Device and method for testing cracking resistance of fireproof coating

Abstract

The invention relates to the technical field of coating detection, in particular to a fireproof coating anti-cracking performance testing device which comprises a testing box body, mounting plates are mounted on two opposite side walls in the testing box body, a test piece is rotatably connected between the two mounting plates, a motor is fixed on the side wall of the testing box body, and the motor is rotatably connected with the test piece. An output shaft of the motor extends into the test box body and is fixedly connected with one end of the test piece; the test piece comprises a first bending plate and a second bending plate which are fixedly connected, the two ends of the first bending plate and the second bending plate are fixedly connected with positioning plates after the first bending plate and the second bending plate are fixedly connected, rotating shafts are fixed to the sides, away from each other, of the two positioning plates, and the test piece is rotationally connected between the mounting plates through the rotating shafts. Through the arrangement of the test piece and the test method, the problem that corners cannot be detected in the performance test of the fireproof coating in the prior art is solved, the function that multiple angles can be tested through one-time test is achieved, and the detection completeness of the cracking resistance of the fireproof coating is improved.

Description

Technical Field

[0001] This invention relates to the field of coating testing technology, and in particular to a testing device and method for testing the crack resistance of fire-retardant coatings. Background Technology

[0002] Chemical refining plants involve large quantities of flammable, explosive, and corrosive substances in their production processes, which are complex and highly dangerous. Once a fire breaks out, it spreads rapidly, is difficult to extinguish, and can easily lead to a major accident. Therefore, fire prevention in chemical plants must be proactive, ensuring that production equipment, pipelines, and structures have good fire resistance. Fire-retardant coatings are special coatings applied to the surface of objects to effectively prevent the spread of flames and extend the fire resistance time of the substrate. Applying fire-retardant coatings to steel structures can effectively improve their fire resistance limit, slow the spread of fire, and buy valuable time for firefighting and personnel evacuation.

[0003] In practical field applications, fire-retardant coatings on steel structures often experience localized cracking, leading to moisture ingress and, in severe cases, coating peeling and corrosion beneath the fireproof layer. Therefore, evaluating the crack resistance of fire-retardant coatings is crucial. Currently, the national standard GB / T 14907-2018, "Fire-retardant Coatings for Steel Structures," specifies requirements for the initial drying crack resistance of fire-retardant coatings, clearly defining the specimens, test methods, and result evaluation. This method uses a 300mm*150mm*6mm flat specimen, only examining the crack resistance of the fire-retardant coating in planar conditions. However, during field service, fire-retardant coatings on steel structures often involve numerous corners, and the crack resistance requirements for these corners are not addressed. Field surveys have revealed that cracking first occurs at internal and external corners, making the evaluation of the crack resistance of fire-retardant coatings at corners particularly necessary. Currently, there are no relevant standard test methods for reference.

[0004] CN202121554007.X discloses a testing device for fire-retardant coatings, mainly used to evaluate the fire resistance performance of fire-retardant coatings; CN202220510236.X discloses a test device for the bonding strength of fire-retardant coatings, mainly used to evaluate the bonding performance of fire-retardant coatings. However, neither of the above patents addresses the crack resistance performance of fire-retardant coatings. Therefore, there is an urgent need to develop a test method for evaluating the crack resistance performance of fire-retardant coatings at corners. Summary of the Invention

[0005] In view of the shortcomings of the prior art, the purpose of this invention is to propose a fire-retardant coating crack resistance test device and test method. By setting up the test specimen and the test method, the problem that the corners and edges cannot be detected in the fire-retardant coating performance test of the prior art is solved, and the function of testing multiple angles in one test is realized, thereby improving the completeness of the fire-retardant coating crack resistance test.

[0006] To achieve the above objectives, the present invention provides the following technical solution:

[0007] This invention claims a fire-retardant coating crack resistance testing device, comprising a test chamber, a cover on the test chamber, mounting plates on opposite side walls inside the test chamber, a test specimen rotatably connected between the two mounting plates, a motor fixed on the side wall of the test chamber, the output shaft of the motor extending into the test chamber and fixedly connected to one end of the test specimen, and ventilation openings on both sides of the test specimen.

