| 摘要 |
PURPOSE:To obtain a thermoplastic resin foam member having uniform fine air bubbles and foamed at high magnification by using inexpensive inorg. gas having no environmental problem as a foaming agent. CONSTITUTION:A thermoplastic resin (polyethylene, polypropylene, polystyrene) is supplied to a vent type extruder to be melted and kneaded and inorg. gas (carbon dioxide, etc.) is introduced into the thermoplastic resin under pressure as a foaming agent from the vent part of the extruder to extrude the thermoplastic resin from an extusion cap while foaming the same and the extrudate is immediately passed through polyethylene glycol vibrated, for example, under such a condition that frequency is 1MHz and amplitude is 10mum and vibration is applied to the extrudate to obtain an objective foamed object. |
