Method for testing redispersibility of paint

Abstract

The invention relates to the technical field of paint detection, in particular to a method for testing the redispersibility of paint. Comprising the following steps: centrifuging paint with a preset volume in a centrifugal barrel; obtaining the hard bottom thickness of the initial paint; adjusting centrifugal parameters based on the thickness of the hard bottom, or performing vibration treatment to generate test paint; pouring out the test paint, taking out the magnetic vibration block, obtaining a hard block area proportion through image scanning, and generating a dispersion characterization coefficient based on the hard block area proportion and the vibration frequency; when it is judged that paint redispersion does not meet a preset standard based on the dispersion characterization coefficient, the vibration time is increased, or a residual hard bottom image at the bottom of the centrifugal cylinder is collected to calculate a hard bottom damage value; the reasons for determining that the paint redispersion does not conform to the preset standard based on the hard bottom damage value comprise insufficient dispersing agent and collapse of the auxiliary system. According to the invention, whether the paint redispersion meets the preset standard or not is effectively detected, and the accuracy of the paint redispersion performance test is improved.

Description

Technical Field

[0001] This invention relates to the field of paint testing technology, and in particular to a method for testing the redispersibility of paint. Background Technology

[0002] Paint redispersibility testing is crucial for paint quality control and practical application. It reflects the paint's ability to redisperse after standing, stratification, or sedimentation during storage, transportation, and use. In industrial production, paint undergoes storage and transportation processes from production to use, and may experience stratification, flocculation, or sedimentation due to temperature changes or prolonged standing. If the redispersibility is poor, it is difficult to restore the paint to a uniform state before use, which will affect the application effect and may also lead to material waste and increased costs. Through this test, the formulation can be optimized, and suitable dispersants and stabilizers can be selected to improve product stability and ensure quality.

[0003] For example, Chinese Patent Application Publication No. CN120253696A discloses a device for testing the dispersibility of painting pigments. This invention discloses a device for testing the dispersibility of painting pigments, including a base, a test cylinder, a double-cone dispersion mechanism, and an anti-agglomeration grinding mechanism. The test cylinder is disposed on the upper wall of the base, the double-cone dispersion mechanism is disposed inside the test cylinder, and the anti-agglomeration grinding mechanism is disposed between the upper and lower walls of the test cylinder. The double-cone dispersion mechanism includes a centrifugal mechanism, a flow-gathering mechanism, and a concentration measuring mechanism. This invention provides a device for testing the dispersibility of painting pigments that can separate granular pigments from powdered pigments and can grind the separated granular pigments into powder while avoiding agglomeration of the powdered pigments.

[0004] It is evident that the existing technology still has the following problems:

[0005] The problem is that it is impossible to adjust the temperature module and combine it with gradient centrifugation to make the tested object form an initial state that closely matches reality before detection, and it is impossible to analyze the dispersion of the tested object by simulating the dispersion process and combining it with the acquired images of the tested object. Summary of the Invention

[0006] To address this, the present invention provides a method for testing the redispersibility of paint, which overcomes the problems in the prior art where the tested material cannot be brought to an actual initial state by adjusting the temperature module and using gradient centrifugation before testing, and where the dispersion of the tested material cannot be analyzed by simulating the dispersion process and acquiring images of the tested material.

[0007] To achieve the above objectives, the present invention provides a method for testing the redispersibility of paint, comprising:

[0008] The paint, which is loaded into a centrifuge tube of a preset volume, is centrifuged. The temperature inside the centrifuge tube is adjusted by the temperature control module and combined with gradient centrifugation to generate the initial paint.

[0009] With the centrifuge tube in a static state, a magnetic vibrating block is added to the centrifuge tube. The magnetic vibrating block can move up and down along the limiting rod. The electromagnetic module set at the bottom of the centrifuge tube is activated to attract the magnetic vibrating block to the bottom of the centrifuge tube, thereby obtaining the initial hard base thickness of the paint.

[0010] Adjust the centrifugation parameters based on the hard base thickness, or perform vibration treatment to generate test paint;

[0011] Invert the centrifuge tube after vibration treatment so that the bottom of the centrifuge tube is facing upward. Turn on the electromagnetic module to attract the magnetic vibration block to the bottom of the centrifuge tube. Pour out the test paint and take out the magnetic vibration block. Obtain the hard block area ratio by image scanning. Generate a dispersion characterization coefficient based on the hard block area ratio and the number of vibrations.

[0012] When the paint redispersion does not meet the preset standard based on the dispersion characterization coefficient, the vibration time is increased, or the image of the remaining hard bottom at the bottom of the centrifuge tube is collected to calculate the hard bottom damage value.

[0013] Based on the hard base breakage value, the reasons why the paint redispersion does not meet the preset standard include insufficient dispersant and failure of the additive system;

[0014] The temperature control module is located on the outer wall of the centrifuge tube, the centrifugation parameters include the centrifuge tube speed and centrifugation time, and the vibration treatment is to vibrate the centrifuge tube up and down.

[0015] Furthermore, the process of adjusting the temperature inside the centrifuge tube via a temperature control module and generating the initial paint using a gradient centrifugation method includes:

[0016] A temperature change curve is generated based on the paint's storage time, and the paint centrifugation time is determined.

[0017] Place a preset volume of paint into a centrifuge cylinder and perform a first centrifugation process for a preset time at the first centrifuge cylinder speed.