[0008] The specimen includes a first bending plate and a second bending plate; the first bending plate and the second bending plate are fixedly connected, and after the first bending plate and the second bending plate are fixedly connected, positioning plates are fixedly connected to both ends. A rotating shaft is fixed on the side of the two positioning plates that are far apart from each other, and the specimen is rotatably connected between the mounting plates through the rotating shaft.

[0009] Preferably, the first bending plate includes a first base plate, a plurality of first inclined plates formed by bending the first base plate in sections, and a plurality of first top plates formed by bending the ends of the plurality of first inclined plates away from the first base plate. The plurality of first top plates have the same height, and adjacent two first top plates are fixedly connected to each other. The first base plate and the first top plate are arranged parallel to each other. The second bending plate includes a second base plate, a plurality of second inclined plates formed by bending the second base plate in sections, and a plurality of second top plates formed by bending the ends of the plurality of second inclined plates away from the second base plate. The plurality of second top plates have the same height, and adjacent two second top plates are fixedly connected to each other. The second base plate and the second top plates are arranged parallel to each other.

[0010] Preferably, the height between the first bottom plate and the first top plate and the height between the second bottom plate and the second top plate are equal.

[0011] Furthermore, the side of the first top plate away from the first inclined plate is fixedly connected to the side of the second top plate away from the second inclined plate.

[0012] Preferably, the angle between the first base plate and the plurality of first inclined plates is α, wherein α is 90 to 180° and each α is different; the angle between the second base plate and the plurality of second inclined plates is β, wherein β is 90 to 180° and each β is different.

[0013] Preferably, the included angle between the plurality of first inclined plates and the first top surface is γ, wherein γ is 180° to 360°; the included angle between the plurality of second inclined plates and the second top surface is δ, wherein δ is 180° to 360°.

[0014] Furthermore, the angle of each α is different from the angle of each β.

[0015] This invention also claims a method for testing the crack resistance of fire-retardant coatings using the aforementioned fire-retardant coating crack resistance testing device, comprising the following steps:

[0016] S1: Sandblast the surface of the specimen to remove surface impurities;

[0017] S2: Apply primer to the test specimen;

[0018] S3: After the primer dries, apply a fireproof coating to the surface of the specimen, then immediately place it into the test chamber for fixation, cover the chamber, and drive the motor to rotate the specimen.

[0019] S4: The test ends after the specimen is completely dry.

[0020] Preferably, in step S2, the specimen is primed within 2 to 5 hours after removing impurities from the specimen surface.

[0021] Preferably, in S3, the initial rotation speed of the specimen is 80-100 r / min, and after running for 30-40 minutes, the rotation speed is adjusted to 40-50 r / min, and the specimen is run for 2-4 hours.

[0022] Compared with the prior art, the present invention has the following beneficial effects:

[0023] The testing device of this invention, through the setting of a first bending plate and a second bending plate, can perform multi-angle internal and external corner tests on the fire-retardant coating after coating. The first motor installed on the test chamber drives the specimen to rotate. During rotation, the airflow disturbance generated can accelerate the drying of the specimen. At the same time, both the first bending plate and the second bending plate are formed by bending the bottom plate once to obtain the inclined plate, and bending the inclined plate twice to obtain the top plate. The direction of the first bending is opposite to the direction of the second bending, so that the surface of the specimen has a bent streamlined structure. At the same time, the specimen has both internal and external corners, which can be tested simultaneously. Under the action of the centrifugal force generated by the rotation of the specimen, the streamlined structure further improves the leveling of the coating on the surface of the specimen and the film thickness is uniform. This can avoid the problem of paint flowing to the corners and edges due to static drying after coating, resulting in thicker film thickness at the corners and causing coating cracking. Under the premise of ensuring uniform coating application, the accuracy of the test results of the crack resistance performance of the fire-retardant coating is improved. Attached Figure Description

[0024] Fig. 1 This is a schematic diagram of the overall structure of a fireproof coating crack resistance testing device according to the present invention;

[0025] Fig. 2 This is a schematic diagram of the specimen structure of a fire-retardant coating crack resistance testing device according to the present invention;

[0026] Fig. 3 This is a schematic diagram of the test structure of a fire-retardant coating crack resistance testing device according to the present invention.

