摘要 |
A method of the production of boards of a lignocellulosic fibrous material wherein a material is broken up into particles and/or fibers that are dried, glued and formed to a mat and pressed to a finished board so that steam is introduced to the mat. According to the present invention, the steam is introduced in a limited amount in a first injection step. This amount is adjusted so that the steam only penetrates into, heats and cures the surface layer of the mat. Thus, a board having a surface layer with a higher density than a middle layer is obtained so that the subsequent calibration compression provides a greater thickness that permits the middle layer to expand while the density of the surface layers is maintained. |