A method for testing the ratio of dark-colored human hair to straight hair and a clamp used therefor

Abstract

The present invention relates to a method for testing the straightness ratio of dark-colored human hair and a clamp used therefor. The method includes five steps: resetting, fixing, straightening, pre-treatment, and testing. The two ends of the support rod of the clamp are composed of two parts, including a sliding rod and a screw rod of different diameters. A step is formed at the diameter change point. Loading block I is set on the sliding rod, and loading block II is set on the screw rod. A light-transmitting hole is set at the joint of loading block I and loading block II; a rotating handle is set at the end of the sliding rod of the support rod; and two pressing plates are respectively set above loading block I and loading block II. The present invention uses ordinary bleaching agent and fluorescent dye to pre-treat the dark-colored human hair, and then with the help of the clamp, the dark-colored human hair is tested without the need for an expensive and maintenance-intensive electron microscope. Instead, a low-cost optical microscope is used for clear observation. The sample volume is large, the testing process is simple, and the testing conditions, testing equipment, and testing costs are reduced, the testing time is shortened, and the testing efficiency is improved.

Description

Technical Field

[0001] The present invention relates to the field of detection of human hair smears, and in particular to a method for detecting the smear-smooth ratio of dark-colored human hair smears and a clamp used therefor. Background Art

[0002] The content of DB41 / T 1364-2018 standard stipulates that "the standard applies to human hair as raw material. Human hair is a hair bundle or a hair bundle that has been combed to form a flat end and has certain length requirements. Straight hair refers to human hair with the same order of roots and ends in a hair bundle or a hair bundle. Non-straight hair refers to human hair with inconsistent order of roots and ends in a hair bundle or a hair bundle. The straight hair ratio refers to the method of taking 100 representative test hair samples from the sample (mark the order of the bundled head and tail of each test hair when sampling), carefully observing the growth direction of the scales on each test hair under a microscope, and determining the root and end order of the test hair based on the growth direction of the scales. Observe whether it is consistent with the marked order of the bundled head and tail of the sample. If the order is consistent, it is considered straight hair, and if the order is inconsistent, it is considered non-straight hair. The straight hair ratio of the sample is calculated according to formula (1). The straight hair ratio is an important indicator of whether human hair has been combed and combed, and is also an important technical basis for such commodities in the field of customs inspection and identification.

[0003] Where: ....................(1)

[0004] S is the smooth hair ratio (%);

[0005] f1 is the number of straight hairs in the hair sample for testing;

[0006] f is the number of hair specimens used for testing, 100.

[0007] When observing samples under an optical microscope, glass slides and coverslips with good light transmittance are typically used. Slides are transparent glass blocks used to hold samples in place during observation under an optical microscope, while coverslips are primarily used to maintain a flat surface for solid samples or to form a uniform layer for liquid samples. Because optical microscopes have a very narrow focal point and a small depth of field, they cannot simultaneously observe morphological features that are not in the same focal point. Furthermore, hair sample size during the hair-to-hair ratio test is often challenging due to its lightness, fineness, softness, and tendency to electrostatically attract, making it difficult to fixate and requiring a large amount of material to be examined. This is particularly true for darker shades of human hair, such as black and dark brown, which reflect light poorly under an optical microscope, making it difficult to directly observe the morphology of the scales on the hair surface. Therefore, scanning electron microscopes (SEMs), with their large depth of field and strong three-dimensional perception, are typically used to observe the morphological features and growth direction of the scales. However, SEMs are expensive and require high maintenance. Furthermore, they suffer from limitations such as limited sample volume and long inspection and identification times. This makes this method demanding in practice, not only in terms of hardware requirements but also in terms of time and workload.

[0008] Therefore, the poor reflectivity of dark-colored human hair and the difficulty in fixing the sample hair are important factors that restrict the use of optical microscopes to observe the surface morphology of human hair. Summary of the Invention

[0009] In response to the challenges of the existing technology, the present invention provides a method for testing the hair-to-hair ratio of dark human hair and a holder for use therein. The secured sample, along with the holder, can undergo pretreatment and optical microscopy observation. The holder not only secures the sample but also replaces a glass slide and cover glass for optical microscopy. Surface scales of the pretreated dark human hair can be observed under an optical microscope, allowing the hair's hair-to-hair ratio to be determined.

