Coloring firmness testing equipment for colored contact lens

Abstract

The invention discloses color contact lens coloring firmness testing equipment which comprises a supporting table, a negative pressure adsorption mold, a profiling grinding head and a driving assembly, and a through hole is formed in the supporting table; the negative pressure adsorption mold is fixed to the supporting table, and an adsorption hole communicating with the through hole and extending to the supporting face is formed in the negative pressure adsorption mold. The profiling grinding head is arranged at the top of the negative pressure adsorption mold, and a driving groove is formed in the top of the profiling grinding head; the driving assembly comprises a driving rod extending into the driving groove, and the driving rod makes contact with the side edge of the driving groove to drive the profiling grinding head to move. The beauty piece is fixed in a negative pressure adsorption mode, the driving rod pushes the profiling grinding head, the motion form of the driving rod cannot be completely transmitted to the beauty piece, the profiling grinding head autonomously moves or rotates along the surface of the beauty piece, the profiling grinding head is always in soft contact with the beauty piece, and the beauty piece is fixed in a negative pressure adsorption mode. Therefore, composite actions such as rubbing, rubbing, rotating and pressing of fingers can be reproduced, and the accuracy and consistency of test results are ensured.

Description

Technical Field

[0001] This invention relates to the field of ophthalmic optical product testing technology, and in particular to a device for testing the colorfastness of colored contact lenses. Background Technology

[0002] Colored contact lenses (also known as cosmetic lenses) are widely popular due to their dual function of decoration and vision correction. Colored contact lenses are functional lenses made by adding a colorant layer to a soft, hydrophilic material, primarily used to change the color of the iris. To ensure safety, colored contact lenses generally employ a "sandwich" structure, sealing the colorant inside the lens substrate to avoid direct contact with the eyeball. In China, these products are classified as Class III medical devices, the highest risk level, and require strict national approval. Their core quality indicators include colorfastness (preventing fading through simulated testing) to ensure that while enhancing appearance, corneal health and wearing safety are maximized.

[0003] According to the national standard GB11417.3-2012 "Ophthalmic Optical Contact Lenses Part 3: Soft Contact Lenses", colorfastness testing is required for cosmetic contact lenses. This fading test verifies the stability of the "sandwich" structure of the colored contact lens, ensuring the colorant layer is effectively sealed during production and wear. Failure to meet the fading test standard indicates a defect in the colorant encapsulation process. Once the colorant detaches, it first causes physical irritation; the detached particles or rough surfaces directly rub against the cornea, causing foreign body sensation or even corneal abrasion. Second, the exposed dye may trigger chemical toxicity reactions and allergic inflammation of the ocular surface tissue. More seriously, the micropores formed after colorant detachment easily breed bacteria, significantly increasing the risk of corneal infection and ulceration, causing irreversible damage to vision.

[0004] The abrasion resistance test of ordinary frame lenses mainly uses externally driven machinery to directly apply force to the lens surface (such as patent numbers CN202110596077.X and CN202022574041.5). Unlike ordinary frame lenses, cosmetic lenses are worn inside the eye. The friction they experience is mainly the slight friction between the skin and the cosmetic lens, as well as the rubbing, pressing, and rotation of fingers when wearing the cosmetic lens. Among these, the force exerted by fingers on the cosmetic lens is most likely to cause the colorant to fall off. Furthermore, since cosmetic lenses are usually curved lenses, ordinary mechanical movements are difficult to track the force according to the curvature accuracy of the curved lens, resulting in uneven force on different parts of the cosmetic lens and inaccurate test results. Therefore, using directly driven mechanical force on the lens surface cannot truly simulate the gentle force exerted by fingers on the cosmetic lens.

[0005] Currently, commonly used methods for testing the colorfastness of cosmetic lenses include vortex oscillation, ultrasonic oscillation, and cotton swab wiping. The main drawbacks of these methods lie in their simulation and subjectivity. The testing environment is overly simplified. Using vortex oscillation or ultrasonic oscillation for mechanical oscillation, or cotton swab wiping, the mechanical force applied by this single physical friction is not standardized. This can lead to false negatives due to either a force far lower than that used in actual care, or false positives due to excessive force caused by the use of ethanol or uneven application of force. The cotton swab wiping method, in particular, is highly susceptible to human error due to varying operator pressure. Furthermore, the lack of contact lens solution in the testing process means that the chemical effects of different solutions on lens colorfastness cannot be ignored. Therefore, existing testing methods cannot comprehensively assess the colorfastness of lenses in real-world wearing scenarios, and the test results may deviate from clinical realities, making them unreliable as absolute evidence of long-term product safety.

