JPH0749637B2 - Method and device for predicting fiber orientation of paper - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial field of application] The present invention relates to the fiber orientation of paper in papermaking from the behavior of stock during the process from discharging from the head box of a paper machine to still being in a fluidized state on the wire. The present invention relates to a method for predicting a value and a device suitable for performing the method.

[Conventional technology]

Conventionally, the fiber orientation has been widely adopted as a standard for judging the characteristics of paper made by papermaking.

The fiber orientation of this paper is generally expressed by the fiber orientation angle and the fiber orientation index, the former means the average fiber arrangement direction, and usually the machine direction is set to zero degree and the clockwise direction is directed downstream of the paper machine. The positive (positive) angle represents the counterclockwise direction with a negative (negative) angle. In the latter, the ratio of the fibers lined up on the horizontal axis to the fibers lined up on the vertical axis when the direction indicating the orientation angle thus represented is taken as the vertical axis and the direction perpendicular to this is taken as the horizontal axis (so-called The aspect ratio is an index, and the fiber orientation index and the aspect ratio of the paper have the following relationship.

The fiber orientation of such paper is closely related to the strength of the paper and paper misalignment (curling, warping, twisting, etc.), and is suitable for PPC (tray accommodation and copying before the copying of small cut paper in a plain paper copying machine). (Layerability and sorter after printing), runnability related to occurrence of meandering and bending in high-speed printing machines and processing machines, NIP suitability (laminating property after printing continuous slip paper used in non-impact printers), etc. is doing.

Generally, when paper is made by hand, the fibers are arranged randomly, so it has an aspect ratio of approximately 1 and is an ideal paper with no habit. However, for machine-made paper, especially when the paper machine is wide and high-speed. The more the fibers are aligned along the machine direction, the larger the aspect ratio becomes, and the different the arrangement of fibers in the cross machine direction and the machine direction at each location (fiber orientation profile becomes non-uniform). Comes to appear strongly. Even in the machine-made paper in such a situation, it is preferable that the fiber orientation index is as close to 0 as possible (that is, the aspect ratio of the paper is 1), and the fiber orientation angle is close to 0 degree. It turns out to be preferable.

As a typical example, newsprint produced without intentionally controlling the stock flow (paper width: 6600 mm, basis weight: 4
The fiber orientation profile in the cross machine direction of 6.5 g / m ² , machine speed; 850 m / min), that is, the fiber orientation angle profile is shown in Fig. 8 (a), and the paper aspect ratio profile is shown in Fig. 8 (a).
It is shown in Figure (b). As is clear from Figs. 8 (a) and 8 (b), in wide-width / high-speed machines, the stock discharged from the headbox of the paper machine is affected by the wall resistance at both ends of the slice, and The flow becomes slower, and as a result, the aspect ratio around the edges of the paper after drying becomes smaller than that at the center, and the fiber orientation angle also deviates significantly from the machine direction, so-called inverted C-shape (downstream of the paper machine. Since the left side is a negative angle and the right side is a positive angle, the profile pattern is such that the fiber orientation angles on both sides open to the opposite side. Paper machine manufacturers and paper manufacturers have conducted extensive research to correct such uneven profile patterns, and have adopted an edge flow control system to control the stock flow at the end and other factors such as recirculation valve opening and paper. The profile pattern is being actively improved by optimizing so-called operating conditions such as the ratio of material speed to wire speed.

In order to judge how the fiber orientation profile pattern has changed by changing the operating conditions, including such edge flow control, it is usual to cut and sample the paper from the reel product that has completed paper making, and perform the zero span tensile test. Method or molecular orientation meter (for example, MOA- manufactured by Kanzaki Paper Co., Ltd.)
2001A) is used to measure the fiber orientation and obtain the profile of the cross machine method.

However, these methods involve a considerable amount of time and a large amount of product loss from the change of operating conditions until the measurement result is obtained. For example, in a newsprint machine, it takes 45 lanes (45000 m) of Jyanboroll at a speed of 860 m / min to make the paper.
It takes 52 to 53 minutes, and the paper is cut from this roll to determine a cross machine direction that is exactly perpendicular to the machine direction of the paper itself and cut into a rectangle of a certain area. At least 6 points in the cross machine direction. It takes about 1 hour to perform the sampling required to determine the fiber orientation profile of the sample, and 12 minutes to determine the fiber orientation of 6 samples with a molecular orientation meter. 2 from the change
Over time, it will be possible to understand how the cross machine direction profile of the paper that was made for the first time has changed.

