Method for Obtaining a Cooking Vessel Having a Colored Hard-Anodized Outer Face

Abstract

Provided is a method for obtaining a cooking vessel comprising the following steps: producing a container having an aluminium outer face and an inner face, carrying out hard anodization of at least the outer face of the container. At least one colouring step is carried out on the anodized outer face following hard anodization, said colouring step employing at least one water-soluble anthraquinone organic dye. Also provided is a culinary article or an electric cooking appliance comprising a cooking vessel obtained by the above method.

Description

CROSS-REFERENCE TO RELATED APPLICATIONS[0001]This application is a continuation of U.S. patent application Ser. No. 14 / 382,699 which is the United States national phase of International Application No. PCT / FR2013 / 050460 filed Mar. 4, 2013, and claims priority to French Patent Application No. 1252086 filed Mar. 7, 2012, the disclosures of which are hereby incorporated in their entirety by reference.FIELD OF THE INVENTION[0002]This invention pertains to the technical field of cooking appliances and utensils with a cooking vessel.[0003]This invention pertains more specifically, but not exclusively, to culinary items such as saucepans, frying pans and woks, as well as electric cooking appliances with a container for holding food.DESCRIPTION OF RELATED ART[0004]There is a known method, as described in Document GB 1 099 486, of producing cooking vessels made of aluminum with a hard-anodized layer on the surface. This surface layer may, if desired, be colored. The surface thus obtained is ...

AI Technical Summary

Benefits of technology

[0013]Performance of hard anodization on at least the exterior surface of the container, in which at least one coloring step is performed on the anodized exterior surface after hard anodization has been performed, said coloring step using at least one water-soluble anthraquinone organic dye. Surprisingly, testing has shown that coloring the anodized exterior surface of a cooking vessel, when done in this way, results in durability, even when the cooking vessel is exposed to flame, without requiring a protective layer such as a sol-gel, varnish, lacquer or PTFE coating.

[0014]According to one advantageous method of implementation, the coloring step uses an immersion in an aqueous solution of one or more water-soluble anthraquinone organic compound(s). The use of organic solvents can thus be avoided.

[0016]Thus, according to one method of implementation, the process includes a step in which a PTFE coating is applied to the interior surface of the container, and the step in which the exterior surface of the container is hard anodized occurs after the step in which the PTFE coating is applied to the interior surface of the container. The anodization performed after the PTFE coating offers the advantage of anodizing only the exterior surface of the container, which shortens the processing time, and decreases the consumption of electricity and acid as compared to the anodization of the exterior surface and the interior surface of the container. Moreover, PTFE supports the sulfuric acid bath usually used in anodization quite well.

Problems solved by technology

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

Ordinarily, the PTFE coating is used primarily to coat the interior surface of cooking vessels, due to the limited mechanical durability of this type of coating.

One disadvantage of the production method described resides in the complexity of the process implemented, which requires many steps.

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