Non-stick pan and preparation method thereof

Abstract

The present application provides a non-stick pan and a preparation method thereof, the preparation method comprising the following steps: placing an amorphous alloy sheet into a hot pressing mold and hot pressing it into a pan, wherein the pressure of the hot pressing molding is controlled to be 200MPa to 400MPa, and the temperature of the hot pressing molding is controlled to be within the supercooled liquid phase region of the amorphous alloy; and the pan is demolded from the hot pressing mold to obtain a non-stick pan. The non-stick pan obtained by the preparation method of the present application has excellent long-lasting non-stick properties, wear resistance and hardness.

Description

Technical Field

[0001] The present application relates to the technical field of household appliances, and more specifically, to a non-stick pan and a preparation method thereof. Background Art

[0002] Non-stick pans will not make food stick to the bottom of the pan when cooking, avoiding the phenomenon of food sticking to the pan that often occurs in traditional pans during cooking, thus avoiding the problem of food burning and the production of harmful substances caused by burning. Non-stick pans not only reduce the difficulty of cleaning the pans, but also make it easy to fry and stir-fry food. Unlike traditional pans that require more grease to prevent food from sticking to the pan, non-stick pans can minimize the use of oil due to their non-stick properties, thereby reducing the user's fat intake, conforming to the modern people's pursuit of low-fat, low-calorie consumption trends. Therefore, non-stick pans have become the first choice for many families.

[0003] The cookware on the market mainly achieves the non-stick effect by coating the inner surface of the cookware with a non-stick layer, among which ceramic coating and silicone resin coating are the more common non-stick layers. Although both ceramic coating and silicone resin coating can be used as the non-stick layer of cookware, there are obvious problems in the use process. For example, the non-stick layer formed by ceramic coating has poor long-term non-stick properties and is easy to fall off after 3 to 6 months of use; the non-stick layer formed by silicone resin coating is easy to turn yellow or gray under high temperature or open flame conditions, and the hardness of the non-stick layer decreases at high temperature, which is easy to produce "re-sticking" phenomenon. Summary of the invention

[0004] The present application aims to provide a non-stick pan and a preparation method thereof, so as to solve the technical problems in the prior art that the non-stick coating of the non-stick pan is not wear-resistant, has poor long-term non-stick property, and is prone to "re-sticking" phenomenon.

[0005] To achieve the above-mentioned purpose, the embodiment of the first aspect of the present application provides a method for preparing a non-stick pan, the preparation method comprising the following steps: placing an amorphous alloy sheet into a hot pressing mold and hot pressing it into a pan, wherein the pressure of the hot pressing is controlled to be 200MPa to 400MPa, and the temperature of the hot pressing is controlled to be in the supercooled liquid phase region of the amorphous alloy; the pan is demolded from the hot pressing mold, thereby preparing a non-stick pan. In the present application, a pan is formed by hot pressing an amorphous alloy, and the amorphous alloy has good plasticity in the temperature range between the glass transition temperature and the crystallization temperature, and within this pressure range, the amorphous alloy has a high deformation rate, which can reduce the heating time of the amorphous alloy, inhibit the crystallization transformation of the amorphous structure in the amorphous alloy, and obtain a pan with low surface energy.

[0006] In some embodiments, the temperature of the hot pressing molding may be controlled to be in a temperature range of 50° C. to 150° C. above the glass transition temperature of the amorphous alloy.

[0007] In some embodiments, the preparation method may further include: after performing the hot pressing forming step and before performing the demoulding step, holding the mold under pressure. In a preferred embodiment, the holding time is not less than 30 seconds. In the present application, holding the hot pressing formed pot under pressure is beneficial to the pot forming to a certain extent and improves the pot forming rate.

