JP4835768B2 - Hardness measuring apparatus for solid and molded article and measuring method thereof - Google Patents

Description

  The present invention relates to a hardness measuring apparatus for a solid product / molded product and a hardness measuring method using the same. The hardness measurement of granulated products and molded products is an important material test item in terms of process control and quality control when manufacturing them. In addition, measuring the hardness of granulated products and molded products is important in selecting handling and packaging containers during transportation, supply and storage of granulated products and molded products, and preventing accidents such as dust explosions. It provides important information. Furthermore, it is an important test item for grasping the caking property of the powder. Thus, it is industrially useful to measure the hardness of a solid product, a granulated product, a molded product, and the like.

  Conventionally, solid hardness measuring devices include a crushing hardness testing device, an indentation hardness testing device, an impact hardness testing device, a wear hardness testing device, and the like.

  These known (known) hardness test apparatuses can measure the hardness of a molded product having a high hardness, that is, a hard to break, with high accuracy reproducibility. However, it is not an appropriate test method (evaluation method) and is difficult to apply to measure the hardness of a molded product having a low hardness, that is, a fragile and soft molding. Moreover, even if it can be applied, accuracy and reproducibility become problems.

  For example, in the case of measuring the hardness of a fragile and soft molded product, the Kiya-type hardness tester uses a low-hardness model and measures a number of times and averages the values. In addition, there are methods of JIS standard M8711, ASTM standard D440-49, etc., in which a large number of molded articles are dropped from a predetermined height a predetermined number of times and then subjected to sieving analysis to measure the amount of destruction. Further, there is a JIS standard M8712 rotation crushing test method which is an improvement and improvement of the dropping method. In this method, a fixed molding is put into a rotating drum with a scraping plate, the drum is rotated at a constant rotation speed, and when a predetermined time is reached, the drum is stopped, and a sieving analysis of the inner molding is performed. The amount of pulverization is measured.

  When measuring the hardness of a fragile and soft molding using a Kiyama hardness tester, the molding must be measured many times and the values must be averaged, which is cumbersome and requires a long time for the measurement. It takes effort. Depending on the type of molded product, quantitative evaluation is often not possible even if the measurement takes time and effort. Even if it can be measured conveniently, its accuracy and reproducibility are problematic.

  In addition, in the drop test method using the drop test apparatus and the rotary crush test method using the rotary crushing apparatus, the operation is complicated because the three operations of the breaking operation, taking out the sample, and sieving are repeated. Furthermore, there has been a problem that large deviations and variations in measured values occur due to the transportation and movement of materials during each operation.

  The present invention has been intensively studied in view of the problems of various existing test apparatuses and operation methods as described above. An object of the present invention is to provide an apparatus capable of measuring the hardness of a soft solid or molded product having a low hardness with a simple operation with high accuracy, good reproducibility, and in a short time, and a measuring method thereof.

  In order to solve the above-described problems, the present inventors have intensively studied a hardness measuring apparatus and method. As a result, a new apparatus provided with a rotating body (cylindrical body or polygonal cylinder) having a devised structure and a method using the apparatus have been found and the present invention has been completed.

  That is, the present invention includes a cylindrical body or polygonal cylinder having a large number of holes on the side surface, at least one scraping blade inside, and a motor that horizontally rotates the cylindrical body or polygonal cylinder at a constant speed. The present invention provides a hardness measurement apparatus for a solid product / molded product and a hardness measurement method for the solid product / molded product using the device.

  Hereinafter, the present invention will be described in detail.

  In the present invention, a cylindrical body or a polygonal cylindrical body having a large number of holes on a side surface is a metal, plastic, or ceramic pipe provided with a number of holes regularly or irregularly, or a metal plate having a predetermined shape. A large number of regular or irregular holes are formed into a cylindrical or polygonal cylinder, and the material type, thickness, hole shape, hole arrangement, etc. can withstand the drop impact of the molded body. There is no particular limitation as long as the particles and powdered particles can easily fall out of the holes.

  Specifically, examples of the metal include iron, stainless steel, aluminum, an aluminum alloy, titanium, a titanium alloy, copper, nickel, and the like, and those plated with the metal. All of these are strong in strength, and stainless steel is desirable in terms of corrosivity, cost, and workability. SUS304 can be suitably used as the stainless steel. Examples of the plastic include resins such as polyvinyl chloride, polyethylene, polypropylene, polystyrene, polycarbonate, and acrylic. In the case of a plastic material, it is preferable in terms of weight reduction and cost, but is slightly inferior to metal in terms of strength and material. Examples of ceramics include alumina, alumina-silica, silica, and zirconia. These are excellent in terms of heat resistance and corrosion resistance, but are somewhat difficult in terms of price and workability. The material of the cylinder or polygonal cylinder of the present invention is not particularly limited, and the thickness of these materials varies depending on the type, but is preferably 1 to 3 mm. If it is thin, the strength will decrease, and if it is thick, the workability will decrease or it will become heavy, making it difficult to carry.

