JP7385201B2 - Interfiber void measuring device, interfiber void measuring method and program - Google Patents

Description

The present invention relates to an apparatus for measuring interfiber voids in a fiber material or a fiber composite material, a method for measuring interfiber voids, and a program.

Conventionally, with respect to fibrous materials such as nonwoven fabrics, a method of determining the average inter-fiber distance of each fiber of a fiber group constituting the fibrous material is known.

For example, Patent Document 1 discloses a method of determining the thickness average interfiber distance of a nonwoven fabric to be measured using a formula based on Wrotnowski's assumption using a measured value of the thickness of the nonwoven fabric. According to the formula based on Wrotnowski's assumption, the distance between fibers A (μm), the thickness h (mm) of the nonwoven fabric, the basis weight e (g/m2), the fiber diameter d (μm) of the fibers constituting the nonwoven fabric, and the fiber density Based on ρ (g/cm3), the thickness average interfiber distance of the nonwoven fabric is determined.

Moreover, Patent Document 2 discloses a method of calculating the average inter-fiber distance of a specific layer of a wet sheet having a three-layer structure.

The above-mentioned Patent Documents 1 and 2 are both methods of determining the average inter-fiber distance on the premise that each fiber of a fiber group constituting a fiber material is in an ideal state in which they are arranged at equal intervals.

Japanese Patent Application Publication No. 2020-048719 Japanese Patent Application Publication No. 2006-223454

In Patent Documents 1 and 2, the average inter-fiber distance is calculated on the premise that the fibers of the fiber group constituting the fiber material are equally spaced, that is, the distance between each fiber is in an ideal state with no variation. Therefore, when there is a large variation in the inter-fiber distance, the average inter-fiber distance calculated by the techniques described in Patent Documents 1 and 2 may deviate greatly from the actual average inter-fiber distance.

Furthermore, the techniques described in Patent Documents 1 and 2 do not take into account the paths of the gaps between fibers (gap paths), especially the gap paths when there are variations in the distance between fibers. Therefore, it is difficult to evaluate characteristics related to sound passing through fiber materials, air flow, resin flow penetrating between fibers in fiber composite materials, and the like.

An object of the present invention is to provide an interfiber void measuring device, an interfiber void measuring method, and a program that can more accurately calculate the characteristics of interfiber voids regarding fiber groups constituting fiber materials and fiber composite materials. do.

In order to achieve the above object, an interfiber void measuring device according to a first aspect of the present invention includes:
three-dimensional image generation means for generating a three-dimensional image of the fiber base material;
Fiber information acquisition means for acquiring coordinate information of each point constituting the void and the distance of each point from each fiber with respect to the void between the fibers of the fiber group included in the fiber base material, based on the three-dimensional image; and,
With respect to the measurement target area of the three-dimensional image, one of the area end faces is set as the end face, a face outside the measurement target area that is in contact with the area end face on the opposite side of the end face is set as the start face, and each point on the start face is set as the start face. In a routine that generates a gap path by sequentially selecting next layer points of interest from a search area in the vicinity of a point adjacent to the point of interest of the layer on the end surface side, each of the points of interest of the next layer is set as a point of interest of the next layer. a gap path generation means for selecting a point having the largest distance from the fiber;
A value twice the maximum value of the distance from each fiber to each point of the gap path generated by the gap path generation means is calculated as the gap diameter, and the average value of the gap diameter for each gap path is calculated as the average gap. A void diameter calculation means for calculating the diameter.

Further, the gap path generating means includes:
If there are multiple points in the search area that have the greatest distance from each fiber, a point that is closer to the opposite point that is opposite to the previous layer point of interest, which is the point of interest immediately before the point of interest, across the point of interest. is selected as the next layer focus point,
It may also be a thing.

In addition, the interfiber void measuring device is
ideal pore diameter calculation means for calculating the pore diameter in an ideal state in which each fiber of the fiber group included in the fiber base material is arranged at equal intervals;
a deviation calculation means for calculating the deviation of the average pore diameter from the ideal pore diameter;
It may also be a thing.

