## 3 Results
### Rubber Hysteresis Results
\begin{table}
\begin{tabular}{c c c c c c} \hline
**Materials** & **Surface** & **Hardness** & **Hysteresis** & **COF @50 mm/s** & **COF @300 mm/s** \\ \hline Rubber OB221/Anti-slip tile & dry & 65 & 0.24 & 1.20 & 1.35 \\ \hline Rubber OB221/Anti-slip tile & wet & 65 & 0.24 & 0.65 & 0.60 \\ \hline Rubber OB221/Anti-slip tile & soapy & 65 & 0.24 & 0.50 & 0.52 \\ \hline Rubber OB202/Anti-slip tile & dry & 65 & 0.35 & 0.56 & 0.67 \\ \hline Rubber OB202/Anti-slip tile & wet & 65 & 0.35 & 0.64 & 0.60 \\ \hline Rubber OB202/Anti-slip tile & soapy & 65 & 0.35 & 0.50 & 0.50 \\ \hline Rubber OB2280/Anti-slip tile & dry & 65 & 0.39 & 0.65 & 0.76 \\ \hline Rubber OB2280/Anti-slip tile & wet & 65 & 0.39 & 0.74 & 0.70 \\ \hline Rubber OB2280/Anti-slip tile & soapy & 65 & 0.39 & 0.68 & 0.55 \\ \hline Rubber OB290/Anti-slip tile & dry & 60 & 0.45 & 0.70 & 0.70 \\ \hline Rubber OB290/Anti-slip tile & wet & 60 & 0.45 & 0.65 & 0.60 \\ \hline \end{tabular}
\end{table} 
Table 3: COF results on the anti-slip tile. surface. One can observe that the friction coefficient on the wet and soapy surface changed with increased rubber hysteresis, while changing the speed from 50 mm/s to 300 mm/s had a lesser impact. The smooth and anti-slip tiles showed different COF values under the same conditions, suggesting effects from both substrate roughness and rubber hysteresis. The change in surface conditions from wet to soapy led to lower COF values, which was expected as soap acts as a lubricant. As the roughness of a tile increases, the ability of surfaces to stick to each other decreases due to lower adhesion. Adhesion is reduced as the number of points in direct contact between the surfaces (asperities) decrease with increased roughness [15]. From the presented results, one can observe that the COF values obtained during the experiments were in some cases larger than one. This was in agreement with the findings of other authors, as rubber COF values can be larger than one [21; 22; 23]. COF values greater than 1 occur during contact with smooth surfaces like glass or tiles and rubber and are a consequence of increased adhesion forces, especially on smooth surfaces [28]. \begin{table}
\begin{tabular}{c c c c c c} \hline \hline \multirow{2}{*}{**Materials**} & **Surface** & **Hardness** & **Hysteresis** & **COF @50 mm/s** & **COF @300 mm/s** \\  & **Condition** & **(Sha)** & **Hysteresis** & **COF @50 mm/s** & **COF @300 mm/s** \\ \hline Rubber OB221/Smooth tile & dry & 65 & 0.24 & 1.82 & 1.90 \\ \hline Rubber OB221/Smooth tile & wet & 65 & 0.24 & 0.38 & 0.25 \\ \hline Rubber OB221/Smooth tile & soapy & 65 & 0.24 & 0.24 & 0.26 \\ \hline Rubber OB202/Smooth tile & dry & 65 & 0.35 & 1.6 & 1.7 \\ \hline Rubber OB202/Smooth tile & wet & 65 & 0.35 & 0.30 & 0.20 \\ \hline Rubber OB202/Smooth tile & soapy & 65 & 0.35 & 0.10 & 0.15 \\ \hline Rubber OB2280/Smooth tile & dry & 65 & 0.39 & 1.71 & 1.77 \\ \hline Rubber OB2280/Smooth tile & wet & 65 & 0.39 & 0.29 & 0.23 \\ \hline Rubber OB2280/Smooth tile & soapy & 65 & 0.39 & 0.26 & 0.18 \\ \hline Rubber OB290/Smooth tile & dry & 60 & 0.46 & 1.60 & 1.70 \\ \hline Rubber OB290/Smooth tile & wet & 60 & 0.46 & 0.26 & 0.20 \\ \hline Rubber OB290/Smooth tile & soapy & 60 & 0.46 & 0.13 & 0.14 \\ \hline \hline \end{tabular}
\end{table} 
Table 4: COF results on the smooth tile. Figure 4: _Cont._