Cooking appliance and method for preparing the same

Abstract

The present application relates to a cooking utensil and a method for preparing the same. The cooking utensil comprises a pot body, at least a portion of the surface of the pot body being provided with a non-stick coating, the non-stick coating comprising a composite non-stick coating comprising a fluoropolymer and a coating layer coated on the surface of the fluoropolymer, the coating layer being made of a conductive metal. The composite non-stick coating of the present application comprises a fluoropolymer and a conductive metal coating layer coated on the surface of the fluoropolymer, wherein the presence of the fluoropolymer can improve the non-stick properties of the non-stick coating while also having certain high and low temperature resistance properties. The conductive metal has high hardness, low friction coefficient, high heat transfer effect, and excellent corrosion resistance. The conductive metal is coated on the surface of the fluoropolymer as the non-stick coating of the pot body, so that the non-stick coating has high hardness, good wear resistance, and excellent non-stick properties, thereby improving the performance stability of the cooking utensil.

Description

Technical Field

[0001] The present invention relates to the technical field of utensils, and in particular to a cooking utensil and a preparation method thereof. Background Art

[0002] In the cookware industry, stainless steel is widely used for its hardness, wear resistance, and stable surface properties. However, stainless steel surfaces lack the ability to prevent food from sticking (e.g., eggs) and have poor resistance to high-temperature discoloration (e.g., oxidation and discoloration). When temperatures exceed 250°C, the surface begins to yellow, and the higher the temperature, the more severe the yellowing. These factors negatively impact the product's appearance and customer experience.

[0003] In the prior art, chemical coatings are often sprayed onto the surface of cooking utensils to achieve a non-stick finish. However, existing chemical coatings, primarily composed of fluorocarbon resins and siloxane sol condensation polymers, have the disadvantage of low hardness (2H-8H) and poor wear resistance when applied to the inner surface of the cookware.

[0004] Therefore, there is an urgent need for a cooking utensil that has long-lasting non-stick properties, wear resistance, and high hardness. Summary of the Invention

[0005] In order to overcome the above-mentioned defects, the present application provides a cooking utensil and a preparation method thereof. The cooking utensil has the advantages of non-stickiness in oil storage, wear resistance and high hardness, which can improve the comprehensive performance of the cooking utensil.

[0006] In a first aspect, an embodiment of the present application provides a cooking utensil, comprising a pot body, wherein at least a portion of the surface of the pot body is provided with a non-stick coating, wherein the non-stick coating comprises a composite non-stick coating, wherein the composite non-stick coating comprises a fluoropolymer and a coating layer covered on the surface of the fluoropolymer, wherein the material of the coating layer comprises a conductive metal.

[0007] In the above technical solution, the composite non-stick coating of the present application includes a fluoropolymer and a conductive metal coating layer coated on the surface of the fluoropolymer. The presence of the fluoropolymer can improve the non-stick performance of the non-stick coating while having certain high-temperature resistance and low-temperature resistance. The conductive metal has strong hardness, low friction coefficient, high heat transfer effect and excellent corrosion resistance. It is coated on the surface of the fluoropolymer and together with the fluoropolymer serves as a non-stick coating for the pot body, so that the non-stick coating has high hardness, good wear resistance and excellent non-stick performance, thereby improving the performance stability of the cooking utensil.

[0008] In some embodiments, the volume ratio of the fluorine-containing polymer to the coating layer is (5-10):1.

[0009] In some embodiments, the particle size of the fluorine-containing polymer is 3 μm to 70 μm.

[0010] In some embodiments, the volume proportion of the fluorine-containing polymer with a particle size of 50 μm to 70 μm in the total fluorine-containing polymer is 50% to 65%.

[0011] In some embodiments, the volume proportion of the fluorine-containing polymer with a particle size of 20 μm to 50 μm in the total fluorine-containing polymer is 25% to 30%.

[0012] In some embodiments, the volume proportion of the fluorine-containing polymer with a particle size of 3 μm to 20 μm in the total fluorine-containing polymer is 10% to 20%.

[0013] In some embodiments, the fluorine-containing polymer includes at least one of polytetrafluoroethylene, ammonium perfluorooctanoate, a copolymer of perfluoropropyl perfluorovinyl ether and polytetrafluoroethylene, a polyperfluoroethylene-propylene copolymer, and an ethylene-tetrafluoroethylene copolymer.

[0014] In some embodiments, the conductive metal is made of at least one of aluminum, stainless steel, and iron.

[0015] In some embodiments, the material of the pot body includes at least one of aluminum alloy, aluminum, stainless steel, iron and low carbon steel.

[0016] In some embodiments, the material of the pot body is the same as the material of the conductive metal wire.

[0017] In some embodiments, the particle size of the composite non-stick coating is 3 μm to 70 μm.

[0018] In some embodiments, the non-stick coating has a thickness of 100 μm to 200 μm.

[0019] In some embodiments, the cooking utensil has a hardness of 100 HV to 200 HV.

[0020] In some embodiments, the surface porosity of the cooking utensil is 3% to 15%.

[0021] In some embodiments, the inner surface roughness of the cooking utensil is 5 μm to 12 μm.

