Coating wet film covering power testing device

Abstract

The utility model relates to a coating wet film covering power testing device, which belongs to the field of coating testing, and comprises a wet film preparation device with gradient upper and lower surfaces and a glass plate with black and white strips at intervals, the wet film preparation device is provided with grooves in the upper face and the lower face, and each face is correspondingly provided with a plurality of adjacent equal-difference gradient grooves with the same number. According to the device for testing the covering power of the coating wet film, the wet film preparation device with the gradient upper surface and the gradient lower surface is used for respectively scraping the wet film on the glass plate with the black and white strips at intervals, and the minimum wet film thickness meeting the covering power of the black and white strips is determined in the dark box, so that the corresponding covering power can be calculated, namely the minimum consumption of covering is met; the influence of local light leakage and non-uniform thickness caused by manual brushing on a test result is avoided, meanwhile, evaluation and comparison of the covering power of the coating wet film can be accurately and quickly realized, and the reproducibility of the test result is relatively higher.

Description

Technical Field

[0001] The utility model belongs to the field of coating testing, and particularly relates to a device for testing the hiding power of wet coatings. Background Art

[0002] Under the background of globalization, with the progress of technology and the deepening of the concepts of environmental protection and energy conservation, the coating industry is constantly upgrading its technology and innovating its products; at the same time, the environmental protection and energy conservation performance of coatings, such as low VOC and pollution-free environmental protection characteristics, will also become important standards for coating products. The future development trend of the coating industry will be the in-depth implementation of technological innovation, environmental protection concepts, adaptation to market changes, and policy guidance. These trends will provide new opportunities for the development of the coating industry, but also bring new challenges. The detection methods that have always accompanied the performance of coatings will also gradually be innovated and improved to keep up with the development trend of coatings.

[0003] The hiding power of a coating is one of the important indicators to measure the performance of the coating. The better the hiding power of the coating, the less coating is required to cover a certain area of the substrate under the same conditions, and the corresponding cost is lower. Thus, an accurate and reasonable hiding power testing device and testing method can not only improve the quality and performance of coatings, but also provide a scientific basis for the production and application of related industries.

[0004] Currently, the commonly used methods for evaluating hiding power are "GB / T 23981.2-2023 Paints and varnishes - Determination of hiding power - Part 2: Black and white panel method" and "GB 5211.17-1988 Comparison of contrast ratio (hiding power) of white pigments". Among them, in "GB / T 23981.2-2023 Paints and varnishes - Determination of hiding power - Part 2: Black and white panel method", manual brushing is required, and the error is relatively large; while in "GB 5211.17-1988 Comparison of contrast ratio (hiding power) of white pigments", although the hiding power is quantified, it cannot accurately reflect the actual use situation of the coating, and at the same time, it has high limitations and is only applicable to measuring dry films and cannot evaluate wet films. Summary of the Invention

[0005] The technical problem to be solved by the utility model is the high limitations, low accuracy, large human error and mismatch with actual applications in the existing hiding power determination methods. The utility model provides a device for testing the hiding power of wet coatings. By setting a wet film preparator with upper and lower two-sided gradients to scrape wet films on a glass plate with alternating black and white stripes respectively, and determining the minimum wet film thickness that satisfies the hiding power of the black and white stripes in a dark box, the corresponding hiding power, that is, the minimum consumption to meet hiding, can be calculated, avoiding the influence of local light leakage and uneven thickness caused by manual brushing on the test results. And according to the test results, the evaluation and comparison of the hiding power of wet coatings can be accurately and quickly realized, and the reproducibility of the test results is relatively higher.

[0006] To solve the above problems, the present utility model is achieved through the following technical solutions:

[0007] The present utility model provides a wet film hiding power testing device for coatings, which includes:

[0008] A wet film preparator with upper and lower surface gradients and a glass plate with alternating black and white stripes;

[0009] The wet film preparator is provided with grooves on its upper and lower surfaces, and each surface is correspondingly provided with a plurality of adjacent equal - difference gradient grooves with the same number.

[0010] The wet film preparator is used to scrape out wet film strips with different wet film thicknesses and reduce the gradient of the grooves to reduce errors; the glass plate with alternating black and white stripes is used to determine the light - transmission situation of different film thicknesses, so as to obtain the minimum wet film thickness that can avoid light.

[0011] A further optimization of the wet film hiding power testing device for coatings of the present utility model is:

[0012] The depth difference between the corresponding grooves on the upper and lower surfaces of the wet film preparator is one - half of the depth difference between adjacent grooves on the same surface.

[0013] The equal - difference gradient is set according to the expected value of the sample to be tested, that is, when the expected value is high, the gradient is large; when the expected value is small, the gradient is small.

