| 摘要 |
PURPOSE:To obtain the foamed body strong against longitudinal enternal force by a method in which the mixture of foaming agent and viscous material is thrown into the mold under rotation, and is centrifugally molded, and after the foaming agent has been foamed under heating, the viscous material is cured. CONSTITUTION:While rotating the mold 11 supported by way of a plurality of ring bodies 10, a mixture 12 is thrown into said mold 11 and centrifugally molded into a tube shape. Said mixture 12 is composed of foaming agent and viscous material. In the centrigugal molding process, the foaming agent in the mixture 12 is foamed. Then, the volume expansion by foaming is directed to internal direction, but as the bubbles occurring there move in the viscous material, they do not become circular and become longitudinally elongated bubbles 13, extending internally in said viscous material. The foam 14 including many elongted bubbles 13 inside is obtained by heating and curing the viscous material subsequently. |
