Microsphere Hardness Testing System

Abstract

This invention provides a microsphere hardness testing system, comprising: a sample pretreatment unit; a diameter measurement unit; a sample testing device including a fixed lower clamp, a replaceable upper clamp, and a displacement control mechanism, wherein the displacement control mechanism controls the upper clamp to move towards the lower clamp to compress the microsphere sample to be tested, wherein an upper clamp of a corresponding size is selected from a set of upper clamps of different sizes according to the diameter D of the microsphere sample; a detection parameter control unit, which is used to set the detection parameters during the detection process to control the compression rate and compression displacement of the upper clamp relative to the lower clamp; a data acquisition unit; and a data analysis and display unit, which is communicatively connected to the data acquisition unit and generates a loading force-compression displacement curve based on the received loading force and compression displacement data, determines the yield stress corresponding to the inflection point of the curve through the loading force-compression displacement curve, and converts the yield stress into a hardness value of the microsphere sample for output and display.

Description

Technical Field

[0001] This utility model relates to the field of hardness testing technology, and in particular to a microsphere hardness testing system, such as a hardness testing system for cosmetic microspheres. Background Technology

[0002] Cosmetic formulations are typically applied directly to the surface of human skin during use, and their tactile characteristics have a significant impact on the user experience. To achieve the desired skin feel, cosmetics often contain particles with specific particle sizes and physical properties, such as spherical particles, to improve the formulation's spreadability, smoothness, and firmness.

[0003] Existing methods for evaluating tactile feel primarily rely on manual trials and subjective evaluations. While these methods can reflect the overall experience of a product during actual use, the results are easily influenced by the tester's skin condition, subjective preferences, and psychological factors, resulting in significant individual differences and making it difficult to achieve objective and repeatable evaluations of tactile performance. Therefore, developing technologies that can objectively evaluate tactile feel through physical means has become a key focus of research and application.

[0004] In existing technologies, common methods for testing particle hardness often employ compression tests on individual microspheres, using compressive mechanical properties as the evaluation index. However, due to slight differences in morphology, density, and material uniformity among individual microspheres, the data obtained by such methods fluctuates significantly and exhibits strong dispersion, thus affecting the accuracy and reliability of the test results. Furthermore, when the filling density or particle size of microspheres varies in different products, traditional testing methods often struggle to effectively correct for errors caused by density variations and are incompatible with samples of different particle sizes, resulting in insufficient adaptability, complex operation, and low testing efficiency. Utility Model Content

[0005] The purpose of this invention is to provide an improved microsphere hardness testing system, which can not only select the appropriate test fixture area according to the microsphere diameter, but also determine the hardness of the microsphere by the yield point. The testing process is fast and simple, and has high accuracy and practicality.

[0006] Therefore, this utility model provides a microsphere hardness testing system, comprising: a sample pretreatment unit for separating, enriching, cleaning, and drying microsphere samples; a diameter measurement unit for measuring the diameter D of the microsphere samples; a sample testing device including a fixed lower clamp, a replaceable upper clamp, and a displacement control mechanism, the displacement control mechanism being used to control the upper clamp to move towards the lower clamp to compress the microsphere sample to be tested, wherein an upper clamp of a corresponding size is selected from a set of upper clamps of different sizes according to the diameter D of the microsphere sample; a detection parameter control unit for setting detection parameters during the testing process to control the compression rate and compression displacement of the upper clamp relative to the lower clamp; a data acquisition unit for real-time acquisition of loading force and compression displacement data during the compression process; and a data analysis and display unit, which is communicatively connected to the data acquisition unit and generates a loading force-compression displacement curve based on the received loading force and compression displacement data, determines the yield stress corresponding to the inflection point of the curve through the loading force-compression displacement curve, and converts the yield stress into a hardness value of the microsphere sample for output and display.

[0007] In the above-described solution of this utility model, by measuring the microsphere diameter D and selecting the corresponding size from a set of upper clamps of different sizes, the uniformity of the applied pressure is ensured, avoiding measurement errors caused by mismatched clamp sizes. Furthermore, this microsphere hardness testing system achieves high-precision, high-repeatability, visual, and highly versatile microsphere hardness testing through controllable compression, real-time force-displacement acquisition, and automatic data analysis.

