Effect of High-Speed Friction Treatment with Fluorine Components on the Changes in Spruce Surface Properties

This study investigated the effects of adding fluorine components to a new wood surface treatment technology called high-speed friction (hereinafter, "HSF"), which rubs wood surfaces at high speeds with a smooth metal surface. The changes in the color, surface roughness, and water contact angle of the spruce surface were evaluated. HSF treatment was performed using a stainless-steel tool coated with polytetrafluoroethylene and an uncoated tool. In addition, fluorinated oil was added as a pretreatment for HSF. The results showed that the spruce surface became darker in color when subjected to HSF. In particular, the brightness of the spruce surface was significantly reduced when rubbed with the uncoated tool. However, the addition of fluorine components to the tool surface and pretreatment suppressed blackening. Surface roughness decreased after HSF treatment; in particular, a smoother wood surface could be formed under the conditions in which fluorine components were added to the tool and wood surface. The contact angle on the spruce surface after HSF treatment improved compared to that without treatment, and it was found that a water-repellent surface with a maximum contact angle of 110 degrees could be formed after HSF treatment with the addition of fluorine components to the tool and wood surface.