JP2016029356A - Device for measuring recording material characteristics and method for measuring recording material characteristics - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a device for measuring recording material characteristics capable of appreciating microscopic environment dependence characteristics of a recording material.SOLUTION: A device for measuring recording material characteristics includes: tension application members 1, 2 for applying tension to a recording material 4; a tension measurement member 8 for measuring the tension applied to the recording material 4; an outer size measurement apparatus 10 for measuring an outer size of the recording material 4 to which the tension is applied; and a structure measurement device 3 for measuring a structure of the recording material 4 to which the tension is applied. In the meantime, the device for measuring the recording material characteristics may be equipped with a humidity measuring device 200 for measuring humidity of the recording material 4.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a recording material property measuring apparatus and a recording material property measuring method.

  An image forming apparatus such as a copying machine, a facsimile machine, a printer, or a complex machine of these is provided with a plurality of roller pairs and a conveying guide member in a conveying path of a recording material such as recording paper used in the image forming apparatus. The recording material is conveyed by these members. When the recording material is conveyed, the recording material is clogged in the conveyance path, or a jam occurs in the recording material.

In order to prevent this, conveyance of various recording materials is confirmed under various environmental conditions, which is a burden for new product development.
On the other hand, recording materials such as recording paper used in image forming apparatuses have conventionally been affected by changes in the moisture content of the recording material due to changes in environmental conditions such as temperature and humidity, tension applied to the recording material, etc. It is known that environment-dependent characteristics such as shape and rigidity change.

  Therefore, a technique for evaluating a thickness characteristic value that is a relationship between the moisture content of the recording material and the thickness of the recording material (see, for example, Patent Document 1), changes in rigidity before and after the deformation of the recording material. A technique for predicting a residual deformation amount of a recording material from the above (for example, see Patent Document 2) has been proposed.

  However, the technique disclosed in Patent Document 1 is a technique specialized in some characteristics such as the thickness of the recording material, and the technique disclosed in Patent Document 2 analogizes the characteristics of the recording material from a specific deformed shape. All of these are techniques for evaluating macro-environment-dependent characteristics of recording materials.

  For this reason, in macro-environment-dependent characteristics evaluation as in the prior art, the phenomenon cannot be accurately evaluated, and characteristics such as curling, wrinkles, etc. that can correspond to the shape of the transport path that differs depending on the type of equipment product. There is an inconvenience that it is difficult to obtain environment-dependent characteristics that can be used in common.

  This is because typical recording paper used as a recording material has a structure in which fine valve fibers are intertwined in a complicated manner, and the macro-environment-dependent characteristics of the recording material are microscopic such as the orientation of valve fibers. This is because the complex structure and the influence of moisture distribution and the like are expressed in a complicated manner.

  An object of the present invention is to provide a recording material characteristic measuring apparatus capable of efficiently evaluating micro-environment-dependent characteristics of a recording material such as paper.

  The recording material characteristic measuring apparatus of the present invention measures a tension applying member for applying tension to the recording material, a tension measuring member for measuring the tension applied to the recording material, and an outer dimension of the recording material to which the tension is applied. And a structure measuring device for measuring the structure of the recording material to which the tension is applied.

  According to the present invention, since the structure constituting the recording material can be measured, the micro-environment-dependent characteristics of the recording material can be evaluated. As a result, the macro-environment-dependent characteristics and micro-environment-dependent characteristics of various recording materials can be evaluated. And can get a relationship.

It is a schematic diagram which shows schematic structure of the recording material characteristic measuring apparatus which concerns on Example 1 of this invention, Comprising: It is explanatory drawing which shows the state before dripping the reagent for evaluation on a recording material. It is a schematic diagram which shows schematic structure of the recording material characteristic measuring apparatus which concerns on Example 1 of this invention, Comprising: It is explanatory drawing which shows the state which dripped the reagent for evaluation to the recording material. It is a figure which shows an example of the detailed structure of the structure measuring apparatus shown in FIG. 1, FIG. It is the elements on larger scale which expanded and showed a part of measurement optical system shown in FIG. It is explanatory drawing which shows typically an example of the tomographic image of the recording material acquired before dripping the reagent for evaluation on a recording material, and before providing the tension | tensile_strength to a recording material. It is explanatory drawing which shows typically an example of the tomographic image of the recording material acquired before dripping the reagent for evaluation on a recording material and after the tension | tensile_strength provision to a recording material. It is explanatory drawing which shows typically an example of the tomographic image acquired in the state which hold | maintained this tension | tensile_strength for a fixed time, after applying the tension | tensile_strength to a recording material before dropping the reagent for evaluation to a recording material. It is explanatory drawing which shows typically an example of the tomographic image of the recording material acquired after the reagent for evaluation to the recording material is dropped and before the tension is applied to the recording material. It is a characteristic view showing the relationship between the magnitude (load) of tension applied to the recording material and the deformation amount of the recording material, and is an explanatory diagram showing the characteristics before dropping the evaluation reagent on the recording material. It is a characteristic view showing the relationship between the magnitude (load) of tension applied to the recording material and the deformation amount of the recording material, and is an explanatory diagram showing the characteristic after dropping the evaluation reagent on the recording material. It is an equivalent circuit diagram of a microstructure model of a recording material. It is a schematic diagram which shows schematic structure of the recording material characteristic measuring apparatus which concerns on Example 2 of this invention, Comprising: It is explanatory drawing which shows the state before dripping the reagent for evaluation on a recording material. It is a schematic diagram which shows schematic structure of the recording material characteristic measuring apparatus which concerns on Example 2 of this invention, Comprising: It is explanatory drawing which shows the state which dripped the reagent for evaluation on the recording material.