[0022] In a second aspect, an embodiment of the present application provides a method for preparing a cooking utensil, comprising the following steps:

[0023] Providing a conductive metal strip, winding the conductive metal strip into a cylindrical shape, and spinning the cylindrical conductive metal strip into a tubular wire or a quasi-tubular wire. During the spinning process, polyfluorinated compound powder is injected to obtain a composite non-stick coating, wherein the composite non-stick coating includes a fluoropolymer and a coating layer covering the surface of the fluoropolymer, wherein the coating layer is a conductive metal wire.

[0024] The base material is stretched and formed into a pot body having a cooking cavity;

[0025] The composite non-stick coating is coated on the inner surface of the pot body, and the inner surface of the pot body is heat-treated to obtain a cooking utensil.

[0026] In the above technical solution, the present application injects polyfluoride compound powder into the metal strip during the wire-forming process, so that the metal strip is transformed into a tubular body or a quasi-tubular body, and polyfluoride compound powder is distributed inside the tubular body or the quasi-tubular body, thereby obtaining a composite non-stick coating. The composite non-stick coating includes a fluoropolymer and a coating layer covered on the surface of the fluoropolymer, and the coating layer is a conductive metal wire. The above-mentioned composite non-stick coating is coated on the inner surface of the pot body and subjected to heat treatment to obtain a cooking utensil. During the heat treatment process, on the one hand, the heat treatment can enhance the bonding force between the conductive metal wire in the composite non-stick material and the pot body, thereby enhancing the bonding force between the non-stick coating and the pot body; on the other hand, the heat treatment can improve the hardness, corrosion resistance and wear resistance of the non-stick coating. The preparation method of the present application is simple in process, and the cooking utensil prepared therefrom not only has good non-stick performance, but also has excellent hardness and wear resistance, thereby improving the performance stability of the cooking utensil.

[0027] In some embodiments, the fluorine-containing polymer includes at least one of polytetrafluoroethylene, ammonium perfluorooctanoate, a copolymer of perfluoropropyl perfluorovinyl ether and polytetrafluoroethylene, a polyperfluoroethylene-propylene copolymer, and an ethylene-tetrafluoroethylene copolymer.

[0028] In some embodiments, the conductive metal strip includes at least one of an aluminum strip, a stainless steel strip, and an iron strip.

[0029] In some embodiments, the volume ratio of the fluorine-containing polymer to the coating layer is (5-10):1.

[0030] In some embodiments, the particle size of the fluorine-containing polymer is 3 μm to 70 μm.

[0031] In some embodiments, the particle size of the fluorine-containing polymer is 3 μm to 70 μm, and the volume proportion of the fluorine-containing polymer with a particle size of 50 μm to 70 μm in the total fluorine-containing polymer is 50% to 65%.

[0032] In some embodiments, the particle size of the fluorine-containing polymer is 3 μm to 70 μm, and the volume proportion of the fluorine-containing polymer with a particle size of 20 μm to 50 μm in the total fluorine-containing polymer is 25% to 30%.

[0033] In some embodiments, the particle size of the fluorine-containing polymer is 3 μm to 70 μm, and the volume proportion of the fluorine-containing polymer with a particle size of 3 μm to 20 μm in the total fluorine-containing polymer is 10% to 20%.

[0034] In some embodiments, the material of the pot body includes at least one of aluminum alloy, aluminum, stainless steel, iron and low carbon steel.

[0035] In some embodiments, the diameter of the filament is 0.8 mm to 2.0 mm.

[0036] In some embodiments, the heat treatment temperature is 380°C to 400°C.

[0037] In some embodiments, the heat treatment time is 5 min to 10 min.

[0038] In some embodiments, the heat treatment is performed in an inert gas atmosphere.

[0039] The technical solution of the present application has at least the following beneficial effects: the composite non-stick coating of the present application includes a fluoropolymer and a conductive metal coating layer coated on the surface of the fluoropolymer, wherein the presence of the fluoropolymer can improve the non-stick performance of the non-stick coating, while having certain high-temperature resistance and low-temperature resistance; the conductive metal has strong hardness, low friction coefficient, high heat transfer effect and excellent corrosion resistance. It is coated on the surface of the fluoropolymer and together with the fluoropolymer serves as a non-stick coating for the pot body, so that the non-stick coating has high hardness, good wear resistance and excellent non-stick performance, thereby improving the performance stability of the cooking appliance. BRIEF DESCRIPTION OF THE DRAWINGS

[0040] The present invention will be further described below with reference to the accompanying drawings and examples.

[0041] Figure 1 This is a flow chart for preparing the cooking utensil of this application. DETAILED DESCRIPTION

[0042] In order to better understand the technical solution of the present invention, the embodiments of the present invention are described in detail below with reference to the accompanying drawings.

[0043] It should be understood that the embodiments described are only a portion of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by persons of ordinary skill in the art without creative work are within the scope of protection of the present invention.

[0044] The terms used in the embodiments of the present invention are only for the purpose of describing specific embodiments and are not intended to limit the present invention. The singular forms "a", "an", "the" and "the" used in the embodiments of the present invention and the appended claims are also intended to include plural forms unless the context clearly indicates otherwise.

