Method for evaluating the lifetime of a non-stick pan coating

Abstract

The application provides a non-stick pot coating life evaluation method, including: subjecting a non-stick pot sample to different cycle working condition simulation wear treatment to obtain a series of test samples corresponding to simulation cycles and having gradientized wear degrees; detecting the surface topography characteristic parameters of each test sample, the topography characteristic parameters including at least one of an arithmetic mean deviation of profile Ra and a maximum height of profile Rz; performing a standardized non-stick performance grade evaluation on each test sample to obtain an evaluation grade; constructing a quantitative correlation model based on the topography characteristic parameters, the corresponding evaluation grade and the corresponding simulation cycle; obtaining the surface topography characteristic parameters of a target non-stick pot to be evaluated; and evaluating the coating service life state of the target non-stick pot based on the surface topography characteristic parameters of the target non-stick pot and the quantitative correlation model. The non-stick pot coating life evaluation method provided by the application realizes non-destructive evaluation of the coating life of an in-use non-stick pot.

Description

Technical Field

[0001] This application relates to the field of kitchenware evaluation technology, and in particular to a method for evaluating the lifespan of non-stick pan coatings. Background Technology

[0002] Non-stick cookware has become widely used in modern kitchens due to its excellent release properties and easy-to-clean characteristics. Its core function relies on the non-stick coating applied to its surface. However, over long-term use, the coating gradually wears down or ages due to factors such as scratches, thermal shock, and chemical corrosion, leading to a decline in non-stick performance and even coating peeling, posing food safety risks. Therefore, establishing a scientific and objective method for assessing coating lifespan is crucial. It not only helps consumers rationally determine when to replace their cookware and avoid health risks, but also provides manufacturers with key information for optimizing material formulations and processes, significantly impacting product quality control and improving user experience.

[0003] In existing technology, the non-stick performance grade is evaluated using the fried egg test method specified in GB / T 32095.2-2015. The procedure is as follows: With the coating surface temperature stable at 150℃ to 170℃, a fresh egg weighing 50 to 60 grams is cracked into the pan and spread out. After the egg white has completely solidified, a plastic spatula with a 0.3 mm thick blade is used to attempt to remove the fried egg from the coating surface. Subsequently, the grade is determined based on the residue remaining on the coating surface after removal, according to the standard's definition.

[0004] However, the inventors discovered in realizing this invention that the evaluation process itself constitutes a cooking abrasion, and the required scraping operation will cause irreversible physical damage to the coating being tested. It is a destructive test and cannot monitor the condition of cookware that is still in use without damage. Summary of the Invention

[0005] The purpose of this application is to provide a method for evaluating the lifespan of non-stick pan coatings, so as to achieve a non-destructive evaluation of the lifespan of non-stick pan coatings in use.

[0006] To address the aforementioned technical problems, the embodiments of this application provide the following technical solutions:

[0007] This application provides a method for evaluating the lifespan of non-stick cookware coatings, including:

[0008] Non-stick pan samples were subjected to wear simulation treatment under different cycles to obtain a series of test samples with gradient wear levels corresponding to the simulation cycle.

[0009] The morphological feature parameters of the coating surface of each of the test samples are detected, and the morphological feature parameters include at least one of the profile arithmetic mean deviation Ra and the profile maximum height Rz;

[0010] The non-stick performance level of each test sample is standardized and evaluated to obtain the evaluation level;

[0011] A quantitative correlation model is constructed based on the morphological feature parameters, the corresponding evaluation level, and the corresponding simulation period.

[0012] Obtain the morphological characteristics of the coating surface of the target non-stick pan to be evaluated;

[0013] Based on the morphological features of the coating surface of the target non-stick pan and the quantitative correlation model, the service life of the coating of the target non-stick pan is evaluated.

[0014] In some modified embodiments of the first aspect of this application, the topographic feature parameters include the arithmetic mean deviation of the profile Ra and the maximum height of the profile Rz;

[0015] The standardized non-stick performance rating is conducted according to the egg frying test method specified in GB / T 32095.2-2015, and the rating levels include Grade I, Grade II and Grade III.

[0016] In some embodiments, the method for constructing the quantitative correlation model includes:

[0017] Based on the distribution of the morphological feature parameters of the test sample whose evaluation level is rated as Level III, the threshold of the profile arithmetic mean deviation Ra corresponding to the end-of-life state and the threshold of the profile maximum height Rz corresponding to the end-of-life state are determined.

[0018] The lifespan termination period is determined based on the simulated wear cycle corresponding to the test sample that has reached the said lifespan termination state.

[0019] In some embodiments, for coatings of different material categories, a quantitative correlation model specifically for the corresponding material coating is constructed.

[0020] In some embodiments, the coating of the nonstick pan sample is any one of a ceramic coating, a polytetrafluoroethylene coating, a diamond coating, or a graphene-reinforced composite coating.

[0021] In some embodiments, a dedicated quantitative correlation model is constructed for the ceramic coating, which defines the lifespan status of the ceramic coating according to the following rules:

[0022] When Ra < 2.7 μm, it is defined as the stage of good performance;

[0023] When 2.7μm≤Ra≤3.6μm, it is defined as the performance stable stage;

[0024] When Ra > 3.6 μm and 180 μm < Rz ≤ 200 μm, it is defined as the performance degradation stage.

[0025] When Ra > 3.6 μm and Rz > 200 μm, it is defined as the end-of-life state.