[0027] In the diagram: 100, test chamber; 200, mounting plate; 300, test piece; 400, motor; 110, ventilation opening; 310, first bending plate; 320, second bending plate; 330, positioning plate; 340, rotating shaft; 311, first base plate; 312, first inclined plate; 313, first top plate; 321, first top plate; 322, second inclined plate; 323, second top plate. Detailed Implementation

[0028] The preferred embodiments of the present invention will be described below with reference to the accompanying drawings. It should be understood that the preferred embodiments described herein are for illustration and explanation only and are not intended to limit the present invention. Furthermore, the embodiments and features in the embodiments of the present invention can be combined with each other without conflict.

[0029] Example 1

[0030] like Figs. 1-3As shown, a fire-retardant coating crack resistance testing device includes a test chamber 100, a cover on the test chamber 100, mounting plates 200 installed on opposite side walls inside the test chamber 100, a specimen 300 rotatably connected between the two mounting plates 200, a motor 400 fixed on the side wall of the test chamber 100, the output shaft of the motor 400 extending into the test chamber 100 and fixedly connected to one end of the specimen 300, and ventilation openings 110 provided on the test chamber 100 located on both sides of the specimen 300;

[0031] The test chamber 100 is used to install the test specimen 300. The test specimen 300 is rotatably connected to the test chamber 100 via the mounting plate 300 and is driven to rotate by the motor 400. During the test, the airflow disturbance generated by the rotation of the test specimen 300 can accelerate the drying of the test specimen 300. Air is exchanged through the vents. At the same time, the centrifugal force generated during rotation further spreads the fireproof coating on the surface of the test specimen evenly after coating, ensuring that the coating film thickness of the test specimen 300 is uniform and preventing the paint from accumulating at the corners, which could cause cracking at the corners due to the thicker film thickness and affect the accuracy of the fireproof coating crack resistance test results.

[0032] The specimen 300 includes a first bending plate 310 and a second bending plate 320; the first bending plate 310 and the second bending plate 320 are fixedly connected, and positioning plates 330 are fixedly connected to both ends of the first bending plate 310 and the second bending plate 320 after being fixedly connected. A rotating shaft 340 is fixed to the side of the two positioning plates 330 that are far apart from each other. The specimen 300 is rotatably connected between the mounting plates 200 through the rotating shaft 340.

[0033] In this embodiment, the first bending plate 310 includes a first base plate 311, a plurality of first inclined plates 312 formed by bending the first base plate 311 in sections, and a plurality of first top plates 313 formed by bending the ends of the plurality of first inclined plates 312 away from the first base plate 311. The plurality of first top plates 313 have the same height, and adjacent first top plates 313 are fixedly connected to each other. The first base plate 311 and the first top plates 313 are arranged parallel to each other. The second bending plate 320 includes a second base plate 321, a plurality of second inclined plates 322 formed by bending the second base plate 321 in sections, and a plurality of second top plates 323 formed by bending the ends of the plurality of second inclined plates 322 away from the second base plate 321. The plurality of second top plates 323 have the same height, and adjacent second top plates 323 are fixedly connected to each other. The second base plate 321 and the second top plates 323 are arranged parallel to each other.

[0034] The first bending plate 310 and the second bending plate 320 are made of metal, specifically steel. The first base plate 311 of the first bending plate 310 is a horizontal plate. The first base plate 311 is half-cut into multiple strips and then bent to form multiple first inclined plates 312. The bending angle between each first inclined plate 312 and the first base plate 311 is different. The ends of the multiple first inclined plates 312 away from the first base plate 311 are bent again, with the bending direction opposite to that of the first inclined plates 312. The opposite bending direction makes the bending... The surface of the bent plate 310 is streamlined, which allows for better spraying of fire-retardant coatings. At the same time, it has better leveling performance. After bending, the multiple first top plates 313 formed are all on the same horizontal plane and parallel to the first bottom plate 311. The second bent plate 320 is formed in the same way as the first bent plate 310. Thus, the arrangement of the first and second bent plates forms multiple inside and outside corners. During the test, the cracking test results between different angles can be used to better set the required angles at the corners in practical applications.