Example 1
Embodiments of a recording material property measuring apparatus and a recording material property measuring method according to the present invention will be described below with reference to the drawings.
(Schematic configuration of recording material characteristic measuring device)
1 and 2 are schematic views showing a schematic configuration of a recording material property measuring apparatus according to Embodiment 1 of the present invention.

In FIGS. 1 and 2, reference numerals 1 and 2 denote tension applying members, 3 a structure measuring device, 4 a recording material, 5 a discharge nozzle (application means), and 6 a monitor.
The tension applying members 1 and 2 are moved in opposite directions while sandwiching the recording material 4.

  The recording material 4 includes a sheet-like object such as paper or film used in the image forming apparatus. In this embodiment, recording paper is used. In this embodiment, an optical interferometer is used as the structure measuring device 3, and details thereof will be described later.

The discharge nozzle 5 discharges the evaluation reagent 7 toward the recording material 4 in order to measure the dimensional change of the internal structure of the recording material 4, and is provided facing the recording material 4. The evaluation reagent 7 is a permeable substance, for example, a liquid, and specifically, a coating material used for the recording material 4 such as pure water or ink is used. That is, the evaluation reagent 7 is a liquid used for confirming a change in the state of the recording material 4 when used for the recording material 4.
The reason why pure water is used is to evaluate the relationship between the recording material 4 and humidity.

  For example, a known load cell 8 (tension measuring member) is fixed to the tension applying members 1 and 2. The tension applied to the recording material 4 by the load cell 8 is measured. For example, a displacement sensor 10 is used as an outer dimension measuring device for measuring the outer dimension by applying tension to the recording material 4. Here, a known optical sensor is used as the displacement sensor 10, and the displacement sensor 10 indirectly measures the outer shape of the recording material 4 by pulse-measuring the amount of movement of the tension applying members 1 and 2 from the reference position. Measure the amount of change in dimensions.

  The tension applying members 1 and 2 are controlled by the control unit 9. The control unit 9 is appropriately loaded with a program according to the characteristics to be acquired, and controls the magnitude of the tension applied to the recording material 4 and the moving speed of the tension applying members 1 and 2.

  Data from the load cell 8 and data from the displacement sensor 10 are input to the control unit 9, and the amount of change in the outer dimension of the recording material 4 corresponding to the magnitude (load) of the applied tension is measured. Further, the internal structure of the recording material 4 before application of the evaluation reagent 7 is visualized and measured.

(Structure of the structure measuring device 3)
As the structure measuring apparatus 3, an optical interferometer apparatus that acquires an image using an optical coherence tomography is used.
As shown in FIG. 3, the optical interferometer device includes a light source unit 21, a light combining / dividing unit 22, a measurement optical system 23, a reference optical system 24, an interference signal detection unit 25, and a signal processing control unit 26. It is roughly composed of

  The light source unit 21 includes a light source 21a and a condenser lens 21b. The light source 21a generates, for example, broadband light P1 having a center wavelength in the near-infrared wavelength region of 0.7 micrometers to 2.0 micrometers and a coherence distance of 20 micrometers or less. This light is low coherence light having partial coherence.

  The broadband light P1 is condensed by the condensing lens 21b, converged on the incident end surface 21d of the light guide fiber 21c, propagates through the light guide fiber 21c, and is guided to the light combining / dividing unit 22.

  The light combining / dividing unit 22 is constituted by, for example, a fiber coupler. The broadband light P1 guided to the light guide fiber 21c is split into measurement light P2 and reference light P3 by the light combining / splitting unit 22.

  For example, the amount of light of the broadband light P1 is divided by 1: 1 by the fiber coupler. The measurement light P2 is guided to a light guide fiber 21e as a measurement optical path. The reference light P3 is guided to the light guide fiber 21f as a reference light path.

