ideally insulators should be removed from the workstation, but if they must stay an ESD Air ionizer can neutralize static buildup.  Delivering a balanced stream of ionized air, ionizers remove static charges from insulating materials and isolated conductors.

Every situation is unique and requires different steps to properly manage a static situation.

Stationary Personnel

Mandatory Steps: 1,2,3

Suggested Steps: 7,9

Optional Steps: 4,5,6,7,10

Mobile Personnel

Mandatory Steps: 4,5,6

Suggested Steps: 9

An ESD mat is a very important part of an ESD protected area.  ESD mats are designed to eliminate static on its surface and of objects placed upon it.   It does this by having a conductive material embedded within the mat that collects the static and sends it to ground (earth). This is usually accomplished by connecting the mat to ground (typically the center screw of an outlet) with a ground cord. It’s important to discharge at a slow rate, therefore a resistor in the ground cord is recommended.

A quick search online or in ESD catalogs reveal a myriad of ESD mat options.   What are the main considerations in choosing an ESD mat?

Material:

ESD mats are generally found in two categories:  Vinyl and Rubber.  ESD Rubber mats are the most widely used mat material because they have a high resistance to heat and most chemicals.  ESD Vinyl mats are also used for tabletop or work surface applications. They are easy to cut, and some varieties provide cushion. The type of material is a primary concern if you will be using a constant monitor because some materials are incompatible with certain constant monitors.

Composition:

ESD mats are available in single, two and three layer material. Mats are made of a single homogenous conductive layer material, two layers of static dissipative rubber material or vinyl with a conductive material sandwiched between two layers.  Thickness, texture, and cushioning of the mat are also concerns depending on the application.  Regardless of composition, all mats should meet or exceed the requirements of ANSI ESD-S20.20.

Size:

ESD matting typically comes in 50′ or 60′ rolls in four standard widths: 24″; 30″; 36″ and 48″.  The material is easy to cut and has a long shelf life so if you have more than one area to cover or expansion is a possibility, purchase a full roll and cut pieces as needed.  Many suppliers also provide ready-to-use pre-cut mats with grounding hardware already installed.  These mats can be more expensive, but it can also be a great time saver.

Electrical Performance:

All static control mats are not created equally.  The ESD mat’s long-term electrical properties are tantamount to successfully controlling an ESD event. The terms insulative, conductive, and dissipative are all terms that subdivide ESD materials based on their individual surface resistance. Surface resistance is a measurement of how easily an electric charge can travel across a medium (Visit here to learn How To Test ESD Mats). Conductive materials have a surface resistance of less than 1 x 10 5 ohms/square. Dissipative items have a surface resistance of more than 1 x 10 5 ohms/square but less than 1 x10 11 ohms/square. An insulative material is one that has a surface resistance of greater than 1 x 10 ¹² ohms/square. Based upon your application, ESD mats should be in either the dissipative or conductive range. Something insulative is not considered ESD safe.

Conclusion:

When choosing an ESD mat, first use your specific application to narrow your choices, such as mat material and electrical properties.  Carefully plan and budget your workstation and estimate wear and tear so that you can choose to purchase a full roll or a pre-cut mat.  Finally, do not let cost dictate your decision – saving a few dollars on low quality matting could have very costly consequences via catastrophic damage, latent failures and customer complaints.

For help choosing your ESD mat, please call Transforming Technologies at 419-841-9552 or email info@transforming-technologies.com

Static Control is one category in the very large Industrial Product market. When ever Transforming Technologies has questions about industries outside our niche, we turn to the Q Source Q-Bot for answers.  Today’s question from the Q Source Resource:

Dear Q-Bot: When I shop QSource.com for certain products, I often see the terms RoHS or RoHS-compliant. What does this mean and why is RoHS-compliance important?

Thanks! — S.R.G. via the Internet

Greetings S.R.G.:
RoHS is the acronym for Restriction of Hazardous Substances. Originating in the European Union (EU), and known as Directive 2002/95/EC, it restricts the use of six hazardous/toxic materials used in electrical and electronic products.

Often referred to as Lead-Free, the RoHS Directive indicates maximum levels for these six materials:

• Lead (Pb): < 1000 ppm (Exposure can lead to neurological disorders—including changes in mental development and behaviors in children)
• Mercury (Hg): < 100 ppm (Exposure can lead to neurological disorders—especially in babies and children)
• Cadmium (Cd): < 100 ppm (Exposure can lead to kidney dysfunction, lung cancer, and prostate cancer)
• Hexavalent Chromium: (Cr VI) < 1000 ppm (Exposure can lead to cancer, irritation, nasal septum perforation, the development of stomach ulcers, kidney and liver damage, convulsions, and even death)
• Polybrominated Biphenyls (PBB): < 1000 ppm (Exposure is possibly carcinogenic to humans)
• Polybrominated Diphenyl Ethers (PBDE): < 1000 ppm (Exposure can lead to liver toxicity, thyroid toxicity, and neurodevelopmental toxicity)

For more discussion on RoHS, visit the Q Source Resource discussion .

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