In addition, the interfiber void measuring device is
comprising an inter-fiber distance calculation means for calculating, as an inter-fiber distance, a value twice the minimum value of the distance from each fiber to each point of the air-gap path generated by the air-gap path generation means;
It may also be a thing.

In addition, the interfiber void measuring device is
comprising detour degree calculation means for calculating a value obtained by dividing the length of the gap path by the distance between the start surface and the end surface as the detour degree;
It may also be a thing.

Furthermore, in the method for measuring interfiber voids according to the second aspect of the present invention,
Generates a three-dimensional image of the fiber base material,
Based on the three-dimensional image, obtain coordinate information of each point constituting the void with respect to the void outside the fibers of the fiber group included in the fiber base material and the distance of each point from the fiber,
With respect to the measurement target area of the three-dimensional image, one of the area end faces is set as the end face, a face outside the measurement target area that is in contact with the area end face on the opposite side of the end face is set as the start face, and each point on the start face is set as the start face. In a routine that generates a gap path by sequentially selecting next layer points of interest from a search area in the vicinity of a point adjacent to the point of interest of the layer on the end surface side, each of the points of interest of the next layer is set as a point of interest of the next layer. Select the point with the greatest distance from the fiber,
A value twice the maximum distance of each point of the gap path from each fiber is calculated as the gap diameter, and an average value of the gap diameters for each gap path is calculated as the average gap diameter.

Further, the program according to the third aspect of the present invention is
a) generating a three-dimensional image of the fiber substrate;
b) obtaining coordinate information of each point constituting the void and the distance of each point from each fiber with respect to voids outside the fibers of the fiber group included in the fiber base material, based on the three-dimensional image; ,
c) With respect to the measurement target area of the three-dimensional image, one of the end faces of the area is set as the end face, a face outside the measurement target area that is in contact with the end face of the area opposite to the end face is set as the start face, and each point on the start face is set as the end face. is sequentially set as a point of interest, and in a routine that generates a gap path by sequentially selecting the next layer point of interest from the search area near the point adjacent to the point of interest on the layer on the end surface side, as the next layer point of interest. selecting a point having the greatest distance from each fiber;
d) Calculate a value twice the maximum value of the distance from each fiber of each point of the void path generated in step c) as the void diameter, and average the average value of the void diameter for each void path. a step of calculating as a void diameter;
have the computer execute it.

According to the present invention, a start plane and an end plane are set with respect to a measurement target area of a three-dimensional image, each point of the start plane is sequentially set as a point of interest, and a point adjacent to the point of interest of a layer on the end plane side is set. In a routine that generates a gap path by sequentially selecting points of interest in the next layer from a search area in the vicinity of , the point having the largest distance from each fiber is selected as the point of interest in the next layer. Further, a value twice the maximum distance of each point of the generated gap path from each fiber is calculated as the gap diameter, and an average value of the gap diameters for each gap path is calculated as the average gap diameter. Therefore, it is possible to calculate more accurate characteristics of the inter-fiber voids by taking into consideration the inter-fiber void paths.

FIG. 1 is a functional block diagram showing an interfiber gap measuring device according to an embodiment of the present invention. It is a flowchart which shows interfiber space|gap calculation processing (main routine) by a computer program. 3 is a flowchart showing a gap path generation process (subroutine) corresponding to step S4 in FIG. 2. FIG. FIG. 2 is a diagram schematically showing fiber groups included in a three-dimensional image on two-dimensional coordinates. FIG. 2 is a schematic diagram for explaining fiber groups and voids in an analysis target area. FIG. 2 is a schematic diagram for explaining a point of interest, a next-layer point of interest, and a search area, in which (A) is a diagram including a starting surface and an end surface, (B) is a diagram including a next-layer focal point that is an opposing point; C) is a diagram including a plurality of next-layer points of interest. FIG. 3 is a diagram showing an example of a gap path according to an embodiment. 8 is a graph showing the distance between each point of the gap path in FIG. 7 and the fiber.

An interfiber void measuring device according to an embodiment of the present invention will be described with reference to the drawings. Below, as an example of the interfiber void measuring device according to the present invention, an interfiber void measuring device 1 shown in FIG. 1 will be illustrated.