[0014] A further optimization of the wet film hiding power testing device for coatings of the present utility model is:

[0015] The wet film preparator is made of stainless steel.

[0016] A further optimization of the wet film hiding power testing device for coatings of the present utility model is:

[0017] The glass plate with alternating black and white stripes is a black - and - white combination strip with equal spacing starting from a black stripe and with black and white stripes alternating with each other.

[0018] A further optimization of the wet film hiding power testing device for coatings of the present utility model is:

[0019] Both the black stripes and the white stripes are made of light - impermeable polyurethane material.

[0020] A further optimization of the wet film hiding power testing device for coatings of the present utility model is:

[0021] Using a reflectometer or spectrophotometer that complies with the provisions of 5.1.4 in "GB / T 23981.1.1 - 2019 Determination of Hiding Power of Paints and Varnishes", adopting D 65 light source, optical structure d / 8, and measuring the tristimulus value Y without including specularly reflected light:

[0022] The test value of the white strip is 80±2;

[0023] The test value of the black strip is not greater than 3.

[0024] A further optimization of the wet film hiding power test device of the present utility model is as follows:

[0025] The glass plate is 22 cm long and 20 cm wide; both the black and white strips are 22 cm long and 2 cm wide;

[0026] The width of the groove is 20 mm;

[0027] The distance between two adjacent grooves is 5 mm.

[0028] A further optimization of the wet film hiding power test device of the present utility model is as follows:

[0029] The black and white combined strips on the glass plate with black and white strips alternating are set to 4 groups, that is, alternately combined in the order of 4 black and 4 white.

[0030] The following is a test method for the wet film hiding power of a coating using the wet film hiding power test device of the present utility model. Through the wet film preparator and the glass plate with black and white strips alternating described above, the upper gradient and the lower gradient of the wet film preparator are respectively determined to obtain the accurate minimum film thickness; then the minimum consumption of the coating wet film to meet hiding is respectively calculated; when the calculation results of the upper gradient and the lower gradient are the same, it is accurate to an integer, that is, the hiding power of the coating is determined.

[0031] A test method for the wet film hiding power of a coating using the wet film hiding power test device of the present utility model includes the following test steps:

[0032] S1. The glass plate with black and white strips alternating is placed horizontally;

[0033] S2. Place the wet film preparator at the top of the glass plate described in step S1, and align its lower side with the upper edge of the first black strip on the glass plate described in step S1;

[0034] S3. Pour sufficient amount of the prepared test coating to the edges of each groove on the wet film preparator; then smoothly and straightly scrape the wet film preparator from the top to the bottom of the glass plate without pause, and this operation needs to be completed within 2 - 3 seconds;

[0035] S4. Quickly place the glass plate described in step S3 inside the test dark box, at a distance of 15 - 20 cm from the frosted glass sheet inside the test dark box, with the end having black and white stripes inclined at an angle of 30 - 45 degrees to the plane. Determine and record the minimum film thickness when the test coating completely covers the black and white stripes simultaneously under 1 and 2 fluorescent lamps respectively. This operation should be completed within 10 s;

[0036] The described test dark box is the dark box described in "GB / T 23981.2 - 2023 Paints and varnishes - Determination of hiding power - Part 2: Black - and - white panel method";

[0037] S5. Select a suitable medium to clean the wet - film applicator, and then use the other side of the wet - film applicator to repeat the operations of steps S3 and S4, and record the corresponding minimum film thickness;

[0038] S6. Hiding - power calculation method and precision:

[0039] The hiding power is calculated according to the following formula:

[0040] X = h×ρ

[0041] Where:

[0042] X - - Hiding power, based on the wet paint film, g / ㎡;

[0043] h - - The minimum film thickness obtained from the test, m;

[0044] ρ - - Specimen density, g / ml;

[0045] When the calculation results of the two tests in steps S4 and S5 are the same, round to an integer to determine the hiding power of the coating; if the calculation results of the two tests are different, then conduct the test again.

[0046] The wet - film hiding - power test device provided by the present utility model takes into account some characteristics of the wet paint film state (such as being easily damaged, wetting state, etc.) and some human factors (such as brushing error, etc.), and specially provides a wet - film applicator with upper and lower surface gradients. By using it in combination with a glass plate with black and white stripes alternating, it can reduce the influence of local light leakage and uneven thickness that may be caused by manual brushing on the test results. In addition, by combining the corresponding hiding - power calculation method and precision setting, it can accurately and quickly evaluate and compare the hiding power of the wet paint film, and the reproducibility of the test results is relatively higher. Brief Description of the Drawings

[0047] Figure 1 It is a schematic structural diagram of the wet - film applicator with upper and lower surface gradients in the present utility model;

[0048] Figure 2This is a schematic structural diagram of the glass plate with alternating black and white stripes in the present utility model.