[0008] In some embodiments, the amorphous alloy sheet can be selected from one of Fe-based amorphous alloy sheets, Zr-based amorphous alloy sheets, Cu-based amorphous alloy sheets, Al-based amorphous alloy sheets, Mg-based amorphous alloy sheets, and Ti-based amorphous alloy sheets. In some embodiments, the amorphous alloy sheet can be a Zr-based amorphous alloy sheet. In some embodiments, the temperature of hot pressing can be controlled at 650°C to 750°C.

[0009] In some embodiments, the thickness of the amorphous alloy sheet may be 3.5 mm to 5 mm, and the thickness of the wall of the prepared non-stick pan may be 2 mm to 4 mm.

[0010] An embodiment of the second aspect of the present application provides a non-stick pan, which is obtained by the preparation method in the embodiment of the first aspect.

[0011] In some embodiments, the non-stick pan can be a flat frying pan, a frying pan, or a wok. DETAILED DESCRIPTION

[0012] The non-stick pan of the present application and the preparation method thereof will be described in detail below.

[0013] However, the present application can be implemented in many different forms and should not be construed as limited to the specific embodiments set forth herein. Rather, the purpose of providing these embodiments is to make this application thorough and complete, and to fully convey the scope of this application to those skilled in the art.

[0014] In order to solve the technical problem of poor non-stick effect of the non-stick layer formed by the coating during use, some non-stick pans on the market use thermal spraying to form a physical non-stick layer on the surface of the pan. Although the physical non-stick layer prepared by thermal spraying increases the wear resistance of the non-stick layer, its non-stick effect is not ideal at present, and its preparation process is complicated. The surface of the prepared physical non-stick layer is rough and needs post-processing such as sanding.

[0015] To this end, the present application provides a new method for preparing a non-stick pan - using amorphous alloy hot pressing. According to the present application, an amorphous alloy is used as a material for forming a non-stick pan. The amorphous alloy is also called liquid metal. It has long-range disorder and short-range order structural characteristics, has lower surface energy, can prevent food from sticking to the pot, and achieves a non-stick effect. At the same time, amorphous alloys do not have structural defects such as grain boundaries, twins, lattice defects, dislocations, stacking faults, etc. like crystalline alloys, nor do they have heterogeneous phases, precipitates, segregation, and other component fluctuations. It is a chaotic disordered structure, which has a high degree of chemical uniformity and consistency. When subjected to external forces, plastic deformation such as grain boundary sliding does not occur, and has higher strength. Therefore, in the present application, the surface of the non-stick pan formed by hot pressing of an amorphous alloy has higher strength and better wear resistance, avoiding the problem of non-stick coating formed by coatings in the prior art being not wear-resistant, thereby extending the service life of the non-stick pan. The non-stick pan prepared according to the method of the present application has excellent non-stick effect, simple process, high dimensional accuracy, good stability, and can achieve a lasting non-stick effect.

[0016] The non-stick pan and the preparation method thereof according to the present application will be described in detail below.

[0017] According to the present application, the pot body of the non-stick pan is formed by hot pressing of an amorphous alloy. The non-stick pan can be a flat frying pan, a frying pan or a wok. The material used to make the non-stick pan is an amorphous alloy sheet, which can be selected from one of Fe-based amorphous alloys, Zr-based amorphous alloys, Cu-based amorphous alloys, Al-based amorphous alloys, Mg-based amorphous alloys and Ti-based amorphous alloys. The above-mentioned amorphous alloys are all common in the market, with the characteristics of wide sources and low prices, which can reduce the preparation cost of non-stick pans and are conducive to the market promotion of non-stick pans. Those skilled in the art can select the specific materials of the above-mentioned amorphous alloys under the guidance of this application, and this application does not make specific restrictions here.

[0018] According to an embodiment of the present application, a Zr-based amorphous alloy can be selected as a material for manufacturing a non-stick pan, and its critical cooling rate can reach below 106K / s, and the maximum forming thickness can reach 30mm. According to a preferred embodiment of the present application, the Zr-based amorphous alloy can be Zr43Ti13Ni10Cu12B22 or Zr50Al22Cr13B11Y4.