[0006] Therefore, there is an urgent need for a testing device that can simulate the colorfastness of colored contact lenses under actual usage conditions. Summary of the Invention

[0007] To address the technical problem that existing lens testing equipment is unsuitable for cosmetic lenses or cannot fully simulate real-world usage environments, leading to discrepancies between test results and clinical realities, this invention provides a color fastness testing device for colored contact lenses to solve the aforementioned problem.

[0008] The technical solution adopted by this invention to solve its technical problem is: a color fastness testing device for colored contact lenses, including a support platform, a negative pressure adsorption mold, a contour grinding head, and a drive assembly. The support platform has a through hole; the negative pressure adsorption mold is fixed on the support platform, and the top of the negative pressure adsorption mold is a support surface for carrying the cosmetic lens. The negative pressure adsorption mold has an adsorption hole that communicates with the through hole and extends to the support surface; the contour grinding head is placed on top of the negative pressure adsorption mold, and the top of the contour grinding head is provided with a drive groove; the drive assembly includes a drive rod extending into the drive groove, and the drive rod drives the contour grinding head to move by contacting the side of the drive groove.

[0009] In an optional embodiment of the present invention, the contouring abrasive head includes a rigid abrasive head and a nonwoven fabric adsorbed onto the bottom of the rigid abrasive head and in contact with the cosmetic patch.

[0010] In an optional embodiment of the present invention, the top of the negative pressure adsorption mold is provided with an annular limiting groove, and the rigid grinding head has an annular limiting block extending into the annular limiting groove.

[0011] In an optional embodiment of the present invention, the support platform can drive the negative pressure adsorption mold to rotate around the center.

[0012] In an optional embodiment of the present invention, the contour grinding head is provided with a connecting drive groove and a drip hole at the bottom of the contour grinding head.

[0013] In an optional embodiment of the present invention, the driving rod is a drip tube, one end of the driving rod extends into the driving groove, and the other end of the driving rod is connected to an infusion tubing.

[0014] In an optional embodiment of the present invention, the top of the drive groove is integrally formed with a pressure cap, and the pressure cap is provided with a drive port for the drive rod to extend into.

[0015] In an optional embodiment of the invention, the bottom of the rigid grinding head has a plurality of actuation grooves; the test equipment further includes an actuation component located within the actuation grooves for applying an oscillating load to the nonwoven fabric.

[0016] In an optional embodiment of the present invention, the actuation assembly includes a linear actuator fixed in the actuation groove and a pressure block driven by the linear actuator to perform up-and-down reciprocating motion.

[0017] In an optional embodiment of the present invention, the linear actuator is a piezoelectric ceramic actuator.

[0018] In an optional embodiment of the present invention, a plurality of adsorption holes are arranged radially outward from the center of the negative pressure adsorption mold, and the through holes are arranged in a one-to-one correspondence with the adsorption holes.

[0019] In an optional embodiment of the present invention, the thickness of the nonwoven fabric is 0.15 mm to 0.2 mm, and the basis weight of the nonwoven fabric is 20 to 25 g / m².

[0020] In an optional embodiment of the present invention, the top of the contour grinding head is further provided with several load-bearing grooves arranged in a circumferential array.

[0021] The beneficial effects of this invention are: (1) The present invention fixes the beauty sheet by negative pressure adsorption, and at the same time places the contour grinding head on the beauty sheet to simulate the touch of the finger on the beauty sheet. The contour grinding head is pushed by the drive rod to make the contour grinding head produce a certain form of movement. The movement of the drive rod is not completely transmitted to the beauty sheet, but the contour grinding head moves or rotates autonomously along the surface of the beauty sheet. The contour grinding head is always in gentle contact with the beauty sheet, so as to reproduce the compound actions of the finger such as kneading, rubbing, rotating and pressing, and ensure the accuracy of the test results.

[0022] (2) The present invention uses the drip tube as a driving rod. While the contour grinding head simulates the compound actions of fingers such as kneading, rubbing, rotating and pressing, the care solution can also be dripped. Thus, the chemical effect of the care solution on the beauty patch is taken into account. The care solution flows to the surface of the beauty patch through the drip hole in the contour grinding head. The drip tube is not only used to drip the care solution, but also to drive the contour grinding head to move. Thus, the structure is simplified and the care solution can be prevented from spilling.

[0023] (3) The contour grinding head in this invention is composed of a rigid grinding head and a non-woven fabric. The curved shape of the bottom of the rigid grinding head is the same as the surface of the beauty patch. The rigidity of the rigid grinding head can ensure the curvature accuracy of the contact part between the contour grinding head and the beauty patch. The deformable properties of the non-woven fabric are used to simulate the soft pad effect of the finger.

[0024] (4) The rigid grinding head in this invention is also equipped with a linear actuator and a pressure block. The linear actuator drives the pressure block to apply a high-frequency oscillation load to the non-woven fabric, simulating the physiological vibration when a human hand rubs. Attached Figure Description

[0025] The present invention will be further described below with reference to the accompanying drawings and embodiments.

