Cosmetic cleaning effect visual evaluation method and application thereof

Abstract

The invention provides a cosmetic cleaning effect visual evaluation method and application thereof, and the method comprises the steps: S1, providing a cosmetic cleaning effect visual evaluation score table which comprises a referable map corresponding to each grade of score; s2, uniformly coating a preset amount of to-be-cleaned substance on a human skin test area to simulate dirt on the surface of the human skin; s3, scoring the human skin test area, and recording the score as T1; s4, fully cleaning a human skin test area by using a test cosmetic; s5, scoring the human skin test area, and recording the score as T2; and S6, calculating the score change rate of the visual evaluation score, wherein the calculation formula of the score change rate delta is delta = [(T2-T1) / T1] * 100%. According to the method, the cleaning effect of the cosmetics can be evaluated more objectively and consistently, and subjectivity and errors in the evaluation process can be reduced.

Description

Technical Field

[0001] The present invention belongs to the technical field of cosmetics, and more specifically, relates to a cosmetic cleaning efficacy visual evaluation method and application thereof. Background Art

[0002] Studies have shown that if the dirt on the surface of human skin is not removed in time, it will cause abnormal physiological functions of the skin and mucous membranes, which will lead to blocked glands and pores, and ultimately accelerate skin aging. The correct use of cleansing cosmetics can better remove dirt on the surface of the skin and reduce the burden on the skin.

[0003] At present, there are many kinds of cleaning cosmetics, and the evaluation of the cleaning effect of each type of cleaning cosmetics depends on professional testing instruments or on the subjective feelings of users. Although professional testing instruments can more accurately detect and feedback various parameters of the skin after using cleaning cosmetics, the cost of use is high; and although the subjective feelings of users are easy to obtain, their reference value is not strong enough. Some researchers also use skin color, skin roughness, light intensity under ultraviolet light, etc. to evaluate the cleaning power of products ("Application of 3 quantitative evaluation methods in product cleaning ability assessment", Lai Qinrun, He Ziyuan, etc., "Daily Chemical Science", Vol. 44, No. 1, 2021; and "Discussion on the evaluation method of the efficacy of cleaning cosmetics", Qin Ou, etc., "Chinese Cosmetic Medicine", Vol. 27, No. 6, 2018). In addition, Chinese patent application CN106290176A discloses a method for testing the skin cleaning power of cleaning products, which uses the chromaticity a0 of the human skin area, the chromaticity a1 of the coating area, and the chromaticity a2 of the cleaned coating area to calculate the cleaning power. Chinese patent CN106370604B discloses that the skin residue index of sunscreen products is calculated by taking ultraviolet photos of human skin and reading the light intensity data a0 of the area on the ultraviolet photos, and taking ultraviolet photos of clean areas and reading the light intensity data a1 of the area on the ultraviolet photos. However, the above method still relies on professional instrument detection to a large extent, is complicated to operate, and is not intuitive enough.

[0004] In order to make the evaluation of the cleaning effect of various types of cleaning cosmetics more convenient, researchers proposed using visual evaluation to give the evaluation results of the cleaning cosmetics ("A method for evaluating the cleaning power of cleaning cosmetics", Liu Hongyan et al., "Science of Daily Chemicals", Vol. 42, No. 11, 2019). However, the current visual evaluation has not formed a reference evaluation standard and can only provide the collected auxiliary images. Therefore, the opinions finally given lack comparability and referenceability.

[0005] Therefore, there is an urgent need to propose a visual evaluation method for the cleansing efficacy of cosmetics and its application, so as to solve the technical problems that the existing evaluation methods for the effects of cleansing cosmetics still rely heavily on professional instrument detection, are relatively complicated to operate, and are not intuitive enough, and that the current visual evaluation has not formed a reference evaluation standard and can only provide the collected auxiliary images, so the opinions finally given also lack comparability and referenceability. Summary of the invention

[0006] In view of the deficiencies in the prior art, the main purpose of the present invention is to propose a method for visually evaluating the cleansing efficacy of cosmetics and its application, aiming to solve at least one of the technical problems that the existing method for evaluating the effect of cleansing cosmetics still relies heavily on professional instrument detection, is relatively complicated to operate and is not intuitive enough, and that the current visual evaluation has not formed a quantifiable reference evaluation standard and can only provide collected auxiliary images, so that the opinions finally given lack comparability and referenceability.