[0026] In some embodiments, the method for evaluating the service life of the target nonstick pan includes:

[0027] Based on the morphological feature parameters of the target non-stick pan, the corresponding equivalent usage period is determined in the quantitative correlation model;

[0028] The remaining usage time of the target non-stick pan is determined based on the difference between the equivalent usage period and the end-of-life period.

[0029] In some embodiments, the method for determining the remaining usage time of the target nonstick pan further includes:

[0030] The cooking data of the target non-stick pan during actual use is collected, and the cooking data includes at least one of the following: daily cooking time, average cooking temperature, and daily cleaning frequency.

[0031] The intensity factor to be used is determined based on the cooking data;

[0032] The remaining usage time is adjusted based on the intensity factor.

[0033] In some embodiments, the method of simulating wear under working conditions includes: linearly rubbing the coating surface of the non-stick pan sample with a friction head;

[0034] The method for detecting the morphological feature parameters of the coating surface of each test sample includes: detecting the local morphological feature parameters of the starting region, the middle region and the ending region of the linear friction path respectively, and calculating the average value of the three as the morphological feature parameters of the test sample.

[0035] In some embodiments, the different cycles of simulated wear treatment are equivalent to usage durations of 0 months, 6 months, 12 months, 18 months, 24 months, 30 months, and 36 months, respectively.

[0036] Compared with existing technologies, the non-stick pan coating life assessment method provided in this application constructs a complete and continuous coating wear evolution sample chain by performing different cycle working condition wear simulation on non-stick pan samples, laying a solid data foundation for establishing a high-precision life prediction model.

[0037] This application creatively introduces the arithmetic mean deviation of the profile Ra and / or the maximum profile height Rz as key evaluation indicators. Ra characterizes the overall uniformity of wear on the coating surface, while Rz characterizes localized extreme damage, achieving precise characterization of the coating's physical morphology from at least one dimension. Through standardized non-stick performance rating, macroscopic, subjective non-stick properties are quantitatively correlated with microscopic, objective morphological characteristic parameters and simulation cycles, thereby constructing a reliable quantitative correlation model.

[0038] When evaluating a target nonstick pan, its surface morphology parameters can be obtained quickly and non-destructively, and its current service life can be assessed based on this model. Because the entire evaluation process completely eliminates the destructive steps of heating, cooking, and physical removal required by traditional methods, it achieves a non-destructive and repeatable assessment of the coating life of in-use nonstick pans. Attached Figure Description

[0039] The above and other objects, features, and advantages of exemplary embodiments of this application will become readily understood by reading the following detailed description with reference to the accompanying drawings. In the drawings, several embodiments of this application are illustrated by way of example and not limitation, with the same or corresponding reference numerals denoteing the same or corresponding parts, wherein:

[0040] Figure 1 The Ra-evaluation level-simulation cycle correlation diagram of the ceramic non-stick long-handled wok in Example 1 is schematically shown;

[0041] Figure 2 The diagram schematically illustrates the correlation between Rz-evaluation level and simulation cycle for the ceramic non-stick long-handled wok in Example 1.

[0042] Figure 3 A schematic diagram illustrating the Ra-evaluation level-simulation cycle correlation of the ceramic-coated soup pot in Example 2 is shown.

[0043] Figure 4 The diagram schematically illustrates the correlation between Rz-evaluation level and simulation cycle for the ceramic-coated soup pot in Example 2;

[0044] Figure 5 The Ra-evaluation level-simulation cycle correlation diagram of the ceramic nonstick frying pan in Example 3 is shown schematically;

[0045] Figure 6 The diagram schematically illustrates the correlation between Rz-evaluation level and simulation cycle for the ceramic nonstick frying pan in Example 3;

[0046] Figure 7 The Ra-evaluation grade-simulation cycle correlation diagram of the non-stick frying pan (PTFE coating) in Example 4 is schematically shown;

[0047] Figure 8 The diagram schematically illustrates the correlation between Rz-evaluation level and simulation cycle for the non-stick pan (PTFE coating) in Example 4. Detailed Implementation

[0048] Exemplary embodiments of the present disclosure will now be described in more detail with reference to the accompanying drawings. While exemplary embodiments of the present disclosure are shown in the drawings, it should be understood that the present disclosure may be implemented in various forms and should not be limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the disclosure to those skilled in the art.

[0049] It should be noted that, unless otherwise stated, the technical or scientific terms used in this application shall have the ordinary meaning as understood by one of ordinary skill in the art to which this application pertains.

[0050] This application provides a method for evaluating the lifespan of non-stick cookware coatings, including:

[0051] Non-stick pan samples were subjected to wear simulation treatment under different cycles to obtain a series of test samples with gradient wear levels corresponding to the simulation cycle.

[0052] In some embodiments, a dedicated quantitative correlation model is constructed for coatings of different material types.

[0053] In some embodiments, the coating of the nonstick pan sample is any one of a ceramic coating, a polytetrafluoroethylene coating, a diamond coating, or a graphene-reinforced composite coating.

[0054] Specifically, the test samples can be multiple independent non-stick pans, each undergoing different cycles of wear treatment. For example, a new non-stick pan with the same coating material can be selected as the non-stick pan sample to construct a quantitative correlation model for the specific coating material. Subsequently, the material of the target non-stick pan's coating can be substituted into its material-specific quantitative correlation model to improve the accuracy of the evaluation. Multiple non-stick pans can be of the same brand and model, and the number of pans can be five, six, seven, eight, or even more. Initial performance consistency verification can be performed on non-stick pan samples with the same coating material. Conditions for initial performance consistency include: coating thickness deviation ≤ 5μm for each non-stick pan (detectable using an eddy current thickness gauge), initial Ra deviation ≤ 0.2μm for each non-stick pan, initial Rz ≤ 5μm for each non-stick pan, and initial non-stick performance of all pans being Grade I. By ensuring the consistency of the initial state of the test samples, errors caused by variations in the manufacturing process despite the same material are avoided, further enhancing data reliability. Alternatively,

[0055] The same non-stick pan can be subjected to multiple stages of wear treatment sequentially. After each stage, it can be used as a test sample for the corresponding cycle, thereby obtaining a series of test samples with gradient wear levels corresponding to the simulation cycle.