[0026] Figure 1 This is a perspective view of a specific embodiment of the color fastness testing device for colored contact lenses according to the present invention; Figure 2 This is a schematic diagram showing the positional relationship between the support platform, the negative pressure adsorption mold, and the contour grinding head in this invention; Figure 3 This is a perspective view of the negative pressure adsorption mold in this invention; Figure 4 yes Figure 3 A cross-sectional view of the negative pressure adsorption mold shown; Figure 5 This is a cross-sectional view of the contour grinding head in this invention; Figure 6 This is a schematic diagram showing the state of the cosmetic patch when the contour grinding head rubs against it in this invention.

[0027] In the diagram, 1. Support platform, 101. Through hole, 2. Negative pressure adsorption mold, 201. Annular limiting groove, 3. Contouring grinding head, 4. Drive assembly, 401. Drive rod, 402. Six-axis robot, 5. Support surface, 6. Beauty film, 7. Adsorption hole, 8. Rigid grinding head, 801. Drive groove, 802. Annular limiting block, 803. Drip hole, 804. Load-bearing groove, 9. Non-woven fabric, 10. Friction surface, 11. Actuation groove, 12. Actuation assembly, 1201. Linear actuator, 1202. Pressure block, 13. Drive port, 14. Infusion tubing, 15. Peristaltic pump, 16. Pressure cap. Detailed Implementation

[0028] Embodiments of the present invention are described in detail below. Examples of these embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present invention, and should not be construed as limiting the present invention.

[0029] Example 1

[0030] like Figures 1-6 As shown, a color fastness testing device for colored contact lenses includes a support platform 1, a negative pressure adsorption mold 2, a contour grinding head 3, and a drive assembly 4. The support platform 1 has a through hole 101 for connecting a blower or a vacuum pump. The negative pressure adsorption mold 2 is fixed on the support platform 1. The top of the negative pressure adsorption mold 2 is a support surface 5 for supporting a cosmetic film 6. The top curved surface shape of the negative pressure adsorption mold 2 is the same as that of the cosmetic film 6, so that the cosmetic film 6 is completely fitted to the support surface 5. The negative pressure adsorption mold 2 has an adsorption hole 7 that communicates with the through hole 101 and extends to the support surface 5. After starting the blower or vacuum pump, the cosmetic film 6 can be adsorbed onto the surface of the negative pressure adsorption mold 2.

[0031] The contour grinding head 3 is placed on top of the negative pressure adsorption mold 2. The lower surface of the contour grinding head 3 is the friction surface 10 that contacts the beauty sheet 6. The top of the contour grinding head 3 is provided with a drive groove 801. The drive assembly 4 includes a drive rod 401 extending into the drive groove 801. The drive rod 401 drives the contour grinding head 3 to move by contacting the side of the drive groove 801. The present invention enables the drive rod 401 to push the contour grinding head 3 through the design of the drive groove 801. The contour grinding head 3 moves along the arc surface of the beauty sheet 6 along a certain trajectory, such as straight back and forth, in circles or figure eights, thereby simulating the compound actions of rubbing, kneading, rotating and pressing with fingers. Compared with the prior art, the drive rod 401 only applies lateral pushing force to the contour grinding head 3 and does not transmit vertical pressure. The contour grinding head 3 can move autonomously along the surface of the beauty sheet 6, thus not damaging the surface of the beauty sheet 6, nor causing uneven force on different parts of the beauty sheet 6.

[0032] The driving source of the driving component 4 can be a six-axis robot 402, whose motion trajectory can be customized by software as a straight reciprocating motion, a circle, or a figure-eight.

[0033] Structure of contour grinding head 3: like Figure 5 and Figure 6As shown, the contour abrasive head 3 includes a rigid abrasive head 8 and a non-woven fabric 9 that is adsorbed on the bottom of the rigid abrasive head 8 and contacts the cosmetic patch 6. The rigid abrasive head 8 is made of metal, and the curvature of its lower surface is precisely matched with the outer arc of the cosmetic patch 6 (usually 8.4mm~8.8mm) to ensure the curvature accuracy of the contact area between the contour abrasive head 3 and the cosmetic patch 6. The non-woven fabric 9 is a medical-grade non-woven fabric with surface roughness calibrated by AFM. A new non-woven fabric 9 can be replaced before each test through a magnetic quick-release structure to avoid cross-contamination and wear and aging. The deformable characteristics of the non-woven fabric 9 enable it to make line contact when initially contacting the cosmetic patch 6, and then change to surface contact due to the elastic deformation of the material after loading, so as to simulate the effect of a finger pad.