[0010] The technical solution of the present invention is: a method for testing the hair-to-hair ratio of dark-colored human hair, with the help of a clamp, according to the following steps:

[0011] The first step is to reset the gripper: Place the gripper flat on the workbench and rotate the two handles of the gripper clockwise. The two handles will drive the two support rods to rotate clockwise, so that the load block I and the load block II gradually move closer until they are close together. At this point, the light hole area is minimized.

[0012] The second step is to fix the sample hair: Arrange the sample hairs marked with the head and tail order one by one along the axial direction of the support rod, place one end on the load block I and the other end on the load block II, place pressure plates on both ends of the sample hair, i.e., on the load block I and the load block II respectively, tighten the fastening screws to tighten the pressure plates, and fix the two ends of the sample hair;

[0013] The third step is straightening: rotate the two rotating handles counterclockwise. The two rotating handles drive the two supporting rods to rotate counterclockwise. The steps on the supporting rods drive the object block I to gradually move away from the object block II, so that the area of ​​the light transmission hole is expanded until the sample hair is completely straightened.

[0014] Step 4, pretreatment: First, mix bleaching powder and hydrogen peroxide in a 1:1 ratio and apply it to the sample hair fixed in the holder to ensure full contact between the sample hair and the bleach. Let it stand for 1-2 hours until the color of the sample hair changes from dark to light yellow or off-white. Rinse the bleach off the sample hair in the holder with clean water. Then, immerse the sample hair in the holder together with the holder in a 0.01g / ml sodium fluorescein aqueous solution, remove immediately, and air dry.

[0015] Step 5: Detection: Place the pre-treated sample hair together with the holder directly on the stage of the optical fiber microscope. The light hole and the light hole of the optical microscope can be overlapped for direct observation. The scale morphology and growth direction of the sample hair surface can be clearly observed. The number of hairs in the straight line, i.e., f1, can be counted using the formula The straight hair ratio of the sample hair can be calculated.

[0016] In the above technical solution, an anti-slip friction tooth block is first set on one side of each pressing plate, and then the side of the pressing plate with the anti-slip friction tooth block is pressed on the two ends of the sample hair, that is, on the loading block I and the loading block II, and the direction of the anti-slip friction tooth block is perpendicular to the sample hair.

[0017] A sample hair holder for testing the hair-straightness ratio of dark-colored human hair comprises a loading block I, a loading block II, a pressing piece, a support rod, a fastening bolt, a light-transmitting hole and a rotating handle. A semicircular groove I is provided in the middle of one end of the loading block I, and a semicircular groove II is provided in the middle of one end of the loading block II. The diameters of the two ends of the supporting rod are different, the small diameter portion is a sliding rod, and the large diameter portion is a screw rod, and a step is formed at the diameter change point. The loading block I is provided on the sliding rod portion, and the loading block II is provided on the screw rod portion. The semicircular groove I and the semicircular groove II are connected to form the light-transmitting hole. A rotating handle is provided at the end of the sliding rod of the supporting rod. Two pressing pieces are respectively provided above the loading block I and the loading block II.

[0018] In the above technical solution, an anti-skid friction tooth block perpendicular to the support rod is provided on the contact surface between each pressing sheet and the sample.

[0019] The beneficial effects of the present invention are mainly reflected in the following aspects:

[0020] First, the present invention uses common bleach and fluorescein to pre-treat dark human hair. With the help of a clamp, dark human hair can be clearly observed directly using a low-cost optical microscope without the need for an expensive electron microscope with high maintenance costs. The sample volume is large, the inspection process is simple and easy to operate, and the inspection conditions, inspection equipment and inspection costs are reduced, the inspection time is shortened, and the inspection efficiency is improved.

