The present invention provides a multi-layered coextruded thermoplastic food casing comprising: at least one thermoplastic porous absorbing layer; and at least one layer having a barrier effect for water vapor and/or oxygen, wherein the at least one layer having a barrier effect for water vapor and/or oxygen has an average layer thickness in a range of from 5 to 60 μm over the entire surface area, wherein the at least one thermoplastic porous absorbing layer comprises as a main component at least one thermoplastic polymer material selected from the group consisting of (co)polyamides and (co)polyolefins, wherein the at least one thermoplastic porous absorbing layer comprises areas having a reduced average layer thickness and areas having a non-reduced average layer thickness, wherein the average layer thickness of the at least one thermoplastic porous absorbing layer in areas having a non-reduced average layer thickness is in a range of from 10 to 200 μm, wherein the average layer thickness in areas having a reduced average layer thickness is lower by 7 to 140 μm and is reduced by a range of from 30 to 85% compared to the areas having a non-reduced average layer thickness of the at least one thermoplastic porous absorbing layer, and wherein both areas having a reduced average layer thickness and a non-reduced average layer thickness comprise pores which are able to absorb a functional additive.

The present disclosure provides a functional additive transferring (co)extruded thermoplastic food casing having a water vapor barrier and/or oxygen barrier effect wherein an inside surface of the thermoplastic food casing has a textured surface which forms a three-dimensional pattern of higher and lower retaining capacity for a functional additive.

The present invention provides a multi-layered coextruded thermoplastic food casing comprising: at least one thermoplastic porous absorbing layer; and at least one layer having a barrier effect for water vapor and/or oxygen, wherein the at least one layer having a barrier effect for water vapor and/or oxygen has an average layer thickness in a range of from 5 to 60 m over the entire surface area, wherein the at least one thermoplastic porous absorbing layer comprises as a main component at least one thermoplastic polymer material selected from the group consisting of (co)polyamides and (co)polyolefins, wherein the at least one thermoplastic porous absorbing layer comprises areas having a reduced average layer thickness and areas having a non-reduced average layer thickness, wherein the average layer thickness of the at least one thermoplastic porous absorbing layer in areas having a non-reduced average layer thickness is in a range of from 10 to 200 m, wherein the average layer thickness in areas having a reduced average layer thickness is lower by 7 to 140 m and is reduced by a range of from 30 to 85% compared to the areas having a non-reduced average layer thickness of the at least one thermoplastic porous absorbing layer, and wherein both areas having a reduced average layer thickness and a non-reduced average layer thickness comprise pores which are able to absorb a functional additive.

The present invention provides a functional additive transferring (co)extruded thermoplastic food casing having a water vapor barrier and/or oxygen barrier effect wherein an inside surface of the thermoplastic food casing has a textured surface which forms a three-dimensional pattern of higher and lower retaining capacity for a functional additive, wherein the thermoplastic food casing having a textured surface in case of a monolayer casing or an inner layer comprising the inside surface having a textured surface in case of a multilayer casing comprises as a main component at least one thermoplastic polymer material selected from the group consisting of (co)polyamides, (co)polyolefins, (co)polyester and vinylidenchloride (co)polymers, wherein the (co)extruded thermoplastic food casing does not comprise a net and/or a material forming a net or any other three dimensional structure on its outside surface, wherein the average thickness of the thermoplastic food casing in the areas having a higher retaining capacity is in a range of from 1 to 100 m, wherein the average thickness of the thermoplastic food casing in the areas having a lower retaining capacity is in a range of from 191 to 2000 m, provided that the thickness difference between the average thickness in the areas having higher retaining capacity and the average thickness in the areas having a lower retaining capacity is in a range of from 160 to 1950 m and that a ratio of the average thickness of the thermoplastic food casing in the areas having a higher retaining capacity and the average thickness of the thermoplastic food casing in the areas having a lower retaining capacity is in a range of from 0.002 to 0.25.