[0035] In this embodiment, the bending directions of the first inclined plate 312 and the first top plate 313 are opposite, and the bending directions of the second inclined plate 322 and the second top plate 323 are also opposite. The height between the first bottom plate 311 and the first top plate 313 and the height between the second bottom plate 321 and the second top plate 323 are equal.

[0036] The angle formed by bending is more natural, providing better substrate conditions for testing the crack resistance performance of fireproof coatings at inside and outside corners. This better ensures the accuracy of the test results for crack resistance performance of fireproof coatings at corners and avoids the situation where the coating cracks due to poor substrate conditions.

[0037] In this embodiment, the side of the first top plate 313 away from the first inclined plate 312 is fixedly connected to the side of the second top plate 323 away from the second inclined plate 322.

[0038] In this embodiment, the angle between the first base plate 311 and the plurality of first inclined plates 312 is α, where α is 0 to 180° and each α angle is different; the angle between the second base plate 321 and the plurality of second inclined plates 322 is β, where β is 0 to 180° and each β angle is different.

[0039] In this embodiment, the included angles between the plurality of first inclined plates 312 and the first top surface 313 are all γ, where γ is 180° to 360°; the included angles between the plurality of second inclined plates 322 and the second top surface 323 are all δ, where δ is 180° to 360°.

[0040] In this embodiment, the angle of each α is different from the angle of each β.

[0041] The device is set to α and β as negative angles, and γ and δ as positive angles. The angle corresponding to each γ is equal to 360° minus the angle corresponding to α, and the angle corresponding to each δ is equal to 360° minus the angle corresponding to β. The different angle settings allow for the simultaneous measurement of multiple angles.

[0042] Example 2

[0043] A method for testing the crack resistance of a fire-retardant coating using the fire-retardant coating crack resistance testing device of Example 1 includes the following steps:

[0044] S1: Sandblast the surface of specimen 300 to remove surface impurities;

[0045] S2: Apply primer to specimen 300;

[0046] S3: After the primer dries, apply a fireproof coating to the surface of the specimen 300, then immediately place it into the test chamber 100 for fixation, cover the cover, and drive the motor 400 to rotate the specimen 300.

[0047] S4: The test ends after the specimen is completely dry.

[0048] In this embodiment, in step S2, the specimen 300 is primed within 2 to 5 hours after impurities are removed from the specimen surface. Primer application within 2-5 hours prevents flash rust from appearing on the metal specimen surface, which would affect the adhesion of the coating.

[0049] In this embodiment, in S3, the initial rotation speed of the specimen 300 is 80-100 r / min. After running for 30-40 minutes, the rotation speed is adjusted to 40-50 r / min, and the specimen runs for 2-4 hours.

[0050] When the specimen 300 is initially rotated, the relatively fast rotation speed ensures that the freshly applied fireproof coating is applied evenly. This avoids the coating from flowing to the corners and accumulating there, which could lead to excessive film thickness and cracking, affecting the accuracy of the fireproof coating crack resistance test results. During rotation, the applied coating flows to the edges or onto the test chamber 100 under the influence of centrifugal force. The film thickness at all angles of the specimen is the same as the plane, resulting in uniform film thickness. After rotating for 30–40 minutes, the coating gradually dries. The rotation speed is then reduced until the coating is completely dry.

[0051] After drying, observe and photograph the fireproof coating surface of the specimen 300, and record the crack condition of the fireproof coating surface, especially at the inside and outside corners. If there are cracks, measure the crack width and length, and judge whether the crack resistance of the fireproof coating is good based on the data.

[0052] Although the present invention has been disclosed above with reference to embodiments, it is not intended to limit the present invention. Any person skilled in the art can make some modifications or alterations to the above-disclosed technical content to create equivalent embodiments without departing from the scope of the present invention. Any simple modifications, equivalent changes and alterations made to the above embodiments based on the technical essence of the present invention without departing from the scope of the present invention shall still fall within the scope of the present invention.