[0045] It should be understood that the term "and / or" as used herein is merely a description of the relationship between associated objects, indicating that three possible relationships exist. For example, "A and / or B" can represent: A exists alone, A and B exist simultaneously, or B exists alone. Furthermore, the character " / " in this document generally indicates that the associated objects are in an "or" relationship.

[0046] An embodiment of the present application provides a cooking utensil, which includes a pot body, at least a portion of the surface of the pot body is provided with a non-stick coating, the non-stick coating includes a composite non-stick coating, the composite non-stick coating includes a fluoropolymer and a coating layer covered on the surface of the fluoropolymer, and the material of the coating layer includes a conductive metal.

[0047] In the above technical solution, the composite non-stick coating has a core-shell structure. Specifically, the composite non-stick coating includes a fluoropolymer and a conductive metal coating layer coated on the surface of the fluoropolymer. The presence of the fluoropolymer can improve the non-stick performance of the non-stick coating while having certain high and low temperature resistance. The conductive metal has strong hardness, low friction coefficient, high heat transfer effect and excellent corrosion resistance. It is coated on the surface of the fluoropolymer and together with the fluoropolymer serves as the non-stick coating of the pot body, so that the non-stick coating has high hardness, good wear resistance and excellent non-stick performance, thereby improving the performance stability of the cooking utensil.

[0048] In the present application, fluorine atoms are present in fluorine-containing polymers, which have low polarity and smooth surface properties, and are non-stick and smooth. In addition, due to the special physical constants of fluorine atoms and the helical structure of the three-dimensional arrangement of fluorine atoms, the heat resistance, chemical corrosion resistance, and resistance to photochemical degradation of fluorine-containing polymers are also very outstanding. Conductive metals have high heat transfer coefficients, hardness, and corrosion resistance. Applying them to non-stick coatings can effectively improve the use effect and service life of cooking utensils. The present application combines fluorine-containing polymers and conductive metals as raw materials for non-stick coatings, and the conductive metal is on the surface of the cooking utensils, which can make the cooking utensils have the advantages of oil storage, non-stickiness, wear resistance, and high hardness.

[0049] In some embodiments, the volume ratio of the fluoropolymer to the coating layer is (5-10):1. Specifically, the volume ratio of the fluoropolymer to the coating layer can be 5:1, 6:1, 7:1, 8:1, 9:1, and 10:1, etc., and other values within the above range are also possible and are not limited here. If the volume ratio of the fluoropolymer to the coating layer is less than 5:1, the metal content will be excessive, affecting the non-stick properties of the product. If the volume ratio of the fluoropolymer to the coating layer is greater than 10:1, the polymer content will be too high, resulting in the conductive metal wire being too soft and difficult to process, affecting the hardness of the product.

[0050] In some embodiments, the particle size of the fluoropolymer is between 3 μm and 70 μm. Specifically, the particle size of the fluoropolymer can be 3 μm, 5 μm, 10 μm, 20 μm, 30 μm, 40 μm, 50 μm, 60 μm, and 70 μm, and other values within the above range are also possible and are not limited herein. If the particle size of the fluoropolymer is larger than 70 μm, the powder particle size and gaps are large, and the density of the non-stick coating formed is low. During the preparation of the cooking utensils, the heat treatment temperature must be high or the heat treatment time is long. Excessively high or long heat treatment temperatures can cause decomposition of the small-sized fluoropolymer particles, reducing performance. If the particle size of the fluoropolymer is smaller than 3 μm, the non-stick coating contains a large amount of fine powder, which reduces the hardness of the composite non-stick coating as a non-stick coating.

[0051] In some embodiments, the volume percentage of the fluoropolymer with a particle size of 50 μm to 70 μm in the total fluoropolymer is 50% to 65%. Specifically, the volume percentage of the fluoropolymer with a particle size of 50 μm to 70 μm in the total fluoropolymer can be 50%, 53%, 55%, 58%, 60%, 63%, 65%, etc., and other values within the above range are also possible and are not limited here. Controlling the volume percentage of the fluoropolymer with a particle size of 50 μm to 70 μm in the total fluoropolymer within the above range can simultaneously improve the hardness and non-stick performance of the non-stick coating.

[0052] In some embodiments, the volume proportion of the fluoropolymer with a particle size of 20 μm to 50 μm in the total fluoropolymer is 25% to 30%. Specifically, the volume proportion of the fluoropolymer with a particle size of 20 μm to 50 μm in the total fluoropolymer can be 25%, 26%, 27%, 28%, 29% and 30%, etc., and of course it can also be other values within the above range, which is not limited here.

[0053] In some embodiments, the volume proportion of the fluoropolymer with a particle size of 3 μm to 20 μm in the total fluoropolymer is 10% to 20%. Specifically, the volume proportion of the fluoropolymer with a particle size of 3 μm to 20 μm in the total fluoropolymer can be 10 μm, 11 μm, 12 μm, 13 μm, 14 μm, 15 μm, 16 μm, 17 μm, 18 μm, 19 μm and 20 μm, etc., and of course it can also be other values within the above range, which is not limited here.

[0054] In the present application, the volume proportion of fluoropolymers with a particle size of 20 μm to 50 μm in the total fluoropolymers and the volume proportion of fluoropolymers with a particle size of 3 μm to 20 μm in the total fluoropolymers are controlled within the above-mentioned ranges, which can fill the powder gaps of large-size powders (50 μm to 70 μm) while forming a certain powder size gradient, thereby significantly improving the film density of the non-stick coating.

