Frying pan with a low surface energy material layer

Abstract

This invention provides a frying pan with a low surface energy material layer that exhibits excellent non-stick properties equivalent to existing fluorine coatings, does not contaminate cooked food or the kitchen environment, and offers high cooking safety. [Solution] A layer of triiron tetroxide (Fe3O4) material 1 is provided on the surface of the frying pan, and the thickness of the low surface energy triiron tetroxide material layer is 0.1 μm to 10 μm. The surface of cookware using low surface energy materials has an excellent non-stick effect. The triiron tetroxide material layer is coated on the food contact surface of metal, especially stainless steel cookware, by plasma spraying or PVD technology. The inverse spinel crystal structure unique to triiron tetroxide ensures the structural stability of the material layer, and its nano-microporous structure forms a nano-pore array that is dispersed in large numbers. The contact area between the food being cooked and the cookware body can be changed by the configuration of this array and nanopores.

Description

Technical Field

[0001] The present invention relates to a frying pan having a low surface energy iron trioxide material layer, a non-stick frying pan made of metal without coating, particularly a frying pan having an iron trioxide material layer and a nano-micro structure concave hole distribution (particularly polygonal concave holes), and applications to electric rice cookers, hot plates, and a manufacturing method thereof.

Background Art

[0002] A low surface energy material refers to a material with low surface energy, generally having characteristics such as being difficult to stick, easy to clean, and self-lubricating. This type of material has a contact angle with water exceeding 120° and exhibits hydrophobic and oleophobic properties. The main reason for the low surface energy is that the adsorption force of surface molecules or structures to liquids is weak, and it is difficult for liquids to spread on the surface.

[0003] Current low surface energy materials mainly include the following types. Fluorine-containing low surface energy materials: The surface energy is reduced by introducing fluorine atoms into the polymer chain. For example, the surface energy of polytetrafluoroethylene (PTFE) is about 20 mN / m.

[0004] Low surface energy friction reducing paints: Mainly used for hydrophobic friction reduction and coating friction reduction, and the friction reduction effect is realized by reducing the shear stress of the fluid on the wall surface.

[0005] Antifouling paints: Utilize the characteristics of low surface energy materials to prevent the adhesion of dirt and are applied to ships, marine structures, etc.

[0006] Low surface energy materials are widely applied in many fields. Ocean engineering: Used for piers, bridges, offshore platforms, etc. to prevent the adhesion of marine organisms and reduce frictional resistance.

[0007] Shipbuilding: Realize the reduction of navigation resistance, prevention of dirt adhesion, and improvement of navigation efficiency.

[0008] Ice and snow sports: Used in skis, ice skates, etc., contributing to reduced friction and improved performance.

[0009] Existing manufacturing processes for low-surface-energy materials typically involve components such as fluororesins, epoxy resins, and composite curing agents. These materials offer excellent weather resistance, lubricity, and environmental friendliness, and have significant market potential. With the development of marine engineering and the shipbuilding industry, the demand for low-surface-energy materials is increasing year by year, and they have great application potential.

[0010] However, no publicly available technology exists for frying pans with a low surface energy triiron tetroxide material layer.

[0011] CN201710462896.9 discloses an alumina ceramic pot body, a method for manufacturing the same, a ceramic-embedded metal inner pot, and cookware. A microporous structure is formed on the inner surface of the alumina ceramic pot body, and the depth of the microporosity is less than the thickness of the alumina ceramic pot body. The ceramic-embedded metal inner pot includes an inner ceramic layer (1), an outer metal layer (3), and a heat-conducting layer (2) between the two layers, with a microporous structure formed on the inner surface of the ceramic layer (1). Generally, it is recommended to avoid using metal spatulas during use and metal scouring pads during cleaning.