[0034] Considering the requirements of the present invention on the softness of the nonwoven fabric 9 and the curvature accuracy of the contact surface, it is necessary to limit the parameters of the nonwoven fabric 9. In this embodiment, the thickness of the nonwoven fabric 9 is 0.15mm ~ 0.2mm, and the basis weight of the nonwoven fabric 9 is 20~25g / m².

[0035] Design of adsorption pore 7: Several adsorption pores 7 are arranged radially outward from the center of the negative pressure adsorption mold 2. The adsorption pores 7 extend to the surface of the negative pressure adsorption mold 2, thereby forming a honeycomb-like array of micropores on the surface of the negative pressure adsorption mold 2 (e.g., ...). Figure 3 As shown), the through hole 101 and the adsorption hole 7 are set one-to-one to form an independent multi-channel air path (divided into center, middle ring and edge). The negative pressure of each area can be continuously adjusted from -0.2kPa to -2.0kPa through the proportional valve to adapt to different sizes of beauty patches 6 and prevent the edges of the beauty patch 6 from curling up or the center from collapsing.

[0036] Because the state during the beauty tablet 6 test was Figure 6 The upward-convex arc-shaped structure shown in the diagram, to prevent the contour grinding head 3 from slipping, is further designed with an annular limiting groove 201 at the top of the negative pressure adsorption mold 2, and the rigid grinding head 8 has an annular limiting block 802 extending into the annular limiting groove 201. For example... Figure 4 As shown, the annular limiting groove 201 is located on the outer edge of the negative pressure adsorption mold 2. When the rigid grinding head 8 is placed on top of the negative pressure adsorption mold 2, the annular limiting block 802 is located in the annular limiting groove 201. After the rigid grinding head 8 and the negative pressure adsorption mold 2 are engaged, they can rotate arbitrarily in the circumferential direction. The inner diameter of the annular limiting block 802 does not need to be completely fitted with the annular limiting groove 201, so that there can be a small lateral sliding space between the rigid grinding head 8 and the negative pressure adsorption mold 2, such as translation within the range of 0~15mm.

[0037] Example 2

[0038] The difference between this embodiment and Embodiment 1 is that the support platform 1 can drive the negative pressure adsorption mold 2 to rotate around the center. For example, a rotary motor can be used as the support platform 1. During the friction processing, the support platform 1 rotates at a constant speed to ensure that every area of ​​the outer arc of the beauty patch 6 is evenly covered, forming a consistent friction trajectory.

[0039] Example 3

[0040] Based on the above embodiments, the contour grinding head 3 is provided with a connecting drive groove 801 and a drip hole 803 at the bottom of the contour grinding head 3. By delivering the care solution into the drip hole 803, a fresh liquid film is always present in the contact area between the nonwoven fabric 9 and the beauty piece 6 to avoid dry friction. At the same time, the chemical effect of the care solution on the beauty piece 6 can also be taken into account, further improving the accuracy of the test results.

[0041] The drip holes 803 are preferably arranged evenly along the circumference to ensure that the care solution evenly wets the entire contact interface.

[0042] In this embodiment, the drive tank 801 is used as the storage chamber for the care solution. It is not necessary to connect the drip hole 803 to the pipeline for delivering the care solution. It is only necessary to drip the care solution into the drive tank 801, thereby avoiding the obstruction of the movement of the rigid grinding head 8 caused by the connection of the pipeline on the rigid grinding head 8.

[0043] In a further design, the drive rod 401 is a drip tube, with one end extending into the drive groove 801 and the other end connected to the infusion tubing 14. For example... Figure 1 As shown, the infusion tubing 14 delivers the nursing solution via a peristaltic pump 15. In this case, the drip tube is not only used to add the nursing solution, but also to drive the contour grinding head 3, which simplifies the structural design and prevents the nursing solution from spilling.

[0044] To ensure the contour grinding head 3 moves accurately along a specified trajectory, it is preferable that the drive groove 801 and the drive rod 401 are in a sliding fit. This can be achieved by creating a slot on the side of the drive groove 801 for sliding fit with the drive rod 401, or by allowing the drive groove 801 to slide with the drive rod 401 through an opening. In this embodiment, as shown... Figure 5 As shown, the top of the drive groove 801 is integrally formed with a pressure cap 16, and the pressure cap 16 is provided with a drive port 13 for the drive rod 401 to extend into. This allows for the precise design of the motion trajectory of the contour grinding head 3 while preserving the liquid storage space.

[0045] Example 4

[0046] Based on the above embodiment, the bottom of the rigid grinding head 8 has several actuation grooves 11; the testing equipment also includes an actuation component 12 located within the actuation grooves 11 for applying an oscillating load to the nonwoven fabric 9. The actuation component 12 can generate micro-amplitude high-frequency oscillations during the movement of the contour grinding head 3, thereby simulating the physiological vibrations when a human hand rubs the fabric, making the test results more accurate.

