Method for evaluating hair care or damage condition of electric hair dryer

Abstract

The invention discloses a method for evaluating the hair care or damage condition of an electric hair dryer. The method comprises the following steps: (1) pre-treating a hair bundle sample; cleaning the hair bundle sample, naturally airing the hair bundle, and observing the condition of hair scales on the surface of hair in the hair bundle by using a scanning electron microscope; (2) testing of an electric hair dryer test group: taking the pretreated hair bundle sample, cleaning, turning on an electric hair dryer, adjusting to a test gear / mode, drying the hair bundle, and combing the hair bundle from top to bottom by using a dense-tooth comb; repeating the operation for 8-10 times; using a scanning electron microscope to observe the condition of hair scales on the surface of the hair in the hair bundle of the electric hair dryer test group, comparing with the pretreated hair bundle and (or) comparing with the treated hair bundle of the natural air-drying control group in combination with a tensile test, and thus evaluating the condition of hair care or damage by the electric hair dryer.

Description

Technical Field

[0001] The invention particularly relates to a method for evaluating the hair care or damage condition of an electric hair dryer. Background Art

[0002] A hair dryer is composed of a group of electric heating wires and a small high-speed fan. When powered on, the electric heating wires generate heat, and the wind blown by the fan passes through the electric heating wires and becomes hot air. In daily life, hair dryers are frequently used products. However, it has been reported in the literature that the rapid heating of hair dryers will cause the hair scales to dry quickly, thereby generating positive high pressure inside the hair and eventually causing cracks on the hair surface; the keratin in the hair is heated, and the water is lost rapidly, causing the hair cortex to change, resulting in the hair swelling, roughness, lack of luster and easy to break. Therefore, if the hair dryer is used for too long, it is easy to cause heat damage to the hair.

[0003] Since hair dryers can cause hair damage, hair dryers with hair care functions have come into being. More and more hair dryers have added hair care modules, such as negative ions, water ions, hair care essence nozzles, etc., in the hope of reducing hair damage, making hair smooth and enhancing gloss.

[0004] However, current research on the hair care effects or hair damage of hair dryers is mostly based on theory, and there are no clear testing methods and evaluation standards. On the market, hair dryer products are advertised in a variety of ways. Some products claim hair care effects through theory, and some claim to have a strengthening effect by selecting a few hair strands to measure their breaking strength, etc. However, this is hardly a reliable means of evaluating the hair care effects or hair damage levels of hair dryers. Summary of the invention

[0005] The object of the present invention is to provide a method for evaluating the hair care or damage condition of a hair dryer.

[0006] To achieve the above object, the present invention adopts the following technical solutions.

[0007] A method for evaluating the hair care or damage of a hair dryer comprises the following steps:

[0008] (1) Pretreatment of the hair bundle sample: washing the hair bundle sample, drying the hair bundle naturally, and observing the hair scales on the surface of the hair in the hair bundle using a scanning electron microscope;

[0009] (2) Testing of the hair dryer test group: Take a hair bundle sample after pretreatment, wash it, then turn on the hair dryer and adjust it to the test gear / mode to blow dry the hair bundle, and then comb the hair bundle from top to bottom with a fine-tooth comb; repeat the above operation 8 to 10 times; use a scanning electron microscope to observe the hair scales on the surface of the hair in the hair bundle of the hair dryer test group, and compare them with the hair bundle after pretreatment, so as to evaluate the hair care or damage of the hair by the hair dryer.