[0008] According to a preferred embodiment of this invention, the diameter of the microsphere sample to be tested can be in the range of 300µm to 3000µm; both the upper and lower surfaces of the lower clamp are planar, wherein the surface area of ​​the lower surface of a set of upper clamps of different sizes is in the range of 7.0mm² to 1260mm²; and the surface area of ​​the upper surface of the lower clamp is greater than or equal to the surface area of ​​the lower surface of the upper clamp. In this embodiment, the upper and lower clamps can be constructed as plates, such as circular or square plates. During testing, microspheres of different diameters correspond to lower surfaces of upper clamps with different areas; larger diameter microspheres require upper clamps with larger lower surface areas. For example, for microspheres with diameters of 300µm to 1200µm, an upper clamp with a surface area of ​​7.0mm² can be selected. 2 Up to 500mm 2 The upper clamp; for microspheres with a diameter of 1200µm to 2100µm, a surface area of ​​500mm² can be selected. 2 Up to 970mm 2 The upper clamp; for example, for microspheres with a diameter of 2100µm to 3000µm, a surface area of ​​970mm² can be selected. 2 Up to 1260mm 2The upper clamp.

[0009] The microsphere hardness testing system of this invention can test microsphere samples from small to large, covering various application scenarios such as cosmetics, pharmaceuticals, and functional microspheres, thus improving the versatility of the testing system. Furthermore, ensuring that the surfaces of the lower and upper clamps in contact with the microsphere sample are flat ensures uniform stress on the microsphere during compression, avoiding localized stress concentration caused by curved or irregular surfaces, thereby improving measurement accuracy and consistency.

[0010] In a preferred embodiment of this invention, the detection parameter control unit can be configured such that: the compression rate of the upper clamp relative to the lower clamp is 0.1 µm / s to 25 µm / s, preferably 0.51 µm / s to 20 µm / s, and most preferably 1 µm / s ≤ v ≤ 15 µm / s; and the compression displacement of the upper clamp relative to the lower clamp is 50%-90% of the diameter D of the microsphere sample. A suitable compression rate can effectively suppress the viscoelastic hysteresis effect of small-sized microspheres during compression, making the force-displacement curve smoother and improving the testing stability and repeatability of small particle samples. Limiting the compression displacement to 50-90% of the microsphere diameter D ensures that the microspheres yield during compression, making the measured hardness results more representative and preventing unnecessary damage to the sensor.

[0011] In a preferred embodiment of this invention, the upper and lower clamps can be made of epoxy resin. For soft microspheres or samples easily damaged by hard materials, using epoxy resin clamps can reduce the hardness of the contact surface, improve data stability, and is suitable for hardness testing of microspheres with fragile surfaces or soft materials. Alternatively, the upper and lower clamps can also be made of stainless steel. The microspheres may include, for example, cosmetic microspheres, pharmaceutical microspheres, food microspheres, functional polymer microspheres, etc., and different clamp materials can be selected according to the hardness of the microspheres.

[0012] According to one aspect of this invention, the sample pretreatment unit may include: a sieve assembly for separating and enriching microsphere samples, a solvent rinsing module for rinsing the microsphere samples with solvent, and a drying module for removing excess solvent by filtration or drying. The sample pretreatment unit effectively removes impurities, solvents, debris, and abnormal particles from the microsphere samples, improving sample consistency. Particle size sorting ensures the uniformity of the detected microsphere size, thereby improving the reliability and repeatability of hardness measurement. Cleaning the microsphere surface with an appropriate solvent removes surface contaminants or residues, ensuring a consistent microsphere surface condition.

[0013] According to one aspect of this utility model, the sample testing device further includes a base, a lower clamp fixedly connected to the base, and an upper clamp detachably fixedly connected to a displacement control mechanism.

