| 摘要 |
<p>PROBLEM TO BE SOLVED: To exhaust gas existing in a pore of a core material in a short time by bringing a wrapping material into close contact with the core material so as not to form the excess end side, by arranging plural holes extending to the core material inside on an end surface of the core material positioned in a part being a gas sucking port at wrapping material sealing time. SOLUTION: Plural holes 1a extending up to an opposed end surface from one end surface are bored in a single plate-like foaming urethane mold 1 by using a drill. In the size of the holes, a diameter or a height is desirably set not more than 1/3 of a plate thickness. Here, a minimum thickness remaining in a bored core material part is desirably set not less than 5 mm. The ratio d/L of the diameter (d) of the holes to the length L of the holes is desirably set not less than 1/100. A core material is arranged in a wrapping material so that an end surface having the holes comes to a part being a gas sucking port when sealing this core material by the wrapping material 2. Next, the inside of the wrapping material is put in a vacuum state by using the gas sucking port. Various gases existing in a continuous pore can be efficiently exhausted by this operation.</p> |