[0010] The present invention has experimentally found that if the hair bundle is washed and dried once or even ten times, no matter whether a hair dryer with a hair care function is used, the condition of the hair scales on the surface of the hair in the hair bundle is not significantly different from that before the treatment, resulting in the inability to effectively evaluate the hair care or damage of the hair dryer; only when the washing + drying treatment is repeated for more than 20 times, the condition of the hair scales on the surface of the hair in the hair bundle is significantly different from that before the treatment, but this leads to a large consumption of manpower and time costs. Therefore, the present invention accelerates the damage of the hair scales on the surface of the hair by combing the hair bundle with a dense-tooth comb, and then combines repeated washing + drying operations for 8 to 10 times, so as to effectively evaluate the hair care or damage of the hair by the hair dryer, and save manpower and time costs. In addition, since the surface of the commercially available hair bundle samples usually has a care agent to make the hair smooth and shiny, it is not suitable for baseline value testing, so in order to ensure the accuracy of the evaluation, it is first pre-treated and cleaned.

[0011] As a specific embodiment of the present invention, the cleaning operation is: using a surfactant solution to apply to both sides of the hair bundle in a W shape, rubbing the front and back sides of the hair bundle with the fingertips for the same time, then rinsing with tap water until no foam remains, clamping the hair bundle with the index finger and the middle finger, and gently pressing the surface of the hair bundle from top to bottom with a lint-free paper towel until the hair bundle is in a state of not dripping water; the above cleaning operation is to ensure that the hair strands in the hair bundle are subjected to the same action, and also to avoid the problems of entanglement and breakage of the hair strands, thereby improving the accuracy of the evaluation results. More specifically, the surfactant solution is a sodium dodecyl sulfate solution with a mass fraction of 1% to 10%, and the amount used is 0.1g / g hair bundle.

[0012] As a preferred embodiment of the present invention, the treatment and testing of the hair bundles are carried out in a constant temperature and humidity room. More preferably, the temperature in the constant temperature and humidity room is 21±1°C and the humidity is 50%±5%RH.

[0013] As a specific embodiment of the present invention, the hair dryer is tilted downward so that the air outlet forms a 45° angle with the hair bundle, and the distance between the air outlet and the hair bundle is 10 to 15 cm to reduce the messiness and tangling of hair in the hair bundle and avoid affecting the accuracy of the evaluation results.

[0014] As a preferred embodiment of the present invention, after drying the hair bundle, a dense-tooth comb is used to comb the front and back sides of the hair bundle from top to bottom 10 times each, the purpose is to make the hair strands in the hair bundle contact the comb teeth evenly and generate friction as much as possible, so that the damage of each hair strand is basically the same. More preferably, the dense-tooth comb is used to comb the hair bundle from top to bottom at a speed of 3 seconds / time to avoid pulling the hair strands and stretching or even breaking them due to excessive speed.

[0015] As a preferred embodiment of the present invention, the dense-tooth comb is made of plastic. Plastic combs are prone to static electricity, which can accelerate the damage of hair scales on the surface of hair, is conducive to testing, and is cheap, lightweight and durable.

[0016] As a further embodiment of the present invention, a test of a naturally dried control group is added; specifically: a hair bundle sample after pre-treatment is taken, washed, and then naturally dried, and then the hair bundle is combed from top to bottom with a fine-tooth comb; the above operation is repeated 8 to 10 times; the hair scales on the surface of the hair in the hair bundle are observed using a scanning electron microscope, and the hair scales are compared with those of the hair bundles in the hair dryer test group.

[0017] The naturally air-dried control group and the hair dryer test group use hair bundle samples from the same batch with the same hair quality, quantity or weight.

[0018] As a further embodiment of the present invention, two hair dryers are used, or the same hair dryer is used in different modes for comparative testing, thereby evaluating its hair care or damage. Similarly, the comparative test uses hair bundle samples of the same batch with the same hair quality, quantity or weight.

[0019] As a further embodiment of the present invention, the hair scales on the hair surface are graded to establish a hair scale damage grade, and then the tested hair bundles are scored based on the grade to evaluate the hair care or damage caused by the hair dryer.

[0020] As a further embodiment of the present invention, a tensile test is performed on the hair bundles before and after the test treatment, such as the hair bundles after the hair dryer test group treatment, to test the breaking strength of the hair to verify whether the results obtained based on the scanning electron microscope observation are accurate.