  In the present invention, the term “cylindrical body” refers to a cylindrical body in which both ends of the cylinder are circular, and the term “polygonal cylindrical body” refers to a cylindrical body in which both ends of the cylinder are polygonal. Examples of polygons include hexagons, heptagons, and octagons.

  In the present invention, a large number of holes are provided on the side surface of the cylinder or polygonal cylinder, and examples of the shape of the holes include a circle, a square, a rectangle, an ellipse, and a rhombus. A circular shape is desirable because it allows the powder particles to pass through easily and is easy to manufacture. The size of the hole varies depending on the size and shape of the solid product / molded product and the size of the particles constituting the solid product / molded product, and cannot be uniquely determined. Increase the property, and prevent the coarsely pulverized product of the solid product / molded product from passing through, so that the particle size of the solid product / molded product is 5 times or more of the particle size and 1 / of the maximum size of the solid product / molded product. 10 or less is desirable. By using a cylindrical body or a polygonal cylinder having a hole having such a shape, it is possible to measure with high accuracy and reproducibility.

  Here, the particle diameter constituting the solid product / molded product is a particle diameter at a position where 80 to 90% is accumulated from the particle size distribution curve. That is, large particles close to the maximum particle size are targeted.

  As for the arrangement of the holes, an irregular type, a 60 ° zigzag type, a 45 ° zigzag type, a parallel type and the like can be mentioned. The aperture ratio is preferably 10% or more, and more preferably 40 to 60%, and the passage of powdered particles is improved.

  The dimensions of the cylinder or polygonal cylinder are not particularly limited, but it is desirable that the volume is 5 to 50 times the volume of the solid product / molded product, so that the accuracy and reproducibility of hardness measurement can be improved. Can be high. Moreover, although the diameter of a cylindrical body or a polygonal cylinder changes with the magnitude | size of a solid molded object, a molded object, the number to be used, etc., usually 30-300 mmphi is desirable and the length is desirably 30-300 mmL.

  If it is small, the measurement accuracy and reproducibility are somewhat lowered, and if it is large, a large amount of solid or molded product is required or the weight of the apparatus becomes large, making it difficult to carry.

  Further, it is desirable that the cylindrical or polygonal cylinder mounting portion for the motor is hermetically sealed, and a ring-shaped plate is attached to the facing solid / molded product charging portion to prevent the sample from flowing out.

  At least one scraping blade is provided inside the cylindrical body or the polygonal cylindrical body. This is also a feature of the apparatus according to the present invention. There are no particular restrictions on the size and number of the scraping blades, but they are large enough to scrape solids and molded products. It is desirable to arrange a number that does not collide with a solid product or a molded product. It is for suppressing excessive powdering. From this point, the number is preferably 1 or 2, and if it is 2, the 180 ° arrangement is desirable.

  A motor is attached to this cylinder or polygonal cylinder, but the rotational speed of the cylinder or polygonal cylinder by the motor is not particularly limited, but is preferably 5 to 100 RPM, more preferably 10 to 50 RPM. Accuracy can be increased. Further, the measurement accuracy can be further increased by keeping the rotation speed constant.

  The solid or molded product is put into this cylindrical body or polygonal cylinder and pulverized while rotating, and the hardness of the solid or molded product is measured. The larger the number of rotations, the larger the diameter of the cylindrical or polygonal cylinder. As a result, it is possible to measure a solid product / molded product having high hardness with good reproducibility. In addition, the smaller the number of rotations, the smaller the diameter of the cylindrical body or polygonal cylinder, and the lower the hardness, the solid or molded product can be measured with high accuracy reproducibility.

  The present invention intermittently or continuously measures the weight of powdered particles falling from a cylindrical or polygonal cylinder side hole, but the apparatus is not particularly limited as long as it can measure the weight within a short time. Although not intended, an electronic balance capable of automatic weighing and continuous recording is desirable.