  The light combining / dividing unit 22 functions as a light dividing unit that divides the optical path of the light from the light source unit 21 into the optical path of the measurement light P2 and the optical path of the reference light P3. Further, it has a function as a light combining unit that combines the measurement light P2 that is reflected / scattered light from the recording material 4 as the measurement target medium and the reference light P3 to generate combined light.

  The measurement optical system 23 includes a collimator lens 23a, galvanometer mirrors (galvano scanners) 23b and 23c, a collimator lens 23d, and a sample stage 23e. An observation window 23f is formed on the sample table 23e, and the recording material 4 is provided so as to face the observation window 23f.

The collimating lens 23a is provided so as to face the entrance / exit end face 21e 'of the light guide fiber 21e. The collimating lens 23a condenses the measurement light P2 emitted from the light guide fiber 21e and converts it into a parallel light beam P4. The parallel light beam P4 is guided to the galvanometer mirrors 23b and 23c.
In FIG. 3, the tension applying members 1, 2, the load cell 8, the displacement sensor 10, and the control unit 9 are omitted for convenience of explanation.

  Here, both galvanometer mirrors 23b and 23c are driven to reciprocate, whereby three-dimensional tomographic image data to be described later is acquired. If one of the galvanometer mirrors 23b and 23c is driven, a one-dimensional tomographic image is obtained.

  The parallel light beam P4 is guided to the collimator lens 23d as scanning light. The collimating lens 23d plays a role of converting scanning light into spot light P5, as shown in an enlarged view in FIG.

  In this embodiment, since the principal ray of the parallel light beam P4 is parallel to the optical axis of the collimating lens 23d, that is, perpendicular to the surface 4a of the recording material 4, it is possible to accurately acquire a tomographic image. Simplification is achieved.

  The surface 4a of the recording material 4 is two-dimensionally scanned with the spot light P5 through the observation window 23f as shown in an enlarged view in FIG. In FIG. 4, the arrow Z indicates the optical axis direction of the collimating lens 23d, and the arrows X and Y indicate the scanning direction orthogonal to the optical axis direction Z.

  The discharge nozzle 5 discharges the evaluation reagent 7 onto the recording material 4. For the evaluation reagent 7, a substance having permeability to the recording material 4 is used. Here, the evaluation reagent 7 is pure water as described above. The discharge nozzle 5 serves to quantitatively discharge the evaluation reagent 7 as droplets 7 a toward the recording material 4.

  When the droplet 7 a adheres to the recording material 4, the droplet 7 a penetrates into the recording material 4 as time elapses. In FIG. 4, the interface 4 d indicates the interface of the permeation region 4 c at time t <b> 2 when time Δt has elapsed, where t <b> 1 is the time when the droplet 7 a is attached to the back surface 4 b of the recording material 4.

  In FIG. 4, the interface 4 f indicates the interface of the infiltration region 4 e at time t <b> 3 when time Δt ′ (Δt ′> Δt) has elapsed from time t <b> 1. The permeation regions 4c and 4e spread with the passage of time after the droplet 7a adheres to the back surface 4b of the recording material 4, and permeate in the thickness direction of the recording material 4, and the depth of the permeation regions 4c and 4e. Deepens. The measurement of the penetration state of the droplet 7a into the recording material 4 will be described in detail later.

  Here, the permeation regions 4 c and 4 e are regions in a state where the voids inside the recording material 4 are filled with the evaluation reagent 7. The interfaces 4d and 4f are a region (penetration regions 4c and 4e) in which the void in the recording material 4 is filled with the evaluation reagent 7, and the void in the recording material 4 is filled with the evaluation reagent 7. This refers to the boundary surface with the unfinished area.

  A part of the spot light P <b> 5 is scattered and reflected on the surface of the recording material 4, and the remaining part reaches the inside of the recording material 4. Further, a part of the spot light P5 is absorbed by the recording material 4.

  Part of the spot light P5 that has reached the inside of the recording material 4 is reflected at the interface 4d (4f) of the permeation region 4c (4e), and the remaining part is refracted at the interface 4d (4f). It reaches the inside of the infiltration region 4c (4e).

  The reflected light reflected by the interface 4d (4f) of the permeation region 4c (4e) and the reflected / scattered light reflected by the surface 4a of the recording material 4 are collected by the collimator lens 23d and are converted into a parallel light beam (return light). Also referred to as P4 or measurement light P2 is guided to the galvanometer mirrors 23b and 23c.

  The measurement light P2 guided to the galvanometer mirrors 23b and 23c is converged by the collimator lens 23a and guided to the incident / exit end face 21e ′ of the light guide fiber 21e, propagates through the light guide fiber 21e, and the light combining / dividing unit 22 Led to.