The interfiber void measuring device 1 is composed of a volatile storage device 5 consisting of a CPU (Central Processing Unit) 3, a RAM (Random Access Memory), etc., a ROM (Read Only Memory), an SSD (Solid State Drive), etc. A non-volatile storage device 7 is provided.

The nonvolatile storage device 7 has installed therein a computer program PG for executing interfiber gap calculation processing, which will be described in detail later. The computer program PG includes modules such as a three-dimensional image generation program PG1 and a fiber information acquisition program PG2.

Note that the three-dimensional image generation program PG1 and the fiber information acquisition program PG2 will be described in detail later.

Furthermore, the nonvolatile storage device 7 stores CT image data DT regarding a tomographic image (CT image) obtained by performing computed tomography (CT) imaging of a fiber base material.

Next, with reference to the flowcharts of FIGS. 2 and 3, the inter-fiber void calculation process performed by the computer program PG will be described in detail.

First, in step S1, the interfiber gap measuring device 1 executes the three-dimensional image generation program PG1 and generates a three-dimensional image TD by performing volume rendering on the CT image data DT.

Note that in this embodiment, ExFact (registered trademark) VR provided by Japan Visual Science Co., Ltd. is used as the three-dimensional image generation program PG1.

As shown in FIG. 4, the interfiber void measuring device 1 measures the fiber group FB included in the fiber base material and the void VD formed between each fiber of the fiber group FB by binarizing a three-dimensional image. identify.

As shown in FIG. 5, an arbitrary fiber FB _i (i is an arbitrary integer from 1 to n) and a void VD are expressed by a set of a plurality of voxels using the voxel method. Although the fibers FB _i and the voids VD are shown in two-dimensional coordinates in FIG. 5 to simplify the explanation, they are actually a collection of voxels (three-dimensional coordinates).

The numerical values (1, 2, 3, 4, 5, 6) written in each voxel constituting any void VD indicate how many voxels are away from the fiber group FB (portion other than the void VD). It is. "1" is written in the outermost voxel of the void region that is in contact with any fiber FB _i of the fiber group FB, "2" is written in the voxel one voxel inside the outermost voxel, and “3” is written in the voxel.

In step S2 of FIG. 2, the interfiber gap measuring device 1 executes the fiber information acquisition program PG2, and, regarding the interfiber gap VD, coordinate information of each point constituting the gap VD and the distance of each point from each fiber. get.

As described above, the numerical value written in each voxel indicates how many voxels are separated from each fiber FB _i . In other words, it can be said that the maximum value of the numerical value described in each voxel of the air gap VD of any air gap path indicates the approximate radius of the air gap between the fibers FB _i in the air gap path, and the sound passing through the air gap path, This is a characteristic value that affects the flow of fluids such as air and resin (for example, the ease of microscopic convection of air).

In addition, the value twice the minimum value of the numerical value written in each voxel of the air gap VD of any air gap path can be said to indicate the approximate distance between fibers in the air gap path, and the sound, air, etc. passing through the air gap path, This is a characteristic value that affects the flow (for example, the difficulty of flowing) of a fluid such as resin.

In step S3 of FIG. 2, the interfiber gap measuring device 1 sets a measurement target area TA from the three-dimensional image TD (FIG. 5). The measurement target area TA is a three-dimensional spatial model with an arbitrary number of voxels, and is preferably a cubic or rectangular parallelepiped area to facilitate characteristic evaluation in each axis direction such as the thickness direction and width direction of the fiber material. .

Next, in step S4 in FIG. 2, the interfiber gap measuring device 1 executes a gap path generation process (flowchart in FIG. 3).

First, in step S41 in FIG. 3, the interfiber gap measuring device 1 sets a start surface SS and an end surface FS for the measurement target area TA. More specifically, as shown simply in two dimensions in FIG. This area end surface is set as the end surface FS, and a surface outside the measurement target area TA that is in contact with the area end surface on the opposite side to the end surface FS is set as the start surface SS.

In step S42, the interfiber void measuring device 1 sequentially sets points (voxels) on the starting surface SS as starting points SP _j of the void path VP _j (j=1 to k, k is the number of voxels on the starting surface SS). . The processing of steps S42 to S48 (loop 1) is repeated until all of the points on the starting surface SS are set to the starting point SP _j .

