Relationship between roughness parameters based on material ratio curve and tactile roughness for sanded surfaces of two hardwoods

The roughness parameters on the material ratio curves were related to tactile roughness for samples of buna and mizunara. The surfaces of the samples were sanded using various grades of coated abrasives and the roughness parameters, reduced peak height (Rpk), core roughness depth (Rk), and reduced valley depth (Rvk), were estimated on the material ratio curves, which were obtained from roughness profiles determined using robust Gaussian regression filter. The values of Rpk and Rk were almost the same for buna and mizunara under the same sanding conditions and increased exponentially with tactile roughness. The coefficients of determination of those parameters and tactile roughness were higher than 0.79 at all cutoff wavelengths. On the other hand, the value of Rvk for mizunara was significantly larger than that for buna because of the deep local valleys. There was no relationship between Rvk and tactile roughness for both species.