Abstract: A tray for packaging food products which may release smelly volatile substances produced from a sheet of substantially open-cell expanded thermoplastic material containing a finely divided solid material provided with adsorbing properties towards said substances, such as for example aluminium oxide, bentonite, kaolin, activated charcoal, zeolites, synthetic polymers with a high melting point such as polyphenyloxide and polyimides, graphite, mica, diatomaceous earth, pumice and clay; the inner surface of said tray is preferably provided with apertures.

Abstract: A method of producing a substantially open-cell, expanded polystyrene sheet, comprising the steps of: forming a mixture comprising from 30 to 95% of polystyrene incorporating an aliphatic hydrocarbon with 4-6 carbon atoms, from 0 to 65% of polystyrene, and from 0.2 to 10% of a nucleating agent, mixing the mixture obtained and melting it by heating inside an extruder, bringing the mixture to a temperature of 130-150° C. in the final portion of the extruder, extruding the mixture in a lower-pressure atmosphere to produce an expanded sheet, which has a low density and a high capacity to absorb aqueous liquids, particularly if a surfactant is added to the starting mixture, and which, when coupled with two films of plastics material gives rise to a laminate suitable for the production, by thermoforming, of trays for foods which may release aqueous liquids.

Abstract: A method of producing a substantially open-cell, expanded polystyrene sheet, comprising the steps of:forming a mixture comprising from 30 to 95% of polystyrene incorporating an aliphatic hydrocarbon with 4-6 carbon atoms, from 0 to 65% of polystyrene, and from 0.2 to 10% of a nucleating agent,mixing the mixture obtained and melting it by heating inside an extruder,bringing the mixture to a temperature of 130-150.degree. C. in the final portion of the extruder,extruding the mixture in a lower-pressure atmosphere to produce an expanded sheet, which has a low density and a high capacity to absorb aqueous liquids, particularly if a surfactant is added to the starting mixture, and which, when coupled with two films of plastics material gives rise to a laminate suitable for the production, by thermoforming, of trays for foods which may release aqueous liquids.

Abstract: A sheet of expanded plastics material with absorbent properties towards aqueous liquids has a structure with intercommunicating cells and comprises at least one surfactant and at least one lubricating agent. The invention also relates to a tray (1) of plastics material for foods which may release liquids, comprising a base (2) and side walls (3), wherein the base (2) has holes (4) of 0.1-1.5 mm diameter in the surface (4) which is intended to contact the food, and is produced from a sheet as described above. Methods of producing the sheet and the tray are also described.

Abstract: A tray of plastics material for foodstuffs which may release liquids including a base and side walls constituted by an upper layer and a lower layer, the layers forming the side walls being joined together while those forming the base are spaced apart to define an interspace, in which the upper layer is pierced by holes having a diameter of 0.2-1.5 mm and is of foamed plastics material including a surfactant and the surface of the upper layer facing the interspace is rough.

Abstract: A method of producing a substantially open-cell, expanded polystyrene sheet, comprising the steps of: forming a mixture comprising from 30 to 95% of polystyrene incorporating an aliphatic hydrocarbon with 4-6 carbon atoms, from 0 to 65% of polystyrene, and from 0.2 to 10% of a nucleating agent, mixing the mixture obtained and melting it by heating inside an extruder, bringing the mixture to a temperature of 130-150° C. in the final portion of the extruder, extruding the mixture in a lower-pressure atmosphere to produce an expanded sheet, which has a low density and a high capacity to absorb aqueous liquids, particularly if a surfactant is added to the starting mixture, and which, when coupled with two films of plastics material gives rise to a laminate suitable for the production, by thermoforming, of trays of foods which may release aqueous liquids.