JP2001140187A - Device for measuring orientation characteristic of fiber, and method for measuring the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a device for measuring orientation characteristics of fiber, capable of measuring the orientation characteristics of the fiber of a target material to be measured in high accuracy by utilizing direction dependency of a light transmitted in the fiber, and further to provide a method for measuring the characteristics. SOLUTION: An irradiation means 3 has a light source lamp 3a for irradiating the light to the target material 1 to be measured, and a detecting means 4 has a photodetector 4a for detecting the light L3 coming out in the direction nearly parallel to the ray axis I of the light irradiated by the irradiation means 3. The photodetector 4a detects the light L3 coming out from the fiber 1a after being transmitted in the fiber direction of the target material to be measured. The sensitive region of the light detector 4a is set in the vertical direction to the surface of the target material to be measured so that the reflected light reflected by the surface of the fiber 1a may not be detected.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an apparatus and a method for measuring fiber orientation characteristics for measuring fiber orientation characteristics of paper and the like.

[0002]

2. Description of the Related Art FIG. 6 is a partial side view of a conventional apparatus for measuring fiber orientation characteristics. FIG. 7 is a diagram illustrating a state in which light emitted by a conventional fiber orientation characteristic measuring device is reflected by paper fibers.

[0003] As shown in FIG.
Japanese Patent Publication No. 3 (JP-A) No. 3 discloses a paper 101 to be measured that moves in the
Halogen lamps that irradiate light from the surface of the
Light source lamp 103a and the light source lamp 103a
The incident light is parallel incident light L ₀ Lens 103b
And the reflected light beam L reflected on the surface of the paper 101 to be measured_Two Detect
And a photodetector 104a such as a photodiode that emits light.
An apparatus for measuring the fiber orientation of paper is described. here,
The light detector 104a is an incident light incident on the paper 101 to be measured.
Line L₀ At a predetermined interval on the circumference centered at
Are arranged, with respect to the incident normal line on the paper 101 to be measured.
Reflected light L reflected at a predetermined angle θ_Two Is detected.

As shown in FIG. 7, an incident light beam L ₀ incident on a single fiber 101 a of a paper 101 to be measured is
A part is reflected on the surface of a, and the reflected light beam has direction dependency. The length direction of the fiber 101a (hereinafter, referred to as fiber direction) reflected rays L ₁ reflected on is a slight to those reflected by the outer peripheral top end of the fiber 101a, fibers 1
Reflected ray L ₂ is reflected in a direction perpendicular to the 01a is larger due to the presence wide reflecting surface along the fiber direction.

FIG. 8 is a diagram showing an intensity distribution of a reflected light beam detected by a photodetector in a conventional paper fiber orientation measuring apparatus. The vertical axis shown in FIG. 8 is the movement direction (Machine Direction (hereinafter, referred to as MD direction)) of the paper 101 to be measured, and the horizontal axis is the direction perpendicular to the MD direction (Cross Directi).
on (hereinafter referred to as the CD direction)), and the origin O is an incident point at which light emitted from the light source lamp 103a (see FIG. 6) enters the paper 101 to be measured.

[0006] Generally, paper fibers are oriented in different directions one by one, and are bent or tangled up, down, left and right, and are not arranged in one direction. However, in the whole paper, the fiber oriented in the MD direction is
Relatively more than fibers that are oriented in the CD direction. For this reason, the incident light beam L ₀ incident on the measured paper 101 is CD
The tendency to reflect in the direction increases. As a result, as shown in FIG. 8, on the basis of the 12 intensity signal photodetector 104a outputs, when determining the intensity distribution of the reflected light L ₂ for each of the photodetectors 104a, ellipse the intensity distribution Can be approximated. Here, the distance between the origin O and each point is the reflected light L detected by each photodetector 104a.
Shows _two strengths, the shortest direction of this distance (the minor axis of the ellipse) is substantially coincident with the fiber direction of the whole paper, fiber M
It shows a tendency to be aligned in the D direction (hereinafter referred to as fiber orientation). As a result, the angle α shown in FIG. 8 represents the angle between the minor axis of the ellipse and the MD direction, is the orientation angle indicating the fiber orientation, and the ratio of the major axis length to the minor axis length of the ellipse is: It represents the strength of fiber orientation as a whole paper (hereinafter referred to as orientation index).

[0007]

However, the conventional paper fiber
In the fiber orientation measuring device, the surface of the paper 101 to be measured is
When the distance between the photodetector 104a and the photodetector 104a changes.
reflected light L incident on a _Two Angle θ changes, the orientation finger
There was a problem that the sensitivity of numbers changed. Also, the measured
If the paper 101 moves in an inclined manner, the photodetector 1
04a reflected light L_Two Angle θ changes,
There was a problem that the sensitivity of the propensity index changed.

