The structure of interfibre bonding in hand sheets made of a hardwood BKP was investigated throughout the sheet formation stages using a transmission electron microscope (TEM), a scanning electron microscope (SEM) and a scanning laser microscope (SLM). The sample preparation techniques for TEM and SLM were newly developed for observation of the bond formation and bond structure.
Observations were made on couched wet webs, pressed wet webs, drying stages of the wet webs and dry sheets . Structures of the bonded zone and bonded fibres were characterized based on these observations. In this paper we discussed how the structures are affected by beating, couching, pressing and drying. We also discussed the roles of these structures in the physical properties of the fibre bonding.