[0012] The triiron tetroxide material layer is harmless to the human body, chemically stable, and has excellent heat resistance. The applicant has already filed an application for a hot plate (CN202323215096.7), but the application effect of a frying pan using the triiron tetroxide material layer or a combination thereof with nano- and micro-structured polygonal holes is even better. [Overview of the Initiative] [Problems that the invention aims to solve]

[0013] To solve the above problems, the objective of this invention is to provide a non-stick metal frying pan without coating, particularly one having a low surface energy triiron tetroxide material layer, a nano-micro structure with a pore distribution, and a thermal spray type triiron tetroxide frying pan that can be manufactured at low cost, as well as applications to various types of pots and pans. [Means for solving the problem]

[0014] To achieve the above objective, this invention employs the following technical means. An Fe3O4 material layer is provided on the surface of the frying pan, and the thickness of the low surface energy triiron tetroxide material layer is set to 1 μm to 400 μm, and the material layer is directly formed by plasma spraying.

[0015] A Fe3O4 material layer is provided on the surface of the frying pan, and a low surface energy triiron tetroxide material layer is applied with a thickness of 0.1 μm to 10 μm, and the triiron tetroxide material layer is coated by PVD (Photovoltaic Veneer).

[0016] A low surface energy triiron tetroxide material layer is applied with a thickness of 0.5 μm to 2 μm using the PVD method. The thickness of the triiron tetroxide material layer is set to 2 μm to 200 μm.

[0017] The metal pot body is provided with uniformly distributed elliptical or polygonal recesses, with a maximum inner dimension of 0.3 to 1.2 mm, a protrusion dimension between adjacent recesses of 0.1 to 0.6 mm, and a recess depth of 0.2 to 0.5 mm. A layer of triiron tetroxide material is applied over the uniformly distributed elliptical or polygonal recesses. The total area of ​​the recesses accounts for 50% or more of the total area of ​​the region.

[0018] The manufacturing method employs thermal spraying (molten thermal spraying), and the thickness of the low surface energy triiron tetroxide material layer can be set to 1 μm to 400 μm, particularly 2 μm to 200 μm, and multiple thermal spraying applications are possible.

[0019] For plasma spraying, triiron tetroxide material powder with a particle size of 15 to 150 μm is used, preferably with powder of 15 to 100 μm supplied for spraying.

[0020] When coating the iron oxide layer by PVD method, the layer thickness is set to be 0.1 μm to 10 μm, particularly 0.5 μm to 2 μm.

[0021] The effect is improved by remelting the Fe3O4 material layer after spraying or directly forming it by plasma spraying. The sprayed material layer has a nano-micro structure and is sprayed using iron oxide material with a particle size of 1 to 180 μm, preferably 10 to 100 μm. Powder spraying is performed by controlling the particle size of the raw material powder, and particularly plasma spraying is adopted. Plasma spraying is preferably performed under an Ar atmosphere.

[0022] The low surface energy iron oxide material layer exhibits an excellent anti-sticking effect in cookware.

[0023] [[ID=~]]

Advantages of the Invention

[0024] The surface of cookware using the low surface energy material of the present invention has an excellent anti-sticking effect. The food contact surface of cookware made of metal, especially stainless steel, is coated with a low surface energy iron oxide material layer by plasma spraying or PVD technology.

[0025] The unique inverse spinel crystal structure of iron oxide ensures the structural stability of the material layer, and its nano-micro porous structure forms a large number of dispersed nano-particle pore arrays. Due to the array and nano-pores, the contact area between the cooked food and the cookware body changes.

[0026] Oil or water is retained in the pores, reducing the amount of heat directly transferred from the cookware body to the cooked food, and preventing sticking due to overheating of the cooked food. Furthermore, the polygonal hole array is more effective than the circular hole, and the concave hole area is large. The oil and water in the cookware are constrained in the concave holes and are subject to the action of surface tension, exerting an excellent anti-sticking effect that cannot be obtained by the iron oxide material layer alone, and achieving the same effect as existing non-stick cookware made of fluorine coating.

