U.S. patent application number 10/539442 was filed with the patent office on 2006-07-13 for easy-to-clean cooking surface.
Invention is credited to Alain Coudurier.
Application Number | 20060150824 10/539442 |
Document ID | / |
Family ID | 32406229 |
Filed Date | 2006-07-13 |
United States Patent
Application |
20060150824 |
Kind Code |
A1 |
Coudurier; Alain |
July 13, 2006 |
Easy-to-clean cooking surface
Abstract
The invention concerns a food cooking surface for a kitchen
utensil or a cooking appliance, characterized in that said cooking
surface is made of a metal alloy of zirconium and of at least
another metal, and whereof the zirconium content is not less than
75%. In accordance with one embodiment of the invention, the alloy
contains less than 10% of elements added to zirconium.
Inventors: |
Coudurier; Alain; (Albens,
FR) |
Correspondence
Address: |
BROWDY AND NEIMARK, P.L.L.C.;624 NINTH STREET, NW
SUITE 300
WASHINGTON
DC
20001-5303
US
|
Family ID: |
32406229 |
Appl. No.: |
10/539442 |
Filed: |
December 17, 2003 |
PCT Filed: |
December 17, 2003 |
PCT NO: |
PCT/FR03/03774 |
371 Date: |
June 20, 2005 |
Current U.S.
Class: |
99/324 |
Current CPC
Class: |
A47J 36/025 20130101;
Y10T 428/12806 20150115; A47J 36/02 20130101 |
Class at
Publication: |
099/324 |
International
Class: |
A21B 3/13 20060101
A21B003/13 |
Foreign Application Data
Date |
Code |
Application Number |
Dec 20, 2002 |
FR |
02/16231 |
Claims
1. Food cooking surface for kitchen utensil or cooking appliance,
characterized in that this cooking surface is a metal alloy of
zirconium and at least one other metal, and the zirconium content
of which is at least 75%.
2. Food cooking surface for kitchen utensil or cooking appliance
according to claim 1, characterized in that the alloy contains less
than 10% of elements in addition to the zirconium.
3. Food cooking surface for kitchen utensil or cooking appliance
according to claim 2, characterized in that it is obtained by the
deposit of a selected thickness of metallic material on a
substrate.
4. Food cooking surface for kitchen utensil or cooking appliance
according to claim 3, characterized in that the deposit is carried
out by cathode sputtering of a massive target.
5. Food cooking surface for kitchen utensil or cooking appliance
according to claim 4, characterized in that the target is obtained
by assembly on a copper substrate of one or more sheets or plates
of material having the desired composition, said sheets or plates
being obtained either by powder sintering or thermal powder
projection, or resulting from casting.
6. Food cooking surface for kitchen utensil or cooking appliance
according to claim 2, characterized in that it is obtained by
assembly of a crystalline metal sheet on a substrate.
7. Food cooking surface for kitchen utensil or cooking appliance
according to claim 6, characterized in that the sheet is obtained
by rolling of an ingot resulting from melting of a mixture of
metals.
8. Food cooking surface for kitchen utensil or cooking appliance
according to claim 7, characterized in that the assembly is carried
out by one of the following techniques: colaminating, brazing, hot
striking.
9. Food cooking surface for kitchen utensil or cooking appliance
according to claim 8, characterized in that the sheet and the
substrate undergo, after assembly, a step of working by
stamping.
10. Food cooking surface for kitchen utensil or cooking appliance
according to claim 9, characterized in that the substrate is
composed of one or more metal sheet(s) of the following materials:
aluminum, stainless steel, cast iron, steel, copper.
11. Food cooking surface for kitchen utensil or cooking appliance
according to claim 8, characterized in that the substrate is
composed of one or more metal sheet(s) of the following materials:
aluminum, stainless steel, cast iron, steel, copper.
12. Food cooking surface for kitchen utensil or cooking appliance
according to claim 8, characterized in that the sheet and the
substrate undergo, after assembly, a step of working by
stamping.
13. Food cooking surface for kitchen utensil or cooking appliance
according to claim 7, characterized in that the sheet and the
substrate undergo, after assembly, a step of working by
stamping.
14. Food cooking surface for kitchen utensil or cooking appliance
according to claim 7, characterized in that the substrate is
composed of one or more metal sheet(s) of the following materials:
aluminum, stainless steel, cast iron, steel, copper.
15. Food cooking surface for kitchen utensil or cooking appliance
according to claim 6, characterized in that the assembly is carried
out by one of the following techniques: colaminating, brazing, hot
striking.
16. Food cooking surface for kitchen utensil or cooking appliance
according to claim 6, characterized in that the sheet and the
substrate undergo, after assembly, a step of working by
stamping.
17. Food cooking surface for kitchen utensil or cooking appliance
according to claim 6, characterized in that the substrate is
composed of one or more metal sheet(s) of the following materials:
aluminum, stainless steel, cast iron, steel, copper.
