| 摘要 |
<p>A closed cell foam body composed of a blend of polystyrene and polyphenylene oxide (PS/PPO), is produced by (a) providing a plurality of pellets comprising a blend of polystyrene and polyphenylene oxide (PS/PPO) and a blowing agent; (b) expanding the pellets to form a plurality of beads of closed cell foam, the beads having a first density and containing at least a portion of the blowing agent; and (c) fusing the beads together in pellets in a mould at an elevated temperature of from 150 to 220{C and elevated pressure such as 1 to 5 bar to form a closed cell foam moulded body having a second density within the range of from 5 to 10 kg/m3 higher than the first density. The pellets may be expanded in the presence of steam. The pellets may be fused together in the presence of steam. The beads may have an average size of 2 to 4 mm. The closed cell foam 5 may form the central core 4 of a sandwich structure 2 having outer layers 6, 8 of a fibre reinforced resin, the resin adhering the outer layers to the core.</p> |
