| 摘要 |
PURPOSE:To reduce the adhesive for sticking to improve the stiffness, by forming the surface material of the diaphragm of the sandwich structure with an impregnated hardened layer due to the coating material where squamous aluminium powder or mica powder is mixed. CONSTITUTION:A core material 9 is formed with a thin conical trapezoidal plastic form material where the top art is cut into a flat face or a stepped thin round plastic form material which has a round thick part in the center. An impregnated hardened layer 11 of the coating material where squamous aluminium powder or mica powder is mixed is provided on one face of the core material 9. A surface layer 10 consisting of materials of a high specific modulus of elasticity such as an aluminium alloy foil is stuck to the other face of the core material 9 by an adhesive 12. Thus, the stiffness due to the form effect is improved. |