In step S43, the interfiber gap measuring device 1 converts the set starting point SP _j to a point of interest FP _n (n=1 to m, where m is the number of layers from the starting surface SS to the layer immediately before the ending surface FS. ), the next layer point of interest FP _n+1 , which is the next point of the gap path VP _j , is selected.

The interfiber gap measuring device 1 sets a point near a point (voxel) adjacent to the point of interest FP _n as a search area SA in the layer (next layer) on the end surface FS side that is in contact with the start surface SS (step S44 ). In this embodiment, the next layer point of interest FP _{n +1 is selected using the 3×3 voxel range around the next layer point (voxel) adjacent to the point of interest FP n} as the search area SA.

The interfiber gap measuring device 1 selects the point having the largest distance from each fiber in the search area SA as the next layer point of interest FP _n+1 (step S45).

As shown in FIG. 6(B), when there are multiple points in the search area SA that are farthest from the fibers (voxels marked 3 in the figure), the interfiber gap measuring device 1 detects the points that are in contact with the starting surface SS side. To the immediately previous point of interest (previous layer point of interest FP _{n- 1) existing in the corresponding area CA (3 x 3 voxels) corresponding to the search area SA in the vicinity of the point adjacent to the point of interest FP n} of the layer (previous layer) Based on this, the next layer focus point FP _n+1 is determined. Specifically, the interfiber gap measuring device 1 selects, as the next layer point of interest FP _n +1, a point that is closer to the opposing point OP, which is opposite to the previous layer point of interest FP _{n−1 ,} across the point of interest FP n. Thereby, for example, it is possible to generate a void path VP _j that takes into account the flow of air when air passes through the fiber material.

As shown in FIG. 6(C), if there are multiple points in the search area SA that are farthest from each fiber and closest to the opposing point OP, one of the points may be selected; The gap path VP _j may be divided into gap paths VP-1 _j , VP-2 _j , etc.

Note that when the point of interest FP _n is a point on the starting surface SS, there is no previous layer closer to the starting surface SS. In this case, if there are multiple points farthest from the fiber within the search area SA, a predetermined point, such as preferentially selecting a point that is in contact with the point of interest FP _n as the next layer point of interest FP _n+1. The next layer focus point FP _n+1 may be selected according to the priority order.

In step S46, the interfiber void measuring device 1 adds the selected next layer point of interest FP _n+1 as a point constituting the void path VP _j , and stores the coordinate information in the nonvolatile storage means. Furthermore, the interfiber gap measuring device 1 stores the distance between the next layer point of interest FP _n+1 constituting the gap path VP _j and the nearest fiber FB _i . The distance between the next layer point of interest FP _n+1 and the fiber FB _i is calculated using the gap information acquired in step S2 of FIG.

The processing in steps S43 to S47 (loop 2) updates the next layer point of interest FP n+1 as a new point of interest FP _n until the next layer point of interest FP _{n +1} selected in step S45 becomes a point on the end surface FS. increment n) and repeat.

The interfiber void measuring device 1 repeatedly executes the above-described process until the end conditions of loop 1 (steps S42 to S48) and loop 2 (steps S43 to S47) are satisfied.

In step S5 of FIG. 2, the interfiber void measuring device 1 calculates each point constituting the void path VP _j for each void path VP _j calculated in the above-described void path generation process (step S4, flowchart of FIG. 3). The maximum value of the distance between the fiber FB _i and the latest fiber FB i is calculated as the void radius, and the value twice the void radius is calculated as the void diameter (void diameter). Furthermore, the interfiber void measuring device 1 calculates the average value of the void diameters for each computed void path VP _j as the actual average void diameter (A).

FIG. 7 is a diagram showing an example of the gap path VP _j generated by the gap path generation process described above. In this example, the distance between adjacent voxels is set to 1. As shown in FIG. 7, in this gap path VP _j , gap paths VP-1 _j to VP-4 _j that are branched in the middle are generated. Further, FIG. 8 is a graph showing the distance between each point of the void paths VP-1 _j to VP-4 _j and the fiber FB _i . For example, the maximum values in the gap path VP-1 _j are two maximum values, maximum value 1 (=5) and maximum value 2 (=4), as shown in FIG. Therefore, the pore diameter is 10, which is twice the maximum value 1 (=5) (it may be set to 9.5 by subtracting the adjustment value of 0.5 from 10), and twice the maximum value 2 (=4). 8 (or 7.5 by subtracting the adjustment value of 0.5 from 8). Further, the average void diameter of each void path VP _j calculated in this manner is the average void diameter.