[0047] Actuation component 12 may, but is not limited to, adopt the following structure: like Figure 5 As shown, the actuation assembly 12 includes a linear actuator 1201 fixed in the actuation groove 11 and a pressure block 1202 driven by the linear actuator 1201 to perform up-and-down reciprocating motion. During the movement of the pressure block 1202, a small vibration pressure is applied to the nonwoven fabric 9. The linear actuator 1201 is a driver capable of outputting linear motion and generating reciprocating oscillation. The linear actuator 1201 can generally be a linear motor, a cylinder, or a piezoelectric ceramic actuator. In this invention, the linear actuator 1201, which can be built into the rigid grinding head 8, is preferably a piezoelectric ceramic actuator. The reason is that linear motors are expensive, bulky, difficult to integrate into the rigid grinding head 8, generate a lot of heat, have a complex control system, and the strong magnetic field they generate can easily affect surrounding sensitive components. Cylinders have drawbacks such as slow response speed, inability to continuously adjust, inability to generate high-frequency small-amplitude movements, high noise, and obvious impact.

[0048] Example 5

[0049] Based on the above embodiments, the top of the contour grinding head 3 is also provided with several load-bearing grooves 804 arranged in a circular array. The static load can be adjusted by placing weights in the load-bearing grooves 804, thereby adjusting the pressure without replacing the contour grinding head 3, and is used to test the color fastness test results of the cosmetic film 6 under different pressure adjustments.

[0050] To verify the accuracy of the test results from the color fastness testing device for colored contact lenses described in this invention, specific experiments are conducted below.

[0051] Example 1: Standard Test Procedure (Evaluation of Color Fastness of Conventional Color Films)

[0052] To ensure the accuracy and repeatability of the test, strict preparation of the test samples, consumables, and environment is required. The test sample was a daily disposable colored contact lens (batch number 20230511) from a commercially available brand (assuming it is a qualified product). Its specifications are: 38% water content, 8.6mm base curve, and 14.2mm diameter. Ten individually packaged lenses were prepared for parallel testing in this batch. The contact lens solution used in the test was a commercially available multi-purpose contact lens solution, whose typical components are polyhexamethylene biguanide (PHMB), poloxaamide, and a buffer system to simulate a real chemical contact environment. The entire test was conducted in a controlled indoor environment, with the temperature maintained at (25±2)℃ and the relative humidity maintained at (60±5)%, to eliminate the influence of environmental fluctuations on the mechanical properties of the materials.

[0053] The testing process is as follows: Equipment parameter settings: The negative pressure adsorption mold 2 is used to fix the beauty patch 6, and its rotation speed is set to 3 rpm to ensure that the surface of the beauty patch 6 is subjected to uniform circumferential friction. The contouring abrasive head 3 is equipped with a brand-new medical-grade polyester fiber cloth, whose radius of curvature (8.7 mm) is precisely matched with the base arc of the beauty patch 6 to ensure contact surface fit. The six-axis robot 402 drives the contouring abrasive head 3 to perform compound motion on the surface of the beauty patch 6. Its trajectory is set to an "8" shape to simulate the multidirectional nature of finger rubbing. The specific parameters are: X-axis amplitude 8 mm, Y-axis amplitude 4 mm, and motion cycle of 2 seconds / time. The normal force applied by the contouring abrasive head 3 to the beauty patch 6 is achieved through weight counterweight, set to 10g (approximately 0.098N), and is monitored in real time by a force sensor. The force control fluctuation range is strictly controlled within ±2%. During the friction process, to keep the cosmetic patch 6 moist and simulate the environment of the contact lens solution, a peristaltic pump 15 was used to continuously supply the contact lens solution at a flow rate of 0.5 mL / min, and the temperature of the contact lens solution was maintained at 34°C to approximate the surface temperature of the human cornea. The duration of a single friction test was set to 60 seconds to simulate the time of a routine rubbing care session.

[0054] Beauty Patch 6 Loading and Friction Processing: Carefully transfer the beauty patch 6 onto the negative pressure adsorption mold 2. Then, activate the negative pressure adsorption, setting the pressure in the central area to -1.0 kPa and the pressure in the edge area to -0.5 kPa, to stably and without damage fix the beauty patch 6. Next, place the contour abrasive head 3 and weights until the high-precision force sensor detects a normal force of 10g. The contour abrasive head 3 then begins to move along a preset "figure-eight" trajectory, while the support platform 1 begins to rotate at a low speed, and the peristaltic pump 15 simultaneously supplies the constant-temperature care solution. The entire friction process lasts 60 seconds.

[0055] After 60 seconds, the drive lever 401 automatically rises and shuts off the negative pressure suction. The operator carefully removes the beauty patch 6 and gently rinses its surface for 10 seconds with fresh care solution at a flow rate of 5 mL to remove any fiber debris that may have detached or adhered due to friction. This ensures accurate image acquisition.