[0021] Second, the holder of the present invention is not only convenient for fixing the sample, but also allows the sample to be adjusted at any time during the observation process. It not only solves the problem that the sample is not easy to fix because it is light, thin, soft and easily adsorbed by electrostatics, but also can replace the slides and cover slips used in optical microscope observation, can be used repeatedly, and reduce the use of experimental consumables such as slides and cover slips.

[0022] Third, since the present invention uses a clamp, after the sample hair is fixed on the clamp, it can be easily straightened by adjusting the distance between the loading blocks. The straightened sample hair has the following advantages during the inspection process: 1) Each sample hair will not interfere with each other, which not only makes it easy to determine the number of sample hairs, but also facilitates microscopic observation; 2) The sample hair that can be straightened can make it easier for the bleaching agent to penetrate into the cortical layer through the gaps in the scale layer, so as to remove the pigment in the cortical layer and achieve bleaching better and faster; 3) The sample hair that can be straightened can make the dye better adhere to the scale layer, which is conducive to clearer subsequent observation; 4) After one fixation, in the subsequent sample pretreatment (bleaching, dye immersion, etc.) until microscopic observation, there is no need for secondary sample preparation, which can not only maximize the consistency of the head and tail order of the sample, but also greatly reduce the sample preparation time. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 It is an axonometric drawing of the structure of the present invention;

[0024] Figure 2 It is an enlarged front cross-sectional view of the present invention when one support rod is installed;

[0025] Figure 3 It is a schematic diagram of the working state of the present invention;

[0026] Figure 4 It is the surface morphology of the unbleached sample observed under an optical microscope;

[0027] Figure 5 It is the surface morphology of the sample after bleaching and not soaked in fluorescent agent observed under an optical microscope;

[0028] Figure 6 The surface morphology of the sample after bleaching and immersion in fluorescent agent is observed under an optical microscope. DETAILED DESCRIPTION

[0029] References Figure 3 A method for testing the hair-to-hair ratio of human hair is to use a clamp and perform the following steps:

[0030] Step 1: Reset the clamp: Place the clamp flat on the workbench and rotate the two handles 7 of the clamp clockwise. The two handles 7 drive the two support rods 3 to rotate clockwise. The screws 3-2 of the support rods 3 move inward along the screw holes 1-2-1 in the object block Ⅱ 1-2, gradually bringing the object blocks Ⅰ 1-1 and Ⅱ 1-2 closer together until they are close together. At this point, the area of ​​the light-transmitting hole 5 is minimized.

[0031] The second step is to fix the sample hair: Arrange the sample hairs 8 marked with the head and tail order one by one along the axial direction of the support rod 3, place one end on the loading block I1-1, and the other end on the loading block II1-2. In order to better fix the sample hair 8, adhere an anti-skid friction tooth block 6 to the contact surface of each pressing block 2 with the sample hair, and place the anti-skid friction tooth block 6 perpendicular to the sample hair 8. Press the pressing block 2 with the anti-skid friction tooth block 6 on the two ends of the sample hair 8, i.e., the loading block I1-1 and the loading block II1-2, respectively. Tighten the fastening screws 4 to tighten the pressing block 2 and the anti-skid friction tooth block 6, and fix the two ends of the sample hair 8.

[0032] The third step is straightening: counterclockwise rotation of the two rotating handles 7 drives the two supporting rods 3 to rotate counterclockwise, and the supporting rods 3 move outward. The steps 3-3 on the supporting rods 3 drive the object block I1-1 to gradually move away from the object block II1-2, so that the area of ​​the light transmission hole 5 is expanded until the sample hair 8 is completely straightened.

[0033] Step 4: Pre-treatment: For dark-colored human hair, especially black and dark brown, the reflectivity under the optical microscope is poor, and the morphology cannot be directly observed using an optical microscope. Figure 4 As shown, bleaching is required. The bleaching agent can be any common bleach used in barber shops, which is generally a mixture of bleaching powder and hydrogen peroxide (the main active ingredients of bleaching powder are: calcium carbonate, ammonium persulfate, ammonium metasilicate, sodium carbonate; the active ingredient of hydrogen peroxide is hydrogen peroxide). After bleaching, the sample hair still cannot be directly observed using an optical microscope. Figure 5 As shown, by utilizing the gaps in the scale structure on the surface of the sample and using a fluorescent agent, the reflectivity of the sample surface can be improved, which can facilitate observation under an optical microscope.