[0027] ​ There is no need to form an antifouling film or the like on the inner surface of the stainless - steel pot body, and it has a substrate structure of stainless steel + thermal spraying. Even when performing high - temperature stir - frying over high heat or dry - frying, no toxic substances or gases are released from the frying pan with the magnetite material layer, which does not pollute the cooked food and the kitchen environment, and has high cooking safety.

[0028] According to the heat - resistance test, the magnetite material layer of the present invention does not have oxidation or cracks on the surface even after continuous use for 1000 hours in a constant temperature environment of 200 °C, and maintains a sticking - prevention performance retention rate of 95% or more. Even after cooling to room temperature after 30 minutes of high - temperature dry - frying at 300 °C, the decrease in the bonding strength between the material layer and the pot body is not significant (bonding strength is 30 MPa or more), and the sticking - prevention performance retention rate is 90% or more, fully meeting the requirements of daily cooking and high - temperature stir - frying over high heat.

[0029] Since the present invention is by thermal spraying or PVD coating of magnetite material, elution of excessive elements hardly occurs, ensuring the hygienic safety of cookware. Cookware with nano - scale pores takes in air and grease during actual use, generates hot air and oil mist during the heating process, and simultaneously supports the floating of food. The villus - like effect due to the fine concavo - convex structure reduces the friction between the food and the inner surface of the pot, achieving the anti - sticking effect by physical means without using chemical coatings, enabling consumers to cook more healthily.

[0030] The present invention allows the use of a metal spatula during use and a metal scrubber during cleaning. The anti - sticking performance reaches the first - level standard, and it will not stick even when continuously frying 50 or more eggs with no oil or a small amount of oil. Especially when using plasma spraying, the use effect is excellent. The formed magnetite material layer is black and has a good appearance.

Brief Description of the Drawings

[0031] [Figure 1] It is a schematic diagram showing the dense arrangement of rectangular concave holes in the pot body according to an embodiment of the present invention. <​​​​​ The present invention will be further described below with reference to the drawings. Embodiments of the present invention will be described in detail, and examples of these embodiments are shown in the drawings. Throughout, the same or similar reference numerals indicate the same object.

[0033] Coated metal frying pan: A triiron tetroxide material 1 is sprayed onto the surface of a stainless steel or iron plate using plasma melting spraying technology. The metal pan body shown in Figure 1 may have a heat-stable layer (additional aluminum composite layer), and is particularly made of stainless steel or iron.

[0034] This embodiment relates to the application of a frying pan having a triiron tetroxide material layer, and uniformly distributed polygonal holes of uniform depth are preferred. The distribution of polygonal holes may be such that they are denser at the bottom of the pan than at the rim. All spaces between adjacent polygonal holes are convex. Small diameter holes 2 and large diameter holes 3 may be mixed.

[0035] The surface of the metal pot body is cleaned, polished (surface roughness is improved by rough polishing) or shot blasted, then cleaned again. Using plasma spraying technology with a non-migratory plasma arc as the heat source, triiron tetroxide or a composite powder material is heated to a molten or semi-molten state, atomized and accelerated by a high-speed flame flow, and sprayed onto the pre-treated workpiece surface to form a strong, porous triiron tetroxide spray coating.

[0036] The triiron tetroxide or composite material powder is preferably in the form of a spherical powder. Triiron tetroxide materials are manufactured and sold using existing technologies, and iron group oxide materials may be added.

[0037] In industrial applications, the Fe3O4 content is typically 90-99.5 wt%. This invention relates to a frying pan having a surface layer made of a metal oxide mainly composed of triiron tetroxide and a composite material with Fe, and in particular a low surface energy triiron tetroxide material layer formed on the pan body by plasma spraying.

[0038] Vacuum deposition or vacuum sputtering is employed as the PVD method. A triiron tetroxide composite target is fabricated according to the following examples, the target is heated to evaporate it, and the vapor is condensed on the substrate surface to form a film. Methods such as electron beam deposition, resistance heating deposition, arc deposition, and laser deposition are used, or DC sputtering, high-frequency sputtering, and magnetron sputtering are used to sputter atoms onto the workpiece surface by impacting the target with high-energy particles.