[0056] Finally, the initial and final images of each beauty patch 6 were compared and analyzed to calculate its area change rate (reflecting the degree of pattern wear or peeling) and average color difference ΔE. The test measures changes in ab (reflecting the degree of color fading) and texture features based on the gray-level co-occurrence matrix (GLCM) (reflecting the wear and tear of the surface microstructure), and generates a test report. Specific experimental data are shown in Table 1.

[0057] Table 1:

[0058] The test results show that the testing equipment described in this invention has high accuracy in testing the color fastness of the beauty film 6.

[0059] Experimental Example 2: Comparative Test with Different Loading Forces

[0060] To eliminate the influence of inherent differences in the beauty patches 6 on the experimental results, this experiment used high-water-content soft contact lenses from the same production batch as in Experiment 1. Four different loading force levels were set up: 5g, 10g, 20g, and 30g. Five beauty patches 6 were tested under each loading force, and the average value was used for statistical analysis. Except for the loading force variable, all other test parameters (including rubbing frequency, rubbing stroke, test time, ambient temperature and humidity, etc.) were strictly consistent with those in Experiment 1 to ensure that any differences in the experimental results were entirely due to variations in loading force.

[0061] The test results of the three core evaluation indicators of color fastness of Beauty Film 6 under different loading forces are shown in Table 2 (data format: mean ± standard deviation).

[0062] Table 2:

[0063] As the loading force gradually increases from 5g to 30g, all three evaluation indicators show a monotonically increasing trend, and exhibit different sensitivity characteristics in different force ranges—in the low force range of 5g to 10g, the indicator changes are relatively gradual, providing a reference for defining the lower limit of regular kneading; in the medium force range of 10g to 20g, the indicator response becomes extremely sensitive, with the pattern area attenuation rate jumping from 2.4% to 5.8% (an increase of approximately 142%), and the color difference ΔE The ab value reaching the human eye-perceptible threshold of 2.3 indicates that this force range poses a significant mechanical challenge to the colored layer. In the high-force range of 20g to 30g, the index shows an explosive increase, simulating severe damage under extreme rubbing. This also proves that simple translational and rotational movements of conventional mechanical structures can cause significant damage to the beauty film 6 and cannot be used to simulate the real-world usage environment of the beauty film 6. The low standard deviation of each data group confirms that the device has good repeatability and stability under these test conditions, reliably capturing subtle differences caused by varying loading forces. The changes in the above parameter indices are consistent with the theoretical values ​​in the colorfastness test of colored contact lenses, indicating that the testing device described in this invention has practical effectiveness.

[0064] Based on the above data, and considering that a 10g loading force can produce quantifiable wear effects (pattern attenuation rate 2.4%, color difference 1.0%) without causing excessive damage due to excessive force, this condition is recommended as the standard test force for simulation testing. This result provides data support for developing scientific and objective testing standards for lens abrasion resistance.

[0065] Experimental Example 3: Comparative Experiment with Different Action Times

[0066] This experimental example aims to use the device described in this invention to examine the cumulative effect of different application times on the colored layer of a colored contact lens under the premise of constant loading force and other unchanged conditions, to verify the device's response sensitivity to time parameters, and to explore the degradation law of color fastness over time.

[0067] To eliminate the influence of inherent differences in the cosmetic contact lenses on the experimental results, this experiment used 25 high-water-content soft contact lenses from the same production batch as in Experiment 1, randomly divided into 5 groups of 5 lenses each. The experiment used friction times of 15 seconds, 30 seconds, 60 seconds, 120 seconds, and 180 seconds as the sole variable. Except for friction time, all other test parameters (including rubbing frequency, rubbing stroke, applied force, ambient temperature and humidity, etc.) were strictly consistent with those in Experiment 1 to ensure that any differences in the experimental results were solely due to variations in friction time.

[0068] The test results of the three core evaluation indicators of color fastness of beauty film 6 under different treatment times are shown in Table 3 (data format: mean ± standard deviation).

[0069] Table 3:

[0070] Based on the experimental results of this example, the device of the present invention can clearly capture the process of gradual degradation of the colored layer as the rubbing time increases, with three indicators (pattern area attenuation rate, average color difference ΔE) showing the degradation. Both ab and texture feature changes showed a significant positive correlation with time, verifying the device's high sensitivity to time parameters. Further analysis revealed that the wear of the coloring layer was not linear, but rather that the wear was relatively small within 60 seconds (simulating normal care time), and the product could still maintain good color fastness. After 60 seconds, the wear rate increased significantly. It is recommended to use 60 seconds as the standard time for simulation testing. This embodiment fully demonstrates the application value of the device of the present invention in parametric research and provides reliable data support for the subsequent establishment of industry standards.