[0056] A rotary friction tester or a linear friction tester can be used to simulate actual usage scenarios. In some embodiments, the method for simulating wear under working conditions includes: performing linear friction on the coating surface of the non-stick pan sample using a friction head;

[0057] The method for detecting the morphological feature parameters of the coating surface of each test sample includes: detecting the local morphological feature parameters of the starting region, the middle region and the ending region of the linear friction path respectively, and calculating the average value of the three as the morphological feature parameters of the test sample.

[0058] Specifically, in everyday cooking, the scraping of the coating by a spatula is mainly a reciprocating sliding linear friction (such as flipping eggs or scooping food). Linear friction can accurately reproduce this mechanical action, more closely reflecting actual user behavior and improving the realism and representativeness of the simulation.

[0059] Non-stick pans experience two types of wear in actual use: wear from stirring with a spatula during cooking and wear from cleaning. A wood rubbing head can be used to apply linear friction to the coating of a non-stick pan sample to simulate the wear caused by stirring with a spatula during cooking. Similarly, a scouring pad can be used to apply linear friction to the coating to simulate the wear caused by cleaning.

[0060] The starting region of the linear friction path can be the 0-3cm segment after the starting point of the friction path, which corresponds to the common starting position for stir-frying on the edge of a non-stick pan.

[0061] The middle region of the linear friction path can be the 4-7cm segment after the starting point of the friction path, which corresponds to the high-frequency contact position at the center of the non-stick pan.

[0062] The termination region of the linear friction path can be a segment 8-10cm after the starting point of the friction path, which corresponds to the edge of the non-stick pan opposite to the starting point.

[0063] Non-contact 3CCD true color confocal microscopes or laser confocal roughness meters can be used to detect the surface morphology of the coating. For example, using a 3CCD true color confocal microscope with 50x magnification (10x eyepiece, 5x objective lens), the local morphological feature parameters of the start, middle, and end segments of the linear friction path can be obtained respectively. Then, the average value of the three can be calculated to obtain the morphological feature parameters of the test sample, so as to comprehensively reflect the overall wear state of the entire friction path and make the correlation between the morphological feature parameters and the actual non-stick performance more accurate.

[0064] In some embodiments, the simulated wear treatment under different working conditions can be flexibly set with gradient simulation cycle intervals according to the evaluation accuracy requirements and coating material characteristics. For example, the cycle interval can be set to 3 months, 6 months, 12 months, etc., to cover the entire lifespan of the non-stick pan coating from brand new and unused to the end of its lifespan.

[0065] In some embodiments, in order to prioritize both evaluation efficiency and data coverage, the different cycles of simulated wear treatment are equivalent to usage durations of 0 months, 6 months, 12 months, 18 months, 24 months, 30 months, and 36 months, respectively.

[0066] Specifically, the simulation cycle corresponds to the actual usage time. The principle is based on the real frequency and intensity of daily cooking and cleaning, and converts the cumulative wear of the coating in actual use into the number of friction cycles that the working condition simulation equipment can precisely control, so as to ensure that the simulated wear level is highly consistent with the real usage scenario.

[0067] The core parameters of wear and tear scenarios can be determined by surveying the regular usage habits of household users.

[0068] The cooking scenario is calculated based on two operations per day, with a net time of 10 minutes each time (only the effective stir-frying time in contact with the spatula and coating is counted), and 300 days of use per year, for a total cooking time of 12,000 minutes over two years.

[0069] The washing process is performed twice a day, with each cleaning session lasting 1 minute (only the effective wiping time in contact with the coating is counted), for a total of 300 days of operation per year, accumulating 1200 minutes over two years.

[0070] The working condition simulation can be achieved by using a linear grinder (such as the American TABER linear grinder) to make the parameters controllable. The specific equipment settings are as follows: use a friction head with a diameter of 2 feet (matching the common contact area of ​​non-stick pans), apply a 600g weight for cooking simulation (equivalent to the normal stir-frying force of an adult), apply a 300g weight for cleaning simulation (equivalent to the pressure of hand washing), and set the friction frequency to 60 reciprocations / minute (corresponding to 120 times / minute in one direction, which is matched to the actual operating frequency through the equipment program).

[0071] Based on the above parameters, the program settings of the linear grinding machine corresponding to each simulation cycle are shown in Table 1.

[0072] Table 1 Linear grinding machine programs corresponding to different simulation cycles (unit: times, one-way)

[0073]

[0074] Seven gradient simulation cycles from 0 months (brand new and unused, without friction treatment, as the initial reference sample) to 36 months (overdue use) are selected in this application, which completely cover the entire life evolution process of the non-stick pan coating from "good performance → stable performance → performance decline → life failure", ensuring that the "topographic feature parameters - evaluation grade - simulation cycle" quantitative correlation model constructed subsequently covers all stages of actual use and improving its scope of application.

[0075] Detect the topographic feature parameters on the surface of the coating of each of the test samples, and the topographic feature parameters include at least one of the profile arithmetic mean deviation Ra and the profile maximum height Rz.