  In the present invention, the molded product includes an organic and / or inorganic powder formed into a specific shape by adhesion, sintering, agglomeration, or the like, and includes a solidified powder. The shape is not particularly limited. The solid product in the present invention refers to a product in which organic and / or inorganic powders are formed into irregular lumps due to adhesion, sintering, aggregation, consolidation or the like. Further, the solid product may be cut out with a knife or the like and shaped to form a molded product. When performing an evaluation test on the degree of consolidation, a mold having a specified shape may be used for measurement as a molded product. Moreover, any of cylindrical pellet, spherical shape, and tablet shape can be applied. However, when the mold can be set as in the solidification degree evaluation test, a tablet shape is preferable because it increases measurement accuracy, improves operability, and is easy to mold. The size is usually preferably 10 to 50 mm in diameter and 5 to 50 mm in thickness.

  An example of the hardness measuring apparatus for solid and molded products in the present invention is shown in FIG.

  The hardness of the solid product / molded product according to the present invention is the weight of the powdered particles for a predetermined time, the change over time of the weight of the powdered particles, the time for reaching the predetermined powdered particle weight, the change over time of the powdered rate, and the powder over a predetermined time. It can be converted into a numerical value by using a conversion rate, a time to reach a predetermined powderization rate, and the like. You can decide which one to use. Here, the pulverization rate is the ratio of the pulverized particle weight to the total weight of the solid product / molded product.

  By operating with the method of the present invention using the apparatus of the present invention, the hardness of any solid product / molded product can be easily and accurately quantified in a short time with good reproducibility, and the hardness can be evaluated quantitatively. it can.

  As is clear from the above, by using the hardness measuring apparatus for solid products / molded products of the present invention, it is easy, accurate and reproducible within a short time, from high hardness to low hardness. It is possible to measure the hardness of solid products and molded products having a wide range of hardness.

  This provides an important test method for process control and quality control when manufacturing these molded products and powders. In addition, it can play an important role in handling of granulated products and molded products during transportation, supply and storage, setting of packaging containers and prevention of disasters such as dust explosions. In addition, it is an important method for grasping and evaluating the solidification property of the granular material during transportation, supply and storage. Thus, the effect of the present invention on the industry is extremely large.

1 shows a hardness measuring apparatus for a solid product / molded product according to the present invention.

  EXAMPLES Hereinafter, although an Example and a comparative example demonstrate this invention further, this invention is not limited to these.

Example 1
Sodium salt sold by Japan Tobacco Inc. is filled into a cylindrical container with an inner diameter of 30 mm and a length of 50 mm made of a 400 mesh stainless steel wire mesh, and pressurized and filled at 2.5 kg / cm ² from the top of the cylinder. Then, it was left in a constant temperature and humidity chamber at a temperature of 25 ° C. and a relative humidity of 40%. Thereafter, the humidity was increased to a relative humidity of 80% over 1 hour while maintaining the temperature at 25 ° C. After the relative humidity was 80%, the state was maintained for 10 hours. After maintaining the relative humidity at 80%, the humidity was decreased over 1 hour while maintaining the temperature at 25 ° C. until the relative humidity reached 40%. When the above was taken as one cycle and exposed for two cycles in a thermo-hygrostat, that is, for 24 hours, it consolidated and became a molded product. This was measured five times for the molding to be powdered by 80% using a hardness measuring apparatus for solids and moldings to which the present invention shown in FIG. 1 was applied. The measurement was possible with good accuracy and good reproducibility, and the average value of the measurement was 91 seconds (standard deviation 1.3, coefficient of variation 1.5%). These results are shown in Table 1.

比較例１
日本たばこ産業（株）販売の食塩を実施例１と同様の操作で固結させ成形物とした後、これを木屋式硬度計にて硬度を５回測定した。測定の平均値は０．８ｋｇ／ｃｍ^２であったものの標準偏差０．５、変動係数５０％であり、バラつきが大きく再現性の悪いものであった。これらの結果を表１に示した。

Comparative Example 1
Sodium salt sold by Nippon Tobacco Inc. was consolidated by the same operation as in Example 1 to obtain a molded product, and then the hardness was measured 5 times with a Kiyama hardness tester. Although the average value of the measurement was 0.8 kg / cm ² , the standard deviation was 0.5 and the coefficient of variation was 50%. The variation was large and the reproducibility was poor. These results are shown in Table 1.

Example 2
In a state in which a triethylenediamine (TEDA) having an average particle size of 250 μm manufactured by Tosoh Corporation is roughly packed in a cylindrical container having an inner diameter of 30 mm and a length of 50 mm made of a 400-mesh stainless steel wire net and left standing in a sealed container, When it was inserted into a 60 ° C. incubator and exposed for 18 hours, it consolidated and became a molded product. This was measured 5 times for the molding to be powdered 80% by using a hardness measuring apparatus for solids and moldings to which the present invention shown in FIG. 1 was applied. It was possible to measure with high accuracy and good reproducibility, and the average value of the measurement was 32 seconds (standard deviation 2.4, coefficient of variation 7.4%). These results are shown in Table 1.