[0018] The second centrifuge cycle is adjusted to the second centrifuge drum speed for the remaining time. During the second centrifuge process, the temperature inside the centrifuge drum is adjusted by the temperature control module based on the ambient temperature change curve to generate the initial paint.

[0019] Wherein, the rotational speed of the first centrifuge tube is less than that of the second centrifuge tube, the preset time is positively correlated with the viscosity of the paint, and the paint centrifugation time includes the preset time and the remaining time.

[0020] Furthermore, the process of obtaining the initial hard base thickness of the paint includes,

[0021] With the centrifuge tube in a static state, open the top sealing cover of the centrifuge tube, align the magnetic vibrating block with the limiting rod, add the magnetic vibrating block into the centrifuge tube so that the magnetic vibrating block can move up and down along the limiting rod, and close the top sealing cover of the centrifuge tube.

[0022] Turn on the electromagnetic module located at the bottom of the centrifuge tube to attract the magnetic vibrating block to the bottom of the centrifuge tube, and read the height of the magnetic vibrating block near the top sealing cover of the centrifuge tube by means of the scale set on the limit rod.

[0023] The thickness of the hard base is calculated based on the height reading and the height of the magnetic vibrating block.

[0024] Both the limiting rod and the centrifuge cylinder are made of transparent material.

[0025] Furthermore, the process of adjusting the centrifugation parameters based on the hard base thickness includes,

[0026] Collect data on the hardened base thickness range of past paints during the stated placement time;

[0027] If the initial hard base thickness of the paint is less than the first hard base thickness, then it is determined that the rotation speed of the second centrifuge should be increased.

[0028] If the initial hard base thickness of the paint is greater than the second hard base thickness, then it is determined that the rotation speed of the second centrifuge should be reduced.

[0029] Wherein, the first hard sole thickness is the minimum value of the hard sole thickness range, the second hard sole thickness is the maximum value of the hard sole thickness range, and the first hard sole thickness is less than the second hard sole thickness.

[0030] Furthermore, if the initial paint hardening thickness is greater than or equal to the first hardening thickness and less than or equal to the second hardening thickness, then it is determined that the initial paint should be vibrated and the number of vibrations is recorded.

[0031] Furthermore, the process of obtaining the hard block area ratio through image scanning includes,

[0032] Invert the centrifuge tube after vibration treatment so that the bottom of the centrifuge tube faces upward and stand still. Turn on the electromagnetic module to attract the magnetic vibration block to the bottom of the centrifuge tube. Open the top sealing cover of the centrifuge tube and pour out the test paint.

[0033] Turn off the electromagnetic module, remove the magnetic vibratory block and let it stand until no paint drips down, then capture an image of the vibratory block;

[0034] The area of ​​the hard block attached to the magnetic vibratory block is calculated based on the image of the vibratory block to calculate the area ratio of the hard block.

[0035] Furthermore, the process of generating the dispersion characterization coefficient based on the area ratio of the hard block and the number of vibrations includes,

[0036] The proportion of dispersed area is calculated based on the proportion of the hard block area.

[0037] The value obtained by dividing the proportion of the dispersed area by the number of vibrations is determined as the dispersion characterization coefficient.

[0038] Furthermore, when the dispersion characterization coefficient is less than the second preset characterization coefficient, it is determined that the paint redispersion does not meet the preset standard; when the dispersion characterization coefficient is greater than or equal to the first preset characterization coefficient and less than the second preset characterization coefficient, the vibration time is increased; and when the dispersion characterization coefficient is less than the first preset characterization coefficient, the remaining hard bottom image at the bottom of the centrifuge is collected to calculate the hard bottom damage value.

[0039] Furthermore, the hard bottom damage value is the ratio of the remaining hard bottom area at the bottom of the centrifuge tube to the total area of ​​the bottom of the centrifuge tube.

[0040] Furthermore, when the hard bottom breakage value is less than the preset breakage value, the reason for not meeting the preset standard is determined to be insufficient dispersant; and when the hard bottom breakage value is greater than or equal to the preset breakage value, the reason for not meeting the preset standard is determined to be the collapse of the additive system.

[0041] Compared with existing technologies, the advantages of this invention are as follows: This invention generates initial paint by adjusting the temperature inside the centrifuge tube using a temperature control module combined with gradient centrifugation. This method precisely controls the preparation environment and process of the initial paint, ensuring that the generated paint sample is closer to its actual state during storage and use in terms of component distribution and particle size. The temperature control module can simulate the effects of different temperature conditions on the paint, avoiding sample property deviations caused by temperature fluctuations. Gradient centrifugation, by gradually adjusting the centrifugal force, allows the particles, additives, and other components in the paint to be distributed according to a reasonable gradient, reducing problems such as localized agglomeration and uneven dispersion that may occur with manual mixing or single centrifugation methods. The resulting initial paint sample has higher stability and a more uniform state, providing a standardized benchmark for subsequent redispersibility testing. When evaluating the redispersibility of the paint after standing and stratification, the stronger consistency of the initial sample allows the test results to more accurately reflect the performance differences of the paint itself, rather than errors in the preparation process, thus effectively eliminating interfering factors and improving the accuracy of paint redispersibility testing.