[0007] In order to achieve the purpose of the invention, the present invention adopts the following technical solutions: In a first aspect, the present invention provides a method for visually evaluating the cleaning efficacy of cosmetics, the method comprising the following steps: Step S1: providing a cosmetic cleaning efficacy visual evaluation rating scale, the visual evaluation rating scale comprising a rating scale based on the area of ​​the substance to be cleaned on the skin surface and a rating scale based on the color of the substance to be cleaned on the skin surface, the visual evaluation rating scale having a reference graph corresponding to each level of rating; Step S2: uniformly applying a predetermined amount of the substance to be cleaned to the test area of ​​human skin to simulate dirt on the surface of human skin; Step S3: scoring the human skin test area based on the cosmetic cleansing efficacy visual evaluation scoring scale, and the scoring value is recorded as T1; Step S4: using the tested cosmetics to fully clean the tested area of ​​human skin; Step S5: scoring the human skin test area based on the cosmetic cleansing efficacy visual evaluation scoring scale, and the scoring value is recorded as T2; Step S6: Calculate the visual evaluation score change rate, the score change rate δ is calculated as follows: δ=[(T2-T1) / T1]×100%.

[0008] Preferably, the scoring value is the sum of the scoring value of the area of ​​the material to be cleaned and the scoring value of the color of the material to be cleaned.

[0009] Preferably, the material to be cleaned includes a sunscreen product.

[0010] Preferably, the substance to be cleaned includes carbon powder.

[0011] Preferably, the cosmetic cleaning efficacy visual assessment rating scale includes a graded rating scale with a score range of 0 to 5 points reflecting the area of ​​the substance to be cleaned on the skin surface.

[0012] Preferably, the visual assessment rating scale includes a reference standard for grading the area of ​​the material to be cleaned: A score of 0 means that there is no visible substance to be cleaned on the surface of the skin test area; 1 point means that there is a small amount of the substance to be cleaned visible to the naked eye on the surface of the skin test area, and the area of ​​the substance to be cleaned has a fuzzy discontinuous boundary line; 2 points means that there is a moderate amount of the substance to be cleaned visible to the naked eye on the surface of the skin test area, the area of ​​the substance to be cleaned has a fuzzy discontinuous boundary line, and the substance to be cleaned is scattered in a small amount in the skin grooves; 3 points means that the surface of the skin test area has a large amount of the substance to be cleaned visible to the naked eye, the area of ​​the substance to be cleaned has a continuous boundary line visible to the naked eye, and the substance to be cleaned is dispersed in the skin groove in a moderate amount; 4 points means that there is a large amount of substance to be cleaned visible to the naked eye on the surface of the skin test area, the substance to be cleaned area has a clear continuous boundary line visible to the naked eye, the substance to be cleaned is mostly scattered in the skin grooves, and part of the substance to be cleaned scattered in the skin grooves is continuous; 5 points means that the surface of the skin test area is completely covered by the substance to be cleaned, the substance to be cleaned area has a very clear continuous boundary line visible to the naked eye, the substance to be cleaned is dispersed in large quantities in the skin grooves, and the substance to be cleaned dispersed in the skin grooves is continuous; The absence of substances to be cleaned visible to the naked eye indicates that the area of ​​substances to be cleaned accounts for 0%-5% of the area of ​​the skin test area; the small amount of substances to be cleaned visible to the naked eye indicates that the area of ​​substances to be cleaned accounts for 6%-29% of the area of ​​the skin test area; the moderate amount of substances to be cleaned visible to the naked eye indicates that the area of ​​substances to be cleaned accounts for 30%-49% of the area of ​​the skin test area; the relatively large amount of substances to be cleaned visible to the naked eye indicates that the area of ​​substances to be cleaned accounts for 50%-79% of the area of ​​the skin test area; the large amount of substances to be cleaned visible to the naked eye indicates that the area of ​​substances to be cleaned accounts for 80%-99% of the area of ​​the skin test area; the complete coverage by substances to be cleaned indicates that the area of ​​substances to be cleaned accounts for 100% of the area of ​​the skin test area; and, The small amount of scattering means that the scattering amount does not exceed 5% of the total amount of the material to be cleaned; the medium amount of scattering means that the scattering amount is 6%-10% of the total amount of the material to be cleaned; the large amount of scattering means that the scattering amount is 11%-15% of the total amount of the material to be cleaned; and the large amount of scattering means that the scattering amount is 16%-20% of the total amount of the material to be cleaned.