18. Food cooking surface for kitchen utensil or cooking appliance
according to claim 5, characterized in that the substrate is
composed of one or more metal sheet(s) of the following materials:
aluminum, stainless steel, cast iron, steel, copper.
19. Food cooking surface for kitchen utensil or cooking appliance
according to claim 4, characterized in that the substrate is
composed of one or more metal sheet(s) of the following materials:
aluminum, stainless steel, cast iron, steel, copper.
20. Food cooking surface for kitchen utensil or cooking appliance
according to claim 2, characterized in that the substrate is
composed of one or more metal sheet(s) of the following materials:
aluminum, stainless steel, cast iron, steel, copper.
21. Food cooking surface for kitchen utensil or cooking appliance
according to claim 1, characterized in that it is obtained by the
deposit of a selected thickness of metallic material on a
substrate.
22. Food cooking surface for kitchen utensil or cooking appliance
according to claim 1, characterized in that it is obtained by
assembly of a crystalline metal sheet on a substrate.
23. A kitchen utensil or cooking appliance having a food contacting
surface constituted by the surface defined in claim 1.
Description
[0001] The present invention relates to the field of articles
intended for the preparation and the cooking of food and more
particularly the cooking surface of these articles in contact with
food to be treated.
[0002] For many years, significant efforts have been developed in
order to facilitate the daily preparation of meals. Among the
notable progress, coatings based on fluorocarbonated polymers as
adhesive coating in kitchen utensils quickly developed since the
end of the 1950's. Such coatings is universally known since the
process presented in the patent FR 1120749 allowed a reliable
attachment of such coatings on various metals, such as
aluminum.
[0003] However, such coatings remain fragile. Thus, clever ways
were developed in order to mechanically reinforce the layer on its
support. Many improvement patents describe methods and means
allowing the scratch resistance of such coatings to be increased,
by acting on the coating and/or the substrate. Despite everything,
such coatings remain sensitive to the repeated use of sharpened or
pointed metallic materials, such as knives or forks.
[0004] In parallel, developments were carried out on mechanically
resistant surfaces on which attempts were made to improve the ease
of cleaning. Metal deposition, such chromium plating on stainless
steel, quasi-crystals, or nonmetallics (silicates, . . . ) thus
appeared.
[0005] Quasi-crystals are a phase or metal compound presenting, at
the crystallographic level, symmetries of axial rotation of the
order of 5, 8, 10 or 12, like the isocahedral and decagonal phases.
Such coatings are in particular described in the patent EP 0 356
287 and have the qualities of scratch resistance, even of
anti-adherence in certain cases.
[0006] The present invention aims at remedying the above mentioned
disadvantages of the prior art, by offering a cooking surface with
improved characteristics of ease of cleaning, of corrosion
resistance, while having a good mechanical resistance.
[0007] The present invention is achieved by a food cooking surface
for a kitchen utensil or cooking apparatus, characterized in that
this cooking surface is a metal alloy of zirconium and at least one
other metal, and the zirconium content of which is at least
75%.
[0008] Metal alloys based on zirconium, such as zircaloys, are
generally known for their exceptional resistance to corrosion, and
their good mechanical resistance to continuous neutronic exposure,
while remaining transparent to thermal neutrons. They are primarily
used in the nuclear industry as an envelope for uranium oxide fuel
bars. Such alloys comprise primarily zirconium with some alloy
elements such as tin, iron, chromium and nickel.
[0009] Surprisingly, it was noted, during tests, that alloys of a
plurality of metals and containing a majority of zirconium, also
presented properties of ease of cleaning when such surfaces were
used as a cooking surface and that foodstuffs remained attached to
the surface, for example after a calcination of the products that
were cooked. This ease of cleaning can be expressed by the
possibility of easily removing elements carbonized on the cooking
surface.
[0010] Advantageously, the alloy contains less than 10% of elements
in addition to zirconium.
[0011] Such materials, of which the alloys termed zircaloys form
part, are more easily obtaining because the crystallization
conditions are less disturbed by alloy elements in small
amounts.
[0012] According to a first mode of implementing the invention, the
food cooking surface for a kitchen utensil or a cooking appliance
is obtained by depositing a suitable thickness of metallic material
on a substrate. This deposition can be carried out by one or the
other of the following processes: thermal projection of a powder of
an adequate granulometry, deposition by electrophoresis of a micro
or submicronic powder, cathode sputtering of a massive target. In
this last case the target can be obtained by assembly on a copper
substrate of one or more sheets or material plates having the
desired composition, the aforementioned sheets or plates being
obtained either by powder sintering or thermal projection of
powder, or resulting from casting. Generally, all the techniques of
physical vapor deposition can be used. Other techniques, such as
hot compaction or electrolytic deposition also can be used.
[0013] This implementation has the advantage of using a small
amount of material and of being able to regulate a low thickness of
material on the substrate in order to produce the cooking
surface.