[0014] In one embodiment of this invention, the diameter measurement unit can be a high-resolution camera, an optical microscope, or a particle size analyzer. High-resolution cameras and optical microscopes are suitable for high-resolution measurement of small to medium-sized microspheres, and combined with image analysis, they can perform statistically accurate size measurements. Particle size analyzers are suitable for measuring a wider range of particle sizes and have stronger statistical and automated capabilities. Hardness assessment relies on the accurate measurement of the microsphere diameter D; both types of equipment can provide reliable measurements, thereby ensuring the accuracy of subsequent force-displacement curves and hardness conversion.

[0015] According to a preferred embodiment of this utility model, the detection parameter control unit is communicatively connected to the displacement control mechanism and includes: a temperature control module for setting and maintaining the detection environment temperature; a time control module for setting the compression duration; a force control module for controlling the magnitude and rate of the loading force; and a position control module for controlling the displacement and stop position of the upper clamp. By simultaneously controlling temperature, time, loading force, and displacement, all key variables in the detection process can be kept constant or fluctuate within a set range, thereby significantly improving the consistency of test conditions. This collaborative control method can reduce random errors caused by changes in the test environment, resulting in higher repeatability and accuracy of test results.

[0016] According to one aspect of this utility model, the data acquisition unit includes a pressure sensor and a displacement sensor that are communicatively connected to the data analysis and display unit.

[0017] According to one embodiment of this utility model, the data analysis and display unit includes: a data receiving module for receiving loading force and compression displacement data from the data acquisition unit; a data analysis module for analyzing and processing the received loading force and compression displacement data, generating a loading force-compression displacement curve, and determining the yield stress corresponding to the inflection point of the curve, so as to convert the yield stress into the hardness value of the microsphere sample; and a display module for displaying the loading force-compression displacement curve, yield stress, and hardness value.

[0018] In the above scheme, the data reception, analysis, and display processes are completed automatically, reducing manual intervention and improving overall testing efficiency. Through automatic analysis of the loading force-compression displacement curve, inflection points and yield stresses are accurately identified, avoiding human error and thus improving the accuracy of hardness conversion. The display module intuitively presents the curves, yield stresses, and hardness values, facilitating rapid understanding of test results and the mechanical properties of the microspheres. Attached Figure Description

[0019] The accompanying drawings, which form part of this utility model, are used to provide a further understanding of the utility model. The illustrative embodiments of the utility model and their descriptions are used to explain the utility model and do not constitute an undue limitation of the utility model. Wherein:

[0020] Figure 1 A structural block diagram of a microsphere hardness testing system according to an embodiment of the present invention is shown;

[0021] Figure 2 This is a schematic diagram of the sample testing device according to the present invention. Detailed Implementation

[0022] The microsphere hardness testing system according to the present invention will now be described with reference to the accompanying drawings and embodiments. In the following description, numerous specific details are set forth to enable those skilled in the art to gain a more complete understanding of the present invention. However, it will be apparent to those skilled in the art that implementations of the present invention may not include some of these specific details. Furthermore, it should be understood that the present invention is not limited to the specific embodiments described. Rather, the present invention can be conceived to be implemented with any combination of the following features and elements, regardless of whether they relate to different embodiments.

[0023] The microsphere hardness testing system and its usage method of this utility model will be described in detail below with reference to specific embodiments, but the implementation of this invention is not limited to the following content.

[0024] exist Figure 1 In the illustrated embodiment, the microsphere hardness testing system 100 according to this invention includes a sample pretreatment unit 1, a diameter measurement unit 2, a sample detection device 3, a detection parameter control unit 4, a data acquisition unit 5, and a data analysis and display unit 6. These units work collaboratively via communication connections to achieve high-precision and repeatable measurement of microsphere hardness. The sample pretreatment unit 1 is used to separate, enrich, clean, and dry the microsphere sample. The diameter measurement unit 2, for example, is a high-resolution camera, optical microscope, or particle size analyzer, used to measure the diameter D of the microsphere sample.