  The reference optical system 24 includes collimating lenses 24a and 24b and a reference mirror 24c. The collimating lens 24a faces the incident / exit end face 21f ′ of the light guide fiber 21f.

  The collimator lens 24a plays a role of converting the reference light P3 emitted from the incident / exit end face 21f ′ into a parallel light beam. The reference light P3 is collected by the collimator lens 24b and guided to the reference mirror 24c that totally reflects the reference light P3.

  The reference light P3 reflected by the reference mirror 24c is collected by the collimating lens 24b and guided to the collimating lens 24a through the original optical path. The reference light P3 is focused by the collimating lens 24a on the incident / exit end face 21f ′ of the light guide fiber 21f, propagates through the light guide fiber 21f, and is guided to the light combining / dividing unit 22.

  The measurement light P2 guided to the light combining / dividing unit 22 by the light guiding fiber 21e and the reference light P3 guided to the light combining / dividing unit 22 by the light guiding fiber 21f are combined and passed through the light guiding fiber 21g as interference light P6. Then, it is guided to the interference signal detection unit 25.

  Here, the optical path length from the photosynthesis / division unit 22 to the surface 4a of the recording material 4 and the optical path length from the photosynthesis / division unit 22 to the reference mirror 24c are equal to each other, but the tomographic image of the recording material 4 is used. The optical path length may be varied within a range in which the value can be acquired.

  The interference signal detection unit 25 includes condenser lenses 25a and 25b and a photoelectric conversion member 25c. The interference light P6 is emitted from the exit end face 21g ′ of the light guide fiber 21g, is condensed by the condensing lens 25a to be a parallel light beam, is converged by the condensing lens 25b, and is applied to the photoelectric conversion member 25c. .

  The photoelectric conversion member 25c photoelectrically converts the interference light P6. The photoelectric conversion signal S1 photoelectrically converted by the photoelectric conversion member 25c is input to the signal processing control unit 26.

The signal processing control unit 26 includes a control unit 26a, a signal processing unit 26b, a storage unit 26c, and a display unit 26d.
The control unit 26a includes the light emission control of the light source 21a, the vibration control of the galvanometer mirrors 23b and 23c, the discharge control of the droplet 7a by the discharge nozzle 5, the acquisition timing control of the photoelectric conversion signal, the signal processing unit 26b, and the storage unit. 26c and display control of the display unit 26d.

  The control unit 26a includes hardware such as a CPU, a ROM, and a RAM, and a predetermined control program. The signal processing unit 26b processes the photoelectric conversion signal S1 with a software program according to the optical coherence tomography, and constructs a tomographic image of the recording material 4 using image intensity data (luminance data) based on the photoelectric conversion signal S1. It has the function to do.

(Basic principle of tomographic image acquisition)
In the optical coherence tomography, a photodetecting element including a spectroscopic element and a line sensor is used as the photoelectric conversion member 25c.
This photodetection element can detect the spectrum over the entire wavelength band of the light emitted from the light source 21a.

  The interference light P6 includes measurement light P2 and reference light P3, which are return light from the surface 4a of the recording material 4 and the inside of the recording material 4. Here, in the recording material 4 of the measurement optical system 23, assuming that the return light is generated only from the position of the optical path length equal to the optical path length from the light combining / dividing unit 22 to the reference mirror 24c, the spectrum in the light detection element is assumed. Interfering light is observed.

In this state, if the optical path length from the light combining / dividing unit 22 to the reference mirror 24c is fixed and the position where the return light is generated is changed in the optical axis direction in the measurement optical system 23, an optical path difference is generated. That is, there is a difference between the optical path length from the light combining / dividing unit 22 to the reference mirror 24c and the optical path length from the light combining / dividing unit 22 to the position where the return light is generated. As the optical path difference increases, the interval between the interference fringes becomes narrower.
In other words, the interval between the observed interference fringes is determined by the position where the return light is generated.

  Since the interference light P6 is synthesized with the return light from the surface 4a of the recording material 4 and the respective parts inside the recording material 4, the fringe spacing of the interference fringes based on the observed spectral interference light also corresponds to this. It will be a thing.

  When the photoelectric conversion signal S1 based on the spectral interference light is Fourier-transformed in the signal processing unit 26b, the spectral decomposition is performed according to the interval between the interference fringes, and thereby the generation position of the return light is specified.

  The amplitude of the spectrum interference light is determined corresponding to the intensity of the return light, and the spectrum intensity of the signal after the Fourier transform (Fourier transform signal) increases as the intensity of the return light from the generation position becomes large.

  That is, the fact that the spectral intensity of the Fourier transform signal corresponding to a certain return light generation position is relatively large means that the intensity of reflected or scattered light at the return light generation position is relatively large.