Further, in step S6, the interfiber void measuring device 1 calculates the ideal void diameter (B), which is the average void diameter in an ideal state. The ideal state is a state in which the fiber groups included in the three-dimensional image TD are assumed to be arranged at equal intervals, and the ideal void diameter is the maximum void diameter in the ideal state assuming that the voids are spherical. It is.

In this embodiment, when it is assumed that the fiber groups included in the three-dimensional image TD have the same fiber diameter, df in an ideal state calculated by the following formula is defined as the ideal void diameter. For example, by substituting the fiber diameter d=2 μm (micrometers) and the void ratio φ=0.92 into the following equation, the ideal void diameter df=6.862 μm is obtained.

Then, in step S7, the interfiber void measuring device 1 divides the average void diameter (A) calculated in step S5 by the ideal void diameter (B) calculated in step S6, and calculates the ideal void diameter by dividing (A÷B). The degree of deviation of the actual average pore diameter (A) from (B) is calculated (the degree of pore diameter deviation).

Here, if the fiber groups included in the three-dimensional image TD are arranged at equal intervals, the actual average pore diameter (A) and the ideal pore diameter (B) will be equal (A = B), and the degree of deviation will be It becomes "1" (the state with the best fiber distribution).

On the other hand, if all the fibers of the fiber group included in the three-dimensional image TD are in contact with each other, the size of the void portion other than the fibers representing the actual average void diameter (A) is the average void diameter in the ideal state. Therefore, the degree of deviation (A÷B) between the actual average pore diameter (A) and the ideal pore diameter (B) is greater than 1 (fiber distribution is poor).

In other words, the degree of deviation is expressed as a value of 1 or more, and the closer it gets to 1, the better the fiber distribution becomes (closer to the ideal state), while the further away from 1, the worse the fiber distribution becomes (closer to the ideal state). Leave).

In addition, in step S8, the interfiber gap measuring device 1 calculates, for each gap path VP _j , a value that is twice the minimum value of the distance between each point constituting the gap path VP _j and the most recent fiber FB _i . Calculate as distance. Furthermore, the interfiber gap measuring device 1 calculates the average value of the interfiber distances for each calculated gap path VP _j as the average interfiber distance.

Specifically, in the case of the void path VP-1 _j in the example shown in FIGS. 7 and 8, the minimum value of the distance between each point of the void path VP-1 _j and the fiber FB _i is the minimum value 1 (=2 ), minimum value 2 (=2), and minimum value 3 (=2). Therefore, the three calculated interfiber distances are 4, which is twice the minimum value 1 to 3 (=2) (or 3.5 by subtracting the adjustment value of 0.5 from 4). Further, the average inter-fiber distance of each void path VP _j calculated in this manner becomes the average inter-fiber distance.

In addition, in step S9, the interfiber void measuring device 1 calculates the length of each void path VP _j , that is, the distance connecting each point constituting the void path VP _j , by calculating the distance between the starting surface SS and the ending surface FS. The value divided by is calculated as the detour degree. Furthermore, the interfiber gap measuring device 1 calculates the average value of the degree of detour for each gap path VP _j as the average degree of detour.

Specifically, in the case of the gap path VP-1 _j in the example shown in FIG. 7, the length of the gap path VP-1 _j is 22.9. Further, the distance between the start surface SS and the end surface FS is 20. Therefore, the degree of detour in this case is 1.145 (22.9÷20). Further, the average detour degree of each gap path VP _j calculated in this manner is the average detour degree.

As explained above, according to the present embodiment, in loop 1 (steps S42 to _S48 ) in _FIG . be done. In addition, in loop 2 (steps S43 to S47) in FIG. 3, the next layer point of interest FP _n+1 is sequentially selected from the search area SA near the point adjacent to the point of interest FP _n of the layer on the end surface FS side, and the gap path is Generate VP _j .

