Surface damage mechanism and chip curling analysis of orthogonal cutting wood-plastic composites

The machining processing of wood-plastic composites (WPCs) has some technological gaps in the field of surface damage mechanism and surface quality monitoring. In this study, orthogonal cutting tests were used to investigate the mechanisms of surface damage and the degree of chip (the material cutting off by cutting tool) curling of WPCs with various tool rake angles (from 5 ° to 40 °) and cutting depths (from 0.1 to 1 mm). Based on observations of the processed surface micromorphology, a surface damage model is proposed to describe the temperature-dependent reduction in adhesion force between polyethylene and wood flour. Chip curling was quantified by the point curvature in the side view. The curvature data for each chip point were negatively correlated with the depth of cut, but the relationship with the tool rake angle was less pronounced. The surface damage mechanism of WPCs during machining was revealed, providing a theoretical basis for improving surface quality through material formulation. The analysis of chip curvature offers theoretical support for the dynamic observation of chip morphology and elucidates the relationship between chip morphology, cutting depth, and tool rake angle. These findings can serve as a foundation for monitoring cutting precision in practical production.