[0076] Specifically, a non-contact 3CCD true-color confocal microscope or a laser confocal roughness meter can be used to detect the surface topography of the coating, and the standard analysis software supporting the equipment is used to automatically calculate Ra (profile arithmetic mean deviation) and Rz (profile maximum height). Among them, the calculation methods of Ra and Rz belong to the conventional means well-known to those skilled in the art and will not be elaborated here.

[0077] Ra is used to characterize the overall uniform wear degree of the coating surface, that is, the overall trend of surface roughness. Since Ra comprehensively reflects the information of all profile points in the area, it can stably reflect the cumulative situation of uniform wear during the long-term use of the coating (such as daily frying and cleaning). Among them, the larger the Ra value, the higher the overall roughness of the coating surface and the more serious the uniform wear.

[0078] Rz is used to characterize local extreme damage conditions, that is, the range of coating thickness under the test area. Rz is more sensitive to local deep scratches, coating peeling depressions and other extreme damages, and can accurately capture non-uniform damages caused by accidental scraping with a metal spatula or local impact during the use of the cookware. Among them, the larger the Rz, the greater the extreme unevenness of the surface.

[0079] The topographic feature parameters can include one of the profile arithmetic mean deviation Ra and the profile maximum height Rz; or, the topographic feature parameters can include both parameters of the profile arithmetic mean deviation Ra and the profile maximum height Rz, and a "whole - local" complementary detection system is formed through two-dimensional collaborative characterization to achieve full coverage of the coating wear state and more accurately and comprehensively capture the complete characteristics of coating wear without omission.

[0080] The non-stick performance level of each test sample was standardized and an evaluation level was obtained.

[0081] In some embodiments, the morphological feature parameters include the contour arithmetic mean deviation Ra and the maximum contour height Rz;

[0082] The standardized non-stick performance rating is conducted according to the egg frying test method specified in GB / T 32095.2-2015, and the rating levels include Grade I, Grade II and Grade III.

[0083] Specifically, according to GB / T 32095.2-2015, take 50-60g of fresh egg, spread it on the coating surface at 150-170℃ until the egg white solidifies, and remove the fried egg with a plastic spatula with a 0.3mm thick tip. Observe the adhesion of the coating surface. Based on the degree of adhesion residue on the coating surface, the non-stick performance is divided into three levels.

[0084] Level I: Eggs can be removed without damage or leaving any residue using a plastic spatula;

[0085] Level II: The egg cannot be removed without damage using a plastic spatula, but the residue can be removed by gently wiping with a damp sponge or cloth;

[0086] Grade III: Residue cannot be removed by gently wiping with a damp sponge or cloth.

[0087] A quantitative correlation model is constructed based on the morphological feature parameters, the corresponding evaluation level, and the corresponding simulation period.

[0088] In one specific implementation, the quantitative correlation model can be constructed using a graphical method.

[0089] Specifically, a correlation diagram of Ra-evaluation level-simulation period can be drawn with the simulation period as the horizontal axis, the evaluation level as the left vertical axis, and the profile arithmetic mean deviation Ra as the right vertical axis.

[0090] A graph showing the relationship between Rz, evaluation level, and simulation period can be plotted with the simulation period as the horizontal axis, the evaluation level as the left vertical axis, and the maximum profile height Rz as the right vertical axis.

[0091] Based on the above graphs, a visual correlation model is established between morphological characteristic parameters, non-stick performance level, and simulation cycle, which can be used for subsequent evaluation of the lifespan of the target non-stick pan.

[0092] In some embodiments, the method for constructing the quantitative correlation model includes:

[0093] Based on the distribution of the morphological feature parameters of the test sample whose evaluation level is rated as Level III, the threshold of the profile arithmetic mean deviation Ra corresponding to the end-of-life state and the threshold of the profile maximum height Rz corresponding to the end-of-life state are determined.

[0094] The lifespan termination period is determined based on the simulated wear cycle corresponding to the test sample that has reached the said lifespan termination state.

[0095] Specifically, key inflection points can be determined by analyzing the variation of morphological characteristic parameters with the simulation cycle. Based on the data sequence of the profile arithmetic mean deviation Ra of the test sample changing with the simulation cycle, the first or second derivative can be calculated within the simulated wear cycle range corresponding to the test sample rated as Level III. When the second derivative reaches a local maximum value within this range, the corresponding simulation cycle point is denoted as the Ra inflection point, and its corresponding Ra value can be denoted as Ra_inflection point, and the corresponding simulation cycle can be denoted as T_Ra.

[0096] Similarly, based on the data sequence of the maximum profile height Rz changing with the simulation cycle, the first or second derivative is calculated within the simulation wear cycle range corresponding to the Level III sample; when the second derivative reaches a local maximum value within this range, the corresponding simulation cycle can be denoted as T_Rz, and the corresponding Rz value can be denoted as Rz_inflection point.

[0097] Furthermore, based on T_Ra and T_Rz, the final lifespan termination period is determined by taking the maximum value or using a weighted average.

[0098] This application achieves the quantification and objectification of non-stick coating life assessment by determining the threshold values ​​of profile arithmetic mean deviation Ra and maximum profile height Rz corresponding to the end-of-life state. It transforms the macroscopic non-stick performance degradation into measurable surface morphology parameters, significantly improving the accuracy, consistency and practicality of the assessment.