[Problems to be Solved by the Invention]

As mentioned above, knowing the fiber orientation of the paper is a very important work to understand various properties of the paper, but the conventional method for measuring the fiber orientation of the paper is very complicated and is in operation. Since there is no simple and quick method for measuring the fiber orientation of paper, there is a drawback that paper cannot be made under good papermaking conditions.

Therefore, it is an object of the present invention to provide a method for easily and quickly predicting the fiber orientation of paper during operation of an actual machine and an apparatus for carrying out the method.

[Means for Solving the Problems]

The present inventors have solved the above problems, a method of obtaining a change in the fiber orientation at a fixed point with various operating conditions, more preferably a change in the profile pattern in the cross machine direction of the fiber orientation easily and in a short time. As a result of many years of earnest research to develop, the flow state of the stock at the stock position in the process from the time when it is finally discharged from the head box of the paper machine until it is still flowing on the wire and the machine at that time. We have succeeded in developing a method and apparatus for predicting the fiber orientation of paper to be made from the conditions.

That is, the inventors of the present invention consciously change the ejection angle of the stock material discharged from the head box and the ratio of the stock speed and the wire speed by using the model paper machine (the stock material discharge angle is the slice of the head box). The installation angle was changed by a frog), the relationship between the stock velocity vector and the wire speed, and the fiber orientation of the paper after drying was examined, and the stock velocity was fixed to a fixed value. Fig. 9 showing the fiber orientation angle when the discharge angle and the wire speed are changed, and Fig. 10 showing the relationship between the wire speed and the molecular orientation index when the discharge angle of the paper stock in this Fig. 9 is -4 degrees. As shown in the figure, various experimental results were obtained, and it was confirmed that the fiber orientation of the paper depends on the velocity difference vector between the stock and the wire as shown in the following results.

(1) The sign of the fiber orientation angle of the paper corresponds to the sign of the velocity difference vector angle between the stock and the wire, and does not necessarily correspond to the sign of the angle of the stock flow.

When the stock flow angle is positive and the ratio of stock speed to wire speed is greater than 1, the stock and wire speed difference vector angle is positive and the fiber orientation angle of the paper is also positive. However, even if the flow angle of the stock is positive, when the ratio of the stock speed to the wire speed is less than 1, the speed difference vector angle between the stock and the wire becomes negative, and the fiber orientation angle of the paper also becomes negative. .

When the flow angle of the stock is negative and the ratio of the stock speed to the wire speed is greater than 1, the velocity difference vector angle between the stock and the wire is negative, and the fiber orientation angle of the paper is also negative. However, when the ratio of the stock speed to the wire speed is smaller than 1 even if the stock flow angle is negative, the speed difference vector angle between the stock and the wire is positive, and the fiber orientation angle of the paper is also positive. .

If the flow angle of the stock is zero, the velocity difference vector angle between the stock and the wire is zero and the fiber orientation angle of the paper is also zero, regardless of the ratio of the stock speed to the wire speed. .

(2) The absolute value of the fiber orientation angle of the paper is approximately 1/3 of the absolute value of the velocity difference vector angle between the stock and the wire.

(3) The aspect ratio of the fiber orientation of the paper becomes minimum when the ratio of the stock speed to the wire speed is 1, and becomes larger as the ratio of the stock speed to the wire speed deviates from 1.

In this way, a certain law was found between the velocity difference vector between the stock and the wire in the wire part and the fiber orientation of the paper after drying.Therefore, by utilizing these factual relationships, the paper machine It is also possible to predict the change in the fiber orientation in the machine direction of the paper from the change over time in the velocity difference vector between the stock and wire at a fixed point, and the change over time in the velocity difference vector between the stock and wire. It is also possible to measure the fiber orientation in the machine direction of the paper as well as in the cross machine direction of the reel product by measuring the velocity difference vector profile pattern in the machine direction.

In order to predict the fiber orientation of the paper based on the above-mentioned knowledge, it is necessary to first measure the velocity difference vector between the paper stock and the wire in a short time.