[0049] Reference numerals:

[0050] 1 - Wet film preparator; 2 - Groove; 3 - Glass plate

[0051] 4 - Black stripe; 5 - White stripe Detailed implementation manners

[0052] In order to make the application, technical solutions and advantages of the present utility model clearer and more understandable, the content of the present utility model will be described in detail in combination with specific embodiments. It should be understood that the embodiments are only used to illustrate the present utility model, rather than limiting the protection scope of the present utility model. Any simple improvement to the preparation method of the present utility model under the premise of the concept of the present utility model belongs to the protection scope of the present utility model.

[0053] Embodiment 1:

[0054] A coating wet film hiding power test device, which includes: a wet film preparator 1 with upper and lower two-sided gradients and a glass plate 3 with alternating black and white stripes;

[0055] The wet film preparator 1 is provided with grooves 2 on its upper and lower two sides, and the same number of a plurality of adjacent equidistant gradient grooves 2 are correspondingly arranged on each side.

[0056] The depth difference between the grooves 2 corresponding to the upper and lower two sides of the wet film preparator 1 is one-half of the depth difference between the adjacent grooves 2 on the same side.

[0057] The wet film preparator 1 is made of stainless steel.

[0058] The glass plate 3 with alternating black and white stripes is an equidistant black and white combined stripe starting with a black stripe 4 and with black and white stripes alternating with each other.

[0059] Both the black stripe 4 and the white stripe 5 are made of opaque polyurethane material.

[0060] Using a reflectometer or spectrophotometer that complies with the provisions of 5.1.4 in "GB / T 23981.1.1 - 2019 Determination of Hiding Power of Paints and Varnishes", adopting D 65 light source, optical structure d / 8, and measuring the tristimulus value Y without including specularly reflected light:

[0061] The test value of the white stripe 5 is 80 ± 2;

[0062] The test value of the black stripe 4 is not greater than 3.

[0063] The glass plate 3 is 22 cm long and 20 cm wide; both the black and white stripes are 22 cm long and 2 cm wide;

[0064] The width of the groove 2 is 20 mm;

[0065] The spacing between two adjacent grooves 2 is 5 mm.

[0066] The black and white combined stripes on the glass plate 3 with black and white stripes are set to 4 groups, that is, they are alternately combined in the order of 4 black and 4 white.

[0067] In this Example 1, the sample 1 used is the Nippon solvent-free epoxy wear-resistant floor topcoat NF EP915 medium gray. The product's specified hiding power requirement is ≤ 250 g / ㎡. The components of the sample are proportioned according to the usage ratio provided in the product instruction manual, and are mixed and stirred evenly according to the agreed pre-shearing procedure (stirring speed and stirring time). The density of the mixed paint is measured to be 1.62 g / ml.

[0068] The test method for the wet film hiding power of the paint in this Example 1 includes the following test steps:

[0069] S1. The glass plate 3 with black and white stripes is placed horizontally (see Figure 2 the placement direction);

[0070] S2. Select a wet film applicator 1 with a gradient interval of 10 μm in the ranges of 100 - 170 μm and 105 - 175 μm. Place the side of the wet film applicator 1 with the range of 100 - 170 μm at the top of the glass plate 3 described in step S1, and align its lower side with the upper edge of the first black stripe 4 on the glass plate 3 described in step S1;

[0071] S3. Pour a sufficient amount (ensuring that each scraped wet film stripe can be scraped for at least 16 cm) of the prepared test paint to the edge of each groove 2 on the wet film applicator 1; then scrape the wet film applicator 1 smoothly, straight, and without pause from the top to the bottom of the glass plate 3, and this operation needs to be completed within 2 - 3 seconds;

[0072] S4. Quickly place the glass plate 3 described in step S3 in the test dark box, 15 - 20 cm away from the frosted glass sheet in the test dark box, and make the end with both black and white stripes form an included angle of 30 - 45 degrees with the plane. Determine and record the minimum film thickness when the test paint completely covers the black stripe 4 and the white stripe 5 simultaneously under 1 and 2 fluorescent lamps respectively, and this operation is completed within 10 s;

[0073] The test dark box is the dark box described in "GB / T 23981.2 - 2023 Paints and varnishes - Determination of hiding power - Part 2: Black - and - white panel method";

[0074] S5. Select a suitable medium to clean the wet film applicator 1, and then repeat the operations of steps S3 and S4 on the other side of the wet film applicator 1 with an interval of 105 - 175 μm, and record the corresponding minimum film thickness;

[0075] S6. Hiding power calculation method and accuracy:

[0076] The hiding power is calculated according to the following formula:

[0077] X = h × ρ

[0078] In the formula:

[0079] X - Hiding power, calculated based on the wet paint film, g / ㎡;

[0080] h - The minimum film thickness obtained from the test, m;

[0081] ρ - Density of the sample, g / ml;

[0082] When the calculation results of the two tests in step S4 and step S5 are the same, round to an integer, that is, determine the hiding power of the paint; if the calculation results of the two tests are different, then retest.