[0099] In some embodiments, a dedicated quantitative correlation model is constructed for the ceramic coating, which defines the lifespan status of the ceramic coating according to the following rules:

[0100] When Ra < 2.7 μm, it is defined as the stage of good performance;

[0101] When 2.7μm≤Ra≤3.6μm, it is defined as the performance stable stage;

[0102] When Ra > 3.6 μm and 180 μm < Rz ≤ 200 μm, it is defined as the performance degradation stage.

[0103] When Ra > 3.6 μm and Rz > 200 μm, it is defined as the end-of-life state.

[0104] Specifically, when Ra < 2.7 μm, the ceramic coating surface is smooth, without obvious scratches or damage, and the non-stick properties are stable. No adhesion occurs during the entire food processing process. According to experimental statistics, the Rz value is usually below 126 μm, which is defined as the stage of good performance.

[0105] When 2.7μm≤Ra≤3.6μm, the ceramic coating shows slight uniform wear, but it does not affect the demolding effect. At this time, the non-stick performance begins to decline, which is defined as the performance stabilization stage.

[0106] When Ra > 3.6 μm and Rz ≤ 200 μm, the surface roughness of the ceramic coating increases significantly, local microcracks expand, and the evaluation level reaches Level III. Conventional cleaning methods can no longer remove food residues adhering to the surface of the ceramic coating. At this time, the Rz value is generally greater than 180 μm, and obvious grooves can be observed on the coating surface through three-dimensional images. This also significantly increases the irregular contact area between the ceramic coating and food, which is defined as the performance degradation stage.

[0107] When Ra > 3.6 μm and Rz > 200 μm, food residue on the ceramic coating surface clumps over a large area after cooking, and some areas show a tendency for food residue to carbonize. This is a specific manifestation of severe damage to the ceramic coating leading to uneven local heat conduction. It is considered that the ceramic non-stick pan has exhausted its lifespan and can no longer be used, which is defined as the end of its lifespan.

[0108] That is, for ceramic coatings, the threshold for the profile arithmetic mean deviation Ra corresponding to the end-of-life state is >3.6μm, and the threshold for the maximum profile height Rz is >200μm.

[0109] By dividing the lifespan of ceramic coatings into four stages—intact performance, stable performance, degradation, and end of life—a refined and quantitative assessment of the ceramic coating degradation process is achieved. Compared to the traditional binary "usable / unusable" judgment, the staged evaluation better reflects the gradual wear pattern of coatings and can truly reflect the complete evolution path from stable performance to gradual deterioration. Each stage uses morphological parameters such as Ra and Rz as criteria, combined with actual usage performance, to define clear thresholds, improving the objectivity and repeatability of the assessment. This method not only supports non-destructive testing of in-use cookware but also enables dynamic tracking and trend prediction of lifespan status. By setting a "degradation stage" as an early warning interval, replacement prompts can be issued to users before the ceramic coating's function significantly declines, effectively avoiding usage inconvenience and food safety risks caused by sudden sticking or coating peeling. Simultaneously, the multi-stage model provides enterprises with a scientific basis for material durability evaluation, product quality assurance definition, and process optimization, enhancing the practical value of the assessment results in R&D, production, and consumer scenarios. Overall, the staged evaluation mechanism significantly improves the accuracy, foresight, and user experience of non-stick ceramic coating lifespan assessment.

[0110] Obtain the morphological characteristics of the coating surface of the target nonstick pan to be evaluated.

[0111] Based on the morphological features of the coating surface of the target non-stick pan and the quantitative correlation model, the service life of the coating of the target non-stick pan is evaluated.

[0112] Specifically, a non-contact 3CCD true color confocal microscope or a laser confocal roughness meter can be used to scan and detect the coating surface of the target non-stick pan, and obtain its profile arithmetic mean deviation Ra and / or profile maximum height Rz.

[0113] Based on the acquired morphological feature parameters, a matching process is performed in the quantitative correlation model to determine their corresponding positions in the multidimensional relationships of Ra-evaluation level-simulation cycle and Rz-evaluation level-simulation cycle, thereby determining the current service life status.

[0114] Non-contact testing methods avoid secondary damage to the coating surface and are suitable for rapid on-site evaluation of non-stick cookware in use. Combined with a pre-built quantitative correlation model, it can achieve non-destructive, quantitative, and highly repeatable evaluation of the coating life status, significantly improving testing efficiency and result objectivity, and providing a scientific basis for user replacement decisions, enterprise quality assurance determination, and product iteration optimization.

[0115] In some embodiments, the method for evaluating the service life of the target nonstick pan includes:

[0116] Based on the morphological feature parameters of the target non-stick pan, the corresponding equivalent usage period is determined in the quantitative correlation model;

[0117] The remaining usage time of the target non-stick pan is determined based on the difference between the equivalent usage period and the end-of-life period.

[0118] Specifically, the Ra value of the target non-stick pan can be substituted into the Ra-evaluation level-simulation cycle correlation graph to find the corresponding simulation cycle, which is the first equivalent usage cycle. Similarly, the Rz value of the target non-stick pan can be substituted into the Rz-evaluation level-simulation cycle correlation graph to find the corresponding simulation cycle, which is the second equivalent usage cycle. When both Ra and Rz are obtained, a weighted average or the maximum value of the first and second equivalent usage cycles can be taken to obtain the final equivalent usage cycle. Subtracting the equivalent usage cycle of the target non-stick pan from the end-of-life cycle yields the remaining usage time.

