JP3030945U - Cut test blade - Google Patents

Abstract

(57) 【Abstract】 PROBLEM TO BE SOLVED: To provide a blade which is excellent in safety and has a long service life and which can be practically used for a test, because there is no need to replace the blade when properly evaluating cut resistance. It is what A cutting test blade of the present invention is JIS Z-.
The hardness is 1000 Hv or more according to the Vickers hardness test method measured based on 2244, and the material is ceramics.

Description

[Detailed description of the device]

[0001]

[Technical field to which the device belongs]

 The present invention relates to a safety glove used to protect a human body from external pressure such as a cut wound, and a cut test blade used for a cut resistance test for evaluating the protection performance of other protective materials against the cut tool.

[0002]

[Prior art]

 When handling cutlery, glass, metal, etc. or working in forests, etc., to protect against cutting the hand by contacting the sharp edges of the cutlery, metal, wood or stone, cut-resistant materials called high-tech fibers such as aramid fiber. Many protective clothing and gloves with excellent creativity have been developed and are in the spotlight.

However, there is no method for evaluating these protective materials, and there is a strong demand for the appearance of such an evaluation method from the industry, and devices such as those found in Japanese Utility Model No. 07-023729 are strongly desired. Cutter blades and razor blades have been used in, but there were problems such as large variation in measured values due to the blade, variation in sharpness between blade manufacturing lots, and replacement of the blade for each measurement.

[0004]

[Problems to be solved by the device]

 The present invention has been devised in view of such a technical background, and is used for threads, cords, knitted fabrics, felts and other cloths, films, rubbers, etc. used for protective materials that are difficult to cut. In order to qualify the cut resistance performance of a material consisting of the following materials, there is no need to replace the blade, and therefore a blade with excellent safety and long service life can be provided for testing.

[0005]

[Means for Solving the Problems]

 In order to achieve such an object, the present invention employs the following blades.

That is, the cutting test blade of the present invention has a hardness of 1000 Hv or more according to the Vickers hardness test method measured according to JIS Z-2244, and is made of a ceramic material. To do.

[0007]

[Embodiment of device]

 The cutting test blade of the present invention is preferably made of ceramics, and the blade of the blade has a V-shape and the V-angle is an acute inner angle.

That is, the cutting mechanism is such that the sample and the cutting tool slide while the compressive stress is increased. Therefore, when the V-shaped angle of the blade is an obtuse angle, the blade does not slip and comes close to a push-cutting mechanism, so that a large amount of stress is required and an appropriate cut resistance value tends not to be obtained. On the contrary, if the internal angle is too small, the blade tends to slip too much, so that the compressive stress is unlikely to increase, and the resistance value tends to be low unless the blade crossover is lengthened.

In the present invention, the V-shaped angle of the blade used preferably has an inner angle of 30 to 90 degrees, more preferably 50 to 70 degrees.

The blades that have been used for cutting tests so far have been razor blades that are generally commercially available or cutter blades that are used for work and the like. It is necessary to stack two of these blades into a V shape, and the angle of the razor blade is 90 degrees, so the maximum angle of interior angle that can be stacked into a V shape is 90 degrees. Since the tip of the cutter blade is cut at 60 degrees, it can be changed to 30 to 90 degrees. Therefore, it has been used for a cut tester described in Japanese Utility Model Publication No. 07-023729.

However, when two sheets are overlapped with each other to form a V shape, a gap is formed at the tip of the V shape, so that the sample is caught in the gap at the tip of the V shape, and there is a problem that a normal cut resistance value cannot be measured. . Therefore, in order to prevent catching, pretreatment such as making holes in the sample was required at the sample preparation stage.

In the present invention, the blade to be preferably used is a single V-shaped blade and has a merit that a pretreatment such as drilling a sample is not necessary because the blade is up to the tip of the V-shape. is there.

Further, since the hardness of the blade is harder, the wear resistance is excellent. Therefore, even if the blade is measured many times with the same blade, the variation of the resistance value is small and it is not necessary to replace the blade. Since only replacement work is required, there is an advantage that the difference between samples can be accurately compared and evaluated with the same blade. That is, when the hardness of the blade is soft, the wear resistance of the blade is poor, so that the resistance value increases when the blade is measured many times. Therefore, it is necessary to replace the blade for each measurement, and even if there are variations in the obtained data, it is not possible to accurately judge whether it is the blade variation or the sample difference. It was difficult to obtain a correct evaluation result.

Generally, commercially available cutter blades are carbon steel and stainless steel, but the hardness of carbon steel measured according to JIS Z-2244 is 900 Hv or less by a Vickers hardness test method, and aramid fiber When an extremely high-strength fabric such as is cut, the resistance value increases with each cutting test due to wear deterioration of the blade, and it is not possible to obtain an appropriate cutting resistance value for the sample. Occurs.

In the present invention, as the material of the blade that is preferably used, a ceramic blade having a hardness higher than that of commercially available carbon steel, stainless steel, or the like is used. Such ceramics may be zirconia-based or silicon carbide-based.

The blade may be polished on one side or on both sides, but the polishing angle is preferably 20 to 60 degrees, the thickness is 0.5 to 1.5 mm, and the width is preferably 10 to 20 mm. More preferably, a blade made of zirconia-based ceramics registered and described in Japanese Patent No. 1622526 is preferable.

