Observations on the deformation of wood cells in the glueing process of veneer

In the production of plywood, it is very important to control thickness of the resulting product, and to reduce the decrease of the product thickness that may occur during hot pressing process. The observations through SEM (scanning electron microscope) micrographs of the glue line field in plywood illustrated the great effects of pressure and temperature on deformation of wood cells and the penetration of glue into the wood cells. These phenomena are closely related to the thickness of the product. Also, pure glue lines (layers composed of adhesive only) were scarcely found in the micrographs.