In loops 1 and 2 described above, among the points in the search area SA, the point farthest from each fiber is selected as the next layer point of interest FP _n+1 . Then, the next layer points of interest FP _n+1 are sequentially calculated until the next layer points of interest FP _n+1 reach the end surface FS, and are stored as points constituting the gap path VP _j .

Furthermore, the inter-fiber void measuring device 1 calculates each point constituting the void path VP _j and the latest fiber FB for each void path VP _j generated in the above-described void path generation process (step S4, flowchart of FIG. 3). A value twice the maximum value of the distance to _i is calculated as the void diameter. Furthermore, the interfiber void measuring device 1 calculates the average value of the void diameters for each computed void path VP _j as the actual average void diameter (A). Furthermore, the interfiber void measuring device 1 calculates the degree of deviation between the ideal void diameter (B), which is the average void diameter in an ideal state, and the actual average void diameter (A).

In addition, in step S8, the interfiber gap measuring device 1 calculates, for each gap path VP _j , a value that is twice the minimum value of the distance between each point constituting the gap path VP _j and the most recent fiber FB _i . Calculate as distance. Furthermore, the interfiber gap measuring device 1 calculates the average value of the interfiber distances for each calculated gap path VP _j as the average interfiber distance.

In addition, in step S9, the interfiber void measuring device 1 calculates the length of each void path VP _j , that is, the distance connecting each point constituting the void path VP _j , by calculating the distance between the starting surface SS and the ending surface FS. The value divided by is calculated as the detour degree. Furthermore, the interfiber gap measuring device 1 calculates the average value of the degree of detour for each gap path VP _j as the average degree of detour.

Therefore, it is possible to more accurately calculate the characteristics of the interfiber voids regarding the fiber groups constituting the fiber material and the fiber composite material. In particular, when the fibers of the fiber group are in close contact with each other, the inter-fiber distance, which represents the characteristics of the inter-fiber voids and is calculated on the premise of an ideal state, deviates greatly from the actual average inter-fiber distance. Even in such cases, the characteristics of the interfiber voids such as the average void diameter, average interfiber distance, and average detour degree can be calculated accurately by using the method described above. It is possible to perform performance evaluation with high accuracy.

Furthermore, since it is possible to calculate the degree of detour of the gap path VP _j , which cannot be calculated with fiber arrangement in an ideal state, it is possible to perform performance evaluation taking into account the fluid flow between the fibers. In particular, since it is possible to evaluate each axial direction of the measurement target area TA, even if there is a bias in the fiber arrangement direction, for example, in the case of a flat fiber material with few fibers arranged in the thickness direction, etc. Gap measurement can be performed with high accuracy in each axial direction.

The interfiber void measuring device, interfiber void measuring method, and program according to the present invention are not limited to the embodiments described above, and various modifications and improvements can be made within the scope of the claims.

In the embodiment described above, the characteristic value of the interfiber voids is calculated based only on the void path VP _j generated from one starting surface SS to the ending surface FS, but the present invention is not limited to this. For example, after generating a gap path VP _j from one of the start surfaces SS to the end surface FS, the start surface SS side and the end surface FS side are swapped to generate a gap path VPr _j in the opposite direction. Then, the void diameter, interfiber distance, detour degree, etc. of the void path VP _j and the void path VPr _j in the opposite direction may be averaged to calculate the characteristic value of the interfiber void. It can also be used to comprehensively evaluate the characteristic values of the fiber material to be analyzed by averaging the characteristic values in each axis direction (X-axis direction, Y-axis direction, and Z-axis direction) of the measurement target area TA. good. In this case, the anisotropy of the fibrous material may be evaluated by evaluating the deviation of the characteristic values in each axial direction.

INDUSTRIAL APPLICATION This invention is suitable for the characteristic evaluation of the interfiber void of the fiber group contained in fiber base materials, such as a nonwoven fabric.

