Table 2.

Surface roughness (R_a, Avg. roughness; Rz, Roughness depth; RSm, Peak spacing) of tested materials.

Material	Ra (µm)	Rz (µm)	RSm (µm)
High density polyethylene (HDPE)	4.63	45.89	1307.50
Stainless steel (316L)	3.45	33.33	1713.59
Viton® rubber	9.83	55.73	5081.31
Acrylonitrile–butadiene–styrene (ABS)	3.26	22.77	1441.73
Polycarbonate	7.50	57.12	395.98
Silicone rubber	13.69	108.66	2131.00
Porex	19.86	100.01	38.61
GAPI PTFE (virgin)	10.94	64.01	2705.20