Comparative Example 2
Triethylenediamine (TEDA) having an average particle size of 250 μm manufactured by Tosoh Corporation was consolidated by the same operation as in Example 2 to obtain a molded product, and then the hardness was measured 5 times with a Kiyama-type hardness meter. Although the average value of the measurement was 0.4 kg / cm ² , the standard deviation was 0.4 and the coefficient of variation was 80%. The variation was large and the reproducibility was poor. These results are shown in Table 1.

Example 3
A constant temperature and humidity chamber with a temperature of 30 ° C and a relative humidity of 80% is roughly packed in a cylindrical container with an inner diameter of 30 mm and a length of 50 mm made of Tosoh Corporation's average particle size 125 µm baking soda using a 400 mesh stainless steel wire mesh. After being exposed for 2.5 hours, the molded product was slightly consolidated and easily broken. This was measured 5 times for the solidified product to be pulverized by 80% using a hardness measuring apparatus for solid and molded products to which the present invention shown in FIG. 1 was applied. It was possible to measure with good accuracy and reproducibility, and the average value of the measurement was 15 seconds (standard deviation 2.5, coefficient of variation 16%). These results are shown in Table 1.

Comparative Example 3
After baking soda with an average particle size of 125 μm manufactured by Tosoh Corporation was made into a molded product by the same operation as in Example 3, the hardness was measured 5 times with a Kiyama-type hardness meter. Measurement was impossible. These results are shown in Table 1.

1 Rotating cylindrical body (made of stainless steel, diameter 80 mm, length 80 mm, hole 3 mm, 2 lifters: 180 ° arrangement, width 10 mm, length 80 mm molded body inlet: 40 mmφ)
2 Constant speed motor (20rpm)
3 Automatic recorder 4 Balance 5 Solid product / Molded product

Claims (3)

An apparatus for measuring the hardness of a solid product / molded product having a hardness of 1.5 kg / cm ² or less with a Kiyama hardness tester with a coefficient of variation of 16% or less, and comprising the solid product / molded product on the side surface When a large number of holes with a size of 5 times the particle size and 1/10 or less of the maximum size of the solid product / molded product and the solid product / molded product are scraped up and dropped inside , Having at least one scraper blade that does not collide with another scraping blade, and having a volume 5 to 50 times the volume of the solid member / molded product, a diameter of 30 to 80 mmφ, and a length A cylinder or polygonal cylinder having a length of 30 to 80 mm, a motor that rotates the cylinder or polygonal cylinder at a constant speed selected from 5 to 100 RPM and horizontally rotates, and falls from the side hole of the cylinder or polygonal cylinder Intermittently weigh or continuously measure the weight of powder particles It consists metered device, solid matter-molded product for hardness measurement apparatus characterized by comprising means for measuring the time to reach a predetermined powdering rate. A large number of holes with a size of 5 times or more of the particle size constituting the solid product / molded product on the side surface and 1/10 or less of the maximum size of the solid product / molded product, and the solid product / molded product inside 5 to 50 times the volume of the solid product / molded article having at least one scraped blade that does not collide with another scraped blade when it is picked up by rotation and falls. The volume, the diameter is 30 to 80 mmφ, the length is 30 to 80 mmL, and the solid or molded product is put into a cylinder or polygonal cylinder, and then the cylinder or polygonal cylinder is selected from 5 to 100 RPM. By horizontally rotating in the axial direction at the rotation speed, the solid product / molded product is scraped up, and the impact of spontaneously dropping it to the lower part of the cylinder or polygonal cylinder is repeatedly applied to destroy the solid product / molded product. Pulverized and drops from the hole on the side of the cylinder or polygonal cylinder Intermittently metered or continuously metered powdered particle weight, by measuring the time to reach a predetermined powdering rate, solid hardness of 1.5 kg / cm ² or less in the Kiya hardness meter The hardness measurement method using the hardness measurement apparatus for a solid product / molded product according to claim 1, wherein the hardness of the mold product / molded product is measured with a coefficient of variation of 16% or less. The method for measuring hardness according to claim 2, wherein the solid product / molded product having a hardness of 1.5 kg / cm ² or less as measured by a Kiyama hardness tester is sodium chloride, triethylenediamine or sodium bicarbonate.

Images