Conventionally, as means for detecting the flow state of a moving object, Japanese Patent Publication No. Sho 59-20103 "velocity detecting device" and Japanese Utility Model Publication No. 60-74059 "fluid flow direction detecting device" have been disclosed. The former is a noisy signal detecting means for detecting a noisy signal obtained from a relatively moving object at two locations located in the moving direction, and means for adjusting the phase of periodic noise in an output signal obtained from these means. To calculate the autocorrelation value of the output of the difference or the sum of the output of one noisy signal and the phase-adjusted output of the other noisy signal. This enables high-accuracy speed detection without being affected. However, the measurement with this device is effective only when the moving direction of the moving object is always constant, and the paper making conditions (slice lip opening, total head, recirculation valve opening, etc.) are the same as those of paper stock in a paper machine. In order to detect how much the stock velocity changes when the flow state (especially the flow direction) changes due to the difference in the flow rate, the downstream side of the flow in the noisy signal detection device installed in two places The device located at the center of the device located on the upstream side is moved at least several places on an arc, and the autocorrelation value is calculated for each movement to obtain the speed at that time, and the stage at which the series of movements is completed In addition, arithmetic processing for determining the flow direction is required. Therefore, it may take more than ten minutes to obtain the flow direction at one measurement point, and if the flow direction changes randomly over time and the width of change is large, the moving position on the arc should be changed. Since it is necessary to significantly increase the number of times, the time required for one measurement point is further increased by the mechanical movement operation and the increase in the number of correlation processes.

Therefore, the latter device has improved such drawbacks. This device uses a noisy signal generated from a substance scattered in a liquid to measure a velocity vector at a predetermined position, and one measurement surface region upstream of the flow and an upstream side downstream of the flow. At least three measurement surface areas are integrally formed on an arc having a radius of a constant length centered on the center point of the measurement surface area, and the upstream noise signal A and the downstream noise signal B1 are respectively placed. , B2, B3 are detected and A and B1, A respectively
And B2, A and B3 cross-correlation value or A and B1 difference auto-correlation value, A
And B2 difference autocorrelation value, A and B3 difference autocorrelation value,
A device for selecting the maximum value of the cross-correlation value or auto-correlation value to determine the flow direction, and a plurality of measurement surface regions that are integrated upstream and downstream are provided on a line perpendicular to the longitudinal direction of the flow path with a space therebetween. It is also a device that can be installed at a location to obtain the profile pattern of the velocity vector in the cross machine direction. However, even with this device, it takes several minutes to obtain the velocity vector of one predetermined measurement position, and the velocity of the stock in the cross machine direction in a practical 3 m width paper machine is utilized by using one correlator. It is necessary to have a velocity vector at intervals of at least 100 mm to obtain the vector profile pattern, so it is convenient for several tens of minutes to one hour or more (several minutes x 3000 mm
/ 10mm) time is required. Moreover, the main drawback of this device is the accuracy of the measurement of the flow direction. That is, the above 3
In order to select the maximum value from the two cross-correlation values or auto-correlation values, there is only mathematical extrapolation means, and the wider the distance between the measurement surface areas located on the downstream side, the more the true flow direction The difference will be large. Also, if there is no maximum value (simple increase, simple decrease, minimum value), the flow direction cannot be measured at all.

Therefore, in the present invention, for the stock material in the process of being in a fluidized state on the wire after being discharged from the head box of the paper machine, for example, space filter type speed detection sensors SF-660B and SF760 manufactured by Ono Sokki Co., Ltd. Such as a light projecting portion that projects light emitted from a light source in a predetermined light projecting area, and light received by the light projecting portion and reflected by an object is arranged to have a special shape. A light receiving unit including an element is used, a known space filter type speed sensor for calculating the speed from the pulse number by shaping the output received and extracted by the light receiving unit into a pulse signal through a band pass filter, and By arranging the space filter type speed sensors adjacent to each other on the same axis in the machine direction, one sensor measures the speed in the machine direction and the other sensor measures the speed in the cross machine direction at the same time. Te is to that investigation that the velocity vector of the stock instantaneous (for example, 0.3 sec / point) at a high accuracy Moreover stock flow direction can be detected reliably even when deviated significantly from the machine direction at the measurement point.

Therefore, by simultaneously measuring the wire speed at the same time as the stock velocity vector and immediately calculating the speed difference vector between the stock and the wire, the paper speed change vector It is possible to predict the variation of the fiber orientation in the machine direction, and the change over time of the velocity difference vector between the stock and the wire at this fixed point can be measured by measuring the fiber orientation angle of the paper as shown in FIG. As shown in Fig. 4, there is not much change in the center of the machine width.Therefore, it is necessary to pay close attention to the fiber orientation at both ends of the paper machine and the stock, whose condition can be grasped to some extent. If not, you can use it as is. However, when it is necessary to predict the fiber orientation over almost the entire machine width, the two space filter type speed sensors as described above are run together in the cross machine direction so that the paper machine crosses the machine direction. If the speed difference vector between the stock and the wire is obtained in a short time either continuously or at predetermined intervals, the cross machine direction of the speed difference vector between the stock and the wire is changed from the profile pattern to the cross machine direction of the reel product. It is possible to predict and display the fiber orientation profile pattern.