[0042] Furthermore, this invention, while the centrifuge drum is stationary, involves opening the top sealing cap, aligning it with the limiting rod, and adding a magnetic vibrating block into the centrifuge drum, allowing the magnetic vibrating block to move up and down along the limiting rod. The top sealing cap is then closed, and the electromagnetic module located at the bottom of the centrifuge drum is activated to attract the magnetic vibrating block to the bottom. The height of the magnetic vibrating block near the top sealing cap is read using a scale on the limiting rod. Based on this height reading and the height of the magnetic vibrating block, the hardened base thickness is calculated. Centrifugation parameters are adjusted according to the hardened base thickness. Through the cooperation of the magnetic vibrating block and the electromagnetic module, the thickness of the hardened base formed after the paint has settled can be accurately measured, providing a quantitative indicator for evaluating the paint's sedimentation state. The scale design on the limiting rod makes the height reading intuitive and controllable. The hardened base thickness data calculated from the height of the magnetic vibrating block itself is objective and accurate. By accurately capturing the hardened base state and optimizing test conditions, the redispersibility of the paint can be more realistically reflected, effectively improving the reliability of the test results and further enhancing the accuracy of paint redispersibility testing.

[0043] Furthermore, this invention obtains the area of ​​hard lumps remaining on the magnetic vibrating block through image scanning, calculates the proportion of hard lumps based on the area of ​​hard lumps, and then obtains the proportion of dispersed area. Combined with the number of vibrations, the dispersion characterization coefficient of the paint is obtained. Based on the dispersion characterization coefficient, it is determined whether the redispersion of the paint meets the redispersion standard. At the same time, when it is determined that it does not meet the redispersion standard, corresponding processing methods are adopted according to the magnitude of the deviation of the dispersion characterization coefficient. By obtaining the area of ​​hard lumps remaining on the magnetic vibrating block through image scanning, the dispersion degree observed by the naked eye is transformed into a specific numerical value, avoiding the bias of subjective judgment. The dispersion characterization coefficient combines the proportion of dispersed area and the number of vibrations, reflecting both the final dispersion state of the paint and the energy required to achieve that state, thus more comprehensively characterizing the redispersion ability of the paint. For cases that do not meet the standard, corresponding processing is carried out according to the magnitude of the coefficient deviation, further improving the accuracy of paint redispersion performance testing.

[0044] Furthermore, this invention acquires images of the hardened bottom remaining at the bottom of the centrifuge after vibration treatment, calculates the area ratio of the remaining hardened bottom, and analyzes the reasons for the paint redispersibility not meeting the redispersibility standard based on the size of the remaining hardened bottom area. If the size of the remaining hardened bottom area is small, the cause is determined to be insufficient dispersant, and the proportion of dispersant in subsequent paint production is adjusted. If the size of the remaining hardened bottom area is too large, the cause is determined to be the collapse of the additive system, and the proportion of each component affecting paint dispersion in subsequent paint production is adjusted. Through image acquisition and area calculation, the unqualified result of paint redispersibility is transformed into quantifiable data of the remaining hardened bottom area, making the characterization of performance defects more specific and objective. Based on the size of the remaining hardened bottom area, stratified attribution is performed, achieving in-depth analysis of the essence of the unqualified result. Adjustments to the production formula are analyzed based on the causes of the unqualified result, forming a closed loop between test data and production optimization, ensuring that the improvement of paint redispersibility performance defects is more targeted, and further improving the accuracy of paint redispersibility performance testing. Attached Figure Description

[0045] Figure 1 This is a schematic flowchart of the paint redispersibility testing method of the present invention;

[0046] Figure 2 This is a schematic diagram of the inverted centrifuge cylinder structure according to an embodiment of the present invention;

[0047] Figure 3 This is a logic diagram for determining whether paint redispersion meets a preset standard in an embodiment of the present invention;

[0048] Figure 4 A logic diagram for determining the reasons for non-compliance with preset standards in an embodiment of the present invention;

[0049] Among them, 1 is a centrifuge tube; 2 is a magnetic vibrating block; 3 is a limiting rod; 4 is an electromagnetic module; and 5 is the bottom of the centrifuge tube. Detailed Implementation

[0050] To make the objectives and advantages of the present invention clearer, the present invention will be further described below with reference to embodiments; it should be understood that the specific embodiments described herein are merely for explaining the present invention and are not intended to limit the present invention.

[0051] Preferred embodiments of the present invention will now be described with reference to the accompanying drawings. Those skilled in the art should understand that these embodiments are merely illustrative of the technical principles of the present invention and are not intended to limit the scope of protection of the present invention.

[0052] It should be noted that, in the description of this invention, unless otherwise explicitly specified and limited, the term "connection" should be interpreted broadly. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium; it can be a connection within two components. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0053] Please see Figure 1 As shown, it is a schematic flowchart of the paint redispersibility test method of the present invention. An embodiment of the present invention provides a paint redispersibility test method, comprising:

[0054] Step S1: Centrifuge the paint of a preset volume into a centrifuge tube, adjust the temperature inside the centrifuge tube using a temperature control module, and generate the initial paint using a gradient centrifugation method.

[0055] Step S2: With the centrifuge tube in a static state, add a magnetic vibrating block to the centrifuge tube. The magnetic vibrating block can move up and down along the limiting rod. Activate the electromagnetic module set at the bottom of the centrifuge tube to attract the magnetic vibrating block to the bottom of the centrifuge tube and obtain the initial hard base thickness of the paint.

[0056] Step S3: Adjust the centrifugation parameters based on the thickness of the hard base, or perform vibration treatment to generate test paint;

[0057] Step S4: Invert the centrifuge tube after vibration treatment so that the bottom of the centrifuge tube is facing upward. Turn on the electromagnetic module to attract the magnetic vibration block to the bottom of the centrifuge tube. Pour out the test paint and take out the magnetic vibration block. Obtain the hard block area ratio through image scanning. Generate the dispersion characterization coefficient based on the hard block area ratio and the number of vibrations.