SUMMARY OF THE INVENTION An object of the present invention is to provide a fiber orientation characteristic measuring apparatus and a measuring method capable of measuring fiber orientation characteristics of an object to be measured with high accuracy by utilizing the direction dependency of light propagating in a fiber. It is to provide.

[0009]

The present invention solves the above-mentioned problems by the following means. Note that the description will be given with reference numerals corresponding to the embodiments of the present invention, but the present invention is not limited to this. The invention according to claim 1 is a fiber orientation characteristic measuring device that irradiates light to a measurement object (1) to measure fiber orientation characteristics of the measurement object, wherein the light is applied to the measurement object. Detecting means (4) for detecting light (L ₃ ) propagated in the direction of the fiber (1a) of the object to be measured and emitted out of the fiber, and based on the light detected by the detecting means, A fiber orientation characteristic measuring device (2) characterized by measuring the fiber orientation characteristics of the above.

According to a second aspect of the present invention, in the apparatus for measuring a fiber orientation characteristic according to the first aspect, the detecting means emerges in a direction substantially parallel to a beam axis (I) irradiated by the irradiating means. This is a fiber orientation characteristic measuring device characterized by detecting light.

[0011] The invention of claim 3 is claim 1 or claim 2.
In the fiber orientation characteristic measuring device according to the above, the detecting means comprises a plurality of photodetectors arranged at predetermined intervals on an imaginary circumference centered on a ray axis (R) irradiated by the irradiating means. (4a), wherein a calculating means (6) for calculating a fiber orientation direction and / or a fiber orientation strength of the object to be measured based on an output signal of the photodetector is provided. This is a measuring device for fiber orientation characteristics.

According to a fourth aspect of the present invention, there is provided a method for measuring fiber orientation characteristics of a measuring object by irradiating the measuring object with light, wherein the light irradiated on the measuring object is provided. Measuring the fiber orientation characteristics of the object to be measured, wherein the light propagates in the fiber direction of the object to be measured and exits the fiber, and the fiber orientation characteristics of the object to be measured are measured based on the detected light. Is the way.

[0013]

Embodiments of the present invention will be described below in detail with reference to the drawings. FIG. 1 is a partial side view of an apparatus for measuring fiber orientation characteristics according to an embodiment of the present invention. FIG. 2 is a partial plan view of the fiber orientation characteristic measuring device according to the embodiment of the present invention. FIG. 3 is a diagram showing a state in which light emitted by the fiber orientation characteristic measuring device according to the embodiment of the present invention propagates in the fiber. FIG.
1 is a block diagram of an apparatus for measuring fiber orientation characteristics according to an embodiment of the present invention.

The object 1 to be measured is made of paper made by affixing plant fiber, mineral fiber, animal fiber, synthetic fiber or a mixture thereof, paper mixed with fibrous inorganic material, synthetic polymer material, etc. And synthetic paper, wood pulp, waste paper and the like, and nonwoven fabrics produced by treating natural fibers, recycled fibers or synthetic fibers without using a loom. The measuring object 1 is carried out, for example, from a dryer part of a paper machine, and moves in the arrow direction (MD direction) shown in FIG.

The measuring device 2 measures the fiber orientation characteristics of the measuring object 1, and as shown in FIGS. 1 and 4,
It includes an irradiation unit 3, a detection unit 4, a processing circuit 5, a calculation circuit 6, a display unit 7, and a printing unit 8. The measuring device 2 is movably attached to guide rails (not shown) provided above and below the object 1 to be measured, and reciprocates (scans) along the guide rails in synchronization with each other. The fiber orientation characteristics in the MD and CD directions are measured.

The irradiating means 3 is a device for irradiating the object to be measured 1 with light. As shown in FIG. 1, a light source lamp 3a for emitting light and a parallel incident light beam for irradiating the light emitted by the light source lamp 3a. and a lens 3b to L _0. When the measuring device 2 reciprocates, the irradiating means 3 irradiates the moving measurement target 1 with light while drawing a zigzag measurement trajectory.

As shown in FIGS. 1 and 3, the detecting means 4 is a light (incident light) L ₀ applied to the object to be measured, and is transmitted (transmitted) in the fiber direction of the object to be measured 1. a device for detecting the light L ₃ emitted outside the fibers 1a Te. The detection means 4, as shown in FIG. 1, and a photodetector 4a of the irradiation means 3 for detecting the light L _3, which substantially comes in a direction parallel to the light axis I of irradiating.