Below is a method for detecting the stock vector and the speed difference vector between the stock and the wire, and the prediction of the fiber orientation of the reel product.
An example of the display method will be described with reference to the drawings.

FIG. 1 is a side view for explaining the outline of an apparatus for carrying out the method for predicting the fiber orientation of paper according to the present invention, and FIG. 2 is a plan view thereof.
FIG. 3 is a conceptual diagram of a method for calculating a paper stock speed vector using two speed sensors, and FIGS. 4 (a) to (d) are speed differences between the paper stock speed vector and the wire speed. A conceptual diagram of the method of calculating the vector, Fig. 5 (a), (b) and Fig. 6 (a), (b) are the paper stock calculated based on the measured values of the paper stock speed vector and wire speed, respectively. Shows a cross-machine direction profile diagram of the speed difference between the wire and the wire and the speed difference vector angle, (a) shows the speed vector of the stock and the wire speed, and (b) shows the stock and the wire. Shows the speed difference and the speed difference vector angle.
FIG. 7 is a diagram showing predicted values and actually measured values of the fiber orientation angle profile in the cross machine direction.

In the drawing, reference numeral 3 denotes a paper material discharged from a discharge port 2 of a head box 1 of a paper machine, which goes to the next drying step (not shown) while being dehydrated on the wire 4. 5 is the position of the stock 3 in the process of being discharged from the discharge port 2 of the head box 1 to being still in a flowing state on the wire 4, and two space filter type speed sensors 6 adjacent to each other on the same axis in the machine direction. 2 is used as a frame for arranging the sensor holding body 8 holding the wires 7 and 7 on the wire 4.
In the case of the structure in which the two space filter type speed sensors 6 and 7 are not moved, it suffices to simply use the frame for fixing the sensor holder 8 and the two space filter type speed sensors 6
In the case of a structure in which the measurement points are changed one after another while moving 7 and 7 in the cross machine direction, the guide body 5a for slidably supporting the sensor holder 8 in the cross machine direction and the sensor holder 8 are moved in the cross machine direction. For this purpose, a moving means such as a lead screw 5b screwed to the sensor holder 8 and a drive source 5c for driving the lead screw 5b may be provided. When the two space filter type speed sensors 6 and 7 held by the sensor holder 8 are installed on the frame 5 as the space filter type speed sensors 6 and 7 as described above, the space filter type of Ono Sokki Co., Ltd. is used. Speed sensor SF-6
When using 60B and SF760, the space between the space filter type speed sensors 6 and 7 should be 80 mm apart on the same axis in the machine direction, and the space filter type speed sensors 6 and 7 should be 515 mm apart from the paper surface.
The space filter type speed sensor 6 measures the flow speed of the stock 3 in the machine direction, and the space filter type speed sensor 7 measures the flow speed of the stock 3 in the cross machine direction. 9 is a space filter type speed sensor 6
And 7, the speeds of the stock 3 in the machine direction and the cross machine direction, and when the sensor holder 8 is moved in the cross machine direction, the movement amount (movement position) of the sensor holder 8 and the speed of the wire 4 The personal computer 9 inputs the speed vector of the stock 3 at the measurement position (how many times the stock is displaced from the machine direction and at what speed) and the stock 3 by this personal computer 9. The velocity difference vector between the wire 4 and the velocity difference vector angle between the stock 3 and the wire 4 are calculated,
The speed difference vector angle between the stock 3 and the wire 4 is displayed. In this calculation, as shown in FIG. 3, the speed V ₁ of the stock 3 in the machine direction is measured by the space filter type speed sensor 6, and the speed V ₂ of the stock 3 in the cross machine direction is calculated by the space filter type speed sensor 7. When measured respectively, from these velocities V ₁ and V ₂ , the velocity vector of the stock 3, that is, the stock 3
The velocity V ₀ and the flow direction θ of the stock material 3 are calculated by the following equations, Based on the vector V _{0 of the} stock 3 and the speed V _{w of the} wire 4, the speed difference vector Vd between the stock 3 and the wire 4 and the speed between the stock 3 and the wire 4 are obtained based on the vector diagram shown in FIG. The difference vector angle α is obtained, and the velocity vector angle α is represented by the following equation.

here In this way, even if the flow direction of the stock 3 is largely deviated from the machine direction, the flow direction of the stock 3 and the speed in that direction can be reliably measured in a short time with high accuracy. When the sensor holder 8 is moved in the cross machine direction, each calculation result at the moving position of the sensor holder 8 can be output as a chart plotted on a chart to draw a profile of the paper in the cross machine direction. You can do it.

