EP3972463A1

EP3972463A1 - Culinary article comprising a thinned side wall

Info

Publication number: EP3972463A1
Application number: EP20726444.1A
Authority: EP
Inventors: Laurent AUBIN
Original assignee: SEB SA
Current assignee: SEB SA
Priority date: 2019-05-23
Filing date: 2020-05-19
Publication date: 2022-03-30
Also published as: WO2020234323A1; CN216797359U; DE202020005889U1; FR3096248B1; FR3096248A1

Abstract

The invention relates to a culinary article (1) comprising a metal cap (2) having a bottom wall (21) and a side wall (31) rising around the bottom wall (21), said bottom wall (21) having an internal face (211) for cooking food and an external face (212) intended to be arranged in proximity to a heat source. According to the invention, said cap (2) is a stamped or flow-formed aluminum alloy sheet of the 6000 or 5000 series, and the bottom wall (21) has a thickness at least 2 times greater than that of the side wall (31), preferably at least 2.5 times greater than that of the side wall (31). The invention also relates to the method for producing said culinary article.

Description

DESCRIPTION

TITLE: CULINARY ARTICLE WITH A THINNED SIDE WALL

The present invention relates to the technical field of cookware or cooking vessels made from a stamped or flow-formed aluminum alloy sheet.

Cooking vessels generally have a base intended to be placed on a cooking zone (such as for example an electric hotplate, an induction hotplate, a fuel burner, or the like), this bottom being surrounded by a side wall rising around the bottom. The upper face of the bottom forms a food cooking surface. The underside of the bottom forms a heating surface.

The present invention relates particularly, but not exclusively, to pan-type cooking vessels. Pan-type cooking vessels can be defined by a height less than their width or diameter. Generally the width or diameter of such cooking vessels is several times greater than their height.

The use of aluminum alloys in the culinary field has been known for years. The good thermal conductivity of aluminum makes it possible to consider the production of cooking vessels with an aluminum alloy body.

In cooking vessels with an aluminum alloy body, the side wall acts as a cooling fin, which helps to limit

the heating of the peripheral part of the bottom. This results in a temperature differential on the bottom, in particular between the center and the periphery of the heating surface.

The distribution of the material used for a cooking vessel can be described by the bottom thickness / side wall thickness ratio. In usual practice for cooking vessels made of aluminum alloy, this bottom thickness / thickness of the side wall ratio does not exceed 1.8, in particular for cooking vessels made from a sheet of aluminum alloy. stamped or flow-formed aluminum. A 28cm diameter pan has a bottom thickness of 5.1mm and a side wall thickness of 2.9mm, a ratio of 1.76. One of the main criteria for evaluating the quality of a cooking vessel is its cooking homogeneity. Cooking homogeneity is the ability of the cooking vessel to cook food evenly, regardless of the location of the food on the bottom of the cooking vessel.

A disadvantage of aluminum alloy cooking vessels made from stamped or flow-formed aluminum alloy foil is the sensitivity of the cooking surface to temperature variations caused by the side wall. During preheating, significant temperature differences can be observed on the cooking surface, for example with a temperature of 180 ° C at the hottest part of the cooking surface and less than 120 ° C at the place the cooler the cooking surface. These temperature differences help to reduce the cooking homogeneity of the food cooked in the cooking vessel.

The objective is to manufacture cooking vessels with a distribution of the material according to its thermal role, in order to improve both its homogeneity and preheating properties while limiting the increase in the weight of the article.

An object of the present invention aims to provide a cooking vessel comprising an aluminum alloy cap made from a stamped or flow-formed aluminum alloy sheet, in which the temperature homogeneity of the surface of cooking is improved, without causing an excessive increase in the mass of the cooking vessel.

This object is achieved with a culinary article comprising a metal cap having a bottom wall and a side wall rising around the bottom wall, said bottom wall having an inner face intended for cooking food and an outer face intended for cooking food. to be placed near a heat source, because said cap is a stamped or flow-formed aluminum alloy sheet of the 6000 series or of the 5000 series and that the bottom wall has a thickness of at least 2 times greater than that of the side wall, preferably at least 2.5 times greater than that of the side wall.

