Method for evaluating water repellency of powder

Abstract

To provide an evaluation method of water repellency of powder capable of easily evaluating the water repellency of the powder.SOLUTION: In the evaluation method of the water repellency of the powder, a solvent is put in a sample container 10, the powder is floated on the solvent, an image in the sample container 10 is acquired from above the sample container 10 at a predetermined time interval, the image is subjected to image processing to calculate a ratio of the powder not sinking in the solvent in the sample container 10 in a predetermined time, and the water repellency of the powder is evaluated by the ratio.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a method for evaluating the water repellency of a powder. [Background technology]

[0002] The test to evaluate the water repellency of fabrics is specified as the water repellency test in JIS L 1092, waterproof test method for textile products. However, the JIS does not specify a method to evaluate the water repellency of powders.

[0003] It has also been proposed to fill a column with powder that is open at the bottom, place a nylon mesh over the opening at the bottom to prevent the powder from falling, bring the bottom opening of the column into contact with a liquid, and evaluate the water repellency of the powder by measuring the rate at which the liquid penetrates the voids in the filled powder. Summary of the Invention [Problem to be solved by the invention]

[0004] The above-mentioned evaluation method of water repellency is affected by other powder properties besides the water repellency of the powder, and there is a problem in that the water repellency cannot be measured directly.

[0005] Therefore, an object of the present invention is to provide a method for evaluating the water repellency of powder, which can easily evaluate the water repellency of powder. [Means for solving the problem]

[0006] In order to solve the above-mentioned problems, the present invention is characterized in that a solvent is placed in a sample container, powder is floated in the solvent, images of the inside of the sample container are obtained from above the sample container at predetermined time intervals, and the images are processed to calculate the proportion of powder in the sample container that does not sink into the solvent over a predetermined time period, and the water repellency of the powder is evaluated based on this proportion.

[0007] Alternatively, multiple containers may be used, powders may be floated in each container, and the water repellency of multiple powders may be evaluated simultaneously. [Effects of the Invention]

[0008] According to the present invention, a solvent is placed in a sample container, powder is floated in the solvent, images of the inside of the sample container are obtained from above the sample container at predetermined time intervals, and the images are processed to calculate the proportion of powder in the sample container that does not sink into the solvent over a predetermined period of time, and the water repellency of the powder is evaluated based on this proportion, making it possible to easily evaluate the water repellency of the powder. [Brief explanation of the drawings]

[0009] [Figure 1] FIG. 1 is a front view of a measuring device for evaluating the water repellency of powder according to Example 1 of the present invention. [Figure 2] FIG. 2 is a perspective view of the components other than the operation console of FIG. 1; [Figure 3] Right side view of Figure 2. [Figure 4] Figure 2. Top view. [Figure 5] FIG. 2 is a perspective view of a state in which a sample container is attached to a sample fixing part used in an embodiment of the present invention. [Figure 6] FIG. 2 is a perspective view of a first frame used in the embodiment of the present invention. [Figure 7] FIG. 3 is a perspective view of a second frame used in the embodiment of the present invention. [Figure 8] 1 is a perspective view illustrating an image processing method according to an embodiment of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0010] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described with reference to the accompanying drawings.

[0011] FIG. 1 is a front view of a powder water repellency evaluation and measurement device 1 according to an embodiment of the present invention, FIG. 2 is a perspective view of the device 1 excluding the operation panel, FIG. 3 is a right side view of FIG. 2, and FIG. 4 is a top view of FIG. 2.

[0012] 1 to 4, the powder water repellency evaluation measuring device 1 has a measurement table 2, a first mount 3, a second mount 4, and an operation table 5. The measurement table 2, the first mount 3, and the second mount 4 are not in contact with or connected to each other, so that vibrations and the like are not transmitted between them.

[0013] As shown in Figures 1 and 2, the measurement stage 2 has a horizontally placed top plate 6, and a position adjustment member 7 is provided on top of the top plate 6. The position adjustment member 7 can fix a sample fixing part 8 thereon, and can also move the sample fixing part 8 in the horizontal direction, back and forth and left and right, to adjust its position. Four legs 9 are provided on the bottom of the top plate 6.

