| 摘要 |
PURPOSE:To provide a lightweight thin-walled resin core having high rigidity, the high degree of freedom of designing and capable of being shortened in the dissolving time liquid. CONSTITUTION:A resin core 1 is constituted of divided shells 3a, 3b composed of a resin material dissolved in a liquid such as a hot water and a plurality of ribs 5, 6 are provided to the inner surfaces of the divided shells 3a, 3b so as to provide intervals in the longitudinal direction of the shells and, in such a state that spheres 4 are received in the spaces between the ribs 5,6, the divided shells 3a, 3b are fixed to form a hollow core main body 3 having a plurality of the spheres 4 arranged therein. |
