Cooker surface

Abstract

A cookware article having a textured surface and a method for manufacturing the cookware article. The method comprises: performing a first forging step to form a three-dimensional body of a cookware article from a sheet material having a first major surface and an opposite second major surface, where the three-dimensional body comprises a concave form, where the first surface constitutes an inner surface and the second surface constitutes an outer surface; performing a second forging step on the three-dimensional body to form a surface texture on the inner surface; a non-stick coating is applied to the textured inner surface.

Description

Technical Field

[0001] This invention relates to a cookware surface, and more particularly to a textured cookware surface and a method for manufacturing such cookware articles, such as pots. Background Technology

[0002] Adding a non-stick coating to cookware allows for cooking with less oil or grease and reduces cleaning time. However, due to daily cleaning and scratches from cookware, much of the non-stick coating tends to wear off or delaminate over time. The surface loses its non-stick properties over time. Furthermore, the non-stick coating may also peel off or detach into the cooked food.

[0003] It is known that the surface of cookware is textured using processes such as sandblasting or shot peening before surface coating is applied. This creates depressions on the surface of the cookware, which can then be covered with the desired surface coating. Because the surface coating is located in the depressions, it is less susceptible to wear or degradation during use, thus extending the service life of the surface coating. However, this surface treatment significantly increases production costs, thereby affecting the product price.

[0004] It is known that incorporating a series of regularly distributed ribs on the flat base of a pot can reduce sticking during use. These ribs are typically formed by stamping aluminum sheets during the pot body construction, and in some cases, a non-stick coating is applied. However, it has been found that these regular rib patterns / lines are also susceptible to repeated wear over time due to their uniform arrangement. Furthermore, there are limitations to the geometry of the ribs achievable using conventional stamping techniques.

[0005] Therefore, there is a need for a cookware surface that can maintain its non-stick properties even after prolonged use. The object of this invention is to provide a cookware surface that can alleviate or solve the aforementioned problems. Summary of the Invention

[0006] According to a first aspect of the present invention, a method for manufacturing a cookware article is provided, the method comprising: performing a first forging step to form a three-dimensional body of the cookware article from a sheet material having a first main surface and an opposite second main surface, wherein the three-dimensional body comprises a concave shape, wherein the first surface constitutes an inner surface and the second surface constitutes an outer surface; performing a second forging step on the three-dimensional body to form a surface texture portion on the inner surface; and applying a non-stick coating portion to the textured inner surface.

[0007] The second forging step can form a surface texture over almost the entire area of ​​the inner surface. The second forging process can form a surface texture over at least 80%, 85%, 90%, or 95% of the inner surface.

[0008] The three-dimensional body formed by the first forging step may include a base and sidewalls / peripheral walls. These walls may be inclined relative to the base. The profile of the sidewalls may be curved.

[0009] The second forging step may form surface textures on the base and sidewalls. The inner surface textures may extend continuously and / or uniformly on the base and sidewalls. The surface textures may be formed on the curved portions or contours of the sidewalls.

[0010] The first forging process can form a final shape that approximates the body of the cookware. This body may include a pot body.

[0011] The method may include roughening the inner surface. The roughening of the inner surface may be performed after the second forging step and / or before applying the non-stick coating.

[0012] Roughening may include applying an additional surface texture to the inner surface. The length of this additional surface texture may be smaller than the length of the original surface texture, for example, at least an order of magnitude smaller. This additional surface texture may follow the outline of the original surface texture.

[0013] Roughening the inner surface can improve the adhesion between the non-stick coating and the inner surface.

[0014] The first forging step and / or the second forging step can be performed under controlled and / or high temperature conditions. The sheet metal and / or the three-dimensional body are preferably heated during the first forging step and / or the second forging step. The first forging step and the second forging step can be performed at substantially the same temperature or at different temperatures.

[0015] The first forging step can be performed using a first pressure member. The second forging step can be performed using a second pressure member. The second pressure member may have a surface texture, for example, a surface texture opposite to that formed on the inner surface.

