JPH1183719A - Method for evaluating plasticity of tempered soil - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for evaluating plasticity of a tempered soil wherein plasticity of a tempered soil under such condition as close to a closed space is evaluated with ease. SOLUTION: At a bottom part of a cylinder 1, a nozzle plate 3 comprising a nozzle hole 2 is fixed with a lock nut 4. A sample S sandwiched between filter papers F is put in the cylinder 1, and pressed by a piston 5. The sample S is pressurized to reduce its volume. Solid volume ratio between when pressurized under low pressure and when under a high pressure is measured, and plasticity is evaluated from its difference. The larger the solid volume ratio difference between when pressurized under low pressure and pressurized under high pressure, the more preferable the filling characteristics of a tempered soil in a closed space.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] The present invention relates to a method for evaluating plasticity of a clay for producing a ceramic product.

[0002]

2. Description of the Related Art As one of the methods for producing ceramic products such as ceramics and fine ceramic products, there is a method in which a plastic clay is formed, dried and fired. Press molding, potter's wheel molding, extrusion molding, and the like are employed for this molding. In any of the molding methods, it is necessary to make the plasticity of the clay suitable.

[0003] The plasticity of the clay is expressed by a shape retention property called "Koshi" and a deformability called "Nobi". As a method for evaluating the plasticity of such a clay, a Pefferkorn method, a compression test, and the like are performed. In these methods, plasticity is evaluated by applying stress to the clay and deforming the clay. But,
In any of the evaluation methods, the evaluation is performed in a state in which the kneaded material has an opening and the kneaded material is easily movable to some extent, instead of being deformed by stress in a closed state. Therefore,
There was hardly any method to evaluate how easily the compacted soil could be filled by being compacted by deformation in a state close to a closed space.

[0004]

SUMMARY OF THE INVENTION The present invention relates to a method in which clay is used for forming a clay, such as wet press molding performed in the manufacture of ceramics and fine ceramics, and re-press molding performed in order to adjust the shape of bricks and roof tiles. It is an object of the present invention to provide a method for evaluating the plasticity of a clay which can be used for evaluating a clay to be used in a molding method in which compaction is performed in a closed space.

[0005]

According to the method for evaluating the plasticity of a kneaded material of the present invention, a kneaded material is put into a cylinder having a nozzle hole covered with a filter, and the kneaded material is pressed with a piston at low pressure and high pressure. The plasticity of the kneaded material is evaluated based on the difference between the solid volume fraction when the kneaded material is squeezed and squeezed at a low pressure and when the material is squeezed at a high pressure.

[0006] The method of the present invention is a method for evaluating the extent to which the mass is changed by sandwiching the mass with a filter in a cylinder, applying pressure with a piston and squeezing the mass. As this evaluation scale, the difference in solid volume fraction between when squeezed at a low pressure and when squeezed at a high pressure is used, and the larger the difference, the better the fillability of the clay in the closed space.

[0007]

FIG. 1 is a sectional view of an apparatus used in a method for evaluating plasticity of a clay according to an embodiment.

A nozzle plate 3 having a nozzle hole 2 at the bottom of a cylinder 1 is fixedly installed by a lock nut 4. The sample S is inserted into the cylinder 1 by the filter paper F, and the piston 5 presses the sample S. The sample S is squeezed to reduce its volume. The solid volume fraction when squeezed at low pressure and when squeezed at high pressure is measured, and the plasticity is evaluated from the difference.

As a result of various experiments, it has been found that the low pressure applied by the piston 5 is preferably 1.96 to 3 MPa. When the low pressure is lower than 1.96 MPa, the fluctuation due to the measured pressure is large, and the dispersion of the evaluation results tends to be large. On the other hand, when the pressure is higher than 3 MPa, the difference from the solid volume fraction in the case of high pressure becomes small, so that there is no clear difference between the evaluation results between the clays.

The high pressure is 19.6 MPa, for example, 19.6 MPa.
-30 MPa was found to be preferable. High pressure is 1
When the pressure is lower than 9.6 MPa, the difference from the solid volume fraction in the case of low pressure becomes small, so that there is no clear difference in the evaluation results between the clays.