[0034] First, mix bleaching powder and hydrogen peroxide in a 1:1 ratio and apply it to the sample hair 8 fixed on the holder, so that the sample hair 8 is fully in contact with the bleach. Let it stand for 1-2 hours until the color of the sample hair changes from dark to light yellow or grayish white. Rinse the bleach off the sample hair 8 on the holder with clean water. Then, immerse the sample hair on the holder together with the holder in a 0.01g / ml sodium fluorescein aqueous solution, remove it immediately, and dry it.

[0035] Step 5: Detection: Place the pre-treated sample hair 8 together with the holder directly on the optical fiber microscope stage. The light hole 5 and the light hole of the optical microscope can be overlapped for direct observation. The scale morphology and growth direction of the surface of the sample hair 8 can be clearly observed, such as Figure 6 As shown, the number of sequential shipments, i.e. f1, is calculated using the formula The straight hair ratio of the sample hair can be calculated.

[0036] like Figure 1 、 Figure 2 As shown, a sample hair holder for testing the straightness ratio of dark-colored human hair includes a loading block I 1-1, a loading block II 1-2, a pressing block 2, a support rod 3, a fastening bolt 4, a light-transmitting hole 5, an anti-slip friction tooth block 6, and a rotating handle 7;

[0037] The diameters of the two ends of the support rod 3 are different. The small diameter part is the slide rod 3-1, and the large diameter part is the screw rod 3-2. A step 3-3 is formed at the diameter change point. The length of the slide rod 3-1 is slightly larger than the length of the object block Ⅰ1-1. The length of the screw rod 3-2 can be determined according to the length of the object block Ⅰ1-1, the object block Ⅱ1-2 and the sample, and can generally be between 30mm and 40mm. A semicircular groove Ⅰ5-1 is milled in the middle of one end of the object block Ⅰ1-1, and a semicircular groove Ⅱ5-2 is milled in the middle of one end of the object block Ⅱ1-2. According to the diameter of the slide rod 3-1, a semicircular groove Ⅰ5-1 is milled in the middle of the one end of the object block Ⅰ1-1. Two through holes 1-1-1 are prefabricated on both sides of the semicircular groove I5-1. The diameter of the through holes 1-1-1 is smaller than the diameter of the screw rod 3-2. Two bolt mounting holes I1-1-2 are prefabricated on the front end of the loading block I1-1 away from the semicircular groove I5-1. According to the diameter of the screw rod 3-2, two blind screw holes 1-2-1 are prefabricated on both sides of the semicircular groove II5-2 of the loading block II1-2. The depth of the blind screw holes 1-2-1 is not less than the length of the screw rod 3-2. Two bolt mounting holes II1-2-2 are prefabricated on the front end of the loading block II1-2 away from the semicircular groove II5-2.

[0038] First, the object-carrying block I1-1 is placed on the slide bar 3-1 part of the two support rods 3 through the two through holes 1-1-1 in the inward direction of the semicircular groove I5-1, and the object-carrying block I1-1 is placed on the step 3-3. Then, the rotating handle 7 is welded to the end of the slide bar 3-1, and the two rotating handles 7 are rotated clockwise to screw the screw 3-2 part of the support rod 3 into the blind hole 1-2-1 in the object-carrying block II1-2; a light-transmitting hole 5 is formed at the junction of the semicircular groove I5-1 and the semicircular groove II5-2.

[0039] An anti-skid friction tooth block 6 is adhered to the contact surface between each pressing plate 2 and the sample 8. The two pressing plates 2 with the anti-skid friction tooth blocks 6 are pressed on the loading block Ⅰ1-1 and the loading block Ⅱ1-2 respectively. The fastening bolts 4 are screwed into the mounting holes Ⅰ1-1-2 and the mounting holes Ⅱ1-2-2 respectively. The fastening bolts 4 are tightened to fasten the two pressing plates 2. The direction of the anti-skid friction tooth block 6 is perpendicular to the support rod 3.