Preferably, the bottom wall has a thickness less than or equal to 15 times that of the side wall, preferably less than or equal to 13.5 times that of the side wall. Preferably, the cap has a diameter / height ratio less than 0.5, and preferably less than 0.3. Preferably, the cap has a diameter / height ratio of between 0.5 and 0.1, and preferably of between 0.3 and 0.1.

The use of aluminum alloys in the culinary field has been known for years. However, the usual alloy grades (Al 1050, Al 1200, Al 3003, Al 4006) have low mechanical strength properties.

The use of 6000 series or 5000 series alloys allows the design of cooking vessels to be redesigned to improve their cooking homogeneity while reducing their mass and limiting the increase in preheating time.

It is recalled that the alloys used must comply with food standards (Zn content <0.25% and Cu content <0.6%).

6000 series (aluminum magnesium silicon)

The alloying elements of this series are magnesium (Mg) and silicon (Si). This alloy family is of great industrial importance. It is widely used for profiles.

They have a very good aptitude for deformation (spinning, stamping mainly) and for cold forming in the annealed state. Their mechanical characteristics are average and are lower than those of alloys 2000 and 7000. These characteristics can be increased by adding silicon which will give the hardening precipitate Mg2Si. They have excellent resistance to corrosion, especially atmospheric corrosion. They weld very well (arc welding or brazing).

They can be divided into two groups:

- a group whose compositions are more loaded with magnesium and silicon (6061, 6082 for example). They are used for structural applications (framework, pylon, etc.), as well as in aeronautics (electrical connections, on-board electronic units, etc.);

- a second category less charged with silicon which consequently will have weaker mechanical characteristics. This is the case with the 6060 which will allow high spinning speeds but which will have lower mechanical characteristics.

It will be used for example in decoration and furnishings, metal carpentry.

It should also be noted the existence of 6101 formerly called Almelec. This alloy has been used extensively for its ability as an electrical conductor. It has been used in particular for the manufacture of medium and high voltage lines in France.

[Table 1]

Composition

The concentrations are in percentage by mass.

Preferably, the aluminum alloy is of the 6000 series of grade 6082. This alloy has a high elastic limit, and is harder than the alloys

of aluminum usually used to make cooking vessels, which makes it possible to consider further reducing the thickness of the side wall of the cooking vessel, due to this better mechanical strength.

5000 series (aluminum magnesium)

The alloying element is magnesium (up to 5%). These are alloys by strain hardening. These alloys have average mechanical characteristics which increase with the level of magnesium. These characteristics will also increase with the rate

work hardening. They have a good aptitude for deformation, this aptitude decreasing if the level of magnesium increases. They have excellent welding behavior and as such are used in welding boilermaking. They also have good behavior at low temperatures. They have good corrosion behavior which justifies their use in marine applications.

They are used in shipbuilding, transport, chemical industry.

[Table 2]

Composition

Others Others

Alloy Si Fe Cu Mn Mg Cr Ni Zn Ti Zr + Ti _ _^ , Al each total

5005 Mm.! He ! 0.50 / I l! / / / the rest

Max. 0.30 0.70 0.20 0.20 1.10 0.10 / 0.25 / / 0.05 0.15

5086 Min. / / / 0.20 3.50 0.05! He ! / / the rest

Max. 0.40 0.50 0.10 0.70 4.50 0.25 / 0.25 0.15 / 0.05 0.15 The concentrations are in percentage by mass.

Advantageously, the aluminum alloy is of the 5000 series of grade 5754. This alloy is harder than the aluminum alloy of the 6000 series of grade 6082, which also makes it possible to consider further reducing the weight. thickness of the side wall of the cooking vessel, due to this better mechanical strength.

[Table 3]

5754 (AW-AIMg3): Nominal chemical composition% (according to standard EN 573-1):

Advantageously, the aluminum alloy is of the 5000 series of grade 5083. This alloy is harder than the aluminum alloy of the 5000 series of grade 5754, which also makes it possible to consider further reducing the thickness of the side wall of the cooking vessel, due to this better mechanical strength.

[Table 4]

5083 (AW-AIMg4,5MnO, 7): Nominal chemical composition% (according to standard EN 573-1):

If desired, the internal face can be partially or fully coated, in particular with a PTFE, ceramic or sol-gel coating.

If desired, the external face can be partially or entirely coated, in particular with an enamel, PTFE, ceramic or sol-gel coating.

