JP2755996B2 - Liquid absorption tester and test method thereof - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a liquid absorptivity tester and a test method therefor, and more particularly, to a rotary wheel having an outer peripheral portion on which an object to be measured is fixed, and the rotary wheel. The present invention relates to a liquid absorptivity tester comprising a driving means for driving a liquid at a given constant speed and a head box for applying a predetermined amount of liquid at a fixed position to a rotating object to be measured, and a test method thereof. is there.

[Conventional technology]

The permeation of the coating liquid at the time of various coatings to paper, paperboard, film, cloth, woven fabric, non-woven fabric and other sheet-like materials, transfer and absorption of ink and dampening solution at the time of printing, etc. It is a phenomenon that involves the wetting of the liquid to the surface and the subsequent penetration behavior. In order to elucidate these phenomena, many methods for measuring absorbance have been proposed and used. For example,
There are the Cobb method, the method of evaluating the water absorption behavior on paper known by the Stecht method, various oil absorption test methods, and the like. All of these measures the permeation and absorptivity in several seconds to several tens of seconds.

As research on the permeability and absorbency caused by the contact between paper and liquid has progressed, the liquid absorption behavior in a very short time after contact has a significant meaning, so a method to evaluate the behavior was considered.

As one of these methods, J.TAPPI paper pulp test method No.51
-87 There is a liquid absorption test method (Bristow method) of paper and itachi. The measurement principle in this method is that a head box to which a known amount of liquid is added is brought into contact with a moving object at an arbitrary constant speed, and the liquid is completely absorbed by the object through a slit. The absorption characteristics of paper and paperboard in a very short time can be known from the absorption time (contact time) and the amount of liquid transfer at this time.

An apparatus for carrying out this method is a driving means that combines a metal rotary wheel having an outer peripheral portion for fixing an object to be measured and a number of transmissions for driving the rotary wheel at an arbitrary constant speed. And a headbox for applying a predetermined amount of liquid at a fixed position to the rotating object to be measured. And the operation of this device,
The measuring method by this device is such that the object to be measured is fixed to the outer peripheral portion of the metal rotary wheel in close contact, a predetermined amount of liquid is supplied to the head box, and then the metal rotary wheel is rotated at an arbitrary constant speed, and the head is rotated. The box is lowered onto the rotating object to be completely absorbed. After the rotation of the rotating wheel is stopped, the object to be measured is removed from the outer periphery, the length of the trace where the liquid is absorbed is measured, and the liquid absorption amount per unit area at the unit contact time is determined from the length. .

[Problems to be solved by the invention]

Conventional liquid absorption testers for liquid absorption tests rely on humans to measure the length of the trace where the liquid has been absorbed. Can measure the length of the absorbed part, determine the amount of liquid absorbed per unit area per unit contact time from the length, and also measure the change in the liquid penetration depth in the thickness direction of the measured object It is an object of the present invention to provide a liquid absorptivity tester and a test method thereof.

[Means for solving the problem]

In order to achieve the above object, the present invention provides a rotating wheel having an outer peripheral portion for fixing an object to be measured, a driving unit for driving the rotating wheel at an arbitrary constant speed, and a rotating measuring object. In a liquid absorption tester comprising a head box for applying a predetermined amount of liquid at a certain position to an object, at least a part of an outer peripheral portion of the rotating wheel is made of an optically transparent material, and the part is transmitted. An optical measuring device for measuring the amount of light to be emitted is provided.

Further, a means for rotating the light source and the photodetector of the optical measuring device at the same angular velocity as the rotary wheel is provided, and the light source and the photodetector are rotated at the same angular speed as the rotary wheel. The detector is arranged inside the outer periphery of the rotating wheel, or one of them is arranged inside the outer periphery of the rotating wheel and the other is arranged outside.

As a light source, a tungsten laser, a neon lamp, a light emitting diode, or the like, or various lasers such as a gas laser, a solid-state laser, a semiconductor laser, or a liquid laser can be used. Junction type element, Cd
A photoconductive element such as S or CdSe, a photomultiplier tube or the like can be used.

In the optical measuring device, various optical elements as required, for example, a plane mirror, a semi-transparent plane mirror, a convex mirror,
Various filters such as a concave mirror, various lenses, various prisms, a wavelength filter, and a deflection filter are used alone or in combination.