[0019] According to some embodiments of the present application, the thickness of the amorphous alloy sheet can be 3.5mm to 5mm, and the pot wall thickness of the non-stick cookware obtained by hot pressing can be 2mm to 4mm. If the pot wall thickness is less than 2mm, the non-stick pan will not be strong enough due to the thin pot wall. When the load is too large, the pot wall is prone to deformation, and at the same time, the risk of using the non-stick pan is increased. If the pot wall thickness is greater than 4mm, the weight of the pot body will increase. On the one hand, it will affect the heat conduction and waste energy when cooking. On the other hand, the pot wall is too heavy, which is not friendly to the elderly and women. It is easy to tip over and spill soup during cooking, which increases the probability of risks during the use of the non-stick pan.

[0020] The preparation method of the non-stick pan according to the present application includes the following steps: placing an amorphous alloy sheet into a hot pressing mold to press-form it into a pan, wherein the pressure of the hot pressing molding is controlled to be 200MPa~400MPa, and the temperature of the hot pressing molding is controlled to be within the supercooled liquid phase region of the amorphous alloy material, that is, between the glass transition temperature and the crystallization temperature; demolding the pan from the hot pressing mold to obtain a non-stick pan.

[0021] According to the present application, the heating temperature range of hot pressing is controlled to be within the supercooled liquid phase region of the amorphous alloy material (i.e., between the glass transition temperature and the crystallization temperature of the amorphous alloy material). When the atoms in the amorphous alloy are transformed from a frozen state to a moving state and subjected to the combined action of the applied stress and the thermal activation energy, the number of atoms that transition in the same direction will be greatly increased, so that it will appear as superplastic deformation on a macro scale, which is beneficial to the processing of the amorphous alloy. If the heating temperature is not within the supercooled liquid phase region of the amorphous alloy material, for example, if the heating temperature is lower than the glass transition temperature, the plasticity of the amorphous alloy will be reduced and it will not be able to be formed. If the heating temperature is higher than the crystallization temperature, the amorphous structure in the amorphous alloy will be transformed into a crystallized structure and the expected non-stick effect produced by the characteristics of the amorphous alloy cannot be achieved. Preferably, the heating temperature of hot pressing is controlled to be within the temperature range of 50°C to 150°C above the glass transition temperature of the amorphous alloy, preferably, within the temperature range of 50°C to 100°C above the glass transition temperature of the amorphous alloy.

[0022] Controlling the pressure range of hot pressing molding in the range of 200MPa to 400MPa can ensure that the amorphous alloy has a high deformation rate in the temperature range between the glass transition temperature and the crystallization temperature, reduce the heating time, and thus inhibit the crystal phase transformation of the amorphous structure. If the pressure is lower than 200MPa, the amorphous alloy sheet will not deform sufficiently, and the size and shape of the formed pot will not meet the requirements; on the contrary, if the pressure is higher than 400MPa, the deformation rate of the amorphous alloy is too fast, which may easily lead to the fracture of the amorphous alloy sheet.

[0023] According to an embodiment of the present application, when a Zr-based alloy is used to prepare a non-stick cookware, the hot pressing temperature can be controlled at 650° C. to 750° C. If the hot pressing temperature is lower than 650° C., the Zr-based amorphous alloy is difficult to deform by hot pressing; if the hot pressing temperature is higher than 750° C., the Zr-based amorphous alloy is prone to nanocrystallization, resulting in a decrease in the non-stick property of the formed non-stick cookware.

[0024] In addition, according to the method for preparing a non-stick pan of the present application, the pressure can be maintained for a period of time (for example, not less than 30 seconds) after hot pressing and before the pan is demolded, so as to improve the forming rate of the hot pressing pan to a certain extent.