Claims

1. A method for testing the hair-to-hair ratio of dark human hair, characterized by: Using the gripper, proceed as follows: The first step is to reset the clamp: place the clamp flat on the workbench and rotate the two rotating handles (7) of the clamp clockwise. The two rotating handles (7) drive the two supporting rods (3) to rotate clockwise, so that the object block I (1-1) and the object block II (1-2) gradually approach each other until they are close to each other. At this time, the area of ​​the light hole (5) is the smallest. The second step is to fix the sample hair: arrange the sample hair (8) marked in the order of head and tail one by one along the axial direction of the support rod (3), place one end on the load block I (1-1), and the other end on the load block II (1-2), place the pressing pieces (2) on the two ends of the sample hair (8), i.e., on the load block I (1-1) and the load block II (1-2), respectively, tighten the fastening screws (4) to tighten the pressing pieces (2), and fix the two ends of the sample hair (8); The third step is straightening: rotate the two rotating handles (7) counterclockwise. The two rotating handles (7) drive the two supporting rods (3) to rotate counterclockwise. The steps (3-3) on the supporting rods (3) drive the object block I (1-1) to gradually move away from the object block II (1-2), so that the area of ​​the light-transmitting hole (5) is expanded until the sample hair (8) is completely straightened. Step 4, pre-treatment: first, mix bleaching powder and hydrogen peroxide in a ratio of 1:1, and apply it to the sample hair (8) fixed on the holder, so that the sample hair (8) is fully in contact with the bleach, and let it stand for 1-2 hours until the color of the sample hair changes from dark to light yellow or grayish white, and then rinse the bleach on the sample hair (8) on the holder with clean water; then immerse the sample hair (8) on the holder together with the holder in a 0.01% sodium fluorescein aqueous solution, and immediately take it out and dry it; Step 5: Detection: Place the pre-treated sample hair (8) together with the holder directly on the stage of the optical fiber microscope. The light hole (5) can be aligned with the light hole of the optical microscope for direct observation. The scale morphology and growth direction of the surface of the sample hair (8) can be clearly observed. The number of hairs in the straight line, i.e., f1, can be calculated using the formula The hair straightening ratio of the sample can be calculated; The clamp used includes a carrier block I (1-1), a carrier block II (1-2), a pressing plate (2), a support rod (3), a fastening screw (4), a light-transmitting hole (5) and a rotating handle (7). A semicircular groove I (5-1) is provided in the middle of one end of the carrier block I (1-1), and a semicircular groove II (5-2) is provided in the middle of one end of the carrier block II (1-2); the diameters of the two ends of the support rod (3) are different, the small diameter part is a slide rod (3-1), and the large diameter part is a screw rod ( 3-2), a step (3-3) is formed at the diameter change position, the object-carrying block I (1-1) is arranged on the sliding rod (3-1), the object-carrying block II (1-2) is arranged on the screw rod (3-2), and the semicircular groove I (5-1) and the semicircular groove II (5-2) are connected to form a light-transmitting hole (5); a rotating handle (7) is arranged at the end of the sliding rod (3-1) of the support rod (3); and two pressing plates (2) are respectively arranged above the object-carrying block I (1-1) and the object-carrying block II (1-2).

2. A method for testing the hair-to-hair ratio of dark human hair as claimed in claim 1, characterized in that: An anti-skid friction tooth block (6) perpendicular to the support rod (3) is provided on the contact surface between each pressing sheet (2) and the sample hair (8); first, an anti-skid friction tooth block (6) is provided on one side of each pressing sheet (2), and then the side of the pressing sheet (2) with the anti-skid friction tooth block (6) is pressed on both ends of the sample hair (8), that is, on the loading block I (1-1) and the loading block II (1-2), and the direction of the anti-skid friction tooth block (6) is perpendicular to the sample hair (8).

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