[0025] See Figure 2The sample testing device 3 includes a fixed lower clamp 31, a replaceable upper clamp 32, and a displacement control mechanism 33. This displacement control mechanism controls the upper clamp 32 to move towards the lower clamp 31 to compress the microsphere sample to be tested. The upper clamp 32 of a specific size is selected from a set of upper clamps 32 of different sizes based on the diameter D of the microsphere sample. The detection parameter control unit 4 sets the detection parameters during the testing process to control the compression rate and displacement of the upper clamp 32 relative to the lower clamp 31. The data acquisition unit 5 includes a pressure sensor 51 and a displacement sensor 52, which are communicatively connected to the data analysis and display unit 6. These sensors are used to acquire key data in real time during the microsphere hardness test. The pressure sensor 51 measures the loading force applied to the microsphere sample by the upper clamp 32, and the displacement sensor 52 monitors the real-time displacement of the upper clamp 32. The displacement sensor 52 can be an optical, laser, or inductive sensor. The data analysis and display unit 6 is communicatively connected to the data acquisition unit and generates a loading force-compression displacement curve based on the received loading force and compression displacement data. The yield stress corresponding to the inflection point of the curve is determined by the loading force-compression displacement curve, and the yield stress is converted into the hardness value of the microsphere sample and output for display.

[0026] In a preferred embodiment of this invention, both the upper clamp 32 and the lower clamp 31 may be made of epoxy resin or stainless steel. Example 1 below illustrates the preferred materials for the upper and lower clamps.

[0027] Example 1:

[0028] This example illustrates the selection of fixture materials. The fixture materials tested include epoxy resin, stainless steel, ceramics, rubber, polymethyl methacrylate (PMMA), polypropylene (PP), polyethylene (PE), polyethylene terephthalate (PET), glass, sandpaper, and nonwoven fabric.

[0029] The selection of fixture material is determined by hardness data obtained from repeated tests on the same sample. If the relative standard deviation (RSD) is ≥20%, the fixture material does not meet the test requirements. The fixture material should meet the requirement of RSD ≤20%, preferably RSD ≤15%, and most preferably RSD ≤10%.

[0030]

[0031] Based on the results in Table 1, suitable clamping materials are epoxy resin, stainless steel, PMMA, ceramic, rubber, PP, PE, and PET. Preferred clamping materials are epoxy resin, stainless steel, PMMA, ceramic, and rubber. Most preferred clamping materials are epoxy resin and stainless steel.

[0032] The following are the hardness values ​​and relative standard deviations (RSD) of representative microsphere samples obtained through optimized selection of fixture materials.

[0033]

[0034] Under the experimental conditions, the RSD of the epoxy resin fixture was as low as 1.3%, which was better than that of the stainless steel fixture (2.1% to 2.6%), indicating that it is more suitable for hardness testing of microsphere soft materials with high repeatability requirements.

[0035] According to the test data in Table 2, epoxy resin fixtures exhibit high repeatability in microsphere hardness testing (RSD as low as 1.3%), making them suitable for applications requiring high data consistency. Stainless steel fixtures, while exhibiting slightly lower repeatability, possess higher mechanical rigidity and durability, making them suitable for high-force or long-term use scenarios. Fixture materials have a significant impact on the measured hardness values. Therefore, by designing interchangeable fixture materials, this hardness testing system can be adapted to different types of microsphere materials, improving the system's versatility and testing accuracy.

[0036] The microsphere hardness testing system 100 of this invention can detect microsphere samples with diameters ranging from 300µm to 3000µm, for example, from 500µm to 1000µm. The microspheres can be selected from cosmetic microspheres, pharmaceutical microspheres, food microspheres, and functional polymer microspheres, etc., and have a wide range of applications.

[0037] In one embodiment, the upper clamp 32 and the lower clamp 31 can be constructed as circular plate structures, with the lower surface of the upper clamp 32 and the upper surface of the lower clamp 31, i.e., the surfaces to be in contact with the microsphere sample, both being planar. Furthermore, the surface area of ​​the lower surface of the set of upper clamps of different sizes can be 7.0 mm². 2 Up to 1260 mm 2 12mm is preferred 2 Up to 710 mm 2 The optimal size is 19 mm. 2 Up to 500 mm 2 .