[0058] Step S5: If the paint redispersion does not meet the preset standard based on the dispersion characterization coefficient, increase the vibration time, or collect the image of the remaining hard bottom at the bottom of the centrifuge tube to calculate the hard bottom damage value.

[0059] Step S6, based on the hard base breakage value, determine the reasons why the paint redispersion does not meet the preset standard, including insufficient dispersant and failure of the additive system;

[0060] The temperature control module is located on the outer wall of the centrifuge tube. The centrifugation parameters include the centrifuge tube speed and centrifugation time. The vibration treatment involves vibrating the centrifuge tube up and down.

[0061] Understandably, the preset volume of paint is loaded into the centrifuge. To ensure smooth vibration processing, the preset volume is generally one-half to two-thirds of the centrifuge volume. If the volume is too small, there will be less paint in the centrifuge, and the paint lumps will not be easily dispersed during vibration. If the volume is too large, the remaining space will not allow the paint to flow and mix fully during vibration, reducing the vibration effect.

[0062] Understandably, for the initial vibration treatment to generate test paint, the vibration time is generally 3 to 8 minutes, and the vibration frequency is 50 to 120 times per minute. Low-viscosity paints are vibrated for a short time at a low frequency, while high-viscosity paints are vibrated for a long time at a high frequency. Those skilled in the art can arrange the vibration themselves, and this will not be elaborated here.

[0063] It is understandable that during the vibration process, the vibrating block vibrates up and down in the centrifuge tube, and a single vibration is considered a complete vibration when it hits the top and bottom of the centrifuge tube.

[0064] Understandably, the temperature control module is fixed to the outer wall of the centrifuge tube using metal clamps and a thermally conductive pad. The clamps are tightened with bolts, and a 0.5mm to 1mm thick thermally conductive silicone pad is sandwiched between the module and the tube wall. The temperature control module is removed before vibration treatment.

[0065] Please see Figure 2 As shown, it is a schematic diagram of the structure of the centrifuge cylinder inverted according to an embodiment of the present invention. The centrifuge cylinder 1 is placed upside down, and the limiting rod 3 is set inside the centrifuge cylinder 1. One end is fixed and closed to the bottom 5 of the centrifuge cylinder, and the other end is open and communicates with the air. Several scale lines are set inside. The magnetic vibrating block 2 is added into the centrifuge cylinder from the open end of the limiting rod 3 and can move freely up and down along the limiting rod 3. The electromagnetic module 4 is set outside the bottom 5 of the centrifuge cylinder and can generate magnetic attraction force on the magnetic vibrating block 2 by controlling the current.

[0066] Specifically, in step S1, the process of adjusting the temperature inside the centrifuge tube using a temperature control module and generating the initial paint using a gradient centrifugation method includes:

[0067] A temperature change curve is generated based on the paint's storage time, and the paint centrifugation time is determined.

[0068] Place a preset volume of paint into a centrifuge cylinder and perform a first centrifugation process for a preset time at the first centrifuge cylinder speed.

[0069] The second centrifuge cycle speed is adjusted to the second centrifuge tube speed for the remaining time of the second centrifuge process. During the second centrifuge process, the temperature inside the centrifuge tube is adjusted by the temperature control module based on the ambient temperature change curve to generate the initial paint.

[0070] The first centrifuge cylinder rotates at a speed lower than the second centrifuge cylinder. The preset time is positively correlated with the paint viscosity. The paint centrifugation time includes the preset time and the remaining time.

[0071] In one specific embodiment, the paint was left to stand for one year, generating a simulated environmental temperature change curve for the four seasons. Specifically: in months 1-3 (winter), the temperature gradually decreased from 5°C to 0°C, with an average monthly decrease of approximately 1.67°C; in months 4-6 (spring), the temperature gradually increased from 0°C to 20°C, with an average monthly increase of approximately 6.67°C; in months 7-9 (summer), the temperature gradually increased from 20°C to 35°C, with an average monthly increase of approximately 5°C; in months 10-12 (autumn), the temperature gradually decreased from 35°C to 5°C, with an average monthly decrease of approximately 10°C. Based on the principle that the preset time is positively correlated with the paint viscosity, the total centrifugation time for the paint was determined to be 90 minutes, of which the preset time was 45 minutes. The remaining time is 45 minutes. Prepare a 1000ml centrifuge tube and slowly pour 500ml of paint that has been stored for one year into the tube, ensuring that the paint does not spill and that the inner wall of the tube is clean. Place the tube in a centrifuge and set the first centrifuge speed to 1500 rpm. Start the centrifuge and perform a first centrifugation process for 45 minutes. This speed was chosen because a lower speed is needed initially to allow the paint to settle. After the first centrifugation process, adjust the centrifuge speed to 3000 rpm (the second centrifuge speed) and perform a second centrifugation process for 45 minutes. This speed is higher than the first speed, which can further promote the formation of a hard base for the paint. During the second centrifugation process, the temperature inside the centrifuge tube is adjusted by the temperature control module based on the ambient temperature change curve generated above. Specifically, the adjustment method is to proportionally compress the temperature change curve corresponding to the 45-minute second centrifugation time over one year. Specifically, for the first 11.25 minutes (corresponding to 1-3 months), the temperature gradually decreases from 5℃ to 0℃, with an average decrease of approximately 0.044℃ per minute; from 11.26 to 22.5 minutes (corresponding to 4-6 months), the temperature gradually increases from 0℃ to 20℃, with an average increase of approximately 0.178℃ per minute; from 22.6 to 33.75 minutes (corresponding to 7-9 months), the temperature gradually increases from 20℃ to 35℃, with an average increase of approximately 0.111℃ per minute; from 33.76 to 45 minutes (corresponding to 10-12 months), the temperature gradually decreases from 35℃ to 5℃, with an average decrease of approximately 0.222℃ per minute; after the second centrifugation process, an initial paint with a hardened base is generated.

