摘要 |
A method for obtaining expanded polystyrene products comprising portions of comparatively very different densities and thus of different mechanical strengths, in which a first mass of pre-expanded polystyrene beads of greater density is caused to partially cohere by means of steam, the resultant mass is placed in a mould of greater dimensions, said mould is completely filled with polystyrene beads of density less than the preceding, and cohesion is completed therein. |