[0038] In specific embodiments, for example for microspheres with a diameter of 300µm to 1200µm, a surface area of ​​7.0 mm² can be selected. 2 Up to 500mm 2 The upper clamp; for microspheres with a diameter of 1200µm to 2100µm, a surface area of ​​500mm² can be selected. 2 Up to 970mm 2 The upper clamp; for example, for microspheres with a diameter of 2100µm to 3000µm, a surface area of ​​970mm² can be selected. 2 Up to 1260mm2 The upper clamp.

[0039] The surface area of ​​the upper surface of the lower clamp 31 is greater than or equal to the surface area of ​​the lower surface of the upper clamp 32. In fact, when compressing the microsphere sample, the microspheres essentially cover the entire lower surface of the upper clamp 32. That is, the surface area of ​​the lower surface of the upper clamp is the contact area between the clamp and the microsphere sample. The upper clamp 32 and the lower clamp 31 can also be constructed in the form of rectangular plates or other suitable shapes, which are also covered within the scope of this application.

[0040] Example 2 below shows a preferred range for the contact area between the fixture and the sample.

[0041] Example 2:

[0042] An appropriate area can maintain the uniformity of mechanical response in the testing of microspheres with different particle sizes, avoiding the situation where the clamp area is too large, resulting in a weak response to yield stress data, or too small, resulting in insufficient data representativeness and reduced repeatability, thereby significantly improving the accuracy and repeatability of hardness test data.

[0043] The contact area between the fixture and the sample is determined by hardness data obtained from repeated tests on the same sample. If the relative standard deviation (RSD) is ≥20%, the contact area between the fixture and the sample does not meet the test requirements. The contact area between the fixture and the sample should meet the requirement of RSD ≤20%, preferably RSD ≤15%, and most preferably RSD ≤10%.

[0044]

[0045] Based on the results in Table 3, the suitable contact area between the fixture and the sample is 7.0 mm. 2 Up to 1260 mm 2 12 mm is preferred 2 Up to 710 mm 2 The optimal size is 19 mm. 2 Up to 500 mm 2 .

[0046] The following are the hardness values ​​and relative standard deviations (RSD) of representative microsphere samples obtained through optimized selection of fixture materials.

[0047] In a preferred embodiment of this invention, the displacement control mechanism 33 is communicatively connected to the detection parameter control unit 4, and the detection parameter control unit 4 is configured such that the compression rate v of the upper clamp 32 relative to the lower clamp 31 is 0.1µm / s to 25µm / s, preferably 0.5µm / s to 20µm / s, and most preferably 1µm / s ≤ v ≤ 15µm / s. Furthermore, the compression displacement of the upper clamp 32 relative to the lower clamp 31 is 50% to 90% of the diameter D of the microsphere sample.

[0048] Below is Example 3 of the test parameter compression rate.

[0049] Example 3:

[0050] A suitable compression rate can effectively suppress the viscoelastic hysteresis effect of small-sized microspheres during the compression process, making the loading force-displacement curve smoother and improving the testing stability and repeatability of small particle samples.

[0051] The compression rate is determined by obtaining hardness data from repeated tests on the same sample. If the relative standard deviation (RSD) is ≥20%, the contact area between the fixture and the sample does not meet the test requirements. The contact area between the fixture and the sample should meet the requirement of RSD ≤20%, preferably RSD ≤15%, and most preferably RSD ≤10%.

[0052]

[0053] Based on the results in Table 4, the suitable compression rate v is from 0.1 µm / s to 25 µm / s, preferably from 0.5 µm / s to 20 µm / s, and most preferably from 1 to ≤v≤15 µm / s.