[0083] Example 2

[0084] The difference between Example 2 and Example 1 is that:

[0085] In this Example 2, the sample 2 used is Shishili high - flash alkyd paint black, and the specified hiding power requirement of the product is ≤ 45 g / ㎡, and the standard density is 1.22 g / ml; select a wet film applicator 1 with intervals of 26 - 40 μm, 25 - 39 μm, and a gradient interval of 2 μm. Stir the sample evenly, and the measured density of the paint is 1.24 g / ml.

[0086] For Comparative Examples 1 and 2, the hiding power of samples 1 and 2 in Examples 1 and 2 was tested twice using "GB / T 23981.2 - 2023 Paints and varnishes - Determination of hiding power - Part 2: Black - and - white panel method". The hiding power test results of the examples and comparative examples are shown in Table 1.

[0087] Table 1 Hiding power test results of examples and comparative examples

[0088]

[0089] Through the hiding power test results in Table 1, compared with the existing measurement methods, the wet film hiding power test device and its test method of the paint of the present invention have more accurate and objective test results, overcoming the problems of large errors, low accuracy, and long time consumption of the existing test methods; at the same time, it can adopt a quantitative method and can more quickly realize the evaluation of the wet film hiding power of the paint.

[0090] In summary, the above are only the preferred embodiments of the present utility model and do not impose any limitations on the present utility model in any way; any equivalent changes, modifications, and evolutions made by those skilled in the art within the scope of the technical solution of the present utility model by using the disclosed technical content are regarded as equivalent embodiments of the present utility model; at the same time, any equivalent changes, modifications, and evolutions made to the above embodiments according to the essential technology of the present utility model still fall within the protection scope of the technical solution of the present utility model.

[0091] In the technical solution of the present utility model, the descriptions of positions involved, such as up, down, upward, downward, etc., are only for clearly describing the corresponding structural connection methods and do not serve as the limitation of the specific actual positions of the present technical solution. In the case of the same or similar structures, connection methods, and principles, they still fall within the protection scope of the technical solution of the present utility model.

[0092] The technical features of the above-described embodiments can be combined arbitrarily. For the sake of brevity of description, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, it should be considered as within the scope described in this specification.

[0093] For the various optimized technical solutions in the present utility model, unless otherwise stated, the various optimized technical solutions can be combined with each other.

[0094] Unless otherwise defined, all professional and scientific terms used herein have the same meaning as those familiar to those skilled in the art. In addition, any methods and materials similar or equivalent to the described content can be applied to the present technical solution.

Claims

1. A wet film hiding power testing device for coatings, characterized in that: It includes a wet film preparator with upper and lower two-sided gradients and a glass plate with alternating black and white stripes; The wet film preparator is provided with grooves on its upper and lower two sides, and each side is correspondingly provided with a plurality of adjacent arithmetic gradient grooves with the same number.

2. The wet film hiding power testing device for coatings according to claim 1, characterized in that: The depth difference between the corresponding grooves on the upper and lower two sides of the wet film preparator is one-half of the depth difference between adjacent grooves on the same side.

3. The wet film hiding power testing device for coatings according to claim 1, characterized in that: The wet film preparator is made of stainless steel.

4. The wet film hiding power testing device for coatings according to claim 1, characterized in that: The glass plate with alternating black and white stripes is a black and white combined stripe with equal spacing starting from a black stripe and alternating black and white stripes.

5. The wet film hiding power testing device for coatings according to claim 1, characterized in that: Both the black stripes and the white stripes on the glass plate with alternating black and white stripes are made of light-impermeable polyurethane material.

6. The wet film hiding power testing device for coatings according to claim 5, characterized in that: Using a reflectometer or spectrophotometer that complies with the provisions of 5.1.4 in "GB / T 23981.1.1-2019 Determination of hiding power of paints and varnishes", and adopting D 65 light source, optical structure d / 8, and measuring the tristimulus value Y without including specularly reflected light: The test value of the white stripe is 80 ± 2; The test value of the black stripe is not greater than 3.

7. The wet film hiding power testing device for coatings according to claim 1, characterized in that: The glass plate is 22 cm long and 20 cm wide; both the black and white stripes are 22 cm long and 2 cm wide; The width of the groove is 20 mm; The spacing between two adjacent grooves is 5 mm.

8. The wet film hiding power testing device for coatings according to claim 4, characterized in that: The black and white combined stripes on the glass plate with alternating black and white stripes are set in 4 groups, that is, alternately combined in the order of 4 black and 4 white.

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