[0013] Preferably, the cosmetic cleaning efficacy visual assessment rating scale includes a graded rating scale with a score range of 0 to 5 points that reflects the color of the substance to be cleaned on the skin surface.

[0014] Preferably, the visual assessment rating scale includes a grading reference standard for the color of the material to be cleaned: 0 points means that there is no color of the substance to be cleaned visible to the naked eye on the surface of the skin test area and the transparency is very high; 1 point means that the color of the substance to be cleaned visible to the naked eye on the surface of the skin test area is very light and highly transparent, and is uneven light gray; 2 points means that the color of the substance to be cleaned visible to the naked eye on the surface of the skin test area is lighter and more transparent, showing an uneven medium gray; 3 points means that the color of the substance to be cleaned visible to the naked eye on the surface of the skin test area is slightly lighter and has medium transparency, and is uneven dark gray; 4 points means that the color of the substance to be cleaned visible to the naked eye on the surface of the skin test area is darker and less transparent, unevenly charcoal black, and the skin texture is visibly rough; 5 points means that the color of the substance to be cleaned visible to the naked eye on the surface of the skin test area is very dark and has very low transparency, and is uniformly pure black or pure carbon black; The fact that there is no color of the substance to be cleaned visible to the naked eye and the transparency is very high indicates that the transparency is 96-100%; the fact that the color of the substance to be cleaned visible to the naked eye is very light and the transparency is very high indicates that the transparency is 76-95%; the fact that the color of the substance to be cleaned visible to the naked eye is lighter and the transparency is higher indicates that the transparency is 56-75%; the fact that the color of the substance to be cleaned visible to the naked eye is slightly lighter and has medium transparency indicates that the transparency is 36-55%; the fact that the color of the substance to be cleaned visible to the naked eye is darker and the transparency is lower indicates that the transparency is 16-35%; the fact that the color of the substance to be cleaned visible to the naked eye is very dark and the transparency is very low indicates that the transparency is 0-15%.

[0015] It should be noted that the methods for measuring transparency include light transmission method, reflection method, transmittance method, transmittance method, light transmission method and colorimetry, etc. According to specific needs, the transparency of the material to be cleaned can be accurately measured by selecting an appropriate measurement method. For example: the reflection method is to determine the transparency of the material to be cleaned by measuring the intensity of the reflected light on the surface of the material to be cleaned. In specific operations, the light source is irradiated on the surface of the object, and then the intensity of the reflected light is measured using a reflection photometer or a reflection spectrometer, and then compared with the intensity of the light that has not passed through the material to be cleaned, the transparency of the material to be cleaned can be obtained.

[0016] Preferably, each score level in the cosmetic cleaning efficacy visual evaluation rating scale corresponds to a picture of the residual condition of the sunscreen product on the skin surface.

[0017] Preferably, each score level in the cosmetic cleaning efficacy visual evaluation rating scale corresponds to a reference picture of the carbon powder residue on the skin surface.

[0018] In a second aspect, the present invention further provides an application of the aforementioned visual evaluation method for the cleansing efficacy of cosmetics in evaluating the cleansing efficacy of cosmetics.