[0016] The first forging step and the second forging step can be performed by driving the pressure member in the same direction, such as the axial direction.

[0017] The surface texture may include an irregular pattern of raised shapes spaced apart by grooves / valve-like portions. The raised shapes themselves may also be irregular. The pattern may be amorphous and / or non-repeating.

[0018] Protruding shapes are typically polygonal in a plane. Protruding shapes in a plane can include triangular and / or quadrilateral shapes. These shapes can have straight and / or curved edges.

[0019] The grooves can be interconnected, for example, in the form of a continuous network. The grooves can surround each protruding shape.

[0020] According to a second aspect of the invention, a cookware article is provided having a textured inner surface manufactured by a method according to a first aspect of the invention.

[0021] The cookware product may include a pot or a pot body. Attached Figure Description

[0022] The specific embodiments of the present invention will now be described in more detail with reference to the accompanying drawings, in which: Figure 1a A top view of the inner surface of a cookware according to the present invention is shown; Figure 1b A schematic cross-sectional view of the surface texture of the cookware is shown; Figure 2 A cross-sectional view of the cookware according to the invention is shown; Figure 3 A schematic diagram of the manufacturing process is shown. Detailed Implementation

[0023] Inner surface texture Figure 1 shows a top view of the inner surface 100 of the cookware according to the present invention.

[0024] Surface 100 has a textured portion. The textured portion includes a plurality of raised portions 101. Between the raised portions 101 are recessed portions 102, and the shape of the recessed portions 102 may be a wrinkle, groove, valley, recess, etc.

[0025] The raised portion 101 is discrete because it is completely surrounded by the recessed portion. The recessed portion 102 is continuous, thus forming channels or valleys between the raised portions 101. A continuous network of valleys is defined across the entire surface.

[0026] The recessed portion 102 separates the adjacent protruding portion 101.

[0027] The raised portions 101 and the recessed portions 102 are arranged in an irregular pattern to create a "wrinkled" or "leather" effect on the cookware surface. This irregular pattern can be a random pattern and / or a repeating pattern.

[0028] The protrusion 101 includes an irregular shape and can be described as an amorphous shape, for example, typically polygonal, but selectively containing one or more curved edges.

[0029] The raised portion 101 may have a flat central portion between the recessed portions 102 on its sides / edges. Alternatively, the profile of the raised portion may be arched or dome-shaped, thus presenting a minimal flat upper surface. In any example, the raised portion typically has arcuate sides, such as... Figure 1b As shown. The sides are steepest at the base of each valley and curve toward the center of the protrusion 101 toward the gentlest / nearest horizontal slope.

[0030] The widths of the protrusions 101 on surface 100 vary. The width of a protrusion can be approximately 1 mm. For example, the minimum width of a protrusion can be 0.5 mm or 1 mm. The maximum width of a protrusion can be 2 mm, 3 mm, 4 mm, 5 mm, 6 mm, 7 mm, 8 mm, 9 mm, or 10 mm. The width of the protrusions on surface 100 can vary between the maximum and minimum values. The width of the protrusions 101 on surface 100 can vary in a random or pseudo-random manner, for example, in an amorphous or random pattern that does not follow mathematical definitions or repeating patterns.

[0031] The height of the protrusion 101 and / or the depth of the recess 102 can be approximately 1 mm. For example, the height and depth can be between 0.1 mm, 0.2 mm, or 0.3 mm and 1 mm, 1.5 mm, or 2 mm. The height of the protrusion is relatively consistent and / or uniform across the entire surface. For example, the peak of the protrusion 101 can be located on a generally flat plane, and / or the base of the recess 102 can be located on a flat plane or at approximately the same depth.

[0032] In other examples, the depth of the recessed portion 102 can vary between the maximum and minimum values ​​mentioned above.