[0119] This method maps measured morphological parameters to "equivalent usage time," enabling a quantitative expression of the coating wear state over time, allowing users to intuitively understand "how much longer it can be used." Combined with a multi-parameter fusion strategy, it improves the accuracy and robustness of the assessment. The entire process does not require damaging the coating, supporting non-contact, rapid, and repeatable assessment of in-use cookware, providing a scientific and objective technical means for user replacement decisions, corporate warranty services, and product life prediction.

[0120] In some embodiments, the method for determining the remaining usage time of the target nonstick pan further includes:

[0121] The cooking data of the target non-stick pan during actual use is collected, and the cooking data includes at least one of the following: daily cooking time, average cooking temperature, and daily cleaning frequency.

[0122] The intensity factor to be used is determined based on the cooking data;

[0123] The remaining usage time is adjusted based on the intensity factor.

[0124] Specifically, based on cooking data, an intensity factor is determined, where the intensity factor Q represents the coating wear acceleration factor relative to baseline usage conditions.

[0125] The baseline usage conditions may include the calibration conditions set during the simulated wear treatment, such as the corresponding force, daily cooking time, number of washes, and friction frequency. For example, the baseline conditions could be: total daily cooking time ≤ 20 minutes, number of washes ≤ 2 times per day, applied force ≤ 600g, friction frequency of 60 cycles / minute, and a corresponding Q of 1.

[0126] When the actual usage intensity is higher than the benchmark, Q > 1 is used; when the actual usage intensity is lower than the benchmark, Q < 1. The value of the usage intensity factor can be determined by the following rule: the final Q is the algebraic sum of 1 and each adjustment amount, and Q ≥ 0.5. If Q is lower than 0.5, it is taken as 0.5.

[0127] Daily cooking time: >20 minutes, Q increases by 0.3; <10 minutes, Q decreases by 0.2;

[0128] Daily cleaning frequency: ≥3 times, Q increases by 0.2; ≤1 time, Q decreases by 0.1;

[0129] Force applied: >600g, Q increases by 0.2; ≤400g, Q decreases by 0.1;

[0130] Friction frequency: ≥60 cycles / minute, Q increases by 0.2; <40 cycles / minute, Q decreases by 0.2.

[0131] The formula for adjusting the remaining usage time based on the intensity factor is as follows:

[0132] T 剩余 =T 剩余 / Q

[0133] In the formula,

[0134] T 剩余 'This is the remaining usage time after correction;'

[0135] T 剩余 Remaining usage time;

[0136] Q is the intensity factor.

[0137] For example, if the target non-stick pan is used for 25 minutes of cooking per day and washed 3 times, with an applied force of 650g and a friction frequency of 50 reciprocations per minute, the intensity factor Q is 1.7. Based on the difference between the equivalent service life and the end-of-life period, if the remaining service life of the target non-stick pan is determined to be 17 months, then the corrected remaining service life is 10 months.

[0138] In some embodiments, the cooking data may also include other parameters that affect lifespan during actual use, such as cooking temperature. The reference temperature may be set to ≤180°C, and corresponding adjustment rules may be set to further optimize the evaluation accuracy.

[0139] By introducing actual usage intensity factors, personalized and dynamic corrections to lifespan assessments are achieved, significantly improving the accuracy and user adaptability of assessment results. A user-specific cookware health record is created, supporting intelligent services such as lifespan warnings and usage suggestion pushes, enhancing user experience and product added value.

[0140] Example 1

[0141] Using a linear abrasive from the American company TABER, the coating on the surface of the cookware was linearly rubbed with a chicken wing wood spatula and a scouring pad, respectively, to simulate the wear and tear on the coating surface when using a spatula to stir-fry and clean the cookware.

[0142] The Z1-32 ceramic non-stick long-handled wok was simulated in its new condition and after 6, 12, 18, 24, 30, and 36 months of use. The program settings for the linear grinder are shown in Table 1.

[0143] The roughness of the coating over the entire observation area was analyzed using a 3CCD true color confocal microscope, and the Ra and Rz values ​​of the Z1-32 ceramic non-stick long-handled wok in each simulation cycle were obtained as shown in Table 2.

[0144] Table 2. Ra and Rz values ​​of Z1-32 ceramic non-stick long-handled wok in each simulation cycle.

[0145]

[0146] The Z1-32 ceramic non-stick long-handled wok was evaluated for each simulation cycle using the method in 4.2.1 of GB / T 32095.2-2015. The evaluation results are shown in Table 3.

[0147] Table 3 Evaluation results of Z1-32 ceramic non-stick long-handled wok in each simulation cycle

[0148]

[0149] Based on the data in Tables 2 and 3, a correlation graph of Ra, evaluation level, and simulation period is established for the Z1-32 ceramic non-stick long-handled wok, with the simulation period as the x-axis, the evaluation level as the left y-axis, and Ra as the right y-axis. Figure 1 As shown.

[0150] Based on the data in Tables 2 and 3, a correlation graph of Rz, evaluation level, and simulation period is established for the Z1-32 ceramic non-stick long-handled wok, with the simulation period as the x-axis, the evaluation level as the left y-axis, and Rz as the right y-axis. Figure 2 As shown.

[0151] Example 2

[0152] The difference between Example 2 and Example 1 is as follows:

[0153] The non-stick pan sample is a C1-18 cm ceramic-coated soup pot.

[0154] The roughness of the coating over the entire observation area was analyzed using a 3CCD true color confocal microscope, and the Ra and Rz values ​​of the C1-18 cm ceramic coated soup pot in each simulation period were obtained as shown in Table 3.

[0155] Table 4. Ra and Rz values ​​of C1-18 cm ceramic-coated soup pot in each simulation period.