[0019] Compared with the prior art, the present invention has the following beneficial effects: 1. A visual evaluation method for the cleaning efficacy of cosmetics and a visual evaluation rating scale for the cleaning efficacy of cosmetics provided by the application of the present invention can evaluate the cleaning effect of cosmetics more objectively and consistently, and can reduce subjectivity and errors in the evaluation process; the visual evaluation rating scale includes a graded scoring reference standard for the area of ​​the material to be cleaned and a graded scoring reference standard for the color of the material to be cleaned to give a scoring value, which comprehensively covers a variety of referenceable and quantifiable situations for the visual evaluation of the cleaning efficacy of cosmetics, and has good universality in this application scenario.

[0020] 2. The visual evaluation method and application of the cosmetic cleaning efficacy of the present invention provides a cosmetic cleaning efficacy visual evaluation scoring scale that includes a scoring map, which does not require the professional operation of a doctor. The tester can intuitively see the residual conditions of the substances to be cleaned corresponding to different scores in combination with the scoring map, making it easier to perform accurate scoring.

[0021] 3. The visual evaluation method and application of the cosmetic cleaning efficacy of the present invention provides a cosmetic cleaning efficacy visual evaluation rating scale that takes into account not only the residual area of ​​the material to be cleaned, but also the color of the material to be cleaned. It is not only suitable for the evaluation of carbon powder-type materials to be cleaned, but also suitable for the evaluation of sunscreen products-type materials to be cleaned, so that the evaluation results are more comprehensive and can more accurately reflect the cleaning effect of cosmetics.

[0022] 4. The visual evaluation method and application of the cosmetic cleaning efficacy of the present invention provides a visual evaluation rating scale for the cosmetic cleaning efficacy, which is divided into a rating table and a rating map. The rating table can be used alone and is not limited to the evaluation of the cleaning effect of carbon powder-type cleaning materials and sunscreen products-type cleaning materials. You can try to construct more rating maps based on the rating table to adapt to different evaluation scenarios or needs.

[0023] 5. A visual evaluation method and application of cosmetic cleaning efficacy provided by the present invention is simple and easy to operate, and can be completed by using a simple image capture device (such as a mobile phone, tablet, etc.) and a UVLOOK Mini sunscreen camera. This method can quickly evaluate the cleaning effect of cosmetics, reduce the difficulty of operation, and save costs.

[0024] 6. The visual evaluation method and application of the cosmetic cleansing efficacy provided by the present invention includes a calculation method for the cosmetic cleansing effect. The cleansing effect of the cosmetic can be further quantified by calculating the score change rate, making the evaluation result scientific and comparable.

[0025] 7. The visual evaluation method for the cleansing efficacy of cosmetics provided by the present invention and its application can help market decision makers better declare the efficacy of products, thereby helping consumers better understand the actual cleansing ability of cosmetics, and has good practicality.

[0026] 8. The visual evaluation method provided by the present invention for visual evaluation of the cleansing efficacy of cosmetics and its application can enable consumers to complete the evaluation of the cleansing efficacy of cosmetics at home due to the availability and low cost of the equipment. This can educate consumers on how to correctly evaluate the cleansing efficacy of cosmetics and improve their ability to select products. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 It is a scoring chart of the residual conditions of carbon powder and sunscreen products with a score of 0 to 5 included in the visual scoring scale of the present invention; Figure 2 is a schematic diagram of three volunteers before and after cleaning the carbon powder in an example of the present invention; Figure 3 Schematic diagram of three volunteers before and after cleaning the sunscreen product in one example of the present invention. DETAILED DESCRIPTION

[0028] The technical solution of the present invention is further described below through specific implementation methods, but the implementation methods of the present invention are not limited thereto.

[0029] The cleaning cosmetics mentioned in the following content are the commercially available product Winona Soft Moisturizing Cleansing Honey, which claims to have cleansing effects; the sunscreen product to be cleaned is Winona Clear Sunscreen Milk; and the toner is a product of Bentu International Trade (Shandong) Group Co., Ltd.