[0033] The width of the recess 102 may be more uniform than the width of the protrusion 101. For example, the width of the recess 102 may be approximately uniform, for example, within a suitable tolerance range.

[0034] The area of ​​the raised portion 101 varies across the entire pattern (e.g., when viewed from a plan view). All the recessed portions 102 can be connected around the raised portion 101, thereby forming a series of peaks and grooves in a cross-sectional view of the surface.

[0035] The planar area occupied by the protruding portion 101 on the surface 100 of the cookware can be greater than or equal to the area occupied by the recessed portion 102. The ratio of the surface area of ​​the protruding portion to the surface area of ​​the recessed portion can be in the range of 1:1, 4:3, 3:2, 2:1, 3:1 or 4:1.

[0036] Although the surface 100 described herein is generally irregular or amorphous, it is formed by stamping during a forging process, as will be described below. Therefore, although the surface pattern may appear random or pseudo-random, it is predetermined.

[0037] Figure 2 A cross-sectional view of a cookware article 200 according to the present invention is shown. In this example, the cookware article 200 includes a pot, but in other examples, the cookware article 200 may also include baking articles, such as baking pans or trays.

[0038] The cookware 200 includes a pot body 201, which is shaped to define a base 202 and peripheral sidewalls 203 surrounding the base 202. Depending on the type of pot, the height and angle of inclination of the sidewalls 203 may vary, and the area of ​​the base may differ. However, all pot bodies 201 generally have a smooth / curved interface or transition between the base and the sidewalls. The curvature may vary depending on the type or depth of the pot and the angle of inclination of the sidewalls 203. The pot body shown has sidewalls 203 that are substantially perpendicular to the base 202.

[0039] In other examples, the pan's plane does not need to be circular; therefore, the peripheral sidewalls 203 can be composed of multiple adjacent sidewalls 203. For example, a polygonal, such as a quadrilateral, pan body can be used. In any such configuration, the corners of the pan can be rounded. The sides also do not need to be straight but can be curved.

[0040] Figure 2 Only one example of a cookware shape is shown. Cookware can take any suitable shape; for example, cookware can have only a base without sides, or the sidewalls can be very shallow, for example, in the form of an edge or flange.

[0041] The inner surface refers to the surface on which food is placed for cooking during use.

[0042] The cookware article 200 includes a handle 205 extending from a side wall 203. The inner surface 204 of the cookware includes the inner portions of the base 202 and the side portion 203. The outer surface includes the outer portions of the base 202 and the side portion 203.

[0043] exist Figure 2 In this example, the inner surface 204 of the cookware 200 includes the aforementioned textured portion, which has a plurality of raised portions 101 and recessed portions 102. The pattern is continuous and covers the entire inner portion of the base 202 and the sidewall 203. In other examples, the pattern may be present on at least 90% of the inner surface.

[0044] While surface textures / patterns can also be provided on the outer surface of the body 201, the outer side of the pot body typically does not have such surface textures. The outer side of the pot can be substantially smooth, or it can include textures different from those on the inner side.

[0045] The surface has a non-stick coating portion, which is shown in Figures 1 to 12. Figure 2 The coating is invisible. It has a thickness of less than 100 μm or 50 μm, for example, between 20 μm and 30 μm. The non-stick coating conforms to the contour / morphology of the aforementioned surface texture and does not disrupt the surface texture formed by the pattern. In other words, the thickness of the surface coating is designed to be thin enough not to fill the recess 102, and / or to be uniform in thickness so that the surface of the non-stick coating follows the original surface contour of the pot body material.

[0046] In some examples, the non-stick coating may partially fill the recess 102. However, the thickness of the non-stick coating is preferably uniform, for example, within typical tolerances.

[0047] The coating is preferably of the PTFE type, but any suitable non-stick coating may also be used.

[0048] In addition to the texture provided by the patterns of raised and recessed portions, the inner surface of the cookware is microtextured to accommodate the surface coating, as will be detailed below. This microtexture provides a rough surface on top of the patterns. Before the application of the surface / non-stick coating, the texture of the cookware surface comprises both macrotexture and microtexture. The coating may smooth out the microtexture so that, after application, the microtexture is no longer present on the outer surface of the coating.