[Action]

Machine speed 790m / min, wire speed 774.5m / min, recirculation valve opening 60%
Fig. 5 (a) shows the velocity vector and wire velocity of the stock measured by the device of the present invention for carrying out the method of the present invention when a newsprint paper having a basis weight of 66.5 mm and a weight of 46.5 g / m ² was produced. The speed difference between the stock and the wire and the speed difference vector angle are shown in FIG.

In addition, a method for carrying out the method of the present invention when a newsprint paper having a paper speed of 792 m / min, a wire speed of 816.5 m / min, a recirculation valve opening of 60% and a 6600 mm width and a basis weight of 46.5 g / m ² is used. Fig. 6 (a) shows the paper stock velocity vector and wire velocity measured by the device of the invention.
Fig. 6 (b) shows the speed difference between the paper stock and the wire and the speed difference vector angle.

How the speed difference between the stock and the wire and the speed difference vector angle (the speed difference vector between the stock and the wire) obtained in this way correspond to the product actually made Molecular orientation meter (MOA-20 manufactured by Kanzaki Paper Co., Ltd.)
FIG. 7 shows the results of comparison with the fiber orientation angle determined by 01A type). From the profile of this fiber orientation angle, it can be seen that the method of the invention corresponds very well to the results of the practice.

Moreover, since such a measurement can be performed in only 0.3 seconds per point, in the case of a practical paper machine with a width of 3 meters, the velocity vector of the stock and the wire velocity at one predetermined measuring position can be measured. Even if you measure 5 times, 1.
Since it requires only 5 seconds (0.3 x 5), two speed sensors are moved at 100 mm / sec at the same time, and 25 points are changed every 100 mm interval to find the average value of 5 times at each measuring point. Even if a cross machine direction profile diagram of the velocity difference vector between the wire and the wire is created, it takes only 2 minutes to display it as a chart on the monitor (moving time 25 seconds + measurement time 25 × 1.5 seconds +
Only the time required for display) was needed.

〔The invention's effect〕

As described above in detail, the method for predicting the fiber orientation of the paper according to the present invention uses the fiber orientation as a criterion for judging the characteristics of the paper made by the paper, and the fiber orientation still flows on the wire after being discharged from the head box of the paper machine. Two space filter type speed sensors are arranged adjacent to each other on the same axis of the machine direction in the process of being in the state until the state, and one speed sensor measures the speed of the stock in the machine direction and the other speed sensor is used. The velocity vector of the stock at the measurement point (the direction and speed of the stock flow) is obtained by measuring the speed of the stock in the cross machine direction with the speed sensor,
The velocity difference vector between the stock and the wire is obtained from the velocity vector of the stock and the wire velocity at the measurement point, and the change in the fiber orientation in the machine direction of the paper is determined from the change with time of the velocity difference vector between the stock and the wire. Is a simple method of predicting in a short time. The number of measurement points is changed one after another while simultaneously moving two speed sensors arranged adjacent to each other on the same axis in the machine direction in the cross machine direction. Thus, if the speed vector profile pattern of the stock in the cross machine direction and the speed vector profile pattern of the stock and the wire are obtained, the speed difference vector profile pattern of the stock and the wire in the cross machine direction is obtained. This is an epoch-making method that can predict and display the fiber orientation profile pattern in the cross machine direction of reel products in a short time. As described above, if the paper orientation of the paper is not completed, the fiber orientation of the paper cannot be measured at once, and it is possible to determine how the fiber orientation profile pattern changes by changing the operating conditions during operation. Since it can be judged in a short time, it is a very large one that contributes to the paper manufacturing industry, and the fiber orientation predicting apparatus of the present invention is a suitable apparatus for carrying out the method of the present invention. The structure is relatively simple and easy to operate and maintain.