[0054] See you again Figure 1 In one embodiment, the sample pretreatment unit 1 may include a sieve assembly 11, a solvent rinsing module 12, and a drying module 13. The sieve assembly 11 is used for preliminary separation and enrichment of the microsphere sample. This sieve assembly can be designed as a multi-layer sieve structure with different pore sizes to allow for grading and screening based on the microsphere particle size. The sieve assembly can operate as a vibrating sieve or a rotary sieve, achieving uniform separation of microspheres through mechanical vibration or rotation, thereby improving separation efficiency and enrichment accuracy. The solvent rinsing module 12 uses solvent to rinse the microsphere sample. The solvent rinsing module may include a jet rinsing system that sprays an appropriate amount of solvent onto the microspheres on the sieve through controllable nozzles to remove surface impurities and residues. The type of solvent can be selected according to the characteristics of the microsphere material; for example, polar or non-polar solvents can be selected to ensure the microsphere surface is clean without damaging the microsphere structure. The rinsing module may also be equipped with a solvent recovery device to achieve recycling and reduce waste. The drying module 13 is used to remove excess solvent from the surface of the microspheres, bringing the microsphere sample to a detectable state. The drying module may employ vacuum filtration drying or oven drying, or a combination of both. Vacuum filtration drying uses negative pressure to extract the solvent from the microsphere sample, and can be combined with low temperature or room temperature conditions to reduce physical or chemical changes in the microspheres; drying uses heated airflow or infrared heating to evaporate the solvent, and the temperature and wind speed can be adjusted according to the material properties of the microspheres to avoid over-drying or deformation of the microspheres.

[0055] See Figure 2The sample testing device 3 also includes a base 30, with a lower clamp 31 fixedly connected to the base. The upper surface of the lower clamp 31 supports the microsphere sample to be tested. An upper clamp 32 is detachably fixedly connected to a displacement control mechanism 33, used to apply a compressive load to the microsphere sample. The upper clamp 32 can be configured with different sizes or shapes of lower surfaces depending on the diameter of the microsphere sample, ensuring precise contact during compression and reducing edge effects. The detachable design of the upper clamp 32 facilitates quick replacement of clamps of different specifications, improving sample adaptability. The displacement control mechanism 33 can be designed as a precision drive unit similar to a rheometer, used to drive the upper clamp 32 to move in a predetermined direction, achieving controllable compression of the microsphere sample. The displacement control mechanism 33 is driven by a stepper motor, servo motor, or precision lead screw, and works in conjunction with a high-resolution displacement sensor to achieve micron-level or even submicron-level displacement control, ensuring precise and controllable displacement of the microsphere during compression. Similar to the characteristics of a rheometer, it can achieve constant-speed compression, constant-force loading, or preset loading curves, ensuring the repeatability and stability of the microsphere hardness testing process. By combining a loading force sensor, the force applied to the microsphere by the upper clamp 32 can be monitored in real time, and the displacement rate can be adjusted through closed-loop control to ensure that the loading process meets the experimental requirements.

[0056] According to a preferred embodiment of the present invention, the detection parameter control unit 4 is communicatively connected to the displacement control mechanism 33, and is used to precisely control key parameters during the microsphere hardness testing process. The detection parameter control unit 4 may include the following functional modules:

[0057] Temperature control module 41: Used to set and maintain the temperature of the microsphere sample testing environment to ensure stable experimental conditions. Temperature control module 41 can achieve a constant temperature environment through closed-loop control with heating elements, cooling elements, or a temperature control chamber and temperature sensor, thereby reducing the impact of temperature changes on microsphere hardness testing.

[0058] Time control module 42: Used to set the compression duration, that is, the duration for which the upper clamp 32 applies load to the microsphere sample. The time control module 42 can set different compression times according to experimental requirements to achieve short-term impact compression or long-term slow compression, thereby evaluating the hardness characteristics of the microspheres under different loading conditions.

[0059] Force control module 43: Used to control the magnitude and rate of the loading force. Force control module 43 can be combined with a loading force sensor to achieve closed-loop control, ensuring precise and controllable force applied by the upper clamp 32. This module can be set to a constant force mode or a constant speed loading mode, so that the force changes experienced by the microsphere during compression meet the experimental design requirements.

[0060] Position control module 44: Used to control the displacement and stop position of the upper clamp 32. The position control module 44 can achieve displacement accuracy at the micrometer or even submicrometer level, and can preset the displacement path or segmented displacement to achieve precise compression and safe stopping of the microsphere, avoiding over-compression or sample damage.

[0061] Through the coordinated operation of the above modules, the detection parameter control unit 4 can achieve comprehensive control over the microsphere hardness testing process, including key parameters such as ambient temperature, loading force, displacement, and time, making the test results more accurate, repeatable, and quantifiable, and providing reliable data support for microsphere hardness evaluation.