[0072] Specifically, this invention generates initial paint by adjusting the temperature inside the centrifuge tube using a temperature control module combined with gradient centrifugation. This method precisely controls the preparation environment and process of the initial paint, ensuring that the generated paint sample more closely resembles its actual state during storage and use in terms of component distribution and particle size. The temperature control module simulates the effects of different temperature conditions on the paint, avoiding sample property deviations caused by temperature fluctuations. Gradient centrifugation, by gradually adjusting the centrifugal force, ensures that the particles, additives, and other components in the paint are distributed according to a reasonable gradient, reducing problems such as local agglomeration and uneven dispersion that may occur with manual mixing or single centrifugation methods. The resulting initial paint sample has higher stability and a more uniform state, providing a standardized benchmark for subsequent redispersibility testing. When evaluating the redispersibility of the paint after standing and stratification, the stronger consistency of the initial sample allows the test results to more accurately reflect the performance differences of the paint itself, rather than errors in the preparation process. This effectively eliminates interfering factors and improves the accuracy of paint redispersibility testing.

[0073] Specifically, in step S2, the process of obtaining the initial hard base thickness of the paint includes,

[0074] With the centrifuge tube in a static state, open the top sealing cover of the centrifuge tube, align the magnetic vibrating block with the limit rod, add the magnetic vibrating block into the centrifuge tube so that the magnetic vibrating block can move up and down along the limit rod, and close the top sealing cover of the centrifuge tube.

[0075] Turn on the electromagnetic module located at the bottom of the centrifuge tube to attract the magnetic vibrating block to the bottom of the centrifuge tube, and read the height of the magnetic vibrating block near the top sealing cover of the centrifuge tube through the scale set on the limit rod.

[0076] The thickness of the hard base is calculated based on the height reading and the height of the magnetic vibrating block.

[0077] Both the limit rod and the centrifuge cylinder are made of transparent material.

[0078] Understandably, activating the electromagnetic module located at the bottom of the centrifuge tube attracts the magnetic vibratory block to the bottom of the centrifuge tube. The scale reading is taken from the open end of the limiting rod. Because the electromagnetic module attracts the magnetic vibratory block, and the hard bottom is mainly formed by the dense accumulation of pigment particles, film-forming substances, etc., and there are still a few gaps or movable intermolecular structures inside, the magnetic vibratory block compresses the hard bottom under the action of electromagnetic attraction, making its thickness smaller. However, the scale reading taken from the open end of the limiting rod is a downward view of the limiting rod scale, so the scale reading is larger, and the calculated thickness of the hard bottom is larger. The errors of the two cancel each other out.

[0079] Specifically, in step S3, the process of adjusting the centrifugation parameters based on the hard base thickness includes:

[0080] Collect data on the hardened thickness range of past paints over a given period of time;

[0081] If the initial hard base thickness of the paint is less than the first hard base thickness, then it is determined that the speed of the second centrifuge should be increased.

[0082] If the initial hard base thickness of the paint is greater than the second hard base thickness, then the speed of the second centrifuge tube will be reduced.

[0083] The first hard sole thickness is the minimum value of the hard sole thickness range, the second hard sole thickness is the maximum value of the hard sole thickness range, and the first hard sole thickness is less than the second hard sole thickness.

[0084] In one specific embodiment, 30 samples of the same type of paint as the target paint, all stored for one year (ensuring consistent storage conditions and initial composition), were selected. For each sample, the hard base thickness was measured using a digital caliper with an accuracy of 0.01 mm. Measurements were taken at three different locations (edge, center, and half radius) for each sample, and the average value was used as the hard base thickness. The thickness data of the 30 samples were statistically analyzed, resulting in a hard base thickness range of 2.5 mm (minimum) to 4.5 mm (maximum). The first hard base thickness was 2.5 mm, and the second hard base thickness was 4.5 mm. The mixture was then centrifuged at a first centrifugal speed of 15... The initial paint sample was prepared by centrifuging at 3000 r / min for 45 min, with the second centrifuge speed at 3000 r / min for 45 min. The temperature was adjusted according to the 1-year curve to obtain the initial paint sample. The hard base thickness of the initial paint sample was measured. If the hard base thickness of the initial paint sample was 1.5 mm, which was less than the first hard base thickness, the second centrifuge speed was increased. If the hard base thickness of the initial paint sample was 5.5 mm, which was greater than the second hard base thickness, the second centrifuge speed was decreased. If the hard base thickness of the initial paint sample was 3.0 mm, which was greater than the first hard base thickness but less than the second hard base thickness, the hard base thickness was deemed acceptable. The initial paint sample was then vibrated, and the number of vibrations was recorded.

[0085] Specifically, in step S3, if the initial paint hard base thickness is greater than or equal to the first hard base thickness and less than or equal to the second hard base thickness, it is determined that the initial paint should be vibrated and the number of vibrations is recorded.