[0014] All these techniques make it possible, in addition, to
obtain deposits having strong cohesion with the substrate on which
they are deposited. The risks of separation of the deposit during
use are thus minimized.
[0015] According to a second mode of implementation of the
invention, the food cooking surface for a kitchen utensil or a
cooking appliance is obtained by assembly of a crystalline metal
sheet having the desired composition on a substrate. This
implementation has the advantage of approaching the known
implementations of assembly of metals, which makes it possible to
be able to adapt known techniques without significant specific
development.
[0016] The zirconium alloy sheets can be obtained by techniques
known in metallurgy, such rolling of an ingot resulting from
melting of a mixture of metals.
[0017] The assembly of the sheet on the substrate can be carried
out by one of the following techniques: colaminating, brazing, hot
striking, in a way known per se. Plating by explosion also can be
considered.
[0018] Advantageously, the sheet and the substrate undergo, after
assembly, a stage of working by stamping. The substrate can be
composed of one or several metal sheet(s) of the following
materials: aluminum, stainless steel, cast iron, steel, copper.
[0019] Other advantages resulting from the tests will appear from
reading the description which will follow, in relation to an
illustrative example of the present invention given as a
nonlimiting example.
[0020] The example of realization of the invention relates to a
deposition by PVD, of an alloy called zircaloy 2 (1.5% of tin,
0.14% of iron, 0.10% of chromium and 0.05% of nickel) on stainless
steel. One face of this deposit underwent an extensive polishing,
close to optical polishing, before the performance of tests, in
order to make it comparable with other cooking surfaces so that the
tests for evaluation of the ease of cleaning such a surface, in a
domestic cooking use, can be compared.
[0021] The system for evaluation of the ease of cleaning makes it
possible to quantify the capabilities of a cooking surface to
return to its original aspect after use. This evaluation system
comprises the following steps: [0022] the surface is locally
covered with a food mixture of known composition, [0023] this
mixture is carbonized in an oven under defined conditions, for
example 210.degree. C. during 20 minutes, [0024] after cooling,
surface is put to soak during a controlled time in a mixture of
water and of detergent, [0025] an abrasive pad is then applied
under a defined constraint using an abrading apparatus (plynometer)
on the soiled surface in a back and forth movement during a given
number of cycles, [0026] the percentage of correctly cleaned
surface is noted and characterizes the ease of cleaning of the
cooking surface.
[0027] The tests carried out on various types of surface thus make
it possible to comparatively evaluate the quality of surfaces as to
their ease of cleaning.
[0028] Of course, the tests are carried out by respecting the same
parameters for each step of the evaluation system: same food
mixture, same surface of application the food mixture, same
carbonization temperature, . . .
[0029] The following comparative table shows the results obtained
on three different cooking surfaces, namely polished stainless
steel, quasi-crystals, and the zircaloy 2 alloy deposited on
stainless steel such as previously described, after polishing, in a
severe test with a food composition based on milk and rice
considered to be difficult to clean once carbonized. Such a test
thus makes it possible to highlight well the differences between
the cleaning quality of the surfaces. TABLE-US-00001 polished
polished Zircaloy 2 stainless Quasi- on stainless steel crystals
steel Quantity of 30% 40% 80% carbonized residue removed
[0030] The table shows without ambiguity the very interesting
results obtained with the alloy zircaloy 2 deposited on stainless
steel. Other tests led on an aluminum base show similar
results.
[0031] It is to be noted that the number of abrasion cycles on the
plynometer was fixed at 15. This small number of cycles highlights
well the quality of ease of cleaning of the surface according to
the invention since there remains no more than 20% of the surface
soiled after 15 back and forth passes of the abrasive pad.
[0032] Repetitive tests after complete cleaning of the surface show
that the ease of cleaning of the alloy presented is not
altered.
[0033] Advantageously, during the deposition process, nitriding of
the layer is carried out by the addition of nitrogen. Such a
nitriding also can be envisioned during a development of the
different layer, by an appropriate heat treatment following
development of said layer. Such a nitriding makes it possible to
increase the hardness of the layer, which confers on the cooking
surface a better abrasion resistance.
[0034] Other techniques of heat treatment can be employed to
increase the hardness of the alloy. For the zircaloy alloys, one
can use the water quenching/tempering from the field b. One can
also use solid phase tempering by laser or equivalent.
[0035] When the implementation of the invention implies the use of
a substrate, the latter is then composed of one or more metal
sheet(s) of the following materials: aluminum, stainless steel,
cast iron, steel, copper. However, the present invention is not
limited to the realization of a layer small thickness of a
crystalline metal compound such as previously described, deposited
or assembled on a thick substrate, but also aims at the realization
of massive material, with or without a substrate, the latter, when
it is present, not having a role of mechanical support for the
layer, but assuring another function, such as the thermal
distribution of heat for a utensil placed on a heat source (frying
pan, sauce pans . . . ).
* * * * *