Antistatic garments

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Anti-static clothing (garments) is required to prevent damage to electrical components or to prevent fires and explosions when working with flammable liquids and gases.

If not controlled, electrostatic discharge can cause product damage to electrostatic sensitive devices and lead to machinery downtime, lost man hours, returned products and warranty costs particularly in the semiconductor and electronics industries.

Antistatic garments are used in many industries such as electronics, communications, telecommunications and defense applications. Static electricity is generally harmless to the individual but it causes 5 billion USD of damage to products each year in the electronics and computer industry.

As computers and electronics become ever more pervasive in consumer products so an increasing number of manufacturers will need to apply anti-static control measures. One such measure is antistatic apparel because people are the greatest source of static charge in the workplace.

The amount of static electricity we feel varies according to factors such as our body and foot size a larger body and bigger feet require more charge to be stored to produce the same voltage. The material our clothes are made from and the soles of our shoes can influence static electricity too. Weather affects it as well. There is more build-up of static charge when the air is dry.

Most people feel harmless shocks at around 2,000-4,000 volts. However electrical components can be damaged by as little as a few volts. It is estimated that between eight percent and 33 percent of product losses - the proportion of products which are rendered faulty - are due to static electricity.

Transportation of electrostatic sensitive devices requires packaging that provides protection from electrostatic hazards in the transportation or storage system. In the case of an ESD protected area designed with continuous grounding of all conductors and dissipative items (including personnel), packaging may not be necessary.

An ESD protected area is: A defined location with the necessary materials,tools and equipment capable of controlling static electricity to a level that minimizes damage to ESD susceptible items. In the ESD protected area, all conductors in the environment, including personnel, shall be bonded or electrically connected and attached to a known ground or contrived ground. This attachment creates an equipotential balance between all items and personnel. Electrostatic protection can be maintained at a potential above a “zero” voltage ground potential as long as all items in the system are at the same potential.

One of the ways to bond or electrically connect personnel to ground is the use of an ESD garment. ESD garments have conductive threads in them, creating a version of a faraday cage that you can wear. ESD garments attempt to shield ESD sensitive devices from harmful static charges from clothing such as wool, silk, and synthetic fabrics on people working with them. For these garments to work properly, they must also be connected to ground with a strap.

Most ESD garments are not conductive enough to provide personal grounding so antistatic foot straps and antistatic wrist straps are also worn. ESD garments are considered an optional method to control ESD.

[edit] See also

[edit] External links

http://www.antistatics.org/estat/publications/vtt_btuo45-051338.pdf] Recommendations for the use and test of ESD protective garments in electronics industry by ESTAT

http://www.esda.org/aboutESDA.html The ESD Association has been a focal point for the development of ESD standards in recent years. Relevant standard is ESD STM2.1—1997: Resistance Test Method for Electrostatic Discharge Protective Garments. This Standard Test Method provides test methods for measuring the electrical resistance of garments used to control electrostatic discharge. It covers procedures for measuring sleeve-to-sleeve and point-to-point resistance.