[0062] In a preferred embodiment of this invention, the data analysis and display unit 6 includes a data receiving module 61, a data analysis module 62, and a display module 63. The data receiving module 61 receives loading force and compression displacement data from the data acquisition unit 5. The data receiving module 61 enables high-speed, continuous data transmission and ensures time synchronization of force and displacement data, providing reliable basic data for subsequent analysis. The data analysis module 62 processes and analyzes the received data. Specifically, the data analysis module 62 generates a loading force-compression displacement curve based on the loading force and displacement data, and automatically identifies the inflection points in the curve using an algorithm to determine the corresponding microsphere yield stress. Subsequently, the data analysis module 62 converts the yield stress into a hardness value for the microsphere sample, realizing automatic calculation from raw test data to quantifiable hardness parameters. The display module 63 visualizes the processing results, simultaneously displaying the loading force-compression displacement curve, the yield stress corresponding to the curve inflection point, and the calculated microsphere hardness value. The display method can employ a graphical interface, a graph, or a numerical table, allowing users to intuitively understand the experimental results. Through the collaborative work of the above modules, the data analysis and display unit 6 not only realizes the real-time acquisition, processing and calculation of microsphere hardness test data, but also provides intuitive and visual results display, providing reliable and accurate experimental basis for the hardness evaluation of microsphere samples.

[0063] The following describes a method for measuring the hardness of microspheres using the aforementioned microsphere hardness testing system 100, which includes the following steps:

[0064] 1) Microsphere sample pretreatment steps: Place the microsphere sample in the sieve assembly 11 and separate and enrich the sample by vibration or rotation sieving; clean the microsphere sample on the sieve using the solvent rinsing module 12; then remove excess solvent by vacuum filtration or drying using the drying module 13 to make the sample detectable.

[0065] 2) Microsphere diameter measurement steps: Use a high-resolution camera, optical microscope or particle size analyzer to determine the average diameter D (unit: µm) of the microsphere sample and record the measurement results.

[0066] 3) Fixture selection steps: Based on the diameter D of the microsphere, select the upper fixture 32 and lower fixture 31 that match the size of the microsphere to ensure uniform contact between the fixture and the microsphere during loading.

[0067] 4) Sample clamping steps: Place the microsphere sample between the upper and lower clamps, ensuring that the force direction is perpendicular to the surface of the microsphere, thereby ensuring the accuracy of the compression process.

[0068] 5) Loading and compression step: The microsphere sample is compressed by the displacement control mechanism 33 using a preset displacement control mode, and the compression displacement is 50% to 90% of the microsphere diameter D.

[0069] 6) Data acquisition and analysis steps: Use data acquisition unit 5 to record the loading force-displacement data during compression, and use data analysis and display unit 6 to generate loading force-displacement curve; based on the generated loading force-displacement curve, use software to automatically identify the curve inflection point, determine the yield stress of the microsphere, and convert the yield stress into the hardness value of the microsphere.

[0070] 7) Repeat testing and statistical analysis steps: For each microsphere sample, the test should be repeated at least three times. Calculate the average hardness (A), standard deviation (STD), and relative standard deviation (RSD). If the relative standard deviation (RSD) ≥ 20%, the test results do not meet the requirements for good repeatability. Preferably, a good repeatability result is RSD ≤ 20%, more preferably RSD ≤ 15%, and most preferably RSD ≤ 10%.

[0071] The above method enables accurate and repeatable hardness measurement of microsphere samples, and by combining the functions of each unit of the detection system 100, the hardness measurement data can be automatically acquired, processed, and displayed.

[0072] Although the present invention has been disclosed above with reference to preferred embodiments, it is not limited thereto. Any modifications and alterations made by those skilled in the art without departing from the spirit and scope of the present invention should be included within the protection scope of the present invention. Therefore, the protection scope of the present invention should be determined by the scope defined in the claims.

