FIELD: food industry.
SUBSTANCE: group of inventions relates to food industry, in particular, to a multilayer co-extruded thermoplastic shell for food products, a method for production thereof and a food product enclosed in a multilayer shell. Multilayer co-extruded thermoplastic shell for food products contains at least one porous inner layer, one of which is the innermost porous layer, the surface of which adjoins the food product enclosed in the shell; at least one layer having barrier action to steam and/or oxygen; at least one adhesive layer, wherein said adhesive layer is not necessarily same or different from said at least one porous inner layer and/or said one layer having barrier action to water vapor and/or oxygen; wherein porosity of said at least one porous inner layer is formed by co-extrusion of first polymer composition comprising polymer and supercritical pore-forming agent, wherein group of all porous inner layers of shell has total porosity from 5 to 90 % by volume, wherein said at least one porous inner layer has a porosity having pores with diameter from 0.01 to 2000 mcm, whereby at least one of said at least one porous inner layer(s) is capable of absorbing, retain, desorb and transfer at least one portable functional additive from said at least one porous inner layer to a food product enclosed in said shell, characterized in that at least one porous inner layer consists of polymer and filler and/or nucleating agent agent, wherein filler is selected from a group consisting of silicon dioxide (dioxides), talc, calcium carbonate (carbonates), barium sulphate, aluminium oxide(s), aluminium hydroxide(s), magnesium hydroxide, titanium dioxide (dioxides), zirconium dioxide, silicate(s) and sodium chloride, and the nucleating agent is selected from a group consisting of carbonates, hydrazine derivatives, azo compounds, semicarbazides, tetrazoles, nitroso compounds, citric acid and citric acid derivatives. Method of producing a multilayer co-extruded thermoplastic shell for food products includes a step of subjecting a combination of a first polymer composition comprising a polymer and a supercritical pore-forming agent, and at least one additional second polymer composition during co-extrusion, said first polymer composition comprising a polymer and a supercritical pore-forming agent, then co-extrusion forms said at least one porous inner layer, wherein first polymer composition, forming at least one porous inner layer, is a polymer composition consisting of a polymer, a supercritical pore-forming agent and a filler and/or a nucleating agent.
EFFECT: providing high strength of shell and improved separation of inner layer.
13 cl, 2 tbl
