| 摘要 |
Method for the preparation of a particle board by building up the board in layers with a middle layer of coarse material, a surface layer of fine material on each side of the board and, optionally, one or more intermediate layers between the middle layer and each surface layer, according to which method the material for the surface layer is fractionated and applied with the finest part of the material of the surface layer next to the previous layer which in the board is placed further in and with the coarsest part of the material of the surface layer at the surface of the board and the surface layer on grinding after pressing is ground down to the desired fineness of the material at the surface of the board. |
