| 摘要 |
<p>The board (1) has a core (10) with upper and lower surfaces (11, 12) covered by fibrous reinforcement layers (4, 6). Rectilinear fibrous elements traverse the core from end to end while being in contact with the layers. The elements act as rectilinear thread segments made of core material e.g. polyurethane based foam or wood. The segments present in a proportion of one hole per square centimeter over 50 square centimeter on core area. The core and the elements have density less than 120 kilogram per cubic meter. Threads (20) in contact with the layers are impregnated with thermosetting resin. The threads are made of glass fiber, carbon fiber, aramid fiber, natural fiber or basalt fiber.</p> |