[0030] The Colorimeter CL400 skin color test probe mentioned in the following content is an instrument from Courage + Khazaka of Germany; the ULM-001 UVLOOK Mini sunscreen camera is an instrument from FIH Mobile Precision Components (Beijing) Co., Ltd.

[0031] The criteria for inclusion of volunteers in the following examples are: ① healthy women aged between 18 and 60 years old; ② healthy skin color in the skin area to be tested, free of skin diseases and factors affecting the experiment; ③ no allergic diseases, no history of allergies to cosmetics and other topical preparations; ④ able to understand the experimental process, voluntarily participate in the experiment, and comply with the test process.

[0032] The criteria for excluding volunteers in the following embodiments are: ① women who are planning to become pregnant, pregnant, lactating, or within six months after giving birth; ② those with severe systemic diseases, immunodeficiency, or autoimmune diseases; ③ those who have used antihistamines in the past week or immunosuppressants in the past month; ④ those whose test sites have participated in other clinical trials in the past three months; ⑤ patients with respiratory diseases who are receiving treatment; ⑥ people who are receiving dermatological treatment; ⑦ patients with insulin-dependent diabetes; ⑧ other corresponding exclusion criteria. Example 1

[0033] This embodiment mainly introduces the use of the method of the present invention to visually score the carbon powder application positions on the inner forearms of 31 volunteers, and compares and analyzes the correlation with the results of other evaluation indicators.

[0034] Volunteer selection: A total of 31 female volunteers were recruited, aged 26 to 59 years old, with an average age of 46.9±8.8 years old.

[0035] Environmental adaptation: Volunteers sat quietly in an environment with a temperature of (21±1)℃ and a humidity of (50±10)% RH for 30 minutes.

[0036] Initial data collection: A 3cm×3cm test area was marked on the inner side of the forearms of both hands of the volunteers, and the Colorimeter CL400 was used to detect the basic value of skin color L*a*b* (T0).

[0037] To establish the dirt model: Apply carbon powder (2 mg / cm2) to the test area with a latex finger cot. 2 ).

[0038] Collect data before dirt cleaning: detect skin color and perform image acquisition and visual scoring (T1).

[0039] Cleaning dirt: Use Winona Soft Moisturizing Cleansing Honey and clean water (negative control) to clean the inner forearms of both hands respectively (cleaning method: take 2 pumps of the product on the palm, apply it to the test area, massage in circles in clockwise and counterclockwise directions 10 times each, and wash with clean water; the negative control is operated in the same way except that no product is used).

[0040] Collect data after dirt cleaning: detect skin color and perform image acquisition and visual scoring (T2).

[0041] Data statistics and analysis: Calculate the skin color difference △E and cleansing power based on the L*a*b* values ​​of skin color at each stage, and calculate the score change rate based on the visual scores at each stage. The calculation formula for skin color difference △E and cleansing power is as follows: △E=SQRT(△L 2 +△a 2 +△b 2 ); Cleaning power = [(△E (before cleaning) - △E (after cleaning)) / △E (before cleaning)] × 100% The results are listed in Table 1 and Table 2 below.

[0042] Table 1: Skin color L*a*b* values ​​at each stage, skin color difference △E and cleansing power (X±SD, n=31)

[0043] Compared with the initial value, the difference is statistically significant. "*" indicates p <0.05, “**” indicates p <0.01, "ns" means p ≥0.05. Compared with the negative control, the difference is statistically significant. "#" indicates p <0.05, “##” indicates p <0.01, "ns" means p ≥0.05.

[0044] Table 2: Visual ratings and rating change rates of carbon powder residue at each stage (X±SD, n=31)

[0045] Compared with before cleaning, the difference is statistically significant. "*" indicates p <0.05, “**” indicates p <0.01, "ns" means p ≥0.05. Compared with the negative control, the difference is statistically significant. "#" indicates p <0.05, “##” indicates p <0.01, "ns" meansp ≥0.05.

