Method for Obtaining a Cooking Vessel Having a Colored, Hard, Anodized Outer Surface

Abstract

Provided is a method for obtaining a cooking vessel that includes the following steps: producing a bowl having an aluminum outer surface and an inner surface; performing hard anodization of at least the outer surface of the bowl; and providing a sol-gel coating on the anodized outer surface. At least one coloring step is carried out following the hard anodization, the coloring step(s) being carried out before and / or during the sol-gel coating step. Also provided is a kitchen item or an electrical cooking appliance that includes a cooking vessel obtained by the above method.

Description

CROSS REFERENCE TO RELATED APPLICATIONS[0001]This application is a divisional of U.S. patent application Ser. No. 13 / 885,785, filed Nov. 18, 2011, entitled “Method for Obtaining a Cooking Vessel Having a Colored, Hard, Anodized Outer Surface”, which is the National Stage Entry of PCT / FR2011 / 052690, filed Nov. 18, 2011, which claims priority to French Patent Application No. 1059522, filed Nov. 19, 2010, which are all incorporated herein by reference in their entirety.FIELD OF THE INVENTION[0002]The present invention relates to the technical field of cooking appliances and utensils comprising a cooking vessel.[0003]The present invention relates more particularly, but not exclusively, to kitchen items such as casseroles, skillets, or woks, and also to electric cooking appliances comprising a bowl designed for containing foods.BACKGROUND OF THE INVENTION[0004]Document GB 1 099 486 discloses the production of aluminum cooking vessels having a hard, anodized surface layer. This surface la...

AI Technical Summary

Benefits of technology

[0016]These arrangements make it possible to protect the pigments and / or dyes used in the coloring step or steps by trapping them in the hard anodized layer and / or in the sol-gel coating. A durable coloring is thus obtainable.

[0018]According to another embodiment, the sol-gel coating step employs inorganic pigments and / or organic pigments and / or organic dyes for coloring purposes. A trapping of the pigments and / or the dyes in the sol-gel coating is thus achievable.

[0020]According to one embodiment then, the step of performing a hard anodization of the outer surface of the bowl is carried out following the step of providing a PTFE coating on the inner surface of the bowl. The anodization performed following the PTFE coating has the advantage of only anodizing the outer surface of the bowl, thus making it possible to reduce the treatment time and to lower the consumption of current and acid compared to the anodization of the outer surface and of the inner surface of the bowl. Furthermore, PTFE effectively withstands the sulfuric acid bath typically employed to perform the anodization. The coloring performed following the PTFE coating and hard anodization steps allows the use of a broader selection of pigments and / or dyes, in particular organic pigments and / or dyes, as lower temperatures are used for the provision of the sol-gel coating than for the provision of the PTFE coating.

[0021]The method optionally comprises a step of performing a preliminary hard anodization of the outer surface and of the inner surface of the bowl prior to the step of providing a PTFE coating on the inner surface of the bowl, the step of performing hard anodization of the outer surface of the bowl being carried out following a step of pickling the outer surface of the bowl subsequent to the step of providing a PTFE coating on the inner surface of the bowl. This preliminary hard anodization treatment involves the inner surface and the outer surface of the bowl and makes it possible to obtain a hard base prior to the provision of the PTFE coating.

[0022]According to another embodiment, the step of performing a hard anodization of the outer surface of the bowl is carried out prior to the step of providing a PTFE coating on the inner surface of the bowl. This hard anodization treatment involves the inner surface and the outer surface of the bowl and makes it possible to obtain a hard base prior to providing the PTFE coating. Compared to a preliminary hard anodization treatment followed by a hard anodization of the outer surface after the provision of the PTFE coating, the proposed method enables the number of steps to be reduced, but imposes the use of pigments or dyes capable of resisting the temperatures encountered during the provision of the PTFE coating, namely inorganic pigments. The choice of colors is then reduced further.

Problems solved by technology

Nevertheless the surface thus obtained is not as easy to clean as a surface coated with a non-stick layer.

Typically, the PTFE coating is mainly used to coat the inside surface of cooking vessels, owing to the limited mechanical resistance of this type of coating.

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