Therefore, a one-dimensional tomographic image in the thickness direction of the recording material 4 can be acquired by determining the luminance distribution corresponding to the return light generation position according to the spectral intensity of the Fourier transform signal.
If these processes are performed while the galvanometer mirrors 23b and 23c are scanned two-dimensionally, a two-dimensional tomographic image of the recording material 4 can be obtained.

  The storage unit 26c has a function of storing the tomographic images in chronological order, and a function of storing a software program necessary for the signal processing unit 26b to perform signal processing. The storage unit 26c also has a function of storing data necessary for estimating the interface and data necessary for calculating the permeation speed, such as a tomographic image scale and a tomographic image acquisition time. The display unit 26d has a function of displaying at least a tomographic image.

  In this embodiment, a scattering suppression transparent object 27 is provided on the surface 4 a of the recording material 4. For the scattering-suppressing transparent object 27, a substance that does not easily penetrate the recording material 4, for example, an adhesive sheet having high transparency with respect to the broadband light P1 is used.

  The reason is to avoid reflection and scattering from the surface 4 a of the recording material 4. By avoiding such reflection / scattering, the ratio of the transmitted light amount can be increased and the S / N ratio of the tomographic image can be improved. It is desirable to use a flexible material for the adhesive sheet.

  That is, when the return light such as scattered light and reflected light from the surface 4a of the recording material 4 is excessively large, the amount of the spot light P5 entering the recording material 4 is relatively small, and the tomographic image There is a risk of hindrance during construction.

  On the other hand, when the scattering suppression transparent object 27 is provided on the surface 4a of the recording material 4, the scattering itself from the surface 4a of the recording material 4 is suppressed, so that the amount of the spot light P5 guided to the inside of the recording material 4 Will increase.

  Further, the reflection / scattering light from the surface 27a of the scattering suppression transparent object 27 and the reflection / scattering light from the surface 4a of the recording material 4 are easily separated because the surface 4a and the surface 27a are separated from each other. Therefore, data acquisition of image intensity based on the return light from the surface 4a of the recording material 4 is facilitated.

  When it is difficult to attach the scattering-suppressing transparent object 27 to the surface 4a of the recording material 4, instead of using the scattering-suppressing transparent object 27, the surface 4a of the recording material 4 is smoothly finished and processed. The scattered light from the surface 4a may be reduced.

  As described above, in this embodiment, the intensity of the return light from the surface 4 a of the recording material 4 is decreased, so that the reflected / scattered light from the inside of the recording material 4 is returned from the surface 4 a of the recording material 4. Therefore, the measurement accuracy can be improved and a tomographic image can be clearly constructed.

(Measurement of structural dimension change)
Hereinafter, changes in the internal structure obtained by using the structure measuring apparatus 3 will be described with reference to FIGS.

  The recording material 4 is mainly composed of a fibrous structure 4p such as pulp and a filling material 4q that fills a gap between the fibrous structure 4p. 5 to 8 schematically show the fibrous structure 4p and the filling material 4q.

  The fibrous structure 4p is configured to be intertwined in a complicated manner, but here, the fibrous body 4p ′ extending in a direction orthogonal to the thickness direction of the recording material 4 and the fibrous body 4p ′ are schematically illustrated here. The description will be made assuming that the fiber body 4p ″ extends in the orthogonal direction. In FIGS. 5 to 8, the orientation directions of the fiber bodies 4p ′ and 4p ″ are also shown in a simplified manner.

As shown in FIG. 5, the structure measuring apparatus 3 acquires a tomographic image G1 before applying a tension to the recording material 4. From the tomographic image G1 shown in FIG. 5, the diameter φD _{0 of} the fibrous structure 4p in the evaluation region of the width W ₀ and the thickness d ₀ of the recording material 4, the length L _{0 of} the fibrous structure 4p, and the fibrous structure An angle θ _{0 formed} by the body 4p to be horizontal (orientation angle of the fibrous structure 4p with respect to the surface 4a of the recording material 4) is measured.

Since the fibrous structure 4p of the recording material 4 is mainly made of natural materials such as pulp, the diameter φD ₀ , length (dimension) L ₀ , angle θ _0, etc. of the fibrous structure 4p are set. It calculates | requires over several arbitrary evaluation area | regions, and calculates | requires the distribution state of these values.

  Further, from these, the density of the fibrous structure 4p and the average orientation direction of the fibrous structure 4p are obtained, and the micro characteristics of the recording material 4 are evaluated by comprehensively considering these. As a result of these micro characteristics, the macro characteristics of the recording material 4 are manifested.

When a tension is applied to the recording material 4, the recording material 4 extends and deforms in the direction in which the tension is applied, as shown in FIG.
By the action of this tension, the evaluation area of the tomographic image G1 changes from the width W ₀ and thickness d ₀ to the width W _T and thickness d _T.
The length of the fibrous structure 4p changes from L ₀ to L _T, the diameter is changed from [phi] D ₀ to [phi] D _T.

