Читать книгу Adhesives for Wood and Lignocellulosic Materials - R. N. Kumar - Страница 29

The hierarchical structure of wood profoundly influences the adhesion phenomenon over a wide range of “length scales”. The adhesive phenomenon occurs first by transport phenomenon (bulk flow, penetration, and diffusion) followed by a number of possible processes ranging from mechanical adhesion to the formation of chemical bonds as shown in Table 1.3. Adhesive penetration in wood is commonly categorized into (a) gross penetration and (b) cell wall penetration. Gross penetration is the flow of liquid adhesive into the porous structure of wood in order to fill the lumens. For cell wall penetration, the adhesive enters the woody cell wall. Adhesive gross penetration and cell wall penetration are both critical to the performance and durability of adhesive joints [32–35].