If desired, a metal insert can be attached under the bottom of the cooking vessel, on the side of the external face, to allow the heating of the cooking vessel on a hotplate by induction.

Preferably, the metal insert is formed by a grid.

This grid can be assembled by striking, for example by cold heading, of

preferably before shaping the alloy sheet. Its thickness is included

between 0.3 and 1 mm, preferably about 0.6 mm. The holes in the grid may

have a diameter of between 2 and 4 mm, preferably about 3 mm.

Preferably, the metal insert is made of a ferromagnetic material.

The metal insert makes the cookware according to the invention compatible with induction heating.

Another object of the invention relates to a method of manufacturing a cookware according to the invention comprising the following steps:

- Provide an aluminum alloy sheet of 6000 series or 5000 series,

- Possibly add a metal insert on the outside, - Stamping or spinning said sheet in the shape of a cap,

- Optionally apply on the internal face partially or entirely a PTFE coating, or ceramic, or sol-gel,

- Optionally apply on the external face partially or entirely an enamel, PTFE, ceramic, or sol-gel coating.

Provide 6000 series or 5000 series aluminum alloy sheet,

- Possibly add a metal insert on the outside,

- Stamping or spinning said cap-shaped sheet having a bottom wall and a side wall rising around the bottom wall, the bottom wall having a thickness at least 2 times greater than that of the side wall, preferably at least 2.5 times greater than that of the side wall,

Another object of the invention relates to the use of a metal cap in the form of a stamped or flow-formed aluminum alloy sheet of the 6000 series or of the 5000 series to improve the preheating time of a culinary article.

Another object of the invention relates to the use of a metal cap in the form of a stamped or flow-turned aluminum alloy sheet of the 6000 series or of the 5000 series, said cap having a bottom wall and a side wall rising around the bottom wall, the bottom wall having a thickness at least 2 times that of the side wall, preferably at least 2.5 times that of the side wall, to improve the preheating time of a culinary article conforming to the aforementioned characteristics.

The means used consists in increasing the thickness of the bottom wall and reducing that of the side wall, which amounts to maximizing the bottom wall / side wall thickness ratio. The difficulty here is to ideally distribute the material according to its thermal role while respecting the imperative of mechanical strength (in particular at the point of attachment of a handle on the side wall).

The implementation of these constructions does not call for specific transformation processes. The parameters used during stamping, flow-forming or forging operations to assemble a base compatible with induction heating are obviously to be adapted to the new thicknesses to be obtained. For example, the strike force for inserting a grid will be for example

significantly revised upwards to compensate for the greater resistance to grid penetration that the new alloy will provide.

The invention will be better understood by studying the embodiments, taken in no way limiting, illustrated in the appended figures, in which:

[Fig. 1] Figure 1 is a schematic sectional representation of an embodiment of a cookware according to the prior art,

[Fig. 2] Figure 2 is a schematic sectional representation of an exemplary embodiment of a cookware according to the invention,

[Fig. 3] Figure 3 is a partial schematic sectional representation of an alternative embodiment of a cookware according to the prior art,

[Fig. 4] Figure 4 is a representation of a metal insert inserted into the bottom of the cookware shown in Figure 3,

[Fig. 5] Figure 5 is a partial schematic representation in section of an alternative embodiment of a cookware according to the invention,

[Fig. 6] Figure 6 is a representation of a metal insert inserted into the bottom of the cookware shown in Figure 5.

Figures 1 and 2 illustrate cookware 1 ’, 1 with a 2’ cap,

2 metal having a bottom wall 21 ', 21 and a side wall 31', 31 rising around the bottom wall 21 ', 21. The cap 2', 2 is a flow-turned aluminum alloy sheet. As a variant, the cap 2 ', 2 could be a stamped aluminum alloy sheet. The bottom wall 21 ′, 21 has an inner face 211 ′, 211 intended for cooking food and an outer face 212 ′, 212 intended to be placed near a heat source. If desired, the internal face 211 ', 211 can be partially or completely coated with a coating, for example a coating. PTFE, or a ceramic coating, or a sol-gel coating. If desired, the outer face 212 ', 212 can be partially or fully coated with a coating, for example a PTFE coating, or a ceramic coating, or a sol-gel coating. If desired, the culinary item T, 1 can include a handle (not shown in Figures 1 and 2) mounted on the cap 2 ', 2.