[0049] The micro-textured areas facilitate the adhesion of the coating, thereby improving the adhesion of the non-stick coating.

[0050] The non-stick coating covers the raised portion 101 and the recessed portion 102. Therefore, the inner surface is completely covered by the non-stick coating.

[0051] The irregular distribution of the raised portions 101 and the recessed portions 102 improves the abrasion resistance of the non-stick coating on the cookware surface. This characteristic is particularly important when the base 202 and sides 203 of the cookware 200 are made of aluminum, as aluminum is relatively soft and easily scratched by harder metal objects, such as tableware. However, the pot body can be made of any conventional metal sheet.

[0052] Due to the texture formed by the pattern, during use, the surface will only be scratched at irregular points at the peaks of the raised portion 101. This scratching has little effect on the overall non-stick performance of the cookware and can prevent the coating from peeling or falling off.

[0053] The coating inside the cavity formed by the recessed portion 102 is not easily damaged by scratches or other factors during use and remains basically intact throughout the lifespan of the cookware.

[0054] Manufacturing method refer to Figure 3 The following describes the manufacturing method of cookware 200. Figure 3 The image below the manufacturing stage schematically shows the surface texture of the cookware formed during this stage.

[0055] Aluminum billet 300, i.e., aluminum sheet, is the initial material used to form the pot body. Alternatively, this billet can include any material suitable for cookware, such as stainless steel, copper, or carbon steel. Both sides of billet 300 are oiled before forging.

[0056] First forging of billet 302 The blank undergoes a first forging. In this stage, the blank is forged into an approximate shape of the cookware 200, even though the blank has the three-dimensional shape of the cookware body 201. The blank 300 can be formed into any shape suitable for the intended use of the cookware described above, including the sidewalls and base.

[0057] The blank 300 is deformed from its flat shape into a three-dimensional profile corresponding to the desired final shape of the inner surface of the pot body 201 by a pressure member or mold 304. The inner and outer surfaces are typically deformed to approximate the final shape. The mold 304 presses the blank 300 into a cavity 306 corresponding to the desired final shape of the outer surface of the pot body 201. The mold 304 is driven to force the blank into the cavity 306.

[0058] The first forging, 302, is performed at a high temperature to improve the billet's response to the pressing process. This reduces stress / strain within the billet during pressing and residual stress within the formed body. The forging temperature depends on the material used but is below its melting point. For aluminum, forging temperatures can exceed 400°C or 500°C. Temperature is controlled during forging, for example, in a temperature-controlled environment / closed space.

[0059] In the example shown, the mold 304 and the cavity are heated to the required temperature. The blank is pressed at a suitable rate and held in a deformed state within the cavity for a period of time to ensure that the blank reaches the required temperature while in a deformed state. At this point, the blank 300 has been formed into the desired final shape, close to that of the body 201. The body 201 in this state is concave but still has a smooth surface texture.

[0060] Pressure component 304 was retrieved.

[0061] Second Forging 308 The cookware undergoes a second forging process, in which surface patterns and textures, such as "pleats" or "leather" effects, are imprinted onto the inner surface 204.

[0062] Specially designed tools are used in the second forging. In this respect, a second pressure member or die 310, different from that used in the first forging, is used in the second forging. The body 201 can be held within the cavity 306 or transferred to a different cavity.

[0063] The second forging is carried out at a controlled high temperature in a manner similar to the first forging. The temperature of the second forging step can be the same as or different from that of the first forging, for example, higher or lower.

[0064] The cavity and pressure member 310 can be maintained / controlled at the desired second forging temperature. This temperature can be a "finish forging" temperature, i.e., a temperature lower than the first forging temperature used to rough-form the billet. At this stage, the dwell time and pressure of the pressure member can also be adjusted to achieve precise details in the surface texture of the body 201.

