August 18, 2020
Signs reminding us to maintain a socially appropriate distance while out in public have become a common sight today. Called a floor graphic or decal, the signs are everywhere — grocery stores, pharmacies and airports, to name a few. People walk on them all the time without giving them a second thought, but maybe they should. To help keep people safe when walking on floor graphics, the graphics are tested and rated for slip resistance — and UL plays a significant role in getting these COVID-19 signs to market.
Aaron Messinger, an engineer with UL’s Environment and Sustainability division, is responsible for testing the performance of graphic flooring materials at UL’s laboratory in Holland, Michigan. He has seen an increase in requests for testing over the past several months: from several projects per year to two to three requests each week.
“It’s always been important to test these products because a person could slip and fall from walking on a floor graphic,” Messinger said. “However, with COVID-19, floor graphics are everywhere, making it even more important to test the slip-resistance of the graphic flooring materials.”
Messinger tests the slip resistance of flooring materials by placing a sample of the material onto a James Machine, which measures the static coefficient of friction (COF) of the material. Static COF is a measure of the friction required to initiate movement between two surfaces.
To reproduce this real-life force, Messinger places a piece of flooring material on the table of the machine and a leather-wrapped weight, called a shoe, applies pressure to the sample as it’s pushed forward through the machine. The point at which the testing foot of the machine begins to slip is the COF. This value is displayed on the digital readout and recorded in short-term memory.
The sample is then rotated 90 degrees and tested again. Messinger repeats the process a total of four times. “We’re testing the quadrants of the sample from each corner of the square. That way, we know that no matter which way a person walks on the flooring material, it would have been tested for slip resistance.”
A good thing because, as we’ve all learned, the signs are everywhere. UL’s testing of graphic flooring materials helps make it possible for us to walk with confidence every time we step on a COVID-19 sign.
Learn more about Slip Resistance Testing and Certification for Floor Materials.