As shown in FIGS. 1 and 2, twelve photodetectors 4a are arranged at a predetermined interval on a virtual circle R centered on a beam axis I irradiated by the irradiation means 3. For example, a photodiode. As shown in FIG.
In a, a sensitive region is set in a direction perpendicular to the surface of the measurement object 1 so as not to detect a reflected light beam reflected on the surface of the fiber 1a. The photodetector 4a converts the detected light into a detection signal (light intensity signal) corresponding to the intensity of this light, and outputs this detection signal to the processing circuit 5 shown in FIG.

The processing circuit 5 is a circuit for processing a detection signal output from the photodetector 4a.
Outputs light intensity information (processed signal) relating to the detected light intensity and the like to the arithmetic circuit 6.

The arithmetic circuit 6 is a circuit for calculating fiber orientation characteristics such as an orientation angle and an orientation index of the measuring object 1 based on the light intensity information output from the processing circuit 5. The arithmetic circuit 6 calculates the fiber orientation by approximating the fiber orientation using a periodic function using a Fourier series, or calculates the von Meis (Vo
n Mises) Calculate fiber orientation using functions and elliptic functions.

FIG. 5 is a view showing fiber orientation characteristics calculated by an arithmetic circuit in the apparatus for measuring fiber orientation characteristics according to the embodiment of the present invention. Here, the vertical axis is the MD direction,
The horizontal axis is the CD direction, the origin O is the incident point of light incident on the measurement target 1, and the angle α is the orientation angle. In general,
If the measurement object 1 is paper or the like, the MD
There are many fibers 1a oriented in the direction. As a result, the light propagating in the fiber 1a propagates in the MD direction, and an elliptical intensity distribution as shown in FIG. 5 can be obtained. Although the orientation angle α is substantially the same between the measurement device 2 and the conventional measurement device shown in FIG. 8, due to the difference in the respective measurement principles, the lengths of the major axis and the minor axis of the ellipse are different. Do not match (orientation index). However, since no official standard is set for the orientation index, there is no problem even if the values differ depending on the measurement principle.

The display means 7 shown in FIG. 4 is a device for displaying the direction of the fiber orientation and the strength of the fiber orientation calculated by the arithmetic circuit 6. The display means 7 displays, for example, the C
It is a CRT display device or the like that displays the orientation angles measured at a plurality of locations in the D direction for each measurement position. Printing means 8
Is a printer or plotter that prints data, graphs, and the like displayed on the display unit 7.

Next, a method for measuring fiber orientation characteristics according to the embodiment of the present invention will be described. As shown in FIGS. 1 and 2, the irradiating unit 3 irradiates the measuring object 1 moving in the arrow direction with light while reciprocating (scanning) in the CD direction.
As shown in FIG. 3, the light that has entered the fiber 1a
Since there is a boundary surface in the radial direction of a, the light is reflected or scattered at this boundary surface and is difficult to propagate to the adjacent fiber 1a, but propagates far in the fiber direction without the boundary surface. Light receiving means 4 is a incident ray L ₁ irradiated to the measuring object 1, the light L ₃ emitted propagated in this fiber direction outside the fibers 1a
The arithmetic circuit 6 calculates the orientation of the fiber orientation of the measurement target 1 and the strength of the fiber orientation based on the output signal of the light receiver 4a. The calculation result is fed back to, for example, the wire part of the paper machine, and the supply amount of the raw material to the wire part, the moving speed of the wire part, and the like are changed.

The fiber orientation characteristic measuring apparatus according to the embodiment of the present invention has the following effects. (1) In the embodiment of the present invention, the light L ₃ irradiating the measuring object 1 from the irradiating means 3 and propagating in the fiber direction of the measuring object 1 and coming out of the fiber 1 a is The detecting means 4 detects the light, and the arithmetic circuit 6 calculates the fiber orientation characteristics of the measuring object 1 based on the detection result. For this reason, not only the surface of the measurement object 1 but also the light that enters in the thickness direction (depth direction), passes through the fiber 1a, and exits from the fiber 1a is detected. Fiber orientation characteristics such as inside can also be calculated. as a result,
Compared with the conventional paper fiber orientation measuring apparatus, the fiber orientation characteristics of the measuring object 1 can be calculated over a wide range with high accuracy.