[0021] Compared with the prior art, the present invention has the following beneficial effects:

[0022] The present invention provides a method for evaluating the hair care or damage of a hair dryer, which can effectively evaluate the hair care or damage of the hair dryer and save manpower and time costs. The present invention provides a specific and standard test method for the care function of the hair dryer, filling the gap in the field. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 These are example pictures of the hair scale damage levels used in the embodiments and comparative examples; wherein A is level 1, B is level 2, C is level 2.5, D is level 3, E is level 3.5, F is level 4, G is level 4.5, and H is level 5.

[0024] Figure 2 These are the surface pictures of the hair before and after the treatment of the natural drying control group and the hair dryer test group in Example 1; wherein A is the hair before the treatment of the natural drying control group, B is the hair after the treatment of the natural drying control group, C is the hair before the treatment of the hair dryer test group, and D is the hair after the treatment of the hair dryer test group.

[0025] Figure 3 These are pictures of the hair surfaces of the control group of hair dryers without hair care function and the test group of hair dryers with hair care function before and after treatment in Example 2; wherein, A is the hair of the control group of hair dryers without hair care function before treatment, B is the hair of the control group of hair dryers without hair care function after treatment, C is the hair of the test group of hair dryers with hair care function before treatment, and D is the hair of the test group of hair dryers with hair care function after treatment.

[0026] Figure 4 These are pictures of the hair surfaces of the naturally dried control group and the hair dryer test group before and after treatment in Comparative Example 1; wherein A is the hair of the naturally dried control group before treatment, B is the hair of the naturally dried control group after treatment, C is the hair of the hair dryer test group before treatment, and D is the hair of the hair dryer test group after treatment.

[0027] Figure 5 These are pictures of the hair surfaces of the naturally dried control group and the hair dryer test group before and after treatment in Comparative Example 2; wherein A is the hair of the naturally dried control group before treatment, B is the hair of the naturally dried control group after treatment, C is the hair of the hair dryer test group before treatment, and D is the hair of the hair dryer test group after treatment. DETAILED DESCRIPTION

[0028] The technical solution of the present invention will be clearly and completely described below in conjunction with the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0029] The following examples used a scanning electron microscope (Axia ChemiSEM, Thermo Fisher Scientific), a hair tester (fibra.one, Diastron), and a flat dense-tooth comb (the comb teeth were spaced >1 mm and <2 mm apart, and the comb teeth were about 2 cm long).

[0030] In order to evaluate the hair care or damage of hair dryers, the following examples are graded according to the condition of the hair scales on the hair surface, thereby establishing the hair scale damage grade, see Table 1.

[0031] Table 1

[0032]

[0033]

[0034] Example 1

[0035] 1. Hair sample pretreatment: Take 2 bundles of healthy Chinese black hair (length 20 cm, width 2 cm, hair weight 3 g, free length 18 cm), use 1% sodium dodecyl sulfate solution, weigh 0.1 g / g, apply it on the front and back sides of the hair bundle in a W shape, rub the front side of the hair bundle with the fingertips for 30 seconds, rub the back side for 30 seconds, then rinse with tap water until no foam remains, pinch the hair bundle with the index finger and middle finger, and press the surface of the hair bundle gently with a lint-free paper towel from top to bottom until the hair bundle is in a dripping state; place it in a constant temperature and humidity room with a temperature of (21±1)°C and a humidity of (50%±5%)RH to dry naturally.

[0036] Take 5 hairs from each of the 2 hair bundles for marking, and cut off 1 cm of the hair 12 to 15 cm from the root, fix it on the conductive glue on the stage, spray gold, and observe its surface structure with a scanning electron microscope, such as Figure 2 A and C. Then 30 hairs were selected from the two hair bundles and fixed with copper rings, and placed on a multifunctional hair testing device to test the diameter and breaking strength of the hair.