[0055] In some embodiments, the fluoropolymer includes at least one of polytetrafluoroethylene, ammonium perfluorooctanoate, a copolymer of perfluoropropyl perfluorovinyl ether and polytetrafluoroethylene, a polyperfluoroethylene-propylene copolymer, and an ethylene-tetrafluoroethylene copolymer. Exemplarily, polytetrafluoroethylene (PTFE) has the lowest surface tension and inertness among solid materials and does not adhere to any substance. Furthermore, polytetrafluoroethylene (PTFE) has the lowest coefficient of friction, excellent self-lubricating properties, and excellent high and low temperature resistance. As a non-stick coating, PTFE provides excellent anti-stick properties for cooking utensils.

[0056] In some embodiments, the conductive metal is made of at least one of aluminum, stainless steel, and iron.

[0057] In some embodiments, the material of the pot body includes at least one of aluminum alloy, aluminum, stainless steel, iron and low carbon steel.

[0058] In some embodiments, the pan body and the metal wire are made of the same material. The same materials have good compatibility, resulting in a good interface fusion between the pan body and the non-stick coating, making the connection between the non-stick coating and the pan body more stable. Furthermore, the non-stick coating and the pan body can effectively transfer stress and prevent delamination when subjected to impact energy.

[0059] In some embodiments, the particle size of the composite non-stick coating is 3 μm to 70 μm. Specifically, the particle size of the composite non-stick coating can be 33 μm, 5 μm, 10 μm, 20 μm, 30 μm, 40 μm, 50 μm, 60 μm and 70 μm, etc. Of course, it can also be other values within the above range, which is not limited here.

[0060] In some embodiments, the thickness of the non-stick coating is 100 μm to 200 μm. Specifically, the thickness of the non-stick coating can be 100 μm, 110 μm, 120 μm, 130 μm, 140 μm, 150 μm, 160 μm, 170 μm, 180 μm, 190 μm, and 200 μm, etc. Of course, other values within the above range are also possible and are not limited here. A non-stick coating thickness greater than 200 μm results in reduced adhesion of the coating, increased raw material consumption, and increased costs. A non-stick coating thickness less than 100 μm results in poor non-stick performance.

[0061] In some embodiments, the hardness of the cooking utensil is 100HV to 200HV. Specifically, the hardness of the cooking utensil can be 100HV, 110HV, 120HV, 130HV, 140HV, 150HV, 160HV, 170HV, 180HV, 190HV and 200HV, etc. Of course, it can also be other values within the above range, which is not limited here.

[0062] In some embodiments, the porosity of the cooking utensils is 3% to 15%. Specifically, the surface porosity of the cooking utensils may be 3%, 5%, 8%, 10%, 12%, and 15%, etc., and may also be other values within the above range, which is not limited herein. It is understood that the porosity of a material refers to the percentage of the volume of pores to the total volume of the material. In the present invention, it is the ratio of the volume of all pores in the cooking utensils to the total volume of the cooking utensils. Controlling the porosity of the cooking utensils of the present application within the above range can improve both the corrosion resistance and non-stick properties of the cooking utensils. If the porosity of the cooking utensils exceeds 15%, the strength of the non-stick coating will be reduced, the thickness of the cooking utensils will increase, and the performance of the cooking utensils will be reduced.

[0063] In a second aspect, an embodiment of the present invention provides a method for preparing a cooking utensil, such as Figure 1 As shown, the following steps are included:

[0064] Providing a conductive metal strip, winding the conductive metal strip into a cylindrical shape, and spinning the cylindrical conductive metal strip into a tubular wire or a quasi-tubular wire. During the spinning process, polyfluorinated compound powder is injected to obtain a composite non-stick coating. The composite non-stick coating includes a fluoropolymer and a coating layer disposed on the surface of the fluoropolymer, wherein the coating layer is a conductive metal wire.

[0065] The base material is stretched and formed into a pot body having a cooking cavity;

[0066] The cooking utensil is obtained by coating the inner surface of the pot body with a composite non-stick coating and performing a heat treatment on the inner surface of the pot body.

[0067] In the above technical solution, the present application injects polyfluoride compound powder into the metal strip during the wire-forming process, so that the metal strip is transformed into a tubular body or a quasi-tubular body, and polyfluoride compound powder is distributed inside the tubular body or the quasi-tubular body, thereby obtaining a composite non-stick coating. The composite non-stick coating includes a fluoropolymer and a coating layer covered on the surface of the fluoropolymer, and the coating layer is a conductive metal wire. The above-mentioned composite non-stick coating is coated on the inner surface of the pot body and subjected to heat treatment to obtain a cooking utensil. During the heat treatment process, on the one hand, the heat treatment can enhance the bonding force between the conductive metal wire in the composite non-stick material and the pot body, thereby enhancing the bonding force between the non-stick coating and the pot body; on the other hand, the heat treatment can improve the hardness, corrosion resistance and wear resistance of the non-stick coating. The preparation method of the present application is simple in process, and the cooking utensil prepared therefrom not only has good non-stick performance, but also has excellent hardness and wear resistance, thereby improving the performance stability of the cooking utensil.

