Compression of White-Pocket Veneer in Hot-Pressed Douglas-Fir Plywood

The characteristics of Douglas-fir plywood containing various amounts of white-pocket veneers were studied. When standard hot-pressing schedules were used, the degree of compression in white-pocket veneers increased as the amount of white-pocket increased. Compared to A-grade veneer, compression of No. 1 WP increased only slightly, while compression of No. 3 WP was more than doubled. The total compression of plywood made from any type veneer can be reduced through use of pressure control during hot-pressing. Reconditioning the plywood partially relieves compression developed during hot-pressing, with the majority of recovery occurring within 2 weeks after pressing. Based on glue-line shear tests, breaking strength of plywood made with white-pocket veneer decreased as amount of white-pocket increased. Percentage of wood failure probably is not a reliable indicator of glue-bond quality when plywood contains white pocket. All grades of white-pocket plywood, pressed with or without pressure control, showed excellent resistance to delamination when subjected to a test procedure considered standard for interior plywood.

You must be logged in to download any documents. Please login (login accounts are free) or learn how to Become a Member