According to the variant embodiments illustrated in Figures 3 and 5, the culinary item T, 1 comprises a handle 5 ', 5 fixed to the cap 2', 2. Furthermore, a metal insert 4 ', 4 is attached to the outer face 212 ', 212 of the bottom wall 2T, 21. Figures 4 and 6 show the metal inserts 4', 4 present in the cookware T, 1 illustrated in Figures 3 and 5. The metal inserts 4 ', 4 are formed by grids. The metal inserts 4 ’, 4 can be made of ferromagnetic material, in particular ferritic stainless steel, to obtain a cookware T, 1 compatible with induction heating. The thickness of the metal inserts is for example of the order of 0.6 mm.

In the prior art cookware illustrated in Figures 1, 3 and 4, the cap 2 'is a sheet of aluminum alloy of the 4000 series of the grade 4006, with a diameter of 28 cm. The 2T bottom wall is around 4.5mm thick. The side wall 3T has a thickness of the order of 3 mm, this side wall thickness corresponding to a minimum thickness measured below the outer edge of the cap 2 ’. The ratio of the thickness of the bottom wall 2T to the thickness of the side wall 3T is of the order of 1.5.

In the cookware according to the invention illustrated in Figures 2, 5 and 6, the cap 2 is an aluminum alloy sheet of the 6000 series of the grade 6082, with a diameter of 28 cm. The height of the cap 2 is of the order of 55 mm, ie a height / diameter ratio of the order of 0.2. The bottom wall 21 has a thickness of the order of 6 mm. The side wall 31 has a thickness of the order of 2 mm, this side wall thickness corresponding to a minimum thickness measured below the outer edge of the cap 2. The ratio between the thickness of the bottom wall 21 and l The thickness of the side wall 31 is of the order of 3. Alternatively, the cap could be either a 5000 series aluminum alloy sheet of grade 5754, or an aluminum alloy sheet. aluminum of the 5000 series of grade 5083. As a variant, the cap could have other diameters, and / or other heights, and / or other bottom wall thicknesses 21, and / or other side wall thicknesses 31.

EXAMPLES

Tests were carried out with two prototypes in alloy 6082 (PR21 and PR22) (28 cm diameter stove, made of 6082 alloy, corresponding to the embodiment of FIG. 5, with a side wall thickness of 2 mm, a bottom wall thickness of 6 mm, a side wall height of 55 mm, a bottom diameter of 225 mm, and a perforated stainless steel grid diameter of 225 mm, shown in Figure 6).

The reference culinary item used is the P028GCBV Expertise pan (28 cm diameter pan Grand Chef Pouring edge, made of alloy 4006, corresponding to the embodiment of Figure 3, with a side wall thickness of 3 mm, a bottom wall thickness of 4.5 mm, a side wall height of 55 mm, a bottom diameter of 210 mm, and a perforated stainless steel grid diameter of 205 mm, shown in Figure 4).

The two grids have an identical central part, the difference in diameter corresponds to a non-perforated outer ring.

PREHEATING TEST

The preheating tests were carried out on an induction hob.

The preheating test consists of placing the empty pan on the heating medium. Once one of the points of the article reaches 180 ° C., the maximum temperature difference between two points on the bottom is measured in order to quantify the criterion of homogeneity. The preheating time corresponds to the time required for a point to reach 180 ° C.

[Table 5]

PRE HEATING TEST

Calculation of the difference in T ° max - min on the cooking surface when T "max = 180” C

Note that increasing the bottom wall / side wall ratio improves the homogeneity of the cookware while reducing its weight.

EGG WHITE TEST

Egg white tests were performed on several induction hobs

(characteristics described in the table below).

This cooking test consists of recording the time required for the coagulation of 150g of egg white to spread over 100% of the cooking surface of the pan. To do this, we pour beaten egg whites in a cold pan. The heating medium is started and then the coagulation percentage is observed after stopping the cooking and rinsing the non-coagulated part of the egg whites under water. The operation is repeated, increasing the cooking time by 10 seconds, until the egg whites have completely coagulated.

The increase in the thickness ratio relative to the standard thus makes it possible to significantly reduce this cooking time while reducing the weight of the culinary article.