[0039] The metal pot body is provided with uniformly distributed elliptical or polygonal recesses, with a maximum inner diameter of 0.3 to 1.2 mm, a protrusion dimension between adjacent recesses of 0.1 to 0.6 mm, and a recess depth of 0.2 to 0.5 mm. The recesses are then coated with a layer of triiron tetroxide material.

[0040] The metal pot body (food contact surface, especially stainless steel or composite stainless steel) is provided with uniformly distributed elliptical or polygonal recessed holes. The elliptical or polygonal holes are arranged in a parallel array or a staggered array. The surface material of the metal pot body may be stainless steel, iron, titanium, or a composite material.

[0041] The recessed holes should be arranged in a parallel or staggered pattern, with a depth of 0.2 to 0.5 mm.

[0042] The pot is divided into several small regions, and one type of elliptical or polygonal hole is placed in each region.

[0043] The total area of ​​the elliptical or polygonal holes accounts for 50% or more of the total area of ​​the region.

[0044] The direction of the holes in a small region may be perpendicular to the direction of the holes in an adjacent region.

[0045] A stainless steel layer may be incorporated into the pot body, which also has a stainless steel layer, by adding an aluminum heat-conducting layer.

[0046] The longitudinal cross-section of the elliptical or polygonal recessed hole shall be corrugated.

[0047] When the spacing between polygonal holes is large, the area of ​​the convex parts becomes smaller than the area of ​​the concave parts, making machining easier.

[0048] The distance from the highest point of the convex portion between polygonal holes to the lowest point of the concave portion shall be 500 micrometers or less.

[0049] The film thickness achieved by PVD coating technology is generally 0.1 to 10 μm, and industrially, 0.3 to 5 μm is standard.

[0050] Micron-scale film thickness has almost no effect on the original dimensions of the workpiece.

[0051] The alloy layer nano-microstructure polygonal hole frying pan includes a metal pan body and has polygonal holes uniformly distributed on the food contact surface. It includes an outer stainless steel layer with parallel or radial arrays of polygonal holes on its surface. In particular, the pan is divided into multiple sub-regions, with the polygonal holes within each sub-region forming a parallel array. The area of ​​each sub-region is 20-100 cm². 2 Let's assume that.

[0052] If the area is not divided into smaller regions, the holes may be concentric or radial polygonal.

[0053] The longitudinal cross-section of the polygonal hole shall be corrugated. The maximum inner diameter of the hole shall be 0.3 to 1.2 mm, the width between holes (rib width) shall be 0.1 to 0.6 mm, preferably 0.3 to 0.5 mm, and the hole depth shall be 0.2 to 0.5 mm, particularly 0.3 to 0.4 mm.

[0054] The rib width of the polygonal hole can be 300, 400, 500 μm, etc.

[0055] The polygonal holes are press-formed using a cemented carbide die, resulting in a hardened layer structure for both the polygonal holes and the pot body. A uniform distribution of polygonal holes is formed by pressing a cemented carbide die with uniform convex ribs onto the pot body plate.

[0056] The total area of ​​the polygonal holes should preferably account for 50% or more of the total area of ​​the region, thereby achieving both physical non-stick performance and a longer lifespan for the pan.

[0057] The food contact surface is made of 304 stainless steel, more preferably 316 stainless steel, and can also be used with cast iron pans.

[0058] By compounding an aluminum layer on the back of stainless steel, creating a steel-aluminum composite or steel-aluminum-steel composite (three-layer steel), weight reduction and uniform heat conduction are achieved.

[0059] The upper convex arc of the wave-shaped structure (the convex rib between the polygonal holes, i.e., the polygonal frame) is narrower than the lower concave arc (the main body of the polygonal hole). In other words, the area of ​​the polygonal frame is smaller than the area of ​​the polygonal concave hole.

