| 摘要 |
<P>PROBLEM TO BE SOLVED: To obtain homogeneous polystyrene-based expandable resin particles by using an underwater cutting type granulator. <P>SOLUTION: There is provided a production method for polystyrene-based expandable resin particles, which method uses an underwater cutting type granulator equipped with a die having plural die holes and an extruder for supplying a molten resin to the die, in which the die has a diverter valve and the diverter valve has a first flow path supplying the molten resin supplied from the extruder to the die holes and a second flow path for discharging it to the outside of the machine, and which method performs a preparatory step of discharging the molten polystyrene-based resin containing a foaming agent to the outside of the machine through the second flow path while supplying the resin from the extruder to the die, and, after the preparatory step, switches the molten polystyrene-based resin flow path to the first flow path to prepare the polystyrene-based expandable resin particles, wherein the preparation step is performed so that the resin pressure of the molten polystyrene-based resin before switching to the first flow path is made to be 10% or more of that after the switching. <P>COPYRIGHT: (C)2013,JPO&INPIT |