[Table 6]

Other tests were carried out with two prototypes in 5754 alloy and with two prototypes in 5083 alloy (28 cm diameter stove, corresponding to the embodiment of Figure 5, with a side wall thickness of 1.9 mm or of 1 mm, a bottom wall thickness of 4.5 mm or 8 mm, a side wall height of 55 mm, a bottom diameter of 225 mm, and a perforated stainless steel grid diameter of 205 mm, shown on figure 4). The reference culinary article used is also the P028GCBV Expertise pan (pan with a diameter of 28 cm Grand Chef Pouring edge, made of alloy 4006, corresponding to the embodiment of Figure 3, with a side wall thickness of 3 mm, a bottom wall thickness of 4.5 mm, a side wall height of 55 mm, a bottom diameter of 210 mm, and a perforated stainless steel grid diameter of 205 mm, shown in Figure 4).

PREHEATING TEST

The preheating tests were carried out on an induction hob under the same conditions as the previous test, except for the average power of around 2000 W instead of 2200W. [Table 7]

PRE HEATING TEST

Calculation of the difference in T ° max - min on the cooking surface when T ° max = 180 ° C

For a given alloy, we note that increasing the bottom wall / side wall ratio improves the homogeneity of heating of the cookware. It is also noted that with the 5000 series alloys a better heating homogeneity than that of the reference cookware can be obtained, by using a higher bottom wall / side wall ratio.

Claims

1. Cookware (1) comprising a metallic cap (2) having a bottom wall (21) and a side wall (31) rising around the bottom wall (21), said bottom wall (21) having an internal face (211) intended for cooking food and an external face (212) intended to be placed near a heat source, characterized in that said cap (2) is an aluminum alloy sheet stamped or flow-turned of the 6000 series or of the 5000 series and in that the bottom wall (21) has a thickness at least 2 times greater than that of the side wall (31), preferably at least 2.5 times greater to that of the side wall (31).

2. Cookware according to claim 1, characterized in that the bottom wall (21) has a thickness less than or equal to 15 times that of the side wall (31), preferably less than or equal to 13.5 times that of the side wall (31).

3. Cookware according to one of claims 1 or 2, characterized in that the inner face (211) is partially or fully coated with a PTFE, or ceramic, or sol-gel coating.

4. Cookware according to one of claims 1 to 3, characterized in that the outer face (212) is partially or entirely coated with an enamel coating, or PTFE, or ceramic, or sol-gel.

5. Cookware according to one of claims 1 to 4, characterized in that a metal insert (4) is attached to the outer face (212).

6. Cookware according to claim 5, characterized in that the insert

metal (4) is formed by a grid.

7. Cookware according to one of claims 5 or 6, characterized in that the metal insert (4) is made of ferromagnetic material.

8. Cookware according to any one of claims 5 to 7, characterized in that it is compatible with induction heating.

9. Cookware according to any one of claims 1 to 8, characterized in that the cap (2) has a diameter / height ratio of less than 0.5, and preferably less than 0.3.

10. Cookware according to any one of claims 1 to 9, characterized in that the cap (2) has a diameter / height ratio between 0.5 and 0.1, and preferably between 0.3 and 0 , 1.

11. A method of manufacturing a cookware according to any of the

claims 1 to 10 comprising the following steps:

- Provide an aluminum alloy sheet of 6000 series or 5000 series,

- Optionally bring on the outer face (212) a metal insert (4),

- Stamping or spinning said cap-shaped sheet (2) having a bottom wall (21) and a side wall (31) rising around the bottom wall (21), the bottom wall (21) having a thickness at least 2 times greater than that of the side wall (31), preferably at least 2.5 times greater than that of the side wall (31),

- Optionally apply on the internal face (211) partially or entirely a PTFE coating, or ceramic, or sol-gel,

- Optionally apply to the external face (212) partially or entirely an enamel, PTFE, ceramic, or sol-gel coating.

12. Use of a metallic cap (2) in the form of an alloy sheet

of stamped or flow-turned aluminum of the 6000 series or of the 5000 series, said cap (2) having a bottom wall (21) and a side wall (31) rising around the bottom wall (21), the bottom wall (21) having a thickness at least 2 times greater than that of the side wall (31), preferably at least 2.5 times greater than that of the side wall (31), to improve the preheating time d 'a cookware (1) according to one of claims 1 to 10.