[0060] One of the core features of this invention is that the area of ​​the protrusions that support the food is 30-50%, particularly 30-45%, of the bottom surface area of ​​the pot, resulting in excellent non-stick performance.

[0061] After ion spraying, the cookware undergoes further polishing and buffing to reduce the roughness of the interior, decrease friction with food, facilitate stirring during cooking, and achieve a non-stick effect equivalent to that of a new PTFE Teflon® coating.

[0062] In particular, its manufacturing cost is low, about half that of other functional frying pans.

[0063] This invention can also be applied to polished and buffed surfaces.

[0064] The pot body is formed from a flat sheet of metal into a dish shape using a hydraulic press. A handle is then attached to the pot body.

[0065] When compounding an aluminum layer on the back of stainless steel, the stainless steel thickness should be approximately 0.5 to 1 mm, and the aluminum layer approximately 1.5 mm. The stainless steel or titanium and aluminum plate are then compounded by pressure welding or explosion bonding.

[0066] Polygonal hole fabrication: A polygonal hole is formed by pressing the stainless steel pan surface with a press machine using an alloy mold that has uniform polygonal hole protrusions. The mold can also be fabricated by electrochemical methods, etc.

[0067] Polygonal hole arrays and nanopores, such as triangles, rectangles, quadrilaterals, pentagons, hexagons, and octagons, can be fabricated by photolithography etching or mold pressing.

[0068] Nanopores can be formed by polishing (dry or slurry method) using abrasives with a size of 30-300 nm (500 nm is also possible), and surface nitriding treatment further improves the results.

[0069] This invention can be applied to various cooking pots, as well as hot plates and electric rice cookers.

[0070] Application to hot plates: The hot plate, which has an alloy layer nano-microstructure polygonal hole non-stick layer, includes upper and lower heating plates and a heating assembly, the heating assembly being located inside the upper and lower heating plates, and the upper and lower heating plates being attached to the lid and base, respectively.

[0071] The pot surface structure has uniform protrusions on the underside of the upper heating plate and the upper surface of the lower heating plate, and is made of stainless steel or aluminum composite metal material. The food contact area is an alloy layer nano-microstructure polygonal pore non-stick layer.

[0072] Although embodiments of the present invention have been illustrated and described above, these embodiments are illustrative and should not be construed as limiting the present invention. Those skilled in the art can modify, alter, substitute, and transform the embodiments without departing from the principles and spirit of the present invention, and all such modifications are included within the scope of the present invention.

Claims

1. A frying pan having a low surface energy triiron tetroxide material layer, characterized in that the triiron tetroxide material layer is provided on the surface of the pan body, and the thickness of the triiron tetroxide material layer by plasma spraying is 1 μm to 400 μm.

2. A frying pan having a low surface energy triiron tetroxide material layer, characterized in that the triiron tetroxide material layer is provided on the surface of the frying pan, and the thickness of the triiron tetroxide material layer formed by the PVD method is 0.1 μm to 10 μm.

3. A frying pan having a low surface energy triiron tetroxide material layer according to claim 2, characterized in that the thickness of the triiron tetroxide material layer is 0.5 μm to 2 μm.

4. A frying pan having a low surface energy triiron tetroxide material layer as described in claim 1, characterized in that the thickness of the triiron tetroxide material layer is 2 μm to 200 μm.

5. A frying pan according to any one of claims 1 to 4, wherein the metal pan body is provided with uniformly distributed elliptical or polygonal recessed holes, The maximum inner diameter of the recessed hole is 0.3 to 1.2 mm. The dimension of the protrusion between adjacent recessed holes is 0.1 to 0.6 mm. The depth dimension of the recessed hole is 0.2 to 0.5 mm. Uniformly distributed elliptical or polygonal concaves The triiron tetroxide material layer is covered over the hole. A frying pan characterized in that the total area of ​​the recessed holes accounts for 50% or more of the total area of ​​the pan.

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