[0065] The inner surface is preferably made of aluminum, which is a relatively soft material and can be formed by stamping with a die.

[0066] Experiments with the force / pressure applied to the stamping press, as well as the temperature and dwell time, revealed that the desired surface texture can be applied not only to the base 202 of the body 201 but also to the sidewalls 203 using the die 310. This includes the arcuate transition between the flat base and the sidewalls. Therefore, the desired surface pattern can be applied to the entire inner surface with just a single, simple additional forging step.

[0067] In this example, the second forging only macro-textures the inner surface 204 of the cookware 200, without forming any texture on the outer surface.

[0068] The pattern of the macroscopic surface texture is engraved on the mold in the form of an inverted image, and the texture is intended to be imprinted onto the inner surface of the cookware 200 by subsequent molding. The pattern on the mold is continuous on the end face of the mold and around the curved perimeter of the mold, for example, extending continuously upward along the side wall of the mold.

[0069] The mold is precisely calibrated so that the second forging can create a clear texture on the entire inner surface, thus texturing the bottom and sides of the pot with a pattern pre-set by the mold used.

[0070] Regarding the effectiveness of the second forging, it is worth noting that the opposite surface textured portion has relatively "sharp" ridges and rounded recesses, thus forming the contours of valleys and protrusions on the body surface. Therefore, the ridges on the die effectively deform the softer aluminum in the body in a repeatable manner without significantly affecting the geometry of the die.

[0071] Preparation of textured bodies After the second forging step, excess material is removed from the edges of the cookware body 201. This defines the edges of the pot body to ensure a consistent shape.

[0072] Excess material also needs to be removed from the bottom of the cookware 200.

[0073] Clean the cookware body 201.

[0074] If the cookware 200 is suitable for an induction cooker, an electromagnetic hole is formed in the base 202. At this stage of the manufacturing process, the electromagnetic hole is attached to the cookware 200.

[0075] Surface roughening 312 In this example, the inner surface of the cookware is sandblasted. This creates a microtexture on the inner surface of the cookware without damaging the macro-pattern formed by the second forging. This microtexture creates a roughness on the inner surface with a length scale of approximately 10 µm or 20 µm or less. The width of a single recess forming the surface roughness can be between 1 µm and 10 µm, for example, between 3 µm and 8 µm.

[0076] Surface roughness can be altered by using different types of sand or other types of shot. Other roughening methods can also be used to achieve the desired surface roughness, such as shot peening, chemical etching, or electrochemical etching.

[0077] The entire inner surface of the body can be roughened. For example, in processes such as sandblasting, different angles or impact methods can be used to process the three-dimensional inner surface, thereby roughening, for example, curved surface areas and sidewalls.

[0078] After roughening treatment, the surface of the cookware body is cleaned a second time.

[0079] Apply non-stick coating 314 Apply the non-stick coating to the entire inner surface of the cookware.

[0080] The non-stick coating is applied with a thickness of less than 50µm, for example, 20µm to 30µm, so that the coating does not significantly alter the pattern formed by the second forging. Therefore, the non-stick coating follows the contour of the macroscopic surface texture of the raised portion 101 and the recessed portion 102. The coating thickness is substantially uniform on the inner surface of the body 201.

[0081] Any conventional application process can be used to apply the non-stick coating, as long as it forms the desired uniform layer. Although the recesses 102 can be partially filled during the coating process, it is preferable to leave most of the recesses 102 open / unfilled. Therefore, the final surface finish will have recesses, and the textured surface will be visible to the naked eye after coating.

[0082] This rough microtexture helps ensure good contact and adhesion between the non-stick coating and the surface of the body 201. The rough texture increases the adhesion surface area and changes the surface angle at the microscopic level, thereby preventing the non-stick coating from peeling off easily from the underlying surface.

[0083] finishing To achieve the final form of the cookware product, any, any combination of, or all of the following steps can be performed: - Apply a coating to the outside of the cookware.

