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Reducing Floor Maintenance Costs while Improving ESD Performance

by Rick Cardinale, Bird Electronic

Bird Electronic, founded in 1942 by J. Raymond Bird, soon became a leader in radio frequency instrumentation. Today, Bird also has moved into digital instrumentation test equipment.

With the development of digital instrumentation came the increased need for controls to prevent ESD events. Improving ESD protection has been an ongoing process since the late 1980s. In 1997, the company determined that an automated PCB production line would be installed and that the entire manufacturing area should be protected against ESD.

This decision led to an evaluation of ESD protective flooring. In 1998, 20,000 square feet of conductive floor tile were installed in the main production area. To help brighten the area, white tile was selected. The floor resistance measured less than 1.0 x 106 W.

High-Cost Maintenance

A bright, high-gloss appearance was part of the selection criterion for the floor. While the electrical properties were unchanging, by 1999, the floor was starting to dull. It was being maintained like a regular tile floor. No waxes or finishes were used; however, the tile manufacturer did recommend using buffing pads.

After consulting with the tile manufacturer and the installer, maintenance was increased to sweeping clean and damp mopping two times per week and buffing once per month. Monthly floor maintenance was $1,700 per month, a $20,400 annual expenditure.

In late 1999, the maintenance schedule was modified to add more buffing since this was the only way to keep the floor shiny. The floor now was swept and damp mopped weekly and buffed twice per month. The floor was clean and shiny, but the cost went up 41% to $2,400 per month, a $28,800 annual expenditure.

Floor-Finish Solution

At this same time, we wanted to evaluate and improve the ESD program. Kimco, our ESD control supplier, recommended that Desco provide an ESD survey, which it does at no charge.

During the survey, floor resistance measurements were taken, and the floor was reliably measuring less than 1.0 x 106 W. The survey led to a discussion of our current goals with regard to the ESD tile floor:

  • Preserve the electrical properties of the floor.
  • Improve the visual characteristics to look clean, bright, and shiny.
  • Reduce the floor maintenance costs.

Desco suggested a high-end dissipative floor finish, assuring us that a specific ESD floor finish would improve the gloss, reduce costs, and not damage the electrical properties of the floor. We were very skeptical, especially since the tile manufacturer had always told us that conductive tile should not be waxed.

Because of our skepticism, we obtained a sample of the floor finish and tested it on about 9 square feet. The test confirmed that the electrical properties of the floor had not been compromised and that the area protected with the dissipative floor finish maintained a shine much better than unprotected areas.

It was now time for a test on the entire floor. In early 2000, our floor maintenance company put down the recommended initial three coats of the floor finish over a weekend. The floor looked beautiful. But within two weeks, it started to take on a yellow look.

We contacted Desco, which responded immediately by sending a regional sales manager to see the floor and a product manager to review the process with the maintenance company. The cause: the mops. While dedicated mops were used, they were brand new cotton mops and not properly rinsed prior to being used, a common problem.

Also, the initial application was too thick. The maintenance people thought if one gallon per 2,000 square feet was good, one gallon per 1,200 square feet would be better.

The floor was stripped and the dissipative floor finish reapplied. This time, we had shiny, mirror-finish floors. Three months later, we still had a shiny floor that measured between 4 x 105 W in low traffic areas to 7 x 106 W in high traffic areas.

These measurements are well within the recommended minimum performance specifications of the ESD Association's ANSI/ESD S20.20 and Flooring Standard ESD STM7.1 for floors and ESD STM97.1 governing floors used for the primary grounding of mobile people. The resistance from the floor to people using heel grounders is well under 35 MW. Additionally, charge generation is well below 100 V in accordance with ESD STM97.2.


After one year of using the high-end dissipative floor finish, all three of the initial goals were met and exceeded:

  • The electrical properties were not compromised. Tribocharging on all personnel also has been reduced to less than 100 V. 
  • The floors are clean and shiny. Black scuffmarks are more easily removed, often with damp mopping.
  • Maintenance costs have been reduced, saving more than 40% or about $12,000 per year.

As a result, all the hard floors now are covered with Statguard Static-Dissipative Floor Finish, improving ESD control throughout the entire plant including R&D and design.

About the Author

Rick Cardinale is the manufacturing/process engineer at Bird Electronic and responsible for defining and implementing the company's ESD control program. He has spent the last 20 years in the electronics industry in the fields of programmable controllers, radiation measurement, data acquisition, and RF test/measurement. Bird Electronic, 30303 Aurora, Solon, OH 44139, 440-519-2328, e-mail:

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