As a test method, in a liquid absorption test method in which a predetermined amount of liquid is applied at a certain position to a sheet-like measurement object moving at a constant speed, the light source and the photodetector of the optical measurement device are measured by the measurement. The method is characterized in that a change in a liquid penetration depth in a thickness direction of an object to be measured is measured while moving the object at the same speed.

(Operation)

In the liquid absorptivity tester, at least a part of the outer periphery of the rotating wheel is made of an optically transparent material, and an optical measuring device for measuring the amount of light transmitted through the part is provided. By continuously detecting the amount of light or light intensity of reflected light or transmitted light, which changes as the measured object absorbs the liquid, the length of the part absorbed by the liquid and the unit contact from the length It is possible to measure a liquid absorption amount per unit area over time, and a change in a liquid penetration depth in a thickness direction of an object to be measured.

If the light source and photodetector are fixed,
It can measure the length of the part where the object has absorbed the liquid.If the light source and the photodetector rotate at the same angular velocity as the rotating wheel, the thickness of the object The change in liquid penetration depth in the direction can be measured.

〔Example〕

Hereinafter, an embodiment of the present invention will be described with reference to a liquid absorption tester shown in the drawings.

1 and 2 show a rotary wheel of a liquid absorption tester according to an embodiment of the present invention. In the drawing, 1 is a rotating wheel, 1a is a hollow cylindrical transparent glass or synthetic resin outer peripheral portion, 1b is a disk-shaped base portion supporting the outer peripheral portion 1a, and 2 is provided at the center of the base portion 1b. The shaft hole 3 through which the drive shaft 5 (FIGS. 3 and 4) penetrates is a fixing portion having a screw hole 3a and fixed to the base portion 1b. The rotary wheel 1 is fixed to a drive shaft 5 by screws 4. 3 and 4, the drive shaft 5 is driven from the electric motor 15 via a first transmission 14a, a second transmission 14b controlled by a control circuit in the control panel 9, and power transmission means (not shown). Driven at any constant speed. In addition, 10 is a speed display plate, and 13 and 13 are on / off switches. An instruction to the control circuit in the control panel 9 can be given by a speed adjustment knob 11 and a transmission switching knob 12.

The head box 7 is a container for liquid injection having a slit having a width of 1 mm and a length of 15 mm at a lower end, and is supported by a support rod 6. The support rod 6 is stationary at a right and left weight balance with the pivot 16 as a fulcrum, and is adjusted by a counterbalance 8 at an end opposite to the head box 7. That is, the pressing force on the object to be measured on the bottom surface of the head box 7 can be adjusted by adjusting the counter balance 8.

In the example shown in FIGS. 3 and 4, the light source 17 and the light detector 18 of the optical measuring device are
Is fixed on the support base 19 of the machine so as to be located inside the outer peripheral portion 1a of the machine. In this example, it is continuously detected by the photodetector that the object to be measured changes the reflection intensity of the light by absorbing the liquid, and the length of the portion absorbing the liquid from the time of the change state. Then, the liquid absorption amount per unit area in the unit contact time can be obtained.

In the example shown in FIGS. 5 and 6, the light source 20 of the optical measuring device is located inside the outer circumference 1a of the rotating wheel,
The photodetector 21 is fixed to the support base 19 of the machine so that the photodetector 21 is located outside the outer peripheral portion 1a. In this example, it is detected from the light source 20 that the amount of light passing through the outer peripheral portion 1a of the rotary wheel 1 and the object to be measured changes due to the absorption of the liquid by the object to be measured, and the time required for the measurement is determined based on the detection required time. The length of the part of the object that has absorbed the liquid can be determined, and then the amount of liquid absorbed per unit area per unit contact time can be determined.

Note that, even if the positions of the light source 20 and the photodetector 21 are reversed, exactly the same operation can be achieved.

Although not shown, the light source 17 or 20 and the photodetector 18 or 21 of the optical measuring device are directly mounted on the rotating wheel 1 and the light source 17 or 20 is utilized by using the drive shaft 5 (for example, wired as hollow). In the example in which the electrical connection to the light detector 20 or the light detector 18 or 21 is made, by continuously detecting the change in the reflected light intensity or the transmitted light amount, the liquid penetration depth in the thickness method of the object to be measured is determined. Can be measured automatically and in real time.