The pressing time is 2.5 hours or more, for example, 2.5 to
5Hr is preferred. That is, it is recognized that the solid volume fraction becomes substantially constant (saturated value) when the pressing time is 2.5 Hr or more, and the solid volume fraction does not often reach the saturated value when the compression time is less than 2.5 Hr.

The inner diameter of the cylinder 1 is 5 to 100 mm
About 10 to 50 mm is particularly preferable. Nozzle hole 2
Has a diameter of preferably 0.5 to 3 mm, more preferably about 1 to 2 mm. The amount of the sample S is preferably such that the thickness of the sample in the direction of the axis of the cylinder axis before pressing is about 3 to 30 mm, particularly about 5 to 20 mm.

The solid volume fraction and the water content are respectively calculated by the following equations. Solid volume fraction (%) = 1 {(water content × 0.01 × true specific gravity of powder + 1) × 100 water content (%) = (weight before drying−100 weight after drying at 100 ° C.) ÷ 10
The weight after drying at 0 ° C. × 100 In the present invention, the clay may be a clay of a natural mineral such as clay or a clay of various ceramic powders such as alumina, silica and zirconia.

[0014]

DESCRIPTION OF THE PREFERRED EMBODIMENTS In the apparatus shown in FIG.
Was set to 10 mm, the diameter of the nozzle hole was set to 1 mm, and five types of C specified in JIS P3801 were used as filter paper.

[0015] Clay and alumina powder were used as samples. The sample amount was 0.4 to 0.6 g. The pressing pressure of the piston is 1.96MPa for low pressure and 19.6M for high pressure.
Pa and the pressing time was 2.5 Hr.

Table 1 shows the water content of each sample before pressing and the measurement results of the solid volume fraction when pressed at a low pressure and when pressed at a high pressure, together with the results of evaluation of filling properties by touch.

[0017]

[Table 1]

From Table 1, there is a correlation between the difference (%) between the case where the solid volume fraction is pressed at a low pressure and the case where the solid volume fraction is pressed at a high pressure and the filling property, and this difference (%) is 6.5. % Or more, especially 7% or more, it was recognized that the kneaded material had good filling properties.

[0019]

As described above, according to the present invention, it is possible to easily evaluate the filling property of the clay in a state close to a closed space.

[Brief description of the drawings]

FIG. 1 is a sectional view of an evaluation device used in the method of the present invention.

[Explanation of symbols]

 1 cylinder 2 nozzle hole 5 piston

Continuation of the front page (72) Inventor Kiichi Oda 5 Communitas S-715 5 Chiyogaoka, Chigusa-ku, Nagoya-shi, Aichi (72) Inventor Saburo Sano Inventor 3-2-3, 15-24, 72-24 ) Inventor Takumi Banno 2-109, Yachiyo Ryo 103, Yachiyo-cho, Kita-ku, Nagoya-shi, Aichi 103 (72) Inventor Shuji Kawai 2-3-22, Mizuho-cho, Handa-shi, Aichi, East Town Room 206 (72) Inventor Oguri Kenta 3-1, 103-1206, Sunadabashi, Higashi-ku, Nagoya City, Aichi Prefecture (72) Inventor Yuji Nomura 2-1-11 Kinjo Wakaen, Kita-ku, Nagoya City, Aichi Prefecture, Corp. E (72) Inventor Akira Ono Nagoya, Aichi Prefecture 1-66 Koonji-cho, Kita-ku

Claims (2)

[Claims] 1. A method comprising: putting a clay into a cylinder having a nozzle hole covered with a filter; pressing the clay with a piston to squeeze the clay; pressing the solid at a low pressure and a solid at a high pressure. A method for evaluating the plasticity of a clay based on the difference in volume fraction. 2. The pressure of claim 1, wherein the low pressure is 1.96 to 3.0 MPa and the high pressure is 19.6.
A method for evaluating the plasticity of a kneaded material, wherein the pressure is at least MPa, the pressing time is at least 2.5 Hr, and filter paper is used as a filter.