[0014] As shown in Fig. 5, nine sample containers 10 can be fixed to the sample fixing section 8. In this embodiment, nine sample containers 10 can be fixed, but the number of sample containers 10 may be one or more, and can be set to any number. The sample containers 10 can be formed into any shape other than that shown in the figure, as long as they are cylindrical and open at the top.

[0015] As shown in Figures 1 to 4 and 6, the first frame 3 has a pair of first support columns 11, 11 on the left and right, first front legs 12, 12 are provided on the front side of each of the first support columns 11, 11, and a first crosspiece 13 is installed between the first support column 11 and the first front leg 12. A plurality of first horizontal crosspieces 14 are installed vertically between the left and right first support columns 11, 11, and a first horizontal crosspiece 14 is installed between the left and right first front legs 12, 12.

[0016] The height of the first front leg 12 is set lower than the height of the underside of the top plate 6, so that the first front leg 12 of the first frame 3 can be installed so that it is positioned below the measurement table 2, as shown in Figures 1 to 4.

[0017] A first mounting portion 15 is provided on the upper end of each of the left and right first support columns 11, 11, and a photographing unit 16 is fixed to the first mounting portion 15. The photographing unit 16 is located above the top plate 6 and is provided in a position where it can photograph the inside of all of the sample containers 10 fixed to the sample fixing portion 8. Furthermore, the photographing unit 16 is provided in a position where the sample containers 10, the first mounting portion 15, the first support columns 11, and the first horizontal beam 14 do not interfere with each other when photographing the inside of the sample containers 10 with the photographing unit 16.

[0018] The photographing unit 16 can be any photographing equipment such as a camera or video camera as long as it can take at least a still image. In addition, any resolution can be used as long as it can identify the powder floating in the solvent.

[0019] 1 to 4 and 7, the second mount 4 has a pair of second front legs 21, 21 on the left and right, and a pair of second rear legs 22, 22 on the left and right. A plurality of second crosspieces 23, 23 are installed between the second front legs 21 and the second rear legs 22. A plurality of second horizontal crosspieces 24, 24 are installed vertically between the left and right second rear legs 22, 22.

[0020] The distance between the left and right second front legs 21, 21 is set shorter than the distance between the first front legs 12, 12 of the first mount 3, and the distance between the left and right second rear legs 22, 22 is set shorter than the distance between the first support columns 11, 11 of the first mount 3. In addition, the distance between the second front legs 21 and the second rear legs 22 is set shorter than the distance between the first support column 11 and the first front leg 12 of the first mount 3. This makes it possible to install the second mount 4 inside the first mount 3, as shown in FIGS. 1 to 3.

[0021] In addition, the heights of the second front legs 21 and the second rear legs 22 are each set lower than the height of the back surface of the tabletop 6, so that the second stand 4 can be installed so that the second front legs 21 of the second stand 4 are positioned below the measurement table 2, as shown in Figures 1 to 4.

[0022] A plurality of second crosspieces 23, 23 are installed between the second front legs 21 and the second rear legs 22. A plurality of second horizontal crosspieces 24, 24 are installed vertically between the left and right second rear legs 22, 22.

[0023] A second support 25 is fixed to the second horizontal beams 24, 24, and a light source 26 is mounted on the second support 25 so as to be rotatable about the axis of the second support 25. The light source 26 is positioned so as not to interfere with the sample container 10 when the photographing unit 16 photographs the interior of the sample container 10, and is also positioned so as to be able to illuminate the entire interior of the sample container 10. In this embodiment, the light source 26 is mounted on the underside of an annular mounting portion 27, extending along its entire periphery. A hole 28 is formed in the center of the mounting portion 27, penetrating it vertically. As shown in FIG. 4 , the entire interior of the sample container 10 can be photographed by the photographing unit 16 through the hole 28. Any light source, such as an LED, can be used as the light source 26.

[0024] A processing unit 30 such as a personal computer is installed on the operation table 5, and image data captured by the photographing unit 16 is sent to the processing unit 30 via a transmission means such as a cable or wirelessly. Furthermore, the photographing unit 16 starts photographing at predetermined intervals in response to a signal from the processing unit 30. The operation table 5 is made of a separate member from the measurement table 2, so that vibrations generated by work on the operation table 5 are not transmitted to the measurement table 2.