[0037] 2. Test of the natural drying control group: Take one of the hair bundles, wash the hair bundle according to the above pre-treatment operation, place it in a constant temperature and humidity room with a temperature of (21±1)℃ and a humidity of (50%±5%)RH to dry naturally for 4 hours, and comb the front and back of the hair bundle from top to bottom at a speed of 3s / time 10 times each with a fine-tooth comb. Repeat the above operation 10 times, that is, perform the above operation 10 times in total.

[0038] Take 5 marked hairs and cut off 1 cm from the root 4 to 7 cm away. Use a scanning electron microscope to observe their surface structure. Figure 2 B. Select 30 hairs from the hair bundle and fix them with copper rings. Place them on the multifunctional hair testing device to test the diameter and breaking strength of the hairs.

[0039] 3. Test of hair dryer test group: Take another hair bundle, wash the hair bundle according to the above pre-treatment operation, tilt the hair dryer downward, fix it on the bracket, make the air outlet and the hair bundle form a 45° angle, and the distance between the air outlet and the hair bundle is 10-15 cm, turn on the hair dryer and turn on its negative ion and water ion functions, adjust to the hot air and maximum wind speed to dry the hair bundle (about 3-4 minutes), comb the front and back of the hair bundle from top to bottom at a speed of 3 seconds / time 10 times each. Repeat the above operation 10 times.

[0040] Take 5 marked hairs and cut off 1 cm from the root 4 to 7 cm away. Use a scanning electron microscope to observe their surface structure. Figure 2 D. Select 30 hair strands from the hair bundle and fix them with copper rings. Place them on a multifunctional hair testing device to test the diameter and breaking strength of the hair.

[0041] The hair bundles of this embodiment were scored according to the above-mentioned hair scale damage grades. The results are shown in Table 2.

[0042] Table 2

[0043] Group Average score before treatment Average score after treatment Natural drying control group 4.5 3.3 Hair dryer test group 4.5 4.1

[0044] The results of hair diameter are shown in Tables 3 and 4, and the results of breaking strength are shown in Tables 5 and 6.

[0045] Table 3

[0046]

[0047] Table 4

[0048]

[0049] Table 4 shows that the statistical analysis results of the diameters showed no significant difference. It can be considered that there is no significant difference in the diameters of the hair selected from each group and they can be used to test the breaking strength.

[0050] Table 5

[0051]

[0052] Table 6

[0053]

[0054] The statistical analysis results of breaking strength showed that the breaking strength increased significantly after hair dryer treatment compared with that before treatment, and there was a significant difference in breaking strength after hair dryer treatment compared with that after natural drying, indicating that the results obtained by observing the hair scales using the scanning electron microscope of the present invention are accurate.

[0055] Example 2

[0056] 1. Hair sample pretreatment: Take 2 bundles of healthy Chinese black hair (length 20 cm, width 2 cm, hair weight 3 g, free length 18 cm), use 1% sodium dodecyl sulfate solution, weigh 0.1 g / g, apply it on the front and back sides of the hair bundle in a W shape, rub the front side of the hair bundle with the fingertips for 30 seconds, rub the back side for 30 seconds, then rinse with tap water until no foam remains, pinch the hair bundle with the index finger and middle finger, and press the surface of the hair bundle gently with a lint-free paper towel from top to bottom until the hair bundle is in a dripping state; place it in a constant temperature and humidity room with a temperature of (21±1)°C and a humidity of (50%±5%)RH to dry naturally.

[0057] Take 5 hairs from each of the 2 hair bundles for marking, and cut off 1 cm of the hair 12 to 15 cm from the root, fix it on the conductive glue on the stage, spray gold, and observe its surface structure with a scanning electron microscope, such as Figure 3 A and C. Then 30 hairs were selected from the two hair bundles and fixed with copper rings, and placed on a multifunctional hair testing device to test the diameter and breaking strength of the hair.