[0071] Experiment Example 4: Repeatability and Reproducibility Verification

[0072] To comprehensively evaluate the reliability and stability of the device of this invention, three representative beauty patches 6 (labeled A, B, and C) from the same batch as in Experimental Example 1 were selected and verified under the standard parameters (loading force 10g, rubbing frequency, stroke, time, etc.) set in Experimental Example 1. Repeatability verification involved the same operator using the same device to independently perform three repeated tests on each sample within a short period. After each test, the beauty patch 6 was reinstalled to ensure independence. Reproducibility verification involved three different operators using three different numbered devices at different times (spanning three working days) to perform a complete test on the same batch of samples. Finally, the precision of the device was comprehensively evaluated by calculating the mean, standard deviation, and coefficient of variation of the three indicators.

[0073] After the test, calculate each indicator (pattern area attenuation rate, average color difference ΔE). The mean, standard deviation, and coefficient of variation (CV = standard deviation / mean × 100%) of the ab texture feature variation were used as the main indicator for evaluating precision. The results are shown in Tables 4 and 5.

[0074] Table 4: Repeatability Validation Results

[0075] Table 5: Reproducibility Validation Results

[0076] The results show that, for both repeatability and reproducibility tests, the coefficients of variation for all evaluation indicators are less than 20%, and the CVs for most indicators are below 10%, indicating that the device of this invention has excellent precision. Specifically, the repeatability CV for pattern area attenuation rate is between 3.2% and 5.0%, the reproducibility CV is between 3.8% and 5.0%, and the average color difference ΔE... The repeatability CV for ab was 4.9%–6.5%, and the reproducibility CV was 4.7%–7.2%. These two indicators were extremely stable, almost unaffected by operator or equipment variations. The CV for texture feature changes was slightly higher (repeatability 9.1%–15.4%, reproducibility 13.0%–18.2%), possibly due to the sensitivity of texture analysis to minor differences in image acquisition (such as illumination uniformity and subtle focus variations). However, all CV values ​​remained below 20%, meeting the routine precision requirements for medical device testing. Furthermore, comparing the mean and standard deviation of repeatability and reproducibility, the values ​​were very close, indicating that no significant systematic errors were introduced between different operators or equipment, demonstrating good transferability of the equipment.

[0077] This test example fully verifies that the testing equipment described in this invention has excellent repeatability and reproducibility. The coefficients of variation of all indicators meet the precision requirements of medical device testing equipment, proving that the equipment can stably and reliably measure lens colorfastness at different times, by different operators, and on different equipment.

[0078] Experimental Example 5: Comparative Experiment with Existing Methods

[0079] Ten tinted lenses from the same batch as in Experiment 1 were randomly divided into three groups for comparative testing. All lenses underwent the same pretreatment (soaking in saline solution for 24 hours) before testing. After testing, the same method was used to calculate three indicators (pattern area attenuation rate, average color difference ΔE). ab, texture feature changes).

[0080] The specific parameters of the three test methods are as follows: The method of this invention uses the equipment of this invention, and the parameter settings are completely consistent with those of Test Example 1; the ethanol swab wiping method refers to the accelerated fading method in existing literature. The operator holds a cotton swab dipped in 75% medical ethanol and wipes the surface of the beauty patch 6 unidirectionally 10 times with a pressure of about 200g (calibrated by a balance). Each wipe covers the entire surface of the beauty patch 6; the vortex oscillation method places a single beauty patch 6 in a 50mL centrifuge tube containing 5mL of physiological saline, tightens the cap, and fixes it on a vortex shaker. It is continuously oscillated at the highest speed (about 3000rpm) for 5 minutes.

[0081] The degree of damage to the color fastness of beauty film 6 by different test methods is shown in Table 6 (data format: mean ± standard deviation).

[0082] Table 6:

[0083] The comparative test results showed extremely significant differences. The three methods caused completely different degrees of damage to the color layer of the cosmetic lens: the ethanol swab wiping method resulted in abnormally high levels of three indicators, with a pattern area attenuation rate as high as 28.5%, color difference reaching 8.7, and texture contrast change reaching 1.85, which are approximately 12 times, 9 times, and 12 times higher than the method of this invention, respectively. This is because 75% ethanol, as an organic solvent, may have a chemical erosion effect on the color layer. In addition, the manual wiping pressure of approximately 200g is far higher than the normal rubbing force, and the dry, hard contact between the cotton swab and the lens can easily cause physical scratches. This intense combination of chemical and mechanical effects caused the test results to deviate significantly from the actual fading situation, which is a typical false positive misjudgment. The vortex oscillation method went to the other extreme, with all three indicators almost zero (pattern area attenuation rate of 28.5%). The reduction rate was only 0.3%, color difference was 0.1, and texture feature change was 0.01. There was no significant difference from the untested original cosmetic film 6, indicating that the interaction force between cosmetic film 6 and the liquid and tube wall during the oscillation process was extremely weak and could not effectively challenge the color layer. Therefore, it was impossible to distinguish the differences in color fastness of different lenses, which was a false negative. The test results of the method of the present invention were moderate and reasonable (pattern area attenuation rate 2.42%, color difference 0.98, texture feature change 0.154). By applying a standardized 10g loading force and controlled rubbing motion in a dry state, the mechanical friction that the human eye may be subjected to in daily care was simulated, while avoiding the interference of chemical solvents. It can truly reflect the wear resistance performance of the lens color layer under normal use conditions and effectively avoid false positive or false negative misjudgments.