[0086] Specifically, this invention involves opening the top sealing cap of the centrifuge tube while it is stationary, aligning it with the limiting rod, and adding a magnetic vibrating block into the centrifuge tube so that the magnetic vibrating block can move up and down along the limiting rod. The top sealing cap is then closed, and the electromagnetic module located at the bottom of the centrifuge tube is activated to attract the magnetic vibrating block to the bottom. The height of the magnetic vibrating block near the top sealing cap is read using a scale on the limiting rod. Based on the height reading and the height of the magnetic vibrating block, the hardened base thickness is calculated. Centrifugation parameters are adjusted according to the hardened base thickness. Through the cooperation of the magnetic vibrating block and the electromagnetic module, the thickness of the hardened base formed after the paint has settled can be accurately measured, providing a quantitative indicator for evaluating the paint's sedimentation state. The scale design on the limiting rod makes the height reading intuitive and controllable. The hardened base thickness data calculated based on the height of the magnetic vibrating block itself is objective and accurate. By accurately capturing the hardened base state and optimizing test conditions, the redispersibility of the paint can be more realistically reflected, effectively improving the reliability of the test results and further enhancing the accuracy of paint redispersibility testing.

[0087] Specifically, in step S4, the process of obtaining the hard block area ratio through image scanning includes,

[0088] Invert the centrifuge tube after vibration treatment so that the bottom of the centrifuge tube faces upward and stand still. Turn on the electromagnetic module to attract the magnetic vibration block to the bottom of the centrifuge tube. Open the top sealing cover of the centrifuge tube and pour out the test paint.

[0089] Turn off the electromagnetic module, remove the magnetic vibratory block and let it stand until no paint drips down, then capture an image of the vibratory block;

[0090] The area of ​​the hard block attached to the magnetic vibratory block is calculated based on the image of the vibratory block to determine the proportion of the hard block area.

[0091] Specifically, disconnect the power supply to the electromagnetic module, wait 10 seconds for the magnetic force to completely disappear, use special plastic tweezers to hold the non-hardened fragment part of the magnetic vibratory block, take it out for image acquisition, and use image processing technology to identify the outline of the hard block. This is known to those in the art and will not be described in detail here. Divide the area of ​​the hard block by the surface area of ​​the magnetic vibratory block to obtain the area ratio of the hard block.

[0092] Specifically, in step S4, the process of generating the dispersion characterization coefficient based on the area ratio of hard blocks and the number of vibrations includes,

[0093] The proportion of dispersed area is calculated based on the proportion of hard block area.

[0094] The value obtained by dividing the proportion of dispersed area by the number of vibrations is determined as the dispersion characterization coefficient.

[0095] It is understandable that the sum of the proportion of dispersed area and the proportion of hard area is 1.

[0096] Understandably, the proportion of hard lumps represents the amount of hard lumps remaining on the magnetic vibrating block, while the proportion of dispersed area represents the degree of dispersion of the paint during the redispersion process. Combined with the number of vibrations, it provides a specific and practical reference for the degree of paint redispersion. The smaller the dispersion characterization coefficient, the lower the degree of paint redispersion, and the larger the dispersion characterization coefficient, the higher the degree of paint redispersion.

[0097] Please see Figure 3 As shown, this is a logic diagram for determining whether the redispersibility of paint meets the preset standard in an embodiment of the present invention. In step S5, when the dispersion characterization coefficient is greater than or equal to the second preset characterization coefficient, it is determined that the redispersibility of paint meets the preset standard; when the dispersion characterization coefficient is less than the second preset characterization coefficient, it is determined that the redispersibility of paint does not meet the preset standard; when the dispersion characterization coefficient is greater than or equal to the first preset characterization coefficient and less than the second preset characterization coefficient, the vibration time is increased; and when the dispersion characterization coefficient is less than the first preset characterization coefficient, the image of the remaining hard bottom at the bottom of the centrifuge tube is collected to calculate the hard bottom damage value.

[0098] In one specific embodiment, the vibration is performed 20 times. The first preset characterization coefficient is set to 0.045, and the second preset characterization coefficient is set to 0.04. When the dispersion characterization coefficient is 0.047, which is greater than the second preset characterization coefficient, the paint redispersion is determined to meet the preset standard. When the dispersion characterization coefficient is 0.043, which is greater than the first preset characterization coefficient but less than the second preset characterization coefficient, the vibration time is increased. When the dispersion characterization coefficient is 0.038, which is less than the first preset characterization coefficient, the image of the remaining hard bottom at the bottom of the centrifuge is collected to calculate the hard bottom damage value.

[0099] It is understandable that the first preset characterization coefficient is smaller than the second preset characterization coefficient. The first and second preset characterization coefficients are negatively correlated with the ratio of the volume of paint added to the centrifuge cylinder to the volume of the centrifuge cylinder. The more paint added to the centrifuge cylinder, the greater the thickness of the hardened bottom. Under the condition that the number of vibrations remains unchanged, the larger the added volume, the larger the residual hardened bottom area. Therefore, the first and second preset characterization coefficients are negatively correlated with the ratio of the volume of paint added to the centrifuge cylinder to the volume of the centrifuge cylinder.

[0100] Preferably, when the number of vibrations is 20, and the ratio of the volume of paint added to the volume of the centrifuge tube to the volume of the centrifuge tube is one-half, the first preset characterization coefficient is 0.045, and the second preset characterization coefficient is 0.04.

