| 摘要 |
PURPOSE:To provide a method for producing foamed polyolefine having a specified cell size and high compression strength efficiently and without quality dispersion. CONSTITUTION:A final foamed product with an expansion ratio of 10 or more is produced from a mixture of polyolefine, a cross linking agent, and a foaming agent. In this method, the foaming agent has a decomposition pattern in which the initial decomposition rate at its decomposition temperature is as low as 1/2 or less of the main decomposition rate. The raw material mixture is charged in a primary mold, and the mold is heated under the pressure of 50kg/cm<2> or more so that 5-30% of the foaming agent is decomposed. The mixture is then expanded primarily by reducing the pressure to give a primary foamed product with a coefficient of cubic expansion of a primary expansion ratio less than 10. The primary foamed product, placed in a secondary mold, is heated under the atomospheric pressure to decompose the residual foaming agent almost completely for the secondary expansion in which the coefficient of cubic expansion is 10 or less to the primary foamed product, thus producing the final foamed product. |