  FIG. 6 schematically shows a state where separation is caused between the fibrous body 4p ′ orthogonal to the tension applying direction and the filling material 4q due to the addition of the tension of the recording material 4, and a void 4r is generated. Yes.

In such a case, the load in the tension applying direction is borne by the fibrous body 4p ″ extending in the direction orthogonal to the fibrous body 4p ′ and the filling material 4q.
When a predetermined tension is applied to the recording material 4 and the tension applying members 1 and 2 are fixed and held for a predetermined time (fixed time) Δt, a fibrous body 4p ″ is obtained as shown in FIG. gap 4s between the fill material 4q occurs. the evaluation region of the recording medium 4 is changed from the width W _T in the width W _T delta _t, the thickness changes from d _T to d _T delta _t.

Further, the diameter of the fibrous structure 4p changes from [phi] D _T to [phi] D _T delta _t, the length of the fibrous structure 4p changes from L _T to L _T delta _t. Due to the change in the length of the fiber body 4p ″ of the recording material 4 and the generation of the gap 4s between the fiber body 4p ″ and the filling material 4q, the load required to maintain the elongation of the recording material 4 is reduced. . This appears as stress relaxation as a macro characteristic of the recording material 4.

(When the evaluation reagent 7 is applied to the recording material 4)
In a state in which the recording material 4 without tension, the dropwise addition of pure water as an evaluation reagent 7, the recording material 4 to swell, the evaluation area of the recording material 4 as shown in FIG. 8 from the width W ₀ shown in FIG. 5 The width changes to _WW and changes from the thickness d ₀ shown in FIG. 5 to the thickness d _W shown in FIG.

Further, the diameter of the fibrous structure 4p changes from the diameter φD ₀ shown in FIG. 5 to φD _W shown in FIG. 8, and the length changes from L ₀ to L _W. By applying tension to the recording material 4 in a state where the recording material 4 is swollen, the characteristic values corresponding to FIGS. 6 and 7 can be obtained. That is, changes in internal structure can be visualized and measured.

(Example of analysis of characteristics of recording material 4)
FIG. 9 is a characteristic diagram schematically showing the relationship between the tension (load) applied to the recording material 4 and the amount of elongation (displacement) of the recording material 4.

  When a load is applied to the recording material 4 and the load is gradually increased, the displacement amount of the recording material 4 increases in proportion to the load, as indicated by 0-A in FIG. This 0-A is called an elastic deformation region of the recording material 4.

  When the load applied to the recording material 4 reaches point A in the vicinity of the predetermined value Fx, when the internal structure of the recording material 4 is viewed microscopically, a gap 4r is generated due to peeling, and the amount of displacement increases with respect to the change in the applied load. A plastic deformation region (AB) is formed between point A and B (predetermined value Fx) indicating the load.

  Next, when the load applied to the recording material 4 is fixed at a predetermined value Fx and a predetermined time Δt has elapsed, when the internal structure of the recording material 4 is viewed microscopically, a gap 4s due to peeling occurs, and the displacement amount of the recording material 4 As a result, the load applied to the recording material 4 gradually decreases while the pressure becomes constant, and a stress relaxation region BC is obtained.

Here, when the load applied to the recording material 4 is gradually reduced, the amount of displacement of the recording material 4 decreases, and the recording material 4 extends by a certain amount with respect to the length before the load is applied in a state where the load is removed. It becomes a state. A region CD where the recording material 4 contracts when the load of the recording material 4 is removed is referred to as a springback region.
The measurement of the springback region is performed by gradually reducing the load applied to the tension applying members 1 and 2 and measuring the change (shrinkage amount) of the width W _{T Δt} of the evaluation region accompanying the decrease in the load.

  The macro Young's modulus of the recording material 4 can be obtained from the inclination of the elastic deformation region 0-A, and the macro stress relaxation rate of the recording material 4 can be obtained from the time change of the stress relaxation region BC. .

  When the evaluation reagent 7 is dropped on the recording material 4 and the load applied to the recording material 4 is gradually increased to obtain the same characteristics as shown in FIG. 9, the characteristic diagram shown in FIG. 10 is obtained.

In FIG. 10, 0-A _W represents the elastic deformation region, A _W -B _W represents the plastic deformation region, B _W -C _W represents the stress relaxation region, and C _W -D _W represents the spring back region. Indicates.

  When the evaluation reagent 7 is dropped on the recording material 4, the recording material 4 swells and becomes soft and easily stretched. Therefore, the deformation amount of the recording material 4 increases with respect to the applied load, so the Young's modulus decreases. . Further, since the amount of shrinkage when the load applied to the recording material 4 is removed due to the swelling of the recording material 4, the amount of spring back is also reduced.