(2) In the embodiment of the present invention, the detection means 4 detects the light L ₃ emitted in a direction substantially parallel to the light axis I irradiated by the irradiation means 3. For this reason, even if the distance between the surface of the measurement object 1 and the irradiation means 3 changes, light always enters the photodetector 4a from a certain direction, so that the fluctuation of the sensitivity of the orientation index is reduced. Can be. Further, the distance between the measurement object 1 and the measurement device 2 can be set freely.

(3) In the embodiment of the present invention, on the virtual circumference R centered on the ray axis I irradiated by the irradiation means 3,
A plurality of photodetectors 4a are arranged at predetermined intervals. For this reason, the light is irradiated from the irradiation means 3 and propagates in the fiber 1a of the measurement object 1, goes out of the fiber 1a, and can make the propagation distance of the light detected by the photodetector 4a constant. .

The present invention is not limited to the embodiment described above, but can be variously modified or changed.
These are also within the scope of the present invention. For example, the measurement target 1 may be a light-permeable cloth or the like, and the irradiation unit 3 may be a semiconductor diode or the like that irradiates a laser beam. In particular, since laser light has a large optical power,
It is possible to increase the intensity of the light L ₃ emitted outside the fibers 1a. The arithmetic circuit 6 may calculate only one of the fiber orientation and the fiber orientation, and the number of the photodetectors 4a is not limited to twelve.
Further, the measuring device 2 may be mounted on a measuring device that continuously scans the basis weight, moisture, thickness, ash, etc. of the paper by scanning in the width direction of the paper machine, or may be used alone in a laboratory. It may be used as an off-line measuring device that performs the following.

[0028]

As described above, according to the present invention, the light radiated to the object to be measured, which is transmitted in the fiber direction of the object to be measured and comes out of the fiber, is detected. Since the fiber orientation characteristics of the object to be measured are measured based on the light detected by the detecting means, the fiber orientation characteristics of the object to be measured are measured with high accuracy by utilizing the direction dependency of the light propagating in the fiber. be able to.

[Brief description of the drawings]

FIG. 1 is a partial side view of an apparatus for measuring fiber orientation characteristics according to an embodiment of the present invention.

FIG. 2 is a partial plan view of a fiber orientation characteristic measuring device according to an embodiment of the present invention.

FIG. 3 is a view showing a state in which light emitted by the fiber orientation characteristic measuring device according to the embodiment of the present invention propagates in the fiber.

FIG. 4 is a block diagram of an apparatus for measuring fiber orientation characteristics according to an embodiment of the present invention.

FIG. 5 is a diagram showing fiber orientation characteristics calculated by an arithmetic circuit in the fiber orientation characteristic measuring device according to the embodiment of the present invention.

FIG. 6 is a partial side view of a conventional apparatus for measuring fiber orientation characteristics.

FIG. 7 is a diagram showing a state in which light irradiated by a conventional fiber orientation characteristic measuring device is reflected by paper fibers.

FIG. 8 is a diagram showing an intensity distribution of a reflected light beam detected by a photodetector in a conventional paper fiber orientation measuring apparatus.

[Description of Signs] 1 Object to be measured 1a Fiber 2 Measuring device 3 Irradiating means 4 Detecting means 6 Arithmetic circuit I Ray axis L ₃ Light out of fiber R Virtual circumference

Claims (5)

[Claims] 1. A fiber orientation characteristic measuring device for irradiating a measuring object with light to measure fiber orientation characteristics of the measuring object, wherein the light irradiating the measuring object and the measuring object Detecting means for detecting light that has propagated in the fiber direction and exited out of the fiber, and a fiber orientation characterized by measuring fiber orientation characteristics of the object to be measured based on the light detected by the detecting means. Characteristic measuring device. 2. The fiber orientation characteristic measuring apparatus according to claim 1, wherein said detecting means detects light leaking in a direction substantially parallel to a beam axis irradiated by said irradiating means. For measuring fiber orientation characteristics. 3. The fiber orientation characteristic measuring device according to claim 1 or 2, wherein the detecting means sets a predetermined interval on a virtual circumference centered on a beam axis irradiated by the irradiating means. A plurality of spaced photodetectors; and a calculating means for calculating a fiber orientation direction and / or a fiber orientation strength of the object to be measured based on an output signal of the photodetector. A characteristic fiber orientation measurement device. 4. The fiber orientation characteristic measuring apparatus according to claim 3, wherein the plurality of photodetectors are circumferentially arranged at equal intervals. 5. A fiber orientation characteristic measuring method for irradiating a measuring object with light to measure fiber orientation characteristics of the measuring object, wherein the light irradiating the measuring object and the measuring object A method of measuring the fiber orientation characteristics of the object to be measured based on the detected light and detecting the light that has propagated out of the fibers.