[0101] When the ratio of the volume of paint added to the volume of the centrifuge tube is seven-twelfths, the first preset characterization coefficient is 0.043 and the second preset characterization coefficient is 0.037.

[0102] When the volume of paint added to the centrifuge tube accounts for two-thirds of the total volume of the centrifuge tube, the first preset characterization coefficient is 0.037, and the second preset characterization coefficient is 0.035.

[0103] Specifically, this invention acquires the area of ​​hard lumps remaining on the magnetic vibrating block through image scanning, calculates the proportion of hard lumps based on the area of ​​hard lumps, and then obtains the proportion of dispersed area. Combined with the number of vibrations, it obtains the dispersion characterization coefficient of the paint. Based on the dispersion characterization coefficient, it determines whether the redispersibility of the paint meets the redispersibility standard. Furthermore, when it is determined that the redispersibility standard is not met, corresponding processing methods are applied based on the magnitude of the deviation of the dispersion characterization coefficient. By acquiring the area of ​​hard lumps remaining on the magnetic vibrating block through image scanning, the degree of dispersion observed by the naked eye is transformed into a specific numerical value, avoiding the bias of subjective judgment. The dispersion characterization coefficient, combining the proportion of dispersed area and the number of vibrations, reflects both the final dispersion state of the paint and the energy required to achieve that state, thus more comprehensively characterizing the redispersibility of the paint. For cases that do not meet the standard, corresponding processing is carried out based on the magnitude of the coefficient deviation, further improving the accuracy of paint redispersibility performance testing.

[0104] Specifically, in step S5, the hard bottom damage value is the ratio of the remaining hard bottom area at the bottom of the centrifuge tube to the total area of ​​the bottom of the centrifuge tube.

[0105] Please see Figure 4 As shown, it is a logic diagram for determining the reasons for not meeting the preset standard in an embodiment of the present invention. In step S6, when the hard bottom breakage value is less than the preset breakage value, the reason for not meeting the preset standard is determined to be insufficient dispersant. When the hard bottom breakage value is greater than or equal to the preset breakage value, the reason for not meeting the preset standard is determined to be the collapse of the additive system.

[0106] In one specific embodiment, a preset breakage value is set to 10%. If the hard bottom breakage value is 8%, which is less than the preset breakage value, the reason for not meeting the preset standard is determined to be insufficient dispersant. If the hard bottom breakage value is 16%, which is greater than the preset breakage value, the reason for not meeting the preset standard is determined to be the collapse of the additive system.

[0107] It is understandable that the preset damage value is positively correlated with the number of vibrations. The more vibrations there are, the fewer hard blocks remain at the bottom of the centrifuge. Therefore, the preset damage value is positively correlated with the number of vibrations.

[0108] Preferably, when the number of vibrations is 20, the preset breakage value is 15%;

[0109] When the vibration frequency is 30 times, the preset breakage value is 10%;

[0110] When the vibration frequency is 50 times, the preset breakage value is 5%.

[0111] Specifically, this invention acquires images of the hardened bottom remaining at the bottom of the centrifuge after vibration treatment, calculates the area ratio of the remaining hardened bottom, and analyzes the reasons for the paint redispersibility not meeting the redispersibility standard based on the size of the remaining hardened bottom area. If the remaining hardened bottom area is small, the cause is determined to be insufficient dispersant, and the proportion of dispersant in subsequent paint production is adjusted. If the remaining hardened bottom area is too large, the cause is determined to be the collapse of the additive system, and the proportion of each component affecting paint dispersion in subsequent paint production is adjusted. Through image acquisition and area calculation, the unqualified result of paint redispersibility is transformed into quantifiable data of remaining hardened bottom area, making the characterization of performance defects more specific and objective. Based on the size of the remaining hardened bottom area, stratified attribution is performed, achieving in-depth analysis of the essence of the unqualified result. Adjustments to the production formula are analyzed based on the causes of the unqualified result, forming a closed loop between test data and production optimization. This ensures that the improvement of paint redispersibility performance defects is more targeted and further improves the accuracy of paint redispersibility performance testing.

[0112] The technical solution of the present invention has been described above with reference to the preferred embodiments shown in the accompanying drawings. However, it will be readily understood by those skilled in the art that the scope of protection of the present invention is obviously not limited to these specific embodiments. Without departing from the principles of the present invention, those skilled in the art can make equivalent changes or substitutions to the relevant technical features, and the technical solutions after these changes or substitutions will all fall within the scope of protection of the present invention.

[0113] The above description is merely a preferred embodiment of the present invention and is not intended to limit the invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A method for testing the redispersibility of paint, characterized in that, include: The paint, which is loaded into a centrifuge tube of a preset volume, is centrifuged. The temperature inside the centrifuge tube is adjusted by the temperature control module and combined with gradient centrifugation to generate the initial paint. With the centrifuge tube in a static state, a magnetic vibrating block is added to the centrifuge tube. The magnetic vibrating block can move up and down along the limiting rod. The electromagnetic module set at the bottom of the centrifuge tube is activated to attract the magnetic vibrating block to the bottom of the centrifuge tube, thereby obtaining the initial hard base thickness of the paint. Adjust the centrifugation parameters based on the hard base thickness, or perform vibration treatment to generate test paint; Invert the centrifuge tube after vibration treatment so that the bottom of the centrifuge tube is facing upward. Turn on the electromagnetic module to attract the magnetic vibration block to the bottom of the centrifuge tube. Pour out the test paint and take out the magnetic vibration block. Obtain the hard block area ratio by image scanning. Generate a dispersion characterization coefficient based on the hard block area ratio and the number of vibrations. When the paint redispersion does not meet the preset standard based on the dispersion characterization coefficient, the vibration time is increased, or the image of the remaining hard bottom at the bottom of the centrifuge tube is collected to calculate the hard bottom damage value. Based on the hard base breakage value, the reasons why the paint redispersion does not meet the preset standard include insufficient dispersant and failure of the additive system; The temperature control module is located on the outer wall of the centrifuge tube, the centrifugation parameters include the centrifuge tube speed and centrifugation time, and the vibration treatment is to vibrate the centrifuge tube up and down.