Furthermore, when the example of FIG. 3, 4 or 5 or 6 is combined with an example in which the light source 17 or 20 and the light detection 18 or 21 of the optical measuring device are directly mounted on the rotating wheel, the measured The liquid absorption amount of the object and the change in the liquid penetration depth in the thickness direction can be simultaneously and automatically measured in real time.

 The operation is performed as follows.

First, the tester is connected to the power supply by the on / off switch 13, and the speed is set. Measurements can be made at any constant speed (usually,
0.5,1.25,2.5,5.0,12.5,25.0,50.0,250mm / s).
After setting the speed, the test piece is closely fixed on the outer peripheral portion 1a of the rotating wheel 1. About 40 μ of distilled water is put into the head box 7. It is preferable to use distilled water to which a coloring dye is added as necessary.

The rotating box 1 is rotated, and the pressing force is adjusted to about 1.02 kgf / cm ² by the counter balance 8.
Is gently lowered onto the test piece. Rotating wheel 1 until distilled water in head box 7 is completely absorbed by the test piece.
When the absorption is completed (when no trace remains on the test piece), the head box 7 is removed from the test piece, and the rotation of the rotary wheel 1 is stopped. Then, the measured piece is detached from the outer peripheral portion 1a. At various speeds, the above operation is performed to cause the optical measurement device to automatically record the measurement result.

〔The invention's effect〕

According to the present invention, at least a part of the outer peripheral portion on which the object to be measured of the rotating wheel is fixed is made of an optically transparent material, and the optical measuring device for measuring the amount of light transmitted through the part is provided. It is possible to automatically determine the length of the part of the device that absorbs the liquid and the amount of liquid absorbed per unit area in the unit contact time, and the light source and the photodetector of the optical measuring device are connected to a rotating wheel. When rotating at the same angular velocity, a change in the liquid penetration depth in the thickness direction of the measured object can be measured.

[Brief description of the drawings]

1 is a longitudinal sectional view of a rotary wheel of a liquid absorption tester showing an embodiment of the present invention, FIG. 2 is a front view of the same rotary wheel, and FIG. 3 is a front view of the same liquid absorption tester. FIG. 4 is a side view of the liquid absorption tester shown in FIG. 3 as a partial cross section, FIG. 5 is a front view of a liquid absorption tester showing another embodiment of the present invention, and FIG. It is the side view which made a partial cross section of the liquid absorption tester of FIG. Reference numeral 1: rotating wheel, 1a: outer peripheral portion, 1b: base portion, 2
…… Shaft hole, 3 …… Fixed part, 3a …… Screw hole, 4… Screw,
5 ... Drive shaft, 6 ... Support rod, 7 ... Head box,
8 counterbalance, 9 control panel, 14a primary transmission, 14b secondary transmission, 15
… Electric motor, 16… Axis, 17,20 …… Light source, 18,21 ……
Light detector.

Claims (5)

(57) [Claims] 1. A rotating wheel having an outer peripheral portion for fixing an object to be measured, a driving means for driving the rotating wheel at an arbitrary constant speed, and a predetermined amount at a fixed position on a rotating object to be measured. A liquid absorption tester comprising a head box for applying the liquid, wherein at least a part of an outer peripheral portion of the rotary wheel is made of an optically transparent material, and the amount of light transmitted through the portion is measured. A liquid absorptivity tester provided with an optical measuring device. 2. The optical measuring device according to claim 1, further comprising a light source and a light detector, and means for rotating the light source and the light detector at the same angular velocity as the rotating wheel. The liquid absorption tester according to (1). 3. The liquid absorptivity test according to claim 1, wherein the light source and the photodetector of the optical measuring device are arranged inside an outer peripheral portion of the rotary wheel. Machine. 4. The optical measuring device according to claim 1, wherein one of the light source and the light detector of the optical measuring device is disposed inside the outer peripheral portion of the rotary wheel, and the other is disposed outside. )
The liquid absorption tester according to the above. 5. A liquid absorptivity test method for applying a predetermined amount of liquid at a predetermined position to a sheet-like measurement target moving at a constant speed, wherein a light source and a photodetector of an optical measurement device are connected to the measurement target. A liquid absorption test method characterized by measuring a change in a liquid penetration depth in a thickness direction of an object to be measured while moving the object at the same speed.