| 摘要 |
<p>PROBLEM TO BE SOLVED: To provide a method for extrusion molding of a foam by which foaming from a bung hole for carbon dioxide fluid to a die is suppressed, degree of the foaming can be adjusted, and a fine foam with high quality can be continuously obtained. SOLUTION: A resin material is melted by a double-screw extruder 1 and carbon dioxide fluid under supercritical condition is injected into a molten resin to obtain a foaming material. This is pressurized by means of a gear pump 30 and is extruded into open atmosphere from the die 35 to obtain the foam by releasing the pressure at a stroke. In this case, as a screw for a part Y for dissolution, diffusion and penetration of the carbon dioxide fluid, a full flight screw is used. In addition, degree of melting and kneading of the resin material is adjusted by slide gates 13 and 13' and the carbon dioxide fluid is prevented from flowing backward. A space between the slide gates and the gear pump also takes an effect like an action of a chamber by a synergistic action of the slide gates, the full flight screw and the gear pump.</p> |
