| 摘要 |
The plate has a middle layer (1) made of a very light, porous and pressure resistant chipboard with a gross density below 500 kilogram per meter cube. Cover layers (2) are made of very thin and firm fiberboard or laminar material with a well closed surface, which has a gross density of more than 500 kilogram per meter cube. The cover layers are glued on the middle layer with poly addition or poly condensation adhesives (4). |