[0156]

[0157] The grade evaluation of each simulation cycle of the C1-18 cm ceramic coated soup pot was carried out using the method in 4.2.1 of GB / T 32095.2-2015. The evaluation results are shown in Table 5.

[0158] Table 5 Evaluation results of C1-18 cm ceramic-coated soup pot in each simulation period

[0159]

[0160] Based on the data in Tables 4 and 5, a correlation graph of Ra, evaluation level, and simulation period was constructed for the C1-18 cm ceramic coated soup pot, with the simulation period as the x-axis, the evaluation level as the left y-axis, and Ra as the right y-axis. Figure 3 As shown.

[0161] Based on the data in Tables 4 and 5, a correlation graph of Rz, evaluation level, and simulation period was constructed for the C1-18 cm ceramic-coated soup pot, with the simulation period as the x-axis, the evaluation level as the left y-axis, and Rz as the right y-axis. Figure 4 As shown.

[0162] Example 3

[0163] The difference between Example 3 and Example 1 is as follows:

[0164] The non-stick pan sample is a B1-24 cm ceramic non-stick frying pan.

[0165] The roughness of the coating over the entire observation area was analyzed using a 3CCD true color confocal microscope, and the Ra and Rz values ​​of the B1-24 cm ceramic nonstick frying pan in each simulation cycle were obtained as shown in Table 6.

[0166] Table 6. Ra and Rz values ​​of B1-24 cm ceramic nonstick frying pan in each simulation period.

[0167]

[0168] The B1-24 cm ceramic non-stick frying pan was evaluated for each simulation cycle using the method in 4.2.1 of GB / T 32095.2-2015. The evaluation results are shown in Table 7.

[0169] Table 7 Evaluation results of B1-24 cm ceramic non-stick frying pan in each simulation period

[0170]

[0171] Based on the data in Tables 6 and 7, a correlation graph was constructed for Ra, evaluation level, and simulation period of a B1-24 cm ceramic non-stick frying pan, with the simulation period as the x-axis, the evaluation level as the left y-axis, and Ra as the right y-axis. Figure 5 As shown.

[0172] Based on the data in Tables 6 and 7, a correlation graph was constructed for the simulation period as the x-axis, the evaluation level as the left y-axis, and Rz as the right y-axis for the B1-24 cm ceramic non-stick frying pan, showing the relationship between Rz, evaluation level, and simulation period. Figure 6 As shown.

[0173] Example 4

[0174] The difference between Example 4 and Example 1 is as follows:

[0175] The non-stick pan sample is a B2-28cm non-stick frying pan (PTFE coating).

[0176] The roughness of the coating over the entire observation area was analyzed using a 3CCD true color confocal microscope, and the Ra and Rz values ​​of the B2-28cm nonstick frying pan in each simulation cycle were obtained as shown in Table 8.

[0177] Table 8. Ra and Rz values ​​of B2-28cm nonstick frying pan in each simulation cycle.

[0178]

[0179] The B2-28cm non-stick frying pan was evaluated for each simulated cycle using the method in 4.2.1 of GB / T 32095.2-2015. The evaluation results are shown in Table 9.

[0180] Table 9 Evaluation results of B2-28cm nonstick frying pan in each simulation cycle

[0181]

[0182] Based on the data in Tables 8 and 9, a correlation graph was constructed with simulation period as the x-axis, evaluation level as the left y-axis, and Ra as the right y-axis for the B2-28cm non-stick frying pan, showing the relationship between Ra, evaluation level, and simulation period. Figure 7 As shown.

[0183] Based on the data in Tables 8 and 9, a correlation graph was constructed for the simulation period (x-axis), evaluation level (left-axis), and Rz (right-axis) of the B2-28cm non-stick frying pan, showing the relationship between Rz, evaluation level, and simulation period. Figure 8 As shown.

[0184] Analysis of Examples 1-4 leads to the following conclusions:

[0185] First, in Examples 1-3, non-stick pans with ceramic coatings were used, and the morphological characteristics of the ceramic coatings showed a significant correlation with the evaluation level:

[0186] When Ra < 2.7 μm, the ceramic coating surface is smooth and no food sticking occurs. The Rz value is generally lower than 126 μm, indicating good non-stick performance.

[0187] When 2.7 μm ≤ Ra ≤ 3.6 μm, Ra and Rz increase slowly (Rz is mostly in the range of 100 to 180 μm), and the non-stick properties begin to decrease. Occasionally there may be slight adhesion, but it can be removed by regular cleaning and does not affect the use.

[0188] When Ra > 3.6 μm and Rz > 180 μm, the non-stick performance evaluation level drops to Level III, obvious grooves appear on the coating surface, the area of ​​food residue adhesion increases, and it is difficult to remove by conventional cleaning.

[0189] When Ra > 3.6 μm and Rz > 200 μm, the adhesion is severe and carbonization tends to occur. Combined with the evaluation level III, it can be judged as the end of the life.

[0190] Furthermore, the frying pan of Example 3 is more durable than the curved pan bottom of Examples 1-2.

[0191] Second, the wear mechanism of the PTFE-coated nonstick pan (Example 4) is fundamentally different from that of the ceramic coating (Examples 1-3):

[0192] The lifespan of PTFE-coated nonstick cookware is theoretically predictable. Its lifespan degradation is characterized by a gradual decrease in surface roughness (Ra, Rz) over time, a mechanism distinct from the "roughness increase" mechanism of ceramic coatings. PTFE-coated nonstick cookware initially exhibits high morphological parameters (Ra ≈ 16.8 μm, Rz ≈ 356 μm), relying on the low surface energy (17–19 dyn / cm) of the fluoropolymer to achieve non-stick properties. The surface microstructure facilitates the formation of an oil film barrier. Under the same simulated operating conditions, the Ra value decreases over time. When Ra drops to the 12–13 μm range, the non-stick performance significantly deteriorates, reaching an evaluation level of III, indicating relatively weak wear resistance.