[0025] According to the present application, the amorphous alloy sheet is pressed and formed in a hot pressing mold. Since the shrinkage rate of the amorphous alloy is very small when it is cooled, the one-time forming can ensure that the obtained pot has good dimensional accuracy and stability, and as long as the precision of the hot pressing mold is high enough, the subsequent processing allowance of the formed pot can be very small, thereby reducing the post-processing process and material waste.

[0026] A specific embodiment of the method for preparing a non-stick pan according to the present application will be described in detail below.

[0027] Example 1

[0028] A Zr43Ti13Ni10Cu12B22 sheet with a thickness of 4 mm was placed in a hot pressing mold and hot pressed into a cookware, wherein the pressure was controlled to be 200 MPa and the temperature to be 700°C, and then the pressure was maintained for 40 seconds. Finally, the cookware was demolded from the hot pressing mold to obtain a Zr-based amorphous non-stick pan with a pot wall thickness of 3 mm and a diameter (outer diameter) of 26 cm.

[0029] Example 2

[0030] A Zr-based amorphous non-stick pan with a thickness of 2.1 mm and an outer diameter of 26 cm was obtained by adopting a method substantially the same as that of Example 1 except that the hot pressing pressure was controlled to be 350 MPa.

[0031] Example 3

[0032] A Zr-based amorphous non-stick pan with a thickness of 3 mm and an outer diameter of 26 cm was obtained by adopting a method substantially the same as that of Example 1 except that the temperature of the hot pressing molding was controlled to be 670°C.

[0033] Example 4

[0034] A Fe72Si5B5Cr13C5 sheet with a thickness of 5 mm was placed in a hot pressing mold and hot pressed into a cookware, wherein the pressure was controlled to be 400 MPa and the temperature was 573°C, and then the pressure was maintained for 50 seconds. Finally, the cookware was demolded from the hot pressing mold to obtain an Fe-based amorphous non-stick pan with a thickness of 4 mm and an outer diameter of 26 cm.

[0035] Example 5

[0036] An Al55-Ti32-B3-Ni8-P2 sheet with a thickness of 3.5 mm was placed in a hot pressing mold and hot pressed into a cookware, wherein the pressure was controlled to be 280 MPa and the temperature to be 493°C, and then the pressure was maintained for 35 seconds. Finally, the cookware was demolded from the hot pressing mold to obtain an Al-based amorphous non-stick pan with a thickness of 2 mm and an outer diameter of 26 cm.

[0037] Comparative Example 1

[0038] A Zr-based non-stick pan with a thickness of 3 mm and an outer diameter of 26 cm was obtained by adopting a method substantially the same as that of Example 3 except that the temperature of the hot pressing molding was controlled to be 570°C.

[0039] Comparative Example 2

[0040] Except for controlling the hot pressing pressure to 500 MPa, a method basically the same as that of Example 4 was adopted to obtain an Fe-based non-stick pan with a thickness of 3.6 mm and an outer diameter of 26 cm.

[0041] Comparative Example 3

[0042] A commercially available aluminum alloy coated pot with an outer diameter of 26 cm was used, and its thickness was measured to be 3.5 mm.

[0043] Comparative Example 4

[0044] A conventional iron pan with an outer diameter of 26 cm purchased from the market was used, and its thickness was measured to be 2.3 mm.

[0045] Performance Testing:

[0046] The performance of the non-stick pans prepared in the above embodiments and comparative examples were tested, and the test results are recorded in the following Table 1.

[0047] (1) Non-stickiness test

[0048] According to the national standard GB / T32095 non-stick pan test method, the non-stick property of non-stick pans is tested according to the fried egg non-stick test. Check the adhesion of fried eggs to the pan and divide the non-stick property of the pan into the following three levels:

[0049] Excellent (○): Using a plastic spatula, the eggs can be removed without damage or residue.

[0050] Good (◎): The egg cannot be removed without damage using a plastic spatula, but the residue can be removed by gently wiping with a wet sponge.