Claims

1. A fire-retardant coating crack resistance testing device, comprising a test chamber (100), characterized in that: The test chamber (100) is covered with a cover. Mounting plates (200) are installed on opposite side walls inside the test chamber (100). A test specimen (300) is rotatably connected between the two mounting plates (200). A motor (400) is fixed on the side wall of the test chamber (100). The output shaft of the motor (400) extends into the test chamber (100) and is fixedly connected to one end of the test specimen (300). Ventilation openings (110) are provided on the test chamber (100) on both sides of the test specimen (300). The specimen (300) includes a first bending plate (310) and a second bending plate (320); the first bending plate (310) and the second bending plate (320) are fixedly connected, and after the first bending plate (310) and the second bending plate (320) are fixedly connected, positioning plates (330) are fixedly connected at both ends. A rotating shaft (340) is fixed on the side of the two positioning plates (330) that are far apart from each other. The specimen (300) is rotatably connected between the mounting plates (200) through the rotating shaft (340).

2. The fire-retardant coating crack resistance testing device according to claim 1, characterized in that: The first bending plate (310) includes a first base plate (311), a plurality of first inclined plates (312) formed by bending the first base plate (311) in sections, and a plurality of first top plates (313) formed by bending the ends of the plurality of first inclined plates (312) away from the first base plate (311). The plurality of first top plates (313) have the same height, and two adjacent first top plates (313) are fixedly connected to each other. The first base plate (311) and the first top plates (313) are arranged in parallel. The second bending plate (320) includes a second base plate (321), a plurality of second inclined plates (322) formed by bending the second base plate (321) in sections, and a plurality of second top plates (323) formed by bending the ends of the plurality of second inclined plates (322) away from the second base plate (321). The plurality of second top plates (323) have the same height, and two adjacent second top plates (323) are fixedly connected to each other. The second base plate (321) and the second top plates (323) are arranged in parallel.

3. The fire-retardant coating crack resistance testing device according to claim 2, characterized in that: The bending directions of the first inclined plate (312) and the first top plate (313) are opposite, and the bending directions of the second inclined plate (322) and the second top plate (323) are also opposite. The height between the first bottom plate (311) and the first top plate (313) and the height between the second bottom plate (321) and the second top plate (323) are equal.

4. The fire-retardant coating crack resistance testing device according to claim 2, characterized in that: The side of the first top plate (313) away from the first inclined plate (312) is fixedly connected to the side of the second top plate (323) away from the second inclined plate (322).

5. The fire-retardant coating crack resistance testing device according to claim 2, characterized in that: The included angle between the first base plate (311) and the plurality of first inclined plates (312) is α, wherein α is 0 to 180° and each α is different; the included angle between the second base plate (321) and the plurality of second inclined plates (322) is β, wherein β is 0 to 180° and each β is different.

6. The fire-retardant coating crack resistance testing device according to claim 5, characterized in that: The included angle between the plurality of first inclined plates (312) and the first top surface (313) is γ, wherein γ is 180 to 360°; the included angle between the plurality of second inclined plates (322) and the second top surface (323) is δ, wherein δ is 180 to 360°.

7. The fire-retardant coating crack resistance testing device according to claim 5, characterized in that: The angle of each α is different from the angle of each β.

8. A method for testing the crack resistance of a fire-retardant coating, comprising using the apparatus described in claims 1 to 7, characterized in that: Includes the following steps: S1: Sandblast the surface of the specimen (300) to remove surface impurities; S2: Apply primer to the specimen (300); S3: After the primer dries, apply a fireproof coating to the surface of the specimen (300), and then immediately place it into the test chamber (100) for fixation. Cover the chamber and drive the motor (400) to rotate the specimen (300). S4: The test ends after the specimen is completely dry.

9. The method for testing the crack resistance of a fire-retardant coating according to claim 8, characterized in that: In S2, the specimen (300) is primed within 2 to 5 hours after removing impurities from the specimen surface.

10. The method for testing the crack resistance of a fire-retardant coating according to claim 8, characterized in that: In S3, the initial rotation speed of the specimen (300) is 80-100 r / min. After running for 30-40 minutes, the rotation speed is adjusted to 40-50 r / min and run for 2-4 hours.

Images