Anatomical evaluation of wood surfaces produced by oblique cutting and face milling

Abstract

The condition of superficial tissues plays an important role in the behavior of adhesive/wood interfaces. Tissues at the wood surface should be the least distorted possible during surfacing in order to avoid the formation of mechanical weak boundary layers. These layers cause significant loss of adhesion of coating films and gluelines during utilization of wood. In this study, sugar maple (Acer saccharum Marsh.), northern red oak (Quercus rubra L.), and eastern white pine (Pinus strobus L.) were surfaced by oblique cutting and face milling, while paper birch (Betula papyrifera Marsh.) was face milled. Cell damage was considerably higher in face milling than in oblique cutting. This damage was manifested in the form of lateral distortion, bending, and rupture of tissues. In general, superficial cell damage presented similar patterns for all species studied, but its severity was quite variable as a function of species and cutting conditions. The present study describes damage patterns and discusses the possible implication of cell damage in wood finishing and gluing.