[0058] 2. Test of the comparison group of hair dryers without hair care function (Group A): Take one of the hair bundles, wash the hair bundle according to the above pre-treatment operation, tilt the hair dryer downward, fix it on the bracket, make the air outlet and the hair bundle form a 45° angle, and the distance between the air outlet and the hair bundle is 10-15 cm, turn on the hair dryer, adjust to the hot air and maximum wind speed to blow dry the hair bundle (about 3-4 minutes), comb the front and back of the hair bundle from top to bottom at a speed of 3 seconds / time 10 times each. Repeat the above operation 10 times.

[0059] Take 5 marked hairs and cut off 1 cm from the root 4 to 7 cm away. Use a scanning electron microscope to observe their surface structure. Figure 3 B. Select 30 hairs from the hair bundle and fix them with copper rings. Place them on the multifunctional hair testing device to test the diameter and breaking strength of the hairs.

[0060] 3. Test of the hair dryer with hair care function (Group B): Take another hair bundle, wash the hair bundle according to the above pre-treatment operation, tilt the hair dryer downward, fix it on the bracket, make the air outlet and the hair bundle form a 45° angle, and the distance between the air outlet and the hair bundle is 10-15 cm, turn on the hair dryer and turn on its negative ion and water ion functions, adjust to the hot air and maximum wind speed to dry the hair bundle (about 3-4 minutes), comb the front and back of the hair bundle from top to bottom at a speed of 3s / time 10 times each. Repeat the above operation 10 times.

[0061] Take 5 marked hairs and cut off 1 cm from the root 4 to 7 cm away. Use a scanning electron microscope to observe their surface structure. Figure 3 D. Select 30 hair strands from the hair bundle and fix them with copper rings. Place them on a multifunctional hair testing device to test the diameter and breaking strength of the hair.

[0062] The hair bundles of this embodiment were scored according to the above-mentioned hair scale damage grades. The results are shown in Table 7.

[0063] Table 7

[0064] Group Average score before treatment Average score after treatment Group A 4 2 Group B 4 4

[0065] The results of hair diameter are shown in Tables 8 and 9, and the results of breaking strength are shown in Tables 10 and 11.

[0066] Table 8

[0067]

[0068]

[0069] Table 9

[0070]

[0071] Table 9 shows that the statistical analysis results of the diameters showed no significant difference. It can be considered that there is no significant difference in the diameters of the hair selected from each group and they can be used to test the breaking strength.

[0072] Table 10

[0073]

[0074] Table 11

[0075]

[0076] The breaking strength statistical analysis results showed that the breaking strength of group B after treatment was significantly increased compared with that before treatment, and there was a significant difference in breaking strength between group B and group A after treatment, indicating that the results obtained by observing the hair scales using the scanning electron microscope of the present invention are accurate.

[0077] Comparative Example 1

[0078] The steps are the same as those in Example 1, except that: the hair bundles of the naturally dried control group and the hair dryer test group are not combed with a fine-tooth comb during the treatment process.

[0079] The surface structure of the naturally dried control group hair before and after treatment is shown in Figure 4 A and B, the surface structure of the hair bundles before and after treatment of the hair dryer test group is shown in Figure 4 C and D; The hair bundles of this comparative example were scored according to the above-mentioned hair scale damage level. The results are shown in Table 12.

[0080] Table 12

[0081] Group Average score before treatment Average score after treatment Natural drying control group 4.5 4.5 Hair dryer test group 4.5 4.5

[0082] The results in Table 12 show that there is no significant change in the hair scales of the two groups of hair bundles after only washing and air-drying or hair-drying with a hair dryer for 10 times; obviously, this comparative example is not suitable for evaluating the hair care or damage caused by a hair dryer.

[0083] Comparative Example 2

[0084] The steps are the same as those in Example 1, except that the test operation on the hair bundles of the natural air-drying control group and the hair dryer test group is repeated twice.

[0085] The surface structure of the naturally dried control group hair before and after treatment is shown in Figure 5 A and B, the surface structure of the hair bundles before and after treatment of the hair dryer test group is shown in Figure 5 C and D; The hair bundles of this comparative example were scored according to the above-mentioned hair scale damage level. The results are shown in Table 13.

