Method for producing a packaged portion of a food product and portion produced by said method
This method for producing a packaged food product portion includes the following steps: providing a cup defining an inner area for receiving the food product; cold pouring, at a temperature below 50° C., the food product into the receiving area of the cup; covering the food product using a thermally insulating lid arranged such that thermally conducting flaps of the cup extend toward the outside of the lid after the covering step; folding the flaps on an outer face of the lid opposite the receiving area; and heat-sealing the flaps on the outer face.
1. A method for producing a packaged food product portion, the method comprising the following steps:
providing a cup defining an inner area receiving a food product,
cold pouring, at a temperature below 50° C., the food product into the inner area of the cup,
covering the food product using a lid arranged such that thermally conducting flaps of the cup, which are thermally conducting, extend outside the lid after the covering step,
folding the thermally conducting flaps on an outer face of the lid opposite the inner area of the cup, and
heat-sealing the thermally conducting flaps on the outer face of the lid,
wherein the lid is thermally insulating and the lid is made up primarily of expanded plastic,
wherein the step for heat-sealing the thermally conducting flaps on the outer face of the lid comprises a pre-sealing step and a final sealing step,
the pre-sealing step comprises applying a first hot sealing iron on the thermally conducting flaps, the thermally conducting flaps being inserted between said first hot sealing iron and the lid, the first hot sealing iron pressing the thermally conducting flaps of the cup against the lid, and
the final sealing step comprises applying a second hot sealing iron on the thermally conducting flaps, the thermally conducting flaps being inserted between said second hot sealing iron and the lid, the second hot sealing iron pressing the thermally conducting flaps against the lid,
wherein said pre-sealing step and said final sealing step further are successive applications following one another within a time interval of less than 2 seconds,
wherein the first hot sealing iron and the second hot sealing iron are distinct from one another, the first hot sealing iron being removed between the pre-sealing step and the final sealing step,
wherein the cup comprises a single sheet, the single sheet having a multilayer structure comprising: a main layer made from metal, defining an inner face of the single sheet, oriented toward the inner area of the cup, and an outer coating deposited on a face of the main layer opposite the inner face of the single sheet and defining an outer face of the single sheet oriented away from the inner area of the cup,
wherein the main layer makes up more than 70% of the thickness of the single sheet, and the outer coating comprises a layer of non-thermo-adhesive lacquer,
wherein the inner face of the single sheet is covered with an inner coating separate from the single sheet, the inner coating comprising a thermo-adhesive layer, defining an inner face of the coating oriented toward the inner area of the cup, and
wherein the lid has a multilayer structure comprising: a main layer made from expanded plastic and an outer coating, the main layer making up more than 90% of the thickness of the lid, and the outer coating comprising a metal layer.
2. The production method according to claim 1 ,
wherein at least one thermo-adhesive material is provided at an interface between the thermally conducting flaps and the lid, and
wherein the pre-sealing step comprises a sub-step of
activating the at least one thermo-adhesive material provided at the interface between the thermally conducting flaps and the lid using heat provided to the at least one thermo-adhesive material by the first hot sealing iron, and
wherein the final sealing step comprises a sub-step of activating at least one thermo-adhesive material provided at an interface between the thermally conducting flaps and the lid using heat provided to the at least one thermo-adhesive material by the second hot sealing iron.
3. The production method according to claim 1 , wherein the thermally conducting flaps comprise an inner face oriented toward the inner area of the cup, an outer face oriented away from the inner area of the cup, and have a first surface heat transfer coefficient between their inner and outer faces, the lid comprises an inner face oriented toward the inner area of the cup and has a second surface heat transfer coefficient between its outer and inner faces, and the ratio of the first surface heat transfer coefficient to the second surface heat transfer coefficient is greater than or equal to 400.
4. The production method according to claim 3 , wherein the first surface heat transfer coefficient is greater than or equal to 10 7 W·m −2 ·K −1 .
5. The production method according to claim 4 , wherein the second surface heat transfer coefficient is less than or equal to 2·5·10 4 W·m −2 ·K −1 .
6. The production method according to claim 1 ,
wherein the thermally conducting flaps have a thermal conductivity greater than or equal to 200 W·m −1 ·K −1 .
7. The production method according to claim 1 , wherein the lid has a thermal conductivity less than or equal to 0.5 W·m −1 ·K −1 .
8. The production method according to claim 1 , wherein the thermally conducting flaps are made up primarily of metal.
9. The production method according to claim 8 , wherein the thermally conducting flaps are made up primarily of aluminum.
10. The production method according to claim 8 , wherein the thermally conducting flaps comprise the main layer made from metal of the single sheet, defining an inner face of the thermally conducting flaps oriented towards the inner area of the cup, and the outer coating of the single sheet, deposited on the face of the main layer opposite the inner face of the single sheet and defining an outer face of the thermally conducting flaps, oriented away from the inner area of the cup.
11. The production method according to claim 10 , wherein the inner face of the thermally conducting flaps is covered with the inner coating comprising the thermo-adhesive layer and a protective layer inserted between the thermo-adhesive layer and the thermally conducting flaps.
12. The production method according to claim 1 , wherein the expanded plastic is an expanded oriented polypropylene.
13. The production method according to claim 1 , wherein the metal layer is deposited by vacuum evaporation of the metal making up said metal layer.
14. The production method according to claim 1 , wherein the pre-sealing step comprises applying the first hot sealing iron at a temperature greater than 120° C. and less than 140° C. on the thermally conducting flaps, pressing the thermally conducting flaps against the lid, and the final sealing step comprises applying the second hot sealing iron at a temperature greater than 120° C. and less than 140° C. on the thermally conducting flaps, pressing the thermally conducting flaps against the lid.