Claims

1. A microsphere hardness testing system, characterized in that, The microsphere hardness testing system (100) includes: The sample pretreatment unit (1) is used to separate, enrich, clean and dry the microsphere sample; A diameter measuring unit (2) is used to determine the diameter D of the microsphere sample; The sample testing device (3) includes a fixed lower clamp (31), a replaceable upper clamp (32), and a displacement control mechanism (33) for controlling the upper clamp (32) to move toward the lower clamp (31) to compress the microsphere sample to be tested, wherein the upper clamp of a corresponding size is selected from a set of upper clamps (32) of different sizes according to the diameter D of the microsphere sample; The detection parameter control unit (4) is used to set the detection parameters during the detection process to control the compression rate and compression displacement of the upper clamp (32) relative to the lower clamp (31); Data acquisition unit (5), which is used to acquire loading force and compression displacement data in real time during the compression process; and The data analysis and display unit (6) is communicatively connected to the data acquisition unit and is configured to generate a loading force-compression displacement curve based on the received loading force and compression displacement data, determine the yield stress corresponding to the inflection point of the curve through the loading force-compression displacement curve, and convert the yield stress into the hardness value of the microsphere sample for output and display.

2. The microsphere hardness testing system according to claim 1, characterized in that, The diameter of the microsphere sample to be tested is in the range of 300µm to 3000µm; The upper surface of the lower clamp (31) and the lower surface of the upper clamp (32) are both planes, wherein the surface area of ​​the lower surface of the set of upper clamps of different sizes is 7.0 mm. 2 Up to 1260mm 2 Within the range; and The surface area of ​​the upper surface of the lower clamp (31) is greater than or equal to the surface area of ​​the lower surface of the upper clamp (32).

3. The microsphere hardness testing system according to claim 1, characterized in that, The detection parameter control unit (4) is configured such that: The compression rate of the upper clamp (32) relative to the lower clamp (31) is from 0.1 µm / s to 25 µm / s; and The compression displacement of the upper clamp (32) relative to the lower clamp (31) is 50%-90% of the diameter D of the microsphere sample.

4. The microsphere hardness testing system according to claim 1, characterized in that, Both the upper clamp (32) and the lower clamp (31) are made of epoxy resin or stainless steel.

5. The microsphere hardness testing system according to any one of claims 1 to 4, characterized in that, The sample pretreatment unit (1) includes: A sieve assembly (11) is used for the separation and enrichment of microsphere samples; Solvent rinsing module (12), which rinses the microsphere sample with solvent; and The drying module (13) removes excess solvent by means of vacuum filtration or drying.

6. The microsphere hardness testing system according to any one of claims 1 to 4, characterized in that, The sample detection device (3) also includes a base (30), the lower clamp (31) is fixedly connected to the base, and the upper clamp (32) is detachably fixedly connected to the displacement control mechanism (33).

7. The microsphere hardness testing system according to any one of claims 1 to 4, characterized in that, The diameter measuring unit (2) is a high-resolution camera, optical microscope or particle size analyzer.

8. The microsphere hardness testing system according to any one of claims 1 to 4, characterized in that, The detection parameter control unit (4) is communicatively connected to the displacement control mechanism (33) and includes: Temperature control module (41), which is used to set and maintain the ambient temperature; The time control module (42) is used to set the compression duration; Force control module (43), which is used to control the magnitude of the loading force and the compression rate; and The position control module (44) is used to control the compression displacement and stop position of the upper clamp (32).

9. The microsphere hardness testing system according to any one of claims 1 to 4, characterized in that, The data acquisition unit (5) includes a pressure sensor (51) and a displacement sensor (52) that are communicatively connected to the data analysis and display unit (6).

10. The microsphere hardness testing system according to any one of claims 1 to 4, characterized in that, The data analysis and display unit (6) includes: The data receiving module (61) is used to receive loading force and compression displacement data from the data acquisition unit (5); The data analysis module (62) is used to analyze and process the received loading force and compression displacement data, generate a loading force-compression displacement curve, and determine the yield stress corresponding to the inflection point of the curve, so as to convert the yield stress into the hardness value of the microsphere sample; and Display module (63) is used to display the loading force-compression displacement curve, the yield stress and the hardness value.

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