[0025] Next, a method for evaluating the water repellency of powder using the measuring device 1 for evaluating the water repellency of powder will be described.

[0026] First, a hydrophilic solvent such as water or an ethanol aqueous solution is filled into the sample container 10. In this embodiment, a 20 to 30 vol % ethanol aqueous solution is used. Also, the light source 26 is retracted to a position where it does not interfere with the operation.

[0027] A plurality of sample containers 10 are fixed to the sample fixing part 8, and the position adjusting member 7 is adjusted so that the photographing part 16 is at a predetermined position where the inside of all the sample containers 10 can be photographed.

[0028] Next, the powder to be measured is floated in the solvent in the sample container 10 .

[0029] Next, the light source 26 is moved to a position where the inside of all the sample containers 10 can be photographed by the photographing unit 16 through the hole 28 and the inside of all the sample containers 10 can be illuminated by the light source 26, and is turned on.

[0030] Next, in response to a signal from the processing unit 30, the photographing unit 16 starts taking images at predetermined intervals and starts counting the measurement time. The photographed image data is sent by the photographing unit 16 to the processing unit 30 each time it is taken. The photographing unit 16 takes color images.

[0031] In the processing unit 30, as shown in Fig. 8(a), a range 40 within the sample container to be subjected to image processing is specified from the captured image data. Note that Fig. 8(a) shows a monochrome image, but it is actually a color image.

[0032] Next, the processing unit 30 converts each captured image data from a color image to a black and white monochrome image as shown in Fig. 8(b). Next, as shown in Fig. 8(c), pixels with values ​​equal to or greater than a preset threshold are determined to be white, and pixels with values ​​smaller than the threshold are determined to be black.

[0033] Next, in the processing unit 30, as shown in FIG. 8(d), the number of pixels determined to be white among all pixels within the designated range in each designated sample container 10 is calculated.

[0034] The threshold value is set according to the color of the powder being measured so that if the powder is floating on the surface of the solvent, it is judged to be white, and if it is sinking in the solvent, it is judged to be black.If the powder is white, by setting it to approximately 200, it can be determined whether the powder is floating on the surface of the solvent or sinking in the solvent.

[0035] Next, for each sample container, the number of pixels judged to be white at the start of measurement is set to 100, and for each image data measured at a specified time interval, the ratio of the number of pixels judged to be white to the number of pixels judged to be white at the start is calculated.

[0036] Next, it is possible to display a graph of the change over time in the ratio of pixels determined to be white, that is, the ratio of pixels where the powder did not settle.

[0037] For example, if a large proportion of powder remains floating in the solvent for a long time, the powder can be judged to have high water repellency. On the other hand, if the powder sinks quickly into the solvent, the powder can be judged to have low water repellency. Furthermore, the water repellency of the measured sample can be evaluated based on the passage of time and the proportion of powder that does not sink, and the water repellency of samples can also be compared.

[0038] Furthermore, by changing the hydrophilicity of the solvent used, it is possible to control the ease with which the powder sinks into the solvent, making it easier to compare the differences in water repellency between different powders.

[0039] As described above, the water repellency of powders can be easily compared with that of other powders by a simple operation, and the water repellency of each powder can be evaluated. [Explanation of symbols]

[0040] 1. Apparatus for evaluating and measuring the water repellency of powders 7 Sample fixing part 10 sample containers 16 Photography Department 26 light source 30 Processing section

Claims

1. A method for evaluating the water repellency of a powder, characterized in that a solvent is placed in a sample container, a powder is floated in the solvent, images of the inside of the sample container are obtained from above the sample container at predetermined time intervals, and the images are processed to calculate the proportion of the powder in the sample container that does not sink into the solvent within the predetermined time, and the water repellency of the powder is evaluated based on this proportion.

2. 2. The method for evaluating the water repellency of powder according to claim 1, wherein a plurality of containers are used, powders are floated in each container, and the water repellency of a plurality of powders is evaluated simultaneously.

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