METHOD FOR MANUFACTURING ELEMENTS OF EXPANDED SYNTHETIC MATERIAL WITH DIFFERENTIAL DENSITY ZONES AND POSSESSING HIGH FLEXURAL AND TENSILE STRENGTH,PLANT FOR IMPLEMENTING SAID METHOD,AND THE PRODUCTS THUS OBTAINED

摘要

Mfr. of elements of expanded synthetic material with different density zones and having high flexural and tensile strength comprises completely expanding pre-expanded polystyrene of density between 15 and 60 kg/m3 in a first variable volume chamber with steam - compressing the thus expanded material to a density of between 300 and 600 kg/m3, cooling the thus expanded material to ambient temp. to stabilise it. The compressed material is then fed into a subsequent expansion chamber, together with pre-expanded polystyrene of density between 15 and 60 kg/m3, and completely expanding the latter using steam. The expanded mass is stabilised with the first mass of compressed material incorporated by cooling to ambient temp.