(Acquisition of characteristics of recording material 4 due to influence of humidity as environmental condition)
By obtaining the humidity data of the recording material 4 by changing the dropping amount of the evaluation reagent 7, the influence of the moisture content of the recording material 4 due to the humidity of the environment can be evaluated. Further, the relationship data between the tensile load and the deformation amount of the recording material 4 under various wet conditions is acquired, and the internal structure shown in FIGS. 5 to 8 is correlated with the tensile load and the displacement amount of the recording material 4 to record. The macroscopic characteristics and the microscopic characteristics of the material 4 can be correlated.

  FIG. 11 shows an equivalent circuit diagram of the microstructure model of the recording material 4. In FIG. 11, k1 is an elastic term in the direction in which the fibers of the fibrous structure 4p oriented in the tension applying direction extend, and d1 is a viscosity term of the fibrous structure 4p. K2 is the elastic term of the fibrous structure 4p oriented in the direction orthogonal to the tension applying direction, and d2 is the viscosity term of the fibrous structure 4p oriented in the direction orthogonal to the tension applying direction. . K3 is the elastic term of the filling material 4q, and d3 is the viscosity term of the filling material 4q.

  These elastic terms k1, k2, k3 and viscosity terms d1, d2, d3 are the relationship between the displacement amount and the load of the recording material 4 when a tensile load is applied to the recording material 4, and the inside of the recording material 4 at this time. It can be determined from the structural change.

  Since the fibrous structure 4p of the recording material 4 is oriented in two axial directions (vertical direction and horizontal direction of the recording material 4) perpendicular to the thickness direction of the recording material 4, a tensile load is applied in both directions. In addition, it is desirable to obtain microscopic characteristics.

  Further, the complexity of the model can be increased by increasing or decreasing the number of pairs of the elastic term k and the viscosity term d according to the composition, amount, density, etc. of the fibrous structure 4p and the filling material 4q constituting the recording material 4. It is desirable to balance the accuracy of the characteristic value.

(Advantages over the prior art)
Since the deformation direction of the recording material 4 varies depending on the conveyance direction, the conventional technique has to evaluate the characteristics against deformation of the recording material 4 under all environmental conditions for each deformation direction.

  In such a conventional evaluation, disturbance factors such as the fine structure variation and non-uniformity of the recording material 4 and the variation of environmental conditions interact with each other, and it is difficult to obtain characteristic values useful for development. It was.

As a result, confirmation tests for all paper types, printing modes, and environmental conditions have not been omitted.
On the other hand, according to the embodiment of the present invention, the environment dependence can be simulated by using the evaluation reagent 7, and the macro characteristic value is measured in association with the microstructure of the recording material 4. Based on this, since the macro characteristic value of the recording material 4 can be evaluated, efficient product development can be realized.

  That is, the embodiment of the present invention includes a structure measuring step for measuring a structure before applying tension to the recording material 4 and a tension applying step for applying tension to the recording material 4 after measuring the outer dimensions of the recording material 4. Is included. And the tension | tensile_strength provided by the tension | tensile_strength provision step is measured, and the external dimension and structure of the recording material 4 corresponding to the tension | tensile_strength are measured.

The evaluation reagent 7 is applied to the recording material 4, each step is executed to measure the tension, and the external dimensions and structure of the recording material 4 corresponding to the tension are measured to evaluate the characteristics of the recording material 4. For example, the microscopic environment-dependent characteristics of the recording material 4 can be measured.
By applying tension to the recording material 4 while increasing the tension applied to the recording material 4 and measuring the amount of change in the external dimensions and the amount of change in the structure of the recording material 4, Young's modulus and macroscopic Young's modulus can be measured.

If the change in load applied to the recording material 4 is measured in a state where the tension applied to the recording material 4 is held for a certain time Δt, the macroscopic stress relaxation rate of the recording material 4 can be measured.
If the amount of shrinkage of the recording material 4 is measured in a state where the load applied to the recording material 4 is removed, the plastic deformation rate of the recording material 4 can be measured.

  Furthermore, if the environment-dependent characteristics are evaluated using two types of liquids such as pure water and ink liquid as evaluation reagents, the recording material 4 is printed with ink liquid on one side and blank on the other side. It is possible to evaluate the environment-dependent characteristics when printing is performed, that is, when the recording material 4 is used as a backing paper.

In this embodiment, the moisture content of the recording material 4 is changed using the evaluation reagent 7, but the present invention is not limited to this.
For example, the entire recording material property measuring apparatus is installed in an environmental tank where temperature and humidity can be controlled, and the recording material 4 is left in the environmental tank for a certain period of time so that the recording material 4 is sufficiently familiar with the environmental tank. Then, environment-dependent characteristics may be measured.
In this case, it is desirable to measure the moisture content using a moisture content measuring device capable of measuring the moisture content of the recording material 4.