[0084] - Base polishing.

[0085] - Polish the outer wall.

[0086] - Use traditional techniques, such as fasteners, to attach one or more handles.

[0087] - Add non-conductive material to the handle.

[0088] - Add markings to cookware or decorate the outside of cookware.

Claims

1. A method for manufacturing a cookware article having a textured inner surface, the method comprising: A first forging step is performed to form a three-dimensional body of the cookware article from a sheet material having a first main surface and an opposite second main surface, wherein the three-dimensional body includes a concave shape, in which the first surface constitutes an inner surface and the second surface constitutes an outer surface; A second forging step is performed on the three-dimensional body to form a surface texture on the inner surface; The inner surface texture is roughened to accommodate the surface coating. A non-stick coating is applied to the inner surface, the thickness of which is designed such that the surface texture remains after coating.

2. The method according to claim 1, wherein, The second forging step forms the surface texture portion on at least 90% of the inner surface of the concave three-dimensional body.

3. The method according to any one of the preceding claims, wherein, The second forging step forms the surface texture portion on the entire inner surface of the three-dimensional body.

4. The method according to any one of the preceding claims, wherein, The non-stick coating forms a layer of 50µm or smaller on the inner surface.

5. The method according to any one of the preceding claims, wherein, The second forging step includes pressing a mold onto the inner surface, the outer surface of which has a predetermined pattern, the predetermined pattern being the opposite of the surface texture formed on the inner surface of the three-dimensional body.

6. The method according to any one of the preceding claims, wherein, The first forging step forms the base and sidewalls of the three-dimensional body, and the second forging step forms the surface texture portion on the inner surface of the base and the inner surface of the sidewalls.

7. The method according to claim 6, wherein, The textured portion exists on the inner surface where the base intersects the sidewall, for example, on the curved transition between the base and the sidewall.

8. The method according to any one of the preceding claims, wherein, The roughening treatment of the surface textured portion results in the formation of micro-textures in the surface textured portion, the length scale of which is at least one order of magnitude smaller than that of the surface textured portion.

9. A cookware product, said cookware product comprising: A three-dimensional body in a concave form having an inner surface and an outer surface, the body comprising an underlying metallic material and a non-stick coating layer on the inner surface; A surface texture portion is pressed into the underlying metal material of the body, the surface texture portion comprising a pattern of discrete raised portions, the discrete raised portions being spaced by valleys located between the raised portions, the pattern extending on the inner surface; The non-stick coating layer is applied over the textured surface, the thickness of which is designed such that the pattern of the textured surface portion exists within the surface coating portion.

10. The cookware article according to claim 9, wherein, The textured portion includes irregular patterns.

11. The cookware article according to claim 9 or 10, wherein, The surface texture is continuous across the entire inner surface.

12. The cookware article according to claim 9 or 10, wherein, Each of the protruding portions is surrounded by a valley-like portion.

13. The cookware article according to claims 9 to 12, wherein, The valley-like portions form a continuous network on the surface texture.

14. The cookware article according to claims 9 to 13, wherein, The protruding portion and the valley-shaped portion have curved sides.

15. The cookware article according to claims 9 to 14, wherein, The protruding portion has an irregular shape on the plane.

16. The cookware article according to claims 9 to 15, wherein, The protruding portion has a width in the range of 0.5 mm to 5 mm.

17. The cookware article according to claims 9 to 16, wherein, The height difference between any protrusion and any valley is in the range of 0.2 mm to 0.8 mm, or in the range of 0.3 mm to 0.5 mm.

18. The cookware article according to claims 9 to 17, wherein, The protruding portion is arc-shaped in cross-sectional profile.

19. The cookware article according to claims 9 to 18, wherein, The underlying metal material includes aluminum.

20. The cookware article according to claims 9 to 19, wherein, The surface texture of the underlying metal material has a rough surface at the junction with the non-stick coating.

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