[0084] This experimental example fully demonstrates that existing testing methods have significant limitations: the ethanol swab wiping method leads to false positive results due to chemical corrosion and excessive mechanical friction, while the vortex oscillation method leads to false negative results due to insufficient force. In contrast, the testing equipment described in this invention can objectively and accurately evaluate the colorfastness of cosmetic film 6 under reasonable physical force and chemical-free medium conditions, possessing higher scientific validity and practical application value, and can be considered a preferred method for standardized testing.

[0085] In summary, this invention effectively avoids false positives in the ethanol swab method and false negatives in the vortex oscillation method. It can objectively evaluate color fastness under standardized physical forces and real media conditions, and has the advantages of high precision, high repeatability and full-process traceability. It can be used as a preferred method for industry-standardized testing.

[0086] In the description of this invention, it should be understood that the terms "center", "upper", "lower", "top", "bottom", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this invention.

[0087] Furthermore, in the description of this invention, unless otherwise stated, "a number" means two or more.

[0088] In this specification, the illustrative expressions of the terms do not necessarily refer to the same embodiments. Moreover, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments.

[0089] Based on the above-described preferred embodiments of the present invention, and through the foregoing description, those skilled in the art can make various changes and modifications without departing from the inventive concept. The technical scope of this invention is not limited to the contents of the specification, but must be determined according to the scope of the claims.

Claims

1. A device for testing the colorfastness of colored contact lenses, characterized in that, include: Support platform (1), the support platform (1) has a through hole (101). The negative pressure adsorption mold (2) is fixed on the support platform (1). The top of the negative pressure adsorption mold (2) is the support surface (5) for carrying the beauty sheet (6). The negative pressure adsorption mold (2) has an adsorption hole (7) that communicates with the through hole (101) and extends to the support surface (5). The contour grinding head (3) is placed on top of the negative pressure adsorption mold (2), and the top of the contour grinding head (3) is provided with a drive groove (801). The drive assembly (4) includes a drive rod (401) extending into the drive groove (801), which drives the contour grinding head (3) to move by contacting the side of the drive groove (801).

2. The color fastness testing device for colored contact lenses according to claim 1, characterized in that: The contouring abrasive head (3) includes a rigid abrasive head (8) and a nonwoven fabric (9) adsorbed on the bottom of the rigid abrasive head (8) and in contact with the cosmetic patch (6).

3. The color fastness testing device for colored contact lenses according to claim 2, characterized in that: The top of the negative pressure adsorption mold (2) is provided with an annular limiting groove (201), and the rigid grinding head (8) has an annular limiting block (802) that extends into the annular limiting groove (201).

4. The color fastness testing device for colored contact lenses according to claim 1, characterized in that: The support platform (1) can drive the negative pressure adsorption mold (2) to rotate around the center.

5. The color fastness testing device for colored contact lenses according to claim 1 or claim 4, characterized in that: The contour grinding head (3) is provided with a connecting drive groove (801) and a drip hole (803) at the bottom of the contour grinding head (3).

6. The color fastness testing device for colored contact lenses according to claim 5, characterized in that: The drive rod (401) is a drip tube. One end of the drive rod (401) extends into the drive groove (801), and the other end of the drive rod (401) is connected to the infusion tubing (14).

7. The color fastness testing device for colored contact lenses according to claim 2, characterized in that: The bottom of the rigid grinding head (8) has several actuation grooves (11); the test equipment also includes an actuation component (12) located in the actuation grooves (11) for applying an oscillating load to the nonwoven fabric (9).

8. The color fastness testing device for colored contact lenses according to claim 6, characterized in that: The top of the drive groove (801) is integrally formed with a pressure cap (16), and the pressure cap (16) is provided with a drive port (13) for the drive rod (401) to extend into.

9. The color fastness testing device for colored contact lenses according to claim 1, characterized in that: The adsorption holes (7) are arranged radially from the center of the negative pressure adsorption mold (2) to the outer periphery, and the through holes (101) are set one-to-one with the adsorption holes (7).

10. The color fastness testing device for colored contact lenses according to claim 1, characterized in that: The top of the contour grinding head (3) is also provided with several load-bearing grooves (804) arranged in a circular array.

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