[0068] The technical solution of the present invention is described in detail below according to specific steps.

[0069] Step S100: providing a conductive metal strip, winding the conductive metal strip into a cylindrical shape, and performing a wire-turning process on the cylindrical metal strip to form a tubular wire or a quasi-tubular wire. During the wire-turning process, polyfluorinated compound powder is injected to obtain a composite non-stick coating.

[0070] In this step, the spinning process and the injection of the polyfluorinated compound are performed simultaneously. The polyfluorinated compound powder can be directly added to the conductive metal wire to ensure that sufficient polyfluorinated compound is filled within the tubular or spherical conductive metal wire, thereby obtaining a composite non-stick coating and ensuring the non-stick properties of the composite non-stick coating. Specifically, the composite non-stick coating includes a fluoropolymer and a coating layer coated on the surface of the fluoropolymer, wherein the coating layer is the conductive metal wire.

[0071] In some embodiments, the fluorine-containing polymer comprises at least one of polytetrafluoroethylene, ammonium perfluorooctanoate, a copolymer of perfluoropropyl perfluorovinyl ether and polytetrafluoroethylene, a polyperfluoroethylene-propylene copolymer, and an ethylene-tetrafluoroethylene copolymer.

[0072] In some embodiments, the conductive metal strip includes at least one of an aluminum strip, a stainless steel strip, and an iron strip.

[0073] In some embodiments, the wire coiling equipment includes at least one of a wire spinning machine, a four-high cold rolling mill, and a square steel rolling die drawing machine.

[0074] In some embodiments, the volume ratio of the fluoropolymer to the coating layer is (5-10):1. Specifically, the volume ratio of the fluoropolymer to the coating layer can be 5:1, 6:1, 7:1, 8:1, 9:1, and 10:1, etc., and other values within the above range are also possible and are not limited here. If the volume ratio of the fluoropolymer to the coating layer is less than 5:1, the metal content will be excessive, affecting the non-stick properties of the product. If the volume ratio of the fluoropolymer to the coating layer is greater than 10:1, the polymer content will be too high, resulting in the conductive metal wire being too soft and difficult to process, affecting the hardness of the product.

[0075] In some embodiments, the particle size of the fluoropolymer is between 3 μm and 70 μm. Specifically, the particle size of the fluoropolymer can be 3 μm, 5 μm, 10 μm, 20 μm, 30 μm, 40 μm, 50 μm, 60 μm, and 70 μm, and other values within the above range are also possible and are not limited herein. If the particle size of the fluoropolymer is larger than 70 μm, the powder particle size and gaps are large, and the density of the non-stick coating formed is low. During the preparation of the cooking utensils, the heat treatment temperature must be high or the heat treatment time is long. Excessively high or long heat treatment temperatures can cause decomposition of the small-sized fluoropolymer particles, reducing performance. If the particle size of the fluoropolymer is smaller than 3 μm, the non-stick coating contains a large amount of fine powder, which reduces the hardness of the composite non-stick coating as a non-stick coating.

[0076] In some embodiments, the volume percentage of the fluoropolymer with a particle size of 50 μm to 70 μm in the total fluoropolymer is 50% to 65%. Specifically, the volume percentage of the fluoropolymer with a particle size of 50 μm to 70 μm in the total fluoropolymer can be 50%, 53%, 55%, 58%, 60%, 63%, 65%, etc., and other values within the above range are also possible and are not limited here. Controlling the volume percentage of the fluoropolymer with a particle size of 50 μm to 70 μm in the total fluoropolymer within the above range can simultaneously improve the hardness and non-stick performance of the non-stick coating.

[0077] In some embodiments, the volume proportion of the fluoropolymer with a particle size of 20 μm to 50 μm in the total fluoropolymer is 25% to 30%. Specifically, the volume proportion of the fluoropolymer with a particle size of 20 μm to 50 μm in the total fluoropolymer can be 25%, 26%, 27%, 28%, 29% and 30%, etc., and of course it can also be other values within the above range, which is not limited here.

[0078] In some embodiments, the volume proportion of the fluoropolymer with a particle size of 3 μm to 20 μm in the total fluoropolymer is 10% to 20%. Specifically, the volume proportion of the fluoropolymer with a particle size of 3 μm to 20 μm in the total fluoropolymer can be 10 μm, 11 μm, 12 μm, 13 μm, 14 μm, 15 μm, 16 μm, 17 μm, 18 μm, 19 μm and 20 μm, etc., and of course it can also be other values within the above range, which is not limited here.

[0079] In the present application, the volume proportion of fluoropolymers with a particle size of 20 μm to 50 μm in the total fluoropolymers and the volume proportion of fluoropolymers with a particle size of 3 μm to 20 μm in the total fluoropolymers are controlled within the above-mentioned ranges, which can fill the powder gaps of large-size powders (50 μm to 70 μm) while forming a certain powder size gradient, thereby significantly improving the film density of the non-stick coating.

[0080] In some embodiments, the diameter of the conductive metal wire is 0.8 mm to 2.0 mm. Specifically, the diameter of the conductive metal wire can be 0.8 mm, 1.0 mm, 1.3 mm, 1.5 mm, 1.8 mm, and 2.0 mm, etc. Of course, it can also be other values within the above range, which is not limited here.