[0051] Poor (×): The residue cannot be removed by wiping with a damp sponge.

[0052] (2) Dimensional deviation rate

[0053] The hot pressing is evaluated based on the pot body depth parameter, and the dimensional deviation rate = (actual hot pressing dimension - design dimension) × 100% / design dimension.

[0054] (3) Long-lasting non-stickiness test

[0055] The non-stick pan's long-lasting non-stick property is tested according to the standard GB / T32095.2-2015. The specific test method is as follows: the wear test is carried out using the 4.3.1 mid-plane wear test method. After each 1,000 wears, the 4.2.1 fried egg non-stick test is used to test the non-stick effect of the pan. The test is stopped until the non-stick level III (×) is reached for 2,000 consecutive times, and the number of wears is recorded.

[0056] Table 1: Performance index test results

[0057]

[0058]

[0059] It can be seen from Table 1 that the non-stick properties of the non-stick pans prepared according to Examples 1 to 5 are significantly better than those prepared according to Comparative Documents 1 and 2, and are particularly better than the aluminum alloy coated pans and conventional pans currently available on the market.

[0060] The specific implementation methods of the present application are described in detail above. Although some embodiments have been shown and described, those skilled in the art should understand that these embodiments may be modified and improved (for example, different features described in different embodiments may be combined) without departing from the principles and spirit of the present application, the scope of which is defined by the claims and their equivalents, and these modifications and improvements should also be within the scope of protection of the present application.

Claims

1. A method for preparing a non-stick pan, characterized in that: The preparation method comprises the following steps: The amorphous alloy sheet is placed in a hot pressing mold and hot pressed into a cookware, wherein the hot pressing pressure is controlled to be 200MPa-400MPa, and the hot pressing temperature is controlled to be within a temperature range of 50°C-150°C above the glass transition temperature of the amorphous alloy, thereby inhibiting the crystallization transformation of the amorphous structure in the amorphous alloy; Demolding the pan from the hot pressing mold to obtain a non-stick pan; The amorphous alloy sheet is selected from one of Fe-based amorphous alloy sheets, Zr-based amorphous alloy sheets, Cu-based amorphous alloy sheets, Al-based amorphous alloy sheets, Mg-based amorphous alloy sheets and Ti-based amorphous alloy sheets.

2. The method for preparing a non-stick pan according to claim 1, characterized in that: The Zr-based amorphous alloy sheet includes Zr 43 Ti 13 Ni 10 Cu 12 B 22 or Zr 50 Al 22 Cr 13 B 11 Y4; the Fe-based amorphous alloy sheet includes Fe 72 Si5B5Cr 13 C5, the Al-based amorphous alloy sheet includes Al 55 Ti 32 B3Ni8P2.

3. The method for preparing a non-stick pan according to claim 1, characterized in that: The preparation method further comprises: maintaining pressure on the mold after performing the hot pressing molding step and before performing the demoulding step.

4. The method for preparing a non-stick pan according to claim 3, characterized in that: The pressure maintaining time shall not be less than 30s.

5. The method for preparing a non-stick pan according to claim 1, characterized in that: The thickness of the amorphous alloy sheet is 3.5 mm to 5 mm.

6. The method for preparing a non-stick pan according to claim 5, characterized in that: The amorphous alloy sheet is a Zr-based amorphous alloy sheet.

7. The method for preparing a non-stick pan according to claim 1, characterized in that: The temperature of the hot pressing molding is controlled at 650°C to 750°C.

8. The method for preparing a non-stick pan according to claim 1, characterized in that: The thickness of the non-stick pan wall is 2mm~4mm.

9. A non-stick pan, characterized in that: The non-stick pan is obtained by adopting the preparation method according to any one of claims 1 to 8.

10. The non-stick pan according to claim 9, characterized in that: The non-stick pan is a flat frying pan, a frying pan or a wok.

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