[0046] As shown in Table 1, after using Winona Soft Moisturizing Cleansing Honey to clean the carbon powder, the L* value increased significantly compared to the initial value, and there was no significant difference in the a* value and b* value, indicating that there was no carbon powder residue on the skin, and the product had a certain effect of brightening the skin. After using water to clean the carbon powder, the L* value decreased significantly compared to the initial value, and there was a significant difference in the a* value and b* value, indicating that there was carbon powder residue on the skin. Winona Soft Moisturizing Cleansing Honey has a cleaning power of 99.22% for carbon powder, which is significantly better than the negative control 89.72%.

[0047] From Table 2 and Figure 2 It can be seen that after using Winona Soft Moisturizing Cleansing Honey to clean the carbon powder, the visual score was 5 before cleaning, which dropped significantly after cleaning to 0 points, indicating that there was almost no residual carbon powder on the skin at this time. After using clean water to clean the carbon powder, the visual score was 5 before cleaning, which dropped significantly after cleaning to 3.32 points, indicating that there was still a lot of residue on the skin at this time. The score change rate of Winona Soft Moisturizing Cleansing Honey was -100%, which was significantly better than the negative control -33.60%. Among them, Figure 2 The numbers in the middle are volunteer number-sample-test time point, A: Winona Soft Moisturizing Cleansing Honey; B: negative control (clear water).

[0048] The correlation analysis of all cleaning power and score change rate data showed that the cleaning power and score change rate showed a significant negative correlation, with a correlation coefficient of -0.847 ( p <0.001).

[0049] In summary, the test results show that the visual scoring scale provided by the present invention can objectively and accurately evaluate the residual carbon powder on the skin.

[0050] Example 2 This example mainly introduces the use of the method of the present invention to visually score the locations where sunscreen products were applied on the backs of both hands of 31 volunteers.

[0051] UV LOOK Mini sunscreen camera is a device for detecting traces of sunscreen products applied. Areas where sunscreen products are applied appear as black images, while areas where sunscreen products are not applied or where sunscreen products have been cleaned appear as grayscale images.

[0052] Volunteer selection: A total of 31 female volunteers were recruited, aged 26 to 59 years old, with an average age of 46.9 ± 8.8 years old.

[0053] Environmental acclimatization: Volunteers sat quietly in an environment with a temperature of (21 ± 1) ℃ and a humidity of (50 ± 10)% RH for 30 min.

[0054] Establish the dirt model: mark a 3cm × 3cm test area on the back of each hand of the volunteer, and apply sunscreen product (2mg / cm 2 ).

[0055] Collect data before dirt cleaning: collect skin images and perform visual scoring (T1).

[0056] Cleaning dirt: Use Winona Soft Moisturizing Cleansing Honey and clean water (negative control) to clean the test area respectively (cleaning method: take 2 pumps of the product on the palm, apply it to the test area, massage in circles in clockwise and counterclockwise directions 10 times each, and wash with clean water; the negative control is operated in the same way except that no product is used).

[0057] Collect data after dirt cleaning: collect skin images and perform visual scoring (T2).

[0058] Data statistics and analysis: Calculate the score change rate based on the visual scores at each stage.

[0059] The results are listed in Table 3 below.

[0060] Table 3: Visual scores and score change rates of sunscreen product residues at each stage (X±SD, n=31)

[0061] Compared with before cleaning, the difference is statistically significant. "*" indicates p <0.05, “**” indicates p <0.01, "ns" means p ≥0.05. Compared with the negative control, the difference is statistically significant. "#" indicates p <0.05, “##” indicates p <0.01, "ns" means p ≥0.05.

[0062] From Table 3 and Figure 3 It can be seen that after using Winona Soft Moisturizing Cleansing Honey to clean sunscreen products, the visual score before cleaning was 5, which dropped significantly after cleaning to 2.45 points, indicating that there are fewer sunscreen products remaining on the skin surface at this time. After using water to clean sunscreen products, the visual score before cleaning was 5, and the score after cleaning was 4.16, with no significant change. At this time, there are still many residues on the skin. The score change rate of Winona Soft Moisturizing Cleansing Honey was -50.97%, which was significantly better than the negative control -16.77%. Among them, Figure 3 The numbers in the middle are volunteer number-sample-test time point, A: Winona Soft Moisturizing Cleansing Honey; B: negative control (clear water).