[Brief description of drawings]

FIG. 1 is a side view for explaining the outline of an apparatus for carrying out the method for predicting the fiber orientation of paper according to the present invention, and FIG. 2 is a plan view thereof.
FIG. 3 is a conceptual diagram of a method for calculating a paper stock speed vector using two speed sensors, and FIGS. 4 (a) to (d) are speed differences between the paper stock speed vector and the wire speed. A conceptual diagram of the method of calculating the vector, Fig. 5 (a), (b) and Fig. 6 (a), (b) are the paper stock calculated based on the measured values of the paper stock speed vector and wire speed, respectively. Shows a cross-machine direction profile diagram of the speed difference between the wire and the wire and the speed difference vector angle, (a) shows the speed vector of the stock and the wire speed, and (b) shows the stock and the wire. Shows the speed difference and the speed difference vector angle.
FIG. 7 is a diagram showing predicted values and measured values of the fiber orientation angle profile in the cross machine direction, and FIG. 8 is a cross machine direction fiber of newsprint produced without intentionally controlling the stock flow. It is a diagram showing an orientation profile,
(A) shows the fiber orientation angle profile, and (b) shows the paper aspect ratio profile. FIG. 9 shows the fiber orientation angle when the stock material speed is fixed and the stock material discharge angle and the wire speed are changed. FIG. 10 shows the stock material discharge angle in FIG. It is a figure which shows the relationship between a wire speed at 4 degrees, and a molecular orientation index. In the drawing 1 …… Headbox 2 …… Discharge port 3 …… Paper material 4 …… Wire 5 …… Frame 5a …… Guide body 5b …… Lead screw 5c …… Drive source 6,7 …… Space filter type speed sensor 8 ...... Sensor holder 9 ...... Personal computer V ₀ …… Paper speed θ …… Paper flow direction V ₁ …… Paper stock machine speed V ₂ …… Paper stock cross machine direction V _w …… Wire speed Vd …… Speed difference vector between stock and wire α …… Speed difference vector angle between stock and wire

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Claims (4)

[Claims] 1. Two space filter type speed sensors are arranged adjacent to each other on the same axis in the machine direction at the stock position in the process of being discharged from the head box of a paper machine and still being in a fluidized state on the wire. , One of the speed sensors measures the speed of the stock in the machine direction and the other speed sensor measures the speed of the stock in the cross-machine direction. Direction and speed), the speed vector of the stock at the measurement point and the wire speed to find the speed difference vector between the stock and the wire, and the change over time of the speed difference vector between the stock and the wire A method for predicting the fiber orientation of paper, characterized by predicting the variation of the fiber orientation in the direction. 2. A velocity vector profile pattern of a stock material in the cross machine direction by moving two speed sensors arranged adjacent to each other on the same axis in the machine direction in the cross machine direction at the same time while changing measurement points one after another. And the speed difference vector profile pattern between the stock and the wire, and the fiber orientation profile pattern in the cross machine direction of the reel product is predicted from this speed difference vector profile pattern between the stock and the wire in the cross machine direction. The method for predicting fiber orientation of paper according to claim 1, which is displayed. 3. A frame (3) immediately above the position of the stock (3) in the process of being discharged from the discharge port (2) of the head box (1) of the paper machine and still being in a fluidized state on the wire (4). 5) A sensor holder (8) holding two space filter type speed sensors (6, 7) adjacent to each other on the same axis in the machine direction, and the two space filter type speed sensors (6, 7). ) Machine-wise stock as measured by ()
Flow velocity and the flow velocity of the stock (3) in the cross machine direction and the velocity of the wire (4) are input, and the velocity vector of the stock (3) at the measurement position, the stock (3) and The speed difference vector between the stock (3) and the wire (4) is calculated by calculating the speed difference vector between the stock (3) and the wire (4). ) And a personal computer (9) for displaying the velocity difference vector angle between the wire (4) and the wire (4). 4. A guide body (5a) for supporting a sensor holder (8) slidably in the cross machine direction by a frame (5) and a moving means for moving the sensor holder (8) in the cross machine direction. It is equipped with a personal computer (9) with two space filter type speed sensors (6, 7).
Input the flow velocity of the stock (3) in the machine direction, the flow velocity of the stock (3) in the cross machine direction, the movement amount of the sensor holding body (8) and the speed of the wire (4) measured by Then, the velocity vector of the stock (3), the velocity difference vector between the stock (3) and the wire (4), and the velocity difference vector angle between the stock (3) and the wire (4) at each measurement position are calculated. The speed difference vector between the stock (3) and the wire (4) and the speed difference vector angle between the stock (3) and the wire (4) can be output as a chart plotted on a chart. Item 5. A device for predicting the fiber orientation of paper according to Item 3.