[0086] Table 13

[0087] Group Average score before treatment Average score after treatment Natural drying control group 4.3 4.2 Hair dryer test group 4.3 4.2

[0088] The results in Table 13 show that the damage to the hair scales of the two groups of hair bundles before and after treatment did not change much, and there was no significant difference between the two groups of hair bundles after treatment; obviously, the method of this comparative example cannot effectively evaluate the hair care or damage caused by the hair dryer.

Claims

1. A method for evaluating the hair care or damage of a hair dryer, characterized in that: The following steps are involved: (1) Pretreatment of the hair bundle sample: washing the hair bundle sample, drying the hair bundle naturally, and observing the hair scales on the surface of the hair in the hair bundle using a scanning electron microscope; (2) Testing of the hair dryer test group: Take a hair bundle sample after pretreatment, wash it, then turn on the hair dryer and adjust it to the test gear / mode to blow dry the hair bundle, and then comb the hair bundle from top to bottom with a fine-tooth comb; repeat the above operation 8 to 10 times; use a scanning electron microscope to observe the hair scales on the surface of the hair in the hair bundle of the hair dryer test group, and compare them with the hair bundle after pretreatment, so as to evaluate the hair care or damage of the hair by the hair dryer.

2. The method for evaluating hair care or damage by a hair dryer according to claim 1, characterized in that: After blow-drying the hair, use a fine-tooth comb to comb the front and back of the hair from top to bottom 10 times each at a speed of 3 seconds per time.

3. The method for evaluating hair care or damage by a hair dryer according to claim 2, characterized in that: Use the surfactant solution to apply it in a W shape on both sides of the hair, rub the front and back sides of the hair with your fingertips for the same amount of time, then rinse with tap water until no foam remains, hold the hair with your index and middle fingers, and press lightly on the surface of the hair with a lint-free paper towel from top to bottom until the hair is no longer dripping.

4. The method for evaluating hair care or damage by a hair dryer according to claim 3, characterized in that: The hair tresses were processed and tested in a constant temperature and humidity room.

5. The method for evaluating the hair care or damage condition of a hair dryer according to claim 4, characterized in that: The temperature in the constant temperature and humidity room is 21±1°C, and the humidity is 50%±5%RH.

6. The method for evaluating the hair care or damage condition of a hair dryer according to claim 5, characterized in that: The hair dryer is tilted downward so that the air outlet forms a 45° angle with the hair bundle, and the distance between the air outlet and the hair bundle is 10-15 cm.

7. The method for evaluating the hair care or damage of a hair dryer according to claim 6, characterized in that: Add a test for a naturally dried control group; specifically: take a hair bundle sample after pre-treatment, wash it, then dry it naturally, and then comb the hair bundle from top to bottom with a fine-tooth comb; repeat the above operation 8 to 10 times; use a scanning electron microscope to observe the hair scales on the surface of the hair in the hair bundle, and compare the hair scales with the hair bundles of the hair dryer test group; the naturally dried control group and the hair dryer test group use hair bundle samples of the same batch with the same hair quality, quantity or weight.

8. The method for evaluating the hair care or damage of a hair dryer according to claim 7, characterized in that: Use two hair dryers, or use the same hair dryer in different modes for comparative testing to evaluate their effects on hair care or damage; the comparative test uses hair samples from the same batch with the same hair quality, quantity or weight.

9. The method for evaluating the hair care or damage condition of a hair dryer according to claim 8, characterized in that: The hair scales on the surface of the hair are graded to establish a hair scale damage grade, and then the tested hair bundles are scored based on the grade to evaluate the hair care or damage caused by the hair dryer.

10. The method for evaluating the hair care or damage condition of a hair dryer according to claim 9, characterized in that: The hair strands before and after the test treatment were subjected to tensile tests to test the breaking strength of the hair strands in order to verify whether the results obtained based on the SEM observations were accurate.

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