| 摘要 |
The board comprises at least two embossed plies 4, 5, laminated either side of a smooth centre ply 6. The embossed plies have predominantly alternating cup 3 and dome 2 embossed shapes across and along the sheet, with a dome in the place of a cup at regular intervals to form clusters 1 of domes or projections on the outer faces of the board. The laminated board may have additional plies alternating between planar and embossed, there always being an embossed ply on each outer edge. An alternative embodiment there is no central flat layer, a tow-ply board whereby the embossed plies are adhered directly to each other at the top of the projections. The plies are preferably composed of a cellulose based fibre. The relative vertical position of embossed plies is preferably offset so that the clusters do not coincide in order to avoid soft spots in the 3-ply board. The pattern of the embossing prevents the sheets from settling in close contact when stacked thus facilitating the automatic feeding of the sheets. |