[0081] Step S200: forming a pot body with a cooking cavity by stretching the base material.

[0082] In some embodiments, the material of the substrate includes at least one of aluminum alloy, aluminum, stainless steel, iron, and low carbon steel. The substrate can be a single-layer substrate or a composite substrate. For example, a single-layer substrate includes only one type of substrate; a composite substrate is formed by combining multiple materials, for example, a substrate formed by combining a layer of aluminum and a layer of stainless steel, and then forming the pot body by stretching. Preferably, the material of the pot body is the same as the material of the metal wire in the composite non-stick coating. The same material has good compatibility, so there is good interface welding between the pot body and the non-stick coating, making the connection between the non-stick coating and the pot body more stable, and the non-stick coating and the pot body can play a good stress transfer role and will not delaminate when subjected to impact energy.

[0083] This application mainly modifies the pot body containing iron or aluminum elements to improve the overall performance of the cooking utensil prepared therefrom. Preferably, the material of the pot body is stainless steel, and the material of the stainless steel pot body is austenite or ferrite. The material of the pot body can be, for example, 304 stainless steel, 430 stainless steel, etc.

[0084] In some embodiments, the base material can also be used to prepare the pot body through other molding processing techniques, which are not limited in this application. For example, the base material can also be used to prepare the pot body through processing techniques such as spinning, extrusion and cutting.

[0085] Step S300: coating the inner surface of the pot body obtained in step S200 with the composite non-stick coating obtained in step S100 to obtain a cooking utensil.

[0086] Step S301: coating the inner surface of the pot-carrying body with a composite non-stick coating.

[0087] In some embodiments, before performing step S301, the pot body needs to undergo mechanical and chemical pretreatment. Specifically, mechanical pretreatment includes degreasing, mechanical sandblasting, sandblasting, and deburring the pot body surface. Degreasing can be performed using a degreaser. Specifically, the degreaser can be a water-based cleaner such as DX106, which has good durability, is not easily precipitated in high-temperature, high-alkaline solutions, has excellent hard water resistance, has superior degreasing and cleaning power compared to NP and OP surfactants, and is adaptable to a wide pH range. The purpose of shot blasting is to remove rust, and the purpose of sandblasting is also to remove rust and increase the laser heat absorption rate to reduce heat waste caused by laser reflection. Quartz sand, yellow sand, copper slag, etc. can be used to spray the pot body surface at high speed.

[0088] In some embodiments, after the mechanical pretreatment and chemical pretreatment of the pot body, the inner surface of the pot body is also subjected to any one of shot blasting, etching and embossing treatment to modify the inner surface of the pot body and improve the oil-collecting capacity of the pot body.

[0089] Embossing is a process that uses high-frequency or deep-engraved rollers to hot-roll a fabric, creating a relief-like, three-dimensional effect and a distinctive sheen. This creates raised structures on the surface of the pot, thereby changing the surface tension of the pot's inner surface. For example, embossing can be used to create raised micro-nanostructures of varying shapes and sizes at different locations on the pot's inner surface using different embossing dies. Shot blasting uses a high-speed stream of projectiles to continuously impact the surface of the workpiece being reinforced, forcing changes in the microstructure and surface roughness of the target material's surface and layer during cyclic deformation. Shot blasting uses spherical or quasi-spherical shots, and shot blasting materials include steel shot, aluminum shot, ceramic micropowder, steel grit, walnut sand, corn cobs, glass beads, resin sand, and plastic sand. Arc-shaped raised micro-nanostructures are created by blasting with spherical or quasi-spherical shots.

[0090] In this embodiment, the shot diameter of the shot blasting treatment is 0.5mm~2.0mm, for example, it can be 0.5mm, 0.8mm, 1mm, 1.2mm, 1.3mm, 1.5mm, 1.7mm, 1.9mm and 2.0mm, etc. Within the above-mentioned limit range, the inner surface of the pot body after shot blasting can form a micro-nano-sized arc-shaped protrusion structure.

[0091] Etching is a technique that uses chemical strong acid corrosion, mechanical polishing, or electrochemical electrolysis to treat the surface of an object. Etching can include at least one of mechanical etching, laser etching, and chemical etching. Laser etching typically uses ultraviolet lasers, fiber lasers, and other lasers. Laser etching is contactless, high-speed, and efficient, and can be used to create structures like square pillars and ribs.

[0092] In some embodiments, the surface modification of the pot body further includes the steps of polishing and degreasing the pot body to form a high-gloss and clean inner surface of the pot body.

[0093] In some embodiments, the present application does not limit the process for forming the non-stick coating. Exemplarily, the method of applying the composite non-stick coating includes at least one of arc spraying, plasma spraying, and supersonic flame spraying.

[0094] In some embodiments, the thickness of the non-stick coating formed by applying the composite non-stick coating to the inner surface of the pot body is 100 μm to 200 μm. Specifically, the thickness of the non-stick coating can be 100 μm, 110 μm, 120 μm, 130 μm, 140 μm, 150 μm, 160 μm, 170 μm, 180 μm, 190 μm, and 200 μm, etc. Of course, other values within the above range are also possible and are not limited here. A non-stick coating thickness greater than 200 μm results in reduced coating adhesion, increased raw material consumption, and increased costs. A non-stick coating thickness less than 100 μm results in poor non-stick performance.