2. The method for testing the redispersibility of paint according to claim 1, characterized in that, The process of adjusting the temperature inside the centrifuge tube using a temperature control module and generating the initial paint using a gradient centrifugation method includes: A temperature change curve is generated based on the paint's storage time, and the paint centrifugation time is determined. Place a preset volume of paint into a centrifuge cylinder and perform a first centrifugation process for a preset time at the first centrifuge cylinder speed. The second centrifuge cycle is adjusted to the second centrifuge drum speed for the remaining time. During the second centrifuge process, the temperature inside the centrifuge drum is adjusted by the temperature control module based on the ambient temperature change curve to generate the initial paint. Wherein, the rotational speed of the first centrifuge tube is less than that of the second centrifuge tube, the preset time is positively correlated with the viscosity of the paint, and the paint centrifugation time includes the preset time and the remaining time.

3. The method for testing the redispersibility of paint according to claim 2, characterized in that, The process of obtaining the initial hard base thickness of the paint includes, With the centrifuge tube in a static state, open the top sealing cover of the centrifuge tube, align the magnetic vibrating block with the limiting rod, add the magnetic vibrating block into the centrifuge tube so that the magnetic vibrating block can move up and down along the limiting rod, and close the top sealing cover of the centrifuge tube. Turn on the electromagnetic module located at the bottom of the centrifuge tube to attract the magnetic vibrating block to the bottom of the centrifuge tube, and read the height of the magnetic vibrating block near the top sealing cover of the centrifuge tube by means of the scale set on the limit rod. The thickness of the hard base is calculated based on the height reading and the height of the magnetic vibrating block. Both the limiting rod and the centrifuge cylinder are made of transparent material.

4. The method for testing the redispersibility of paint according to claim 3, characterized in that, The process of adjusting the centrifugation parameters based on the hard base thickness includes: Collect data on the hardened base thickness range of past paints during the stated placement time; If the initial hard base thickness of the paint is less than the first hard base thickness, then it is determined that the rotation speed of the second centrifuge should be increased. If the initial hard base thickness of the paint is greater than the second hard base thickness, then it is determined that the rotation speed of the second centrifuge should be reduced. Wherein, the first hard sole thickness is the minimum value of the hard sole thickness range, the second hard sole thickness is the maximum value of the hard sole thickness range, and the first hard sole thickness is less than the second hard sole thickness.

5. The method for testing the redispersibility of paint according to claim 4, characterized in that, If the initial paint hardening thickness is greater than or equal to the first hardening thickness and less than or equal to the second hardening thickness, then it is determined that the initial paint should be vibrated and the number of vibrations should be recorded.

6. The method for testing the redispersibility of paint according to claim 5, characterized in that, The process of obtaining the hard block area ratio through image scanning includes: Invert the centrifuge tube after vibration treatment so that the bottom of the centrifuge tube faces upward and stand still. Turn on the electromagnetic module to attract the magnetic vibration block to the bottom of the centrifuge tube. Open the top sealing cover of the centrifuge tube and pour out the test paint. Turn off the electromagnetic module, remove the magnetic vibratory block and let it stand until no paint drips down, then capture an image of the vibratory block; The area of ​​the hard block attached to the magnetic vibratory block is calculated based on the image of the vibratory block to calculate the area ratio of the hard block.

7. The method for testing the redispersibility of paint according to claim 6, characterized in that, The process of generating the dispersion characterization coefficient based on the area ratio of the hard block and the number of vibrations includes: The proportion of dispersed area is calculated based on the proportion of the hard block area. The value obtained by dividing the proportion of the dispersed area by the number of vibrations is determined as the dispersion characterization coefficient.

8. The method for testing the redispersibility of paint according to claim 7, characterized in that, When the dispersion characterization coefficient is less than the second preset characterization coefficient, it is determined that the paint redispersion does not meet the preset standard; when the dispersion characterization coefficient is greater than or equal to the first preset characterization coefficient and less than the second preset characterization coefficient, the vibration time is increased; and when the dispersion characterization coefficient is less than the first preset characterization coefficient, the remaining hard bottom image at the bottom of the centrifuge is collected to calculate the hard bottom damage value.

9. The method for testing the redispersibility of paint according to claim 8, characterized in that, The hard bottom damage value is the ratio of the remaining hard bottom area at the bottom of the centrifuge tube to the total area of ​​the bottom of the centrifuge tube.

10. The method for testing the redispersibility of paint according to claim 9, characterized in that, When the hard bottom breakage value is less than the preset breakage value, the reason for not meeting the preset standard is determined to be insufficient dispersant; when the hard bottom breakage value is greater than or equal to the preset breakage value, the reason for not meeting the preset standard is determined to be the collapse of the additive system.

Images