[0063] In summary, the test results show that the visual rating scale provided by the present invention can accurately distinguish the cleaning effects of the product and clean water, indicating that the rating scale can objectively and accurately evaluate the residual situation of sunscreen products on the skin.

[0064] Those skilled in the art should recognize that the above embodiments are only used to illustrate the present invention, and are not used to limit the present invention. As long as they are within the spirit of the present invention, any changes or modifications to the above embodiments will fall within the scope of the claims of the present invention.

Claims

1. A method for visually evaluating the cleaning efficacy of cosmetics, characterized in that: The method comprises the following steps: Step S1: providing a cosmetic cleaning efficacy visual evaluation rating scale, the visual evaluation rating scale comprising a rating scale based on the area of ​​the substance to be cleaned on the skin surface and a rating scale based on the color of the substance to be cleaned on the skin surface, the visual evaluation rating scale having a reference graph corresponding to each level of rating; Step S2: uniformly applying a predetermined amount of the substance to be cleaned to the test area of ​​human skin to simulate dirt on the surface of human skin; Step S3: scoring the human skin test area based on the cosmetic cleansing efficacy visual evaluation scoring scale, and the scoring value is recorded as T1; Step S4: using the tested cosmetics to fully clean the tested area of ​​human skin; Step S5: scoring the human skin test area based on the cosmetic cleansing efficacy visual evaluation scoring scale, and the scoring value is recorded as T2; Step S6: Calculate the visual evaluation score change rate, the score change rate δ is calculated as follows: δ=[(T2-T1) / T1]×100%.

2. A method for visually evaluating the cleaning efficacy of cosmetics according to claim 1, characterized in that: The scoring value is the sum of the scoring value of the area of ​​the material to be cleaned and the scoring value of the color of the material to be cleaned.

3. A method for visually evaluating the cleaning efficacy of cosmetics according to claim 1, characterized in that: The substances to be cleaned include sunscreen products.

4. A method for visually evaluating the cleansing efficacy of cosmetics according to claim 1, characterized in that: The substance to be cleaned includes carbon powder.

5. A method for visually evaluating the cleaning efficacy of cosmetics according to claim 2, characterized in that: The cosmetic cleaning efficacy visual evaluation rating scale includes a graded rating scale with a score range of 0 to 5 points reflecting the area of ​​the substance to be cleaned on the skin surface.

