WATER EXPANDED POLYSTYRENE PARTICLES

摘要

The invention relates to a method for producing polystyrene foam particles, according to which polystyrene beads containing water as only inflating agent are expanded. The method comprises the following steps: a) the polystyrene beads are expanded at temperatures above 100 DEG C; b) the expanded beads are dried in dry air at between 20 and 95 DEG C for between 1 and 10 hours; c) the dried particles are expanded further at between 100 and 140 DEG C using water vapour; and d) steps b) and c) are repeated until the desired bulk density is obtained.