(Example 2)
(Schematic configuration of recording material characteristic measuring device)
12 and 13 are schematic diagrams showing a schematic configuration of a recording material property measuring apparatus according to Embodiment 2 of the present invention.

In the second embodiment, the recording material property measuring apparatus according to the first embodiment of the present invention includes a humidity measuring apparatus 200. Other configurations are the same as those in the first embodiment, and thus the description thereof is omitted.
The humidity measuring device 200 is provided on the opposite side of the ejection nozzle 5 with the recording material 4 interposed therebetween.

In this embodiment, the moisture content of the recording material 4 is changed according to the amount dropped from the ejection nozzle 5, and the humidity of the recording material 4 at that time is measured by the humidity measuring device 200 provided in the vicinity of the recording material 4. When this humidity measuring device 200 is provided, the influence of the environmental change of the recording material 4 can be quantitatively evaluated.
When the humidity measuring apparatus 200 is provided in this way, it is possible to measure the optimum humidity so that the recording material 4 is not clogged during conveyance, and to manage the appropriate humidity.

In this embodiment, the humidity measuring device 200 is provided on the side opposite to the discharge nozzle 5 with the recording material 4 interposed therebetween. However, when the influence of the permeation speed of the evaluation reagent 7 is large, the humidity measuring device 200 side Alternatively, the recording material 4 may be provided on both the discharge nozzle 5 side and the opposite side.
Further, it is not necessary to fix the position of the humidity measuring apparatus 200. For example, by providing the humidity measuring apparatus 200 at a position that can be moved in parallel to the surface of the recording material 4, the evaluation reagent 7 is applied or the internal structure of the recording material 4 is observed. It is also possible to adopt a configuration that can be retracted.

1, 2 ... tension applying member 3 ... structure measuring device 4 ... recording material 8 ... load cell (tension measuring member)
10. Displacement sensor (external dimension measuring device)
200 ... Humidity measuring device

Japanese Patent No. 522167 Japanese Patent No. 4803018

Claims (11)

A tension applying member that applies tension to the recording material;
A tension measuring member that measures the tension applied to the recording material;
An external dimension measuring device for measuring the external dimensions of the recording material to which the tension is applied;
A recording material property measuring apparatus, comprising: a structure measuring device that measures the structure of the recording material to which the tension is applied. The recording material property measuring apparatus according to claim 1,
A humidity measuring device for measuring the humidity of the recording material;
An apparatus for measuring a recording material characteristic, comprising: an application unit that applies a permeable substance to the recording material. In the recording material property measuring apparatus according to claim 1 or 2,
The recording material characteristic measuring apparatus, wherein the structure measuring apparatus is composed of an optical interferometer that acquires an image using an optical coherence tomography. In the recording material property measuring apparatus according to claim 2 or 3,
The structure measuring apparatus measures the structure of the recording material according to the humidity of the recording material before and after the application of the tension. The recording material property measuring apparatus according to any one of claims 1 to 4,
Change the tension applied by the tension applying member, measure the outer dimensions and structure of the recording material corresponding to the change,
A recording material characteristic measuring apparatus characterized by fixing an outer dimension of the recording material and measuring a tension acting on the recording material and a structure of the recording material. In the recording material property measuring apparatus according to any one of claims 2 to 5,
After applying a material having permeability to the recording material by the application means, at least change the tension applied by the tension applying member, and measure the external dimensions and structure of the recording material corresponding to the change, Alternatively, the recording material characteristic measuring apparatus is characterized in that the outer dimensions of the recording material are fixed and the tension acting on the recording material and the structure of the recording material are measured. The recording material property measuring apparatus according to any one of claims 2 to 6,
The recording material characteristic measuring apparatus according to claim 1, wherein there are at least two kinds of penetrating substances applied to the recording material by the applying means. In the recording material property measuring apparatus according to any one of claims 2 to 7,
The recording material characteristic measuring device, wherein the humidity measuring device is movable in parallel with the surface of the recording material. A structure measuring step for measuring the structure before applying tension to the recording material;
A tension applying step for applying tension to the recording material after measuring the outer dimensions of the recording material,
A recording material characteristic measuring method, comprising: measuring a tension applied in the tension applying step; and measuring an outer dimension and a structure of the recording material corresponding to the tension. In the recording material characteristic measuring method according to claim 9,
A method for measuring characteristics of a recording material, comprising measuring a change in load applied to the recording material while maintaining a tension applied to the recording material. In the recording material characteristic measuring method according to claim 9 or 10,
A recording material characteristic measuring method, comprising: measuring a shrinkage amount of the recording material in a state where a load applied to the recording material is removed.