The present invention will be further described with reference to the drawings.

That is, FIG. 1 is a plan view (a), (b) side view, and (c) a sectional view taken along the line AA of an embodiment of the cutting test blade of the present invention. In this ceramic V-shaped blade, the V-shaped angle C of the blade was 60 degrees, and the polishing B of the blade was one side, and the polishing angle D was 30 degrees, but only the blade edge E after polishing was 40 degrees, and further polishing was performed. processed. The blade having a thickness F of 1 mm, a width G of 12.7 mm and a length H of 64.5 mm was used.

2 and 3 are graphs showing the wound resistance (g) after each single use in Example 2 and Comparative Example 1. Such a cutting test blade is used by being attached to the cutting blade fitting 1 of the cutting tester shown in FIG. In this cut tester, the cut blade 11 is attached by a blade mount 1 so as to be sandwiched by thin plates from both sides, and a compressive stress detection detector 3 is provided above the blade mount 1. Is a unit that descends vertically, preferably at a constant speed.

On the other hand, the sample holder 2 holds the sample by means of two sample holding plates 22 each having a slit 23. The sample is inserted into the slit 23 while cutting with the cutting blade 11. To do. The compressive stress at that time, that is, the cut resistance is detected by the detector 3, recorded and measured.

According to the cutting test blade of the present invention, the cutting resistance value can be accurately measured with stable sharpness without deterioration of the cutting tool.

[0022]

【Example】

 Next, the present invention will be described in more detail by way of examples. Example 1 A cutting test blade comprising a ceramic V-shaped blade as shown in FIG. 1 was used. This blade has a Vickers hardness of 1300 Hv made of zirconia-based ceramics, the V-shaped angle of the blade is 60 degrees, the blade is polished on one side, the polishing angle is 30 degrees, and only the blade edge is processed to 40 degrees. The thickness was 1 mm, the width was 12.7 mm, and the length was 64.5 mm.

This blade was attached to a cutability tester as shown in FIG. The samples were work gloves made of 5 double-twisted yarns of 20-count spun yarn made of aramid fiber (made by Kevlar) and knitted in 7 gauge, and 5 spun yarns of 10-count cotton fiber. We prepared two types of commercially available work gloves organized with 7 gauges. Cut resistance was measured for these samples.

A detector having a capacity of 50 kg was used for the cutability tester, a sandwich plate of the sample was made of iron, and a slit having a width of 10 mm was used, and a water resistant abrasive paper # 240 was used as a slip stopper. I stuck it. Further, the descending speed of the blade was 500 mm / min (constant speed).

When the above-mentioned work gloves were cut under such cutting conditions, the cut resistance of the aramid fiber work gloves was 1088 g, and that of the cotton fiber work gloves was 552 g. Example 2 Further, when the above-mentioned aramid fiber work gloves were continuously measured with the ceramic V-shaped blade of Example 1 above 100 times or more, the average of the measured N numbers was 5, but as shown in the graph of FIG. Even after 100 or more measurements, no deterioration of the blade was observed, and the cut resistance value did not change. Comparative Example 1 Two carbon steel cutter blades with a Pickers hardness of 870 Hv were attached to a V-shape of 60 degrees, and two 20-spun spun yarns made of aramid fiber (made by Kevlar) were drawn together to form 7 gauges with 7 gauge. The knitted work gloves were measured under the conditions of Example 1.

As a result, as shown in FIG. 3, it was confirmed that the measured values of the carbon steel blades for the second time and the third time increased from the values measured for the first time, and the sharpness of the blade deteriorated and worn. It was

[0027]

[Effect of device]

 According to the present invention, it is possible to measure stable and accurate cut resistance with safe and easy operation without the need to replace the blade even if it is continuously measured 100 times or more.

[Brief description of drawings]

FIG. 1 is a plan view (a), (b) side view, and (c) a sectional view taken along the line A-A showing an example of a cutting test blade according to the present invention.

FIG. 2 is a graph showing the cut resistance (g) for each single use of the cut test with the blade of Example 2.

FIG. 3 is a graph showing cut resistance (g) for each single use of the blade of Comparative Example 1.

FIG. 4 is a schematic view of a cut resistance tester for measuring using the ceramic blade of the present invention.

[Explanation of symbols]

 B: Polished surface C: V-shaped angle D: Polished angle DE E: Blade edge F: Thickness G: Width H: Length 1: Cutting tool blade mounting tool 2: Sample holder 3: Compressive stress detector 11: Cutting test blade 22: Sample gripping plate 23: Slit

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Susumu Kano 1-1-1 Oe, Otsu City, Shiga Prefecture Toray Co., Ltd. Seta Factory

Claims (4)

[Scope of utility model registration request] 1. The hardness according to the Vickers hardness test method measured according to JIS Z-2244 is 1000 Hv.
The above is the cutting tool for cutting test, characterized in that the material is ceramics. 2. The cutting test blade according to claim 1, wherein the ceramic is zirconia-based or silicon carbide-based. 3. The cutting test blade according to claim 1, wherein the blade has a V-shape. 4. The cutting test blade according to claim 1, wherein the blade is a single blade.