[0095] Step S302: heat-treating the surface of the non-stick coating formed in step S301 to obtain a cooking utensil.

[0096] In some embodiments, the heat treatment temperature is between 380°C and 400°C. Specifically, the heat treatment temperature can be 380°C, 385°C, 390°C, 395°C, and 400°C, and other values within the above range are also possible and are not limited herein. If the heat treatment temperature is lower than 380°C, the fluoropolymer powder will not be completely melted, making film formation difficult. If the heat treatment temperature is higher than 400°C, the fluoropolymer powder will carbonize and decompose, failing to provide an anti-sticking effect.

[0097] In some embodiments, the heat treatment time is 5 minutes to 8 minutes. Specifically, the heat treatment time can be 5 minutes, 6 minutes, 7 minutes, 8 minutes, etc. Of course, it can also be other values within the above range, which is not limited here.

[0098] In some embodiments, the heat treatment is performed in an inert gas atmosphere. The inert gas may be, for example, argon, nitrogen, helium, etc., which is not limited in this application.

[0099] The cooking utensil obtained by the preparation method of the present application can achieve a high level of food non-stick properties while also improving the hardness and corrosion resistance of the cooking utensil. After heat treatment, the hardness of the non-stick coating and the bonding strength between the non-stick coating and the pot body are further enhanced, thereby achieving a cooking utensil with high hardness, wear resistance, corrosion resistance and excellent non-stick properties.

[0100] The following uses a stainless steel pot as an example to further illustrate the embodiments of the present application in multiple embodiments. The embodiments of the present application are not limited to the following specific embodiments. Within the scope of the unchanged principal rights, appropriate changes can be made to the implementation.

[0101] Example 1

[0102] Step S100, taking a stainless steel sheet with a thickness of 0.2 mm, winding the stainless steel sheet into a cylindrical structure, and then using a wire spinning machine to spin the cylindrical stainless steel sheet for wire spinning. During the spinning process, polytetrafluoroethylene (polytetrafluoroethylene with a median particle size of 3 μm, a volume proportion of 10%; polytetrafluoroethylene with a median particle size of 20 μm, a volume proportion of 25%; polytetrafluoroethylene with a median particle size of 70 μm, a volume proportion of 65%) is injected. After the wire spinning process, a tubular or tubular-like stainless steel wire coating layer is obtained, and polytetrafluoroethylene is distributed inside the coating, that is, a composite non-stick coating is obtained, wherein the volume ratio of the stainless steel wire to the polytetrafluoroethylene is 1:5.

[0103] Step S200: forming a 304 stainless steel pot body with a cooking cavity by stretching a stainless steel plate, and performing degreasing, mechanical sandblasting, shot blasting, sandblasting and chemical corrosion pretreatment on the surface of the 304 stainless steel pot body.

[0104] Step S300: The composite non-stick coating obtained in step S100 is coated on the inner surface of the stainless steel pot by arc wire spraying, and the stainless steel pot is heat-treated in a high-temperature oven at 400° C. for 5 minutes to obtain the cooking utensil of the present invention.

[0105] Example 2

[0106] Different from Example 1, in step S100, the volume ratio of the stainless steel wire to the polytetrafluoroethylene is 1:4.

[0107] Example 3

[0108] Different from Example 1, in step S100, the volume ratio of the stainless steel wire to the polytetrafluoroethylene is 1:6.

[0109] Example 4

[0110] Different from Example 1, in step S100, the volume ratio of the stainless steel wire to the polytetrafluoroethylene is 1:8.

[0111] Example 5

[0112] Different from Example 1, in step S100, the volume ratio of the stainless steel wire to the polytetrafluoroethylene is 1:10.

[0113] Example 6

[0114] Different from Example 1, in step S100, the volume ratio of the stainless steel wire to the polytetrafluoroethylene is 1:12.

[0115] Example 7

[0116] Different from Example 1, in step S100: polytetrafluoroethylene with a median particle size of 3 μm accounts for 20% by volume; polytetrafluoroethylene with a median particle size of 20 μm accounts for 30% by volume; polytetrafluoroethylene with a median particle size of 70 μm accounts for 50% by volume.

[0117] Example 8

[0118] The difference from Example 1 is that in step S100 , the volume proportion of polytetrafluoroethylene with a median particle size of 70 μm is 100%.

[0119] Example 9

[0120] The difference from Example 1 is that in step S100 , the volume proportion of polytetrafluoroethylene with a median particle size of 20 μm is 100%.

[0121] Comparative Example 1

[0122] Step S100: forming a 304 stainless steel pot body with a cooking cavity by stretching a stainless steel plate, and performing degreasing, mechanical sandblasting, shot blasting, sandblasting and chemical corrosion pretreatment on the surface of the 304 stainless steel pot body.

[0123] Step S200: Applying ceramic coating to the inner surface of the stainless steel pot body by electric arc wire spraying to form a non-stick coating, thereby obtaining a cooking utensil.

