| 摘要 |
PURPOSE:To obtain a plastic foam of high-foaming magnification, by a method wherein cavity faces of both split molds are positioned by bringing them into contact with a fitted plastic composition and the movable cavity face is moved backward according to the cubical expansion of the composition due to dielectric heating. CONSTITUTION:A top force 30 is clamped with a bottom force 20 by fitting a predetermined quantity of a plastic composition on a cavity face 21 of the bottom force 20. In this instance, clamping of both the forces is performed so that a cavity face 31 of the top force 30 welds slightly a plastic composition 11 with pressure. Although dielectric heating and plastic fusion of the plastic composition 11 of the inside of a cavity 70 are performed through application of high-frequency voltage to the same the voltage applied to the plastic composition is used for the dielectric heating of the plastic composition as it is and the plastic composition is plasticized and fused. As the plastic composition 11 is expanded along with plasticization and fusion of the same, volume of the same is increased more than that of the first stage by amount equivalent to backward movement of a movable part 32 further and the cavity face 31 of the movable part 32 forms plane which is flush with a divided face 38 of a top force body 33, one side of a molded object can be made into a smooth plane. |