[0193] Experiments show that after 12 months of equivalent use, the non-stick properties of polytetrafluoroethylene coated non-stick pans can no longer meet the requirements for normal use.

[0194] In summary, ceramic-coated nonstick pans can last for more than 24 months under typical usage intensity, and some products (such as the Z1-32 wok) still maintain basic functions after 36 months; the wear resistance and non-stick performance stability of ceramic coatings are generally better than those of polytetrafluoroethylene coatings.

[0195] The above description is merely a specific embodiment of this application, but the scope of protection of this application is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in this application should be included within the scope of protection of this application. Therefore, the scope of protection of this application should be determined by the scope of the claims.

Claims

1. A method for evaluating the lifespan of a non-stick cookware coating, characterized in that, include: Non-stick pan samples were subjected to wear simulation treatment under different cycles to obtain a series of test samples with gradient wear levels corresponding to the simulation cycle. The morphological feature parameters of the coating surface of each of the test samples are detected, and the morphological feature parameters include at least one of the profile arithmetic mean deviation Ra and the profile maximum height Rz; The non-stick performance level of each test sample is standardized and evaluated to obtain the evaluation level; A quantitative correlation model is constructed based on the morphological feature parameters, the corresponding evaluation level, and the corresponding simulation period. Obtain the morphological characteristics of the coating surface of the target non-stick pan to be evaluated; Based on the morphological feature parameters of the coating surface of the target non-stick pan and the quantitative correlation model, the service life status of the coating of the target non-stick pan is evaluated. The morphological feature parameters include the arithmetic mean deviation of the contour Ra ​​and the maximum height of the contour Rz; The standardized non-stick performance rating is conducted according to the egg frying test method specified in GB / T 32095.2-2015, and the rating levels include Grade I, Grade II and Grade III. The method for constructing the quantitative correlation model includes: Based on the data sequence of the profile arithmetic mean deviation Ra of the test sample as a function of the simulation period, within the simulated wear period range corresponding to the test sample rated as Level III, the second derivative of the profile arithmetic mean deviation Ra with respect to the simulation period is calculated, and the simulation period T_Ra corresponding to the maximum value of the second derivative within the range is determined. Based on the data sequence of the maximum profile height Rz of the test sample changing with the simulation cycle, within the simulated wear cycle range corresponding to the test sample rated as Level III, the second derivative of the maximum profile height Rz with respect to the simulation cycle is calculated, and the simulation cycle T_Rz corresponding to the maximum value of the second derivative within this range is determined. Based on T_Ra and T_Rz, the lifespan termination period is determined by taking the maximum value or using a weighted average.

2. The method for evaluating the lifespan of non-stick cookware coatings according to claim 1, characterized in that, For coatings of different material types, a dedicated quantitative correlation model is constructed for each material coating.

3. The method for evaluating the lifespan of non-stick cookware coatings according to claim 2, characterized in that, The coating of the non-stick pan sample is any one of ceramic coating, polytetrafluoroethylene coating, diamond coating, or graphene-reinforced composite coating.

4. The method for evaluating the lifespan of non-stick cookware coatings according to claim 3, characterized in that, A dedicated quantitative correlation model is constructed for ceramic coatings, which defines the service life status of the ceramic coatings according to the following rules: When Ra < 2.7 μm, it is defined as the stage of good performance; When 2.7μm≤Ra≤3.6μm, it is defined as the performance stable stage; When Ra > 3.6 μm and 180 μm < Rz ≤ 200 μm, it is defined as the performance degradation stage; When Ra > 3.6 μm and Rz > 200 μm, it is defined as the end of lifetime state.

5. The method for evaluating the lifespan of non-stick cookware coatings according to claim 1, characterized in that, Methods for evaluating the coating lifespan of the target nonstick pan include: Based on the morphological feature parameters of the target non-stick pan, the corresponding equivalent usage period is determined in the quantitative correlation model; The remaining usage time of the target non-stick pan is determined based on the difference between the equivalent usage period and the end-of-life period.

6. The method for evaluating the lifespan of non-stick cookware coatings according to claim 5, characterized in that, The method for determining the remaining usage time of the target non-stick pan further includes: The cooking data of the target non-stick pan during actual use is collected, and the cooking data includes at least one of the following: daily cooking time, average cooking temperature, and daily cleaning frequency. The intensity factor to be used is determined based on the cooking data; The remaining usage time is adjusted based on the intensity factor.

7. The method for evaluating the lifespan of non-stick cookware coatings according to claim 1, characterized in that, The method for simulating wear under working conditions includes: linearly rubbing the coating surface of the non-stick pan sample with a friction head; The method for detecting the morphological feature parameters of the coating surface of each test sample includes: detecting the local morphological feature parameters of the starting region, the middle region and the ending region of the linear friction path respectively, and calculating the average value of the three as the morphological feature parameters of the test sample.

8. The method for evaluating the lifespan of non-stick cookware coatings according to claim 1, characterized in that, The simulated wear treatments under different operating conditions are equivalent to usage periods of 0 months, 6 months, 12 months, 18 months, 24 months, 30 months, and 36 months, respectively.

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