[0124] Comparative Example 2

[0125] Step S100: forming a 304 stainless steel pot body with a cooking cavity by stretching a stainless steel plate, and performing degreasing, mechanical sandblasting, shot blasting, sandblasting and chemical corrosion pretreatment on the surface of the 304 stainless steel pot body.

[0126] Step S200: applying polytetrafluoroethylene coating to the inner surface of the stainless steel pot by electric arc wire spraying to form a non-stick coating, thereby obtaining a cooking utensil.

[0127] Performance Testing

[0128] The following procedures were carried out under the same environment to perform performance tests on Examples 1 to 9 and Comparative Examples 1 to 2:

[0129] (1) Thickness measurement is to place the cross section of the product under a microscope to observe and measure the relevant thickness.

[0130] (2) Wear resistance test The wear resistance test was carried out according to the national standard GB / T 32388 for cookware products.

[0131] (3) Use Rockwell hardness tester to test the hardness of the product.

[0132] The above test results are shown in Table 1 below.

[0133] Table 1. Performance parameters of various embodiments and comparative examples

[0134]

[0135] According to the data in Table 1 above, the composite non-stick coating of the cooking utensils prepared in Examples 1 to 9 includes a fluoropolymer and a conductive metal coating layer coated on the surface of the fluoropolymer. The presence of the fluoropolymer can improve the non-stick properties of the non-stick coating while also providing certain high and low temperature resistance. The conductive metal has high hardness, low friction coefficient, high heat transfer effect, and excellent corrosion resistance. The conductive metal is coated on the surface of the fluoropolymer to form a non-stick coating for the pot body, resulting in the non-stick coating having high hardness, good wear resistance, and excellent non-stick properties, thereby improving the performance stability of the cooking utensils.

[0136] In Comparative Example 1, ceramic coating is directly sprayed on the inner surface of a stainless steel pot body. The non-stick coating of the cooking utensil prepared therefrom is relatively thin, and has poor hardness and wear resistance, which cannot meet the requirements of the cooking utensil.

[0137] In Comparative Example 2, polytetrafluoroethylene coating is directly sprayed on the inner surface of the stainless steel pot body. The thickness of the non-stick coating of the cooking utensil prepared therefrom is also relatively thin, and the hardness and wear resistance are obviously not as good as the cooking utensil prepared in Example 1 of the present application.

Claims

1. A method for preparing a cooking utensil, characterized in that: The following steps are involved: Providing a conductive metal strip, winding the conductive metal strip into a cylindrical shape, and spinning the cylindrical conductive metal strip into a tubular wire or a quasi-tubular wire. During the spinning process, polyfluorinated compound powder is injected to obtain a composite non-stick coating. The composite non-stick coating has a core-shell structure and includes a fluoropolymer and a coating layer covering the surface of the fluoropolymer. The coating layer is a conductive metal wire. The volume ratio of the fluoropolymer to the coating layer is (5-10):

1. The particle size of the fluoropolymer is 3 μm to 70 μm. The base material is stretched and formed into a pot body having a cooking cavity; The composite non-stick coating is coated on the inner surface of the pot body, and the inner surface of the pot body is heat-treated to obtain a cooking utensil.

2. The preparation method according to claim 1, characterized in that The method includes at least one of the following technical features a to g: a. The fluorinated polymer comprises at least one of polytetrafluoroethylene, ammonium perfluorooctanoate, a copolymer of perfluoropropyl perfluorovinyl ether and polytetrafluoroethylene, a polyfluoroethylene-propylene copolymer, and an ethylene-tetrafluoroethylene copolymer; b. The conductive metal strip comprises at least one of an aluminum strip, a stainless steel strip and an iron strip; c. The volume proportion of the fluoropolymer having a particle size of 50 μm to 70 μm in the total fluoropolymer is 50% to 65%; d. The volume proportion of the fluoropolymer having a particle size of 20 μm to 50 μm in the total fluoropolymer is 25% to 30%; e. The volume proportion of the fluoropolymer having a particle size of 3 μm to 20 μm in the total fluoropolymer is 10% to 20%; f. The material of the pot body includes at least one of aluminum alloy, aluminum, stainless steel, iron and mild steel; g. The diameter of the wire is 0.8 mm ~2.0 mm.

3. The preparation method according to claim 1, characterized in that The method includes at least one of the following technical features a to c: a. The heat treatment temperature is 380 ℃ ~ 400 ℃; b. The heat treatment time is 5min~10min; c. The heat treatment is carried out in an inert gas atmosphere.

4. A cooking utensil, characterized in that: The cooking utensil is made by the preparation method according to any one of claims 1 to 3.

5. The cooking appliance according to claim 4, characterized in that The material of the pot body is the same as that of the conductive metal wire.

6. The cooking appliance according to claim 4, characterized in that The cooking appliance includes at least one of the following features a to e: a. The particle size of the composite non-stick coating is 3μm~70μm; b. The composite non-stick coating forms a non-stick coating on the inner surface of the pot body, and the thickness of the non-stick coating is 100μm~200μm; c. The hardness of the cooking utensil is 100HV ~ 200HV; d. The surface porosity of the cooking utensil is 3% to 15%; e. The inner surface roughness of the cooking utensil is 5 μm to 12 μm.

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