6. A method for visually evaluating the cleaning efficacy of cosmetics according to claim 5, characterized in that: The visual assessment scale includes reference standards for grading the area of ​​the material to be cleaned: A score of 0 means that there is no visible substance to be cleaned on the surface of the skin test area; 1 point means that there is a small amount of the substance to be cleaned visible to the naked eye on the surface of the skin test area, and the area of ​​the substance to be cleaned has a fuzzy discontinuous boundary line; 2 points means that there is a moderate amount of the substance to be cleaned visible to the naked eye on the surface of the skin test area, the area of ​​the substance to be cleaned has a fuzzy discontinuous boundary line, and the substance to be cleaned is scattered in a small amount in the skin grooves; 3 points means that the surface of the skin test area has a large amount of the substance to be cleaned visible to the naked eye, the area of ​​the substance to be cleaned has a continuous boundary line visible to the naked eye, and the substance to be cleaned is dispersed in the skin groove in a moderate amount; 4 points means that there is a large amount of substance to be cleaned visible to the naked eye on the surface of the skin test area, the substance to be cleaned area has a clear continuous boundary line visible to the naked eye, the substance to be cleaned is mostly scattered in the skin grooves, and part of the substance to be cleaned scattered in the skin grooves is continuous; 5 points means that the surface of the skin test area is completely covered by the substance to be cleaned, the substance to be cleaned area has a very clear continuous boundary line visible to the naked eye, the substance to be cleaned is dispersed in large quantities in the skin grooves, and the substance to be cleaned dispersed in the skin grooves is continuous; The absence of substances to be cleaned visible to the naked eye indicates that the area of ​​substances to be cleaned accounts for 0%-5% of the area of ​​the skin test area; the small amount of substances to be cleaned visible to the naked eye indicates that the area of ​​substances to be cleaned accounts for 6%-29% of the area of ​​the skin test area; the moderate amount of substances to be cleaned visible to the naked eye indicates that the area of ​​substances to be cleaned accounts for 30%-49% of the area of ​​the skin test area; the relatively large amount of substances to be cleaned visible to the naked eye indicates that the area of ​​substances to be cleaned accounts for 50%-79% of the area of ​​the skin test area; the large amount of substances to be cleaned visible to the naked eye indicates that the area of ​​substances to be cleaned accounts for 80%-99% of the area of ​​the skin test area; the complete coverage by substances to be cleaned indicates that the area of ​​substances to be cleaned accounts for 100% of the area of ​​the skin test area; and, The small amount of scattering means that the scattering amount does not exceed 5% of the total amount of the material to be cleaned; the medium amount of scattering means that the scattering amount is 6%-10% of the total amount of the material to be cleaned; the large amount of scattering means that the scattering amount is 11%-15% of the total amount of the material to be cleaned; and the large amount of scattering means that the scattering amount is 16%-20% of the total amount of the material to be cleaned.

7. A method for visually evaluating the cleansing efficacy of cosmetics according to claim 2, characterized in that: The cosmetic cleaning efficacy visual evaluation rating scale includes a graded rating scale with a score range of 0 to 5 points that reflects the color of the substance to be cleaned on the skin surface.

8. A method for visually evaluating the cleansing efficacy of cosmetics according to claim 7, characterized in that: The visual assessment rating scale includes reference standards for grading the color of the material to be cleaned: 0 points means that there is no color of the substance to be cleaned visible to the naked eye on the surface of the skin test area and the transparency is very high; 1 point means that the color of the substance to be cleaned visible to the naked eye on the surface of the skin test area is very light and highly transparent, and is uneven light gray; 2 points means that the color of the substance to be cleaned visible to the naked eye on the surface of the skin test area is lighter and more transparent, showing an uneven medium gray; 3 points means that the color of the substance to be cleaned visible to the naked eye on the surface of the skin test area is slightly lighter and has medium transparency, and is uneven dark gray; 4 points means that the color of the substance to be cleaned visible to the naked eye on the surface of the skin test area is darker and less transparent, unevenly charcoal black, and the skin texture is visibly rough; 5 points means that the color of the substance to be cleaned visible to the naked eye on the surface of the skin test area is very dark and has very low transparency, and is uniformly pure black or pure carbon black; The fact that there is no color of the substance to be cleaned visible to the naked eye and the transparency is very high indicates that the transparency is 96-100%; the fact that the color of the substance to be cleaned visible to the naked eye is very light and the transparency is very high indicates that the transparency is 76-95%; the fact that the color of the substance to be cleaned visible to the naked eye is lighter and the transparency is higher indicates that the transparency is 56-75%; the fact that the color of the substance to be cleaned visible to the naked eye is slightly lighter and has medium transparency indicates that the transparency is 36-55%; the fact that the color of the substance to be cleaned visible to the naked eye is darker and the transparency is lower indicates that the transparency is 16-35%; the fact that the color of the substance to be cleaned visible to the naked eye is very dark and the transparency is very low indicates that the transparency is 0-15%.

9. A method for visually evaluating the cleansing efficacy of cosmetics according to claim 5 or 7, characterized in that: Each level of score in the cosmetic cleaning efficacy visual evaluation rating scale corresponds to a reference picture of the residual condition of the substance to be cleaned on the skin surface.

10. Use of the visual evaluation method for the cleansing efficacy of cosmetics according to any one of claims 1 to 9 in evaluating the cleansing efficacy of cosmetics.

Images