1 Interfiber void measuring device, 3 CPU, 5 Volatile storage device, 7 Non-volatile storage device, CA Corresponding area, DT CT image data, FB Fiber group, FP _n point of interest, FP _n+1st layer point of interest, FP _{n- 1} front layer focus point, OP opposing point, PG computer program, PG1 3D image generation program, PG2 fiber information acquisition program, SA search area, TA measurement target area, TD 3D image, VD void

Claims (7)

three-dimensional image generation means for generating a three-dimensional image of the fiber base material;
Fiber information acquisition means for acquiring coordinate information of each point constituting the void and the distance of each point from each fiber with respect to the void between the fibers of the fiber group included in the fiber base material, based on the three-dimensional image; and,
With respect to the measurement target area of the three-dimensional image, one of the area end faces is set as the end face, a face outside the measurement target area that is in contact with the area end face on the opposite side of the end face is set as the start face, and each point on the start face is set as the start face. In a routine that generates a gap path by sequentially selecting next layer points of interest from a search area in the vicinity of a point adjacent to the point of interest of the layer on the end surface side, each of the points of interest of the next layer is set as a point of interest of the next layer. a gap path generation means for selecting a point having the largest distance from the fiber;
A value twice the maximum value of the distance from each fiber to each point of the gap path generated by the gap path generation means is calculated as the gap diameter, and the average value of the gap diameter for each gap path is calculated as the average gap. A void diameter calculating means for calculating the diameter.
An interfiber void measuring device characterized by: The gap path generating means includes:
If there are multiple points in the search area that have the greatest distance from each fiber, a point that is closer to the opposite point that is opposite to the previous layer point of interest, which is the point of interest immediately before the point of interest, across the point of interest. is selected as the next layer focus point,
The interfiber void measuring device according to claim 1. ideal pore diameter calculation means for calculating the pore diameter in an ideal state in which each fiber of the fiber group included in the fiber base material is arranged at equal intervals;
a deviation calculation means for calculating the deviation of the average pore diameter from the ideal pore diameter;
The interfiber void measuring device according to claim 1 or 2, characterized in that: comprising an inter-fiber distance calculation means for calculating, as an inter-fiber distance, a value twice the minimum value of the distance from each fiber to each point of the air-gap path generated by the air-gap path generation means;
The interfiber void measuring device according to any one of claims 1 to 3. comprising detour degree calculation means for calculating a value obtained by dividing the length of the gap path by the distance between the start surface and the end surface as the detour degree;
The interfiber void measuring device according to any one of claims 1 to 4. Generates a three-dimensional image of the fiber base material,
Based on the three-dimensional image, obtain coordinate information of each point constituting the void with respect to the void outside the fibers of the fiber group included in the fiber base material and the distance of each point from the fiber,
With respect to the measurement target area of the three-dimensional image, one of the area end faces is set as the end face, a face outside the measurement target area that is in contact with the area end face on the opposite side of the end face is set as the start face, and each point on the start face is set as the start face. In a routine that generates a gap path by sequentially selecting next layer points of interest from a search area in the vicinity of a point adjacent to the point of interest of the layer on the end surface side, each of the points of interest of the next layer is set as a point of interest of the next layer. Select the point with the greatest distance from the fiber,
Calculating a value twice the maximum distance of each point of the void path from each fiber as the void diameter, and calculating the average value of the void diameters for each void path as the average void diameter.
A method for measuring interfiber voids characterized by the following. a) generating a three-dimensional image of the fiber substrate;
b) obtaining coordinate information of each point constituting the void and the distance of each point from each fiber with respect to voids outside the fibers of the fiber group included in the fiber base material, based on the three-dimensional image; ,
c) With respect to the measurement target area of the three-dimensional image, one of the end faces of the area is set as the end face, a face outside the measurement target area that is in contact with the end face of the area opposite to the end face is set as the start face, and each point on the start face is set as the end face. is sequentially set as a point of interest, and in a routine that generates a gap path by sequentially selecting the next layer point of interest from the search area near the point adjacent to the point of interest on the layer on the end surface side, as the next layer point of interest. selecting a point having the greatest distance from each fiber;
d) Calculate a value twice the maximum value of the distance from each fiber of each point of the void path generated in step c) as the void diameter, and average the average value of the void diameter for each void path. a step of calculating as a void diameter;
A program that causes a computer to execute