The Slip-Resistance Effect of Tread Grooves and Floor Roughness on Different Liquid Thickness

The coefficient of friction between shoe sole and floor is the most critical environment factor influencing slipping risks. When the shoes tread on the surface covered by liquid, the slip resistant of floors are reduced by the squeeze-film effect and the risks of falling are increased. The prior researches discussed mostly the relationship between floor roughness and COF, the discussions of the impact of liquid thickness on COF are relatively rare. This study measured the slip resistance effect of tread groove and floor roughness under different liquid thickness by adopting Brungraber Mark II slipmeter. The results showed that the tread groove, floor roughness and liquid thickness are all factors influencing the COF.The COF of non-tread groove footwear decreases significantly while the liquid thickness larger than 1mm or the floor roughness Ra less than 2μm.