METHOD OF MAKING FOAMED POLYSTYRENE SLABS WITH HIGH COMPRESSION STRENGTH Russian patent published in 2010 - IPC C08J9/22 B29C47/00 

FIELD: chemistry.

SUBSTANCE: invention describes a method of making foamed polystyrene slabs with high compression strength by mixing polystyrene with a nucleating agent and other process additives, feeding the mixture into the melting zone of an extruder, melting the mixture, mixing the molten mixture with a foaming agent selected from a group which includes fluorocarbons, carbon dioxide and their mixture, in a mixing zone, cooling the mixture to foaming temperature and extrusion of foamed polystyrene to form slabs. The method is characterised by that the ratio of the specific carrying capacity of the extruder at the homogenisation-cooling step (Ko) to the specific carrying capacity of the extruder at the step for melting and mixing with the foaming agent (Kc) Ko/Kc = 30-37, and the ratio of the amount of supplied foaming agent (in moles) to the specific carrying capacity of the extruder at the step for melting and mixing with the foaming agent (Kc) is in the range of 0.07-0.20.

EFFECT: low density of obtained foamed polystyrene slabs with retention of high compression strength and improved heat insulation properties.

6 cl, 1 tbl, 14 ex