JPH0723729Y2 - Cut resistance measuring device - Google Patents

Description

[Detailed Description of the Invention] [Industrial application] The present invention relates to a cut resistance measuring device for a material which is hard to be cut by a bullet or a blade such as a protective material such as a bulletproof vest and safety gloves.

[Prior Art] In recent years, a lot of protective clothing and gloves made of a fiber having excellent cut resistance, which is so-called high-tech fiber such as aramid fiber for protecting a human body from external stress such as a blade, have been developed and are in the spotlight. .

However, there is no method for evaluating these protective materials, and the appearance of such an evaluation method has been strongly desired by the industry.

[Problems to be Solved by the Invention] The present invention has been devised in view of such technical background, and yarns, cords, knitted fabrics, felts and other fabrics used for protective materials that are difficult to cut. And film,
It is intended to provide a cut resistance measuring device capable of accurately evaluating cut resistance performance of a material such as rubber.

[Means for Solving the Problem] In order to achieve such an object, the present invention employs the following configurations.

That is, the cut resistance measuring device of the present invention is a vertically moving V-shaped cutting blade having a flat blade with the blade facing the outside of a V-shaped sharp edge, and the cutting blade. Sample holders having slits for inserting the cut wounds are provided so as to face each other, and a detector provided on either one of the cut blade side and the sample holder side is used for the cut wounds. It is characterized by detecting a compressive stress applied when a blade cuts a sample.

[Operation] The present invention is an apparatus for evaluating the cuttability of a material such as a protective material, which has been conventionally regarded as a material that is difficult to cut, and has a specific structure for that purpose.

First, the positional relationship between the cutting blade and the sample is vertically opposed to each other.

That is, it is important to set so that only a compressive stress is detected by a detector, for example, a sensor such as a compression cell. When a stress in the lateral direction is applied, the stress component appears as an error.

Also, by making the cutting blade and the sample face each other in a vertical relationship, there is no need for a tool mounting tool or a guide rail for the sample holder, so there is no need to worry (correction) the frictional resistance. It is possible to detect only the cut resistance.

The blade to be used may be a single-edged blade or a double-edged blade, but a V-shaped blade installed so that the blade faces outward, that is, a blade having flat blades attached to both sides with the blade facing outward from the apex of V is used. .

The blade may be a single blade or a double blade, but a commercially available single-edged shaving blade or cutter blade may be used easily.

Further, as a method of evaluation, the sample is cut at the same time on the left and right sides with a V-shaped blade, but according to this method, there is no variation or error in the obtained data, and there is no lateral stress. There is an advantage that the value can be accurately evaluated only by the value of the compressive stress.

In addition, a V-shaped cutting blade having an acute inner angle is used. That is, the cut wound mechanism is such that the sample and the cutting tool slide while the compressive stress is increased.

Therefore, when the angle (internal angle) of the apex of the V-shaped cutting tool V is an obtuse angle, the tool does not slip and comes close to the push-cutting mechanism, which requires a large amount of stress.
There is a drawback that an appropriate cut resistance value cannot be obtained. On the other hand, if the internal angle is too small, the blade will slip too much to increase the compressive stress, and the resistance value will not be obtained unless the blade crossover is lengthened.

For these reasons, the angle (internal angle) of the apex of the V-shaped cutting blade preferably used in the present invention is 90 to 30.
The V-shaped cutting blade has an inner angle of 70 to 50 degrees, and more preferably 70 to 50 degrees. A more appropriate cutting resistance value can be obtained by the V-shaped cutting blade.

In addition, the sample holder has a slit into which the cutting blade is inserted and passed. This sample holder is preferably composed of two sample holding plates having a sample slip stopper (mechanism) and a pedestal for fixing the plates.

The sample is held non-slip by the cleat plate's non-slip, and is also held so as to minimize elongation of the sample. That is, when the sample slips or the elongation becomes large, the sample comes into contact with almost the entire blade portion, making it difficult to cut, and in particular, it may be impossible to measure a knitted fabric having a large elongation.

For this reason, the width of the slit is preferably 10 mm or less.
As a non-slip method, it is preferable to laminate a material with high friction such as rubber on the sandwich plate, but in some cases,
A sheet having irregularities such as sandpaper may be attached and used.

The above-mentioned sample gripping plate of the present invention can be easily attached to the mount by bolts or the like.

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

That is, FIG. 1 is a schematic view showing a main part of the cut resistance measuring device of the present invention.

In the figure, a blade mounting tool 1 is attached with two cutting blades 11 so as to be sandwiched by a thin plate from the front and back, and a compressive stress detection detector 3 is provided on the upper part of the blade mounting tool 1, and these are integrally formed. It 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, and the cutting blade 11 inserts the sample into the slit 23 while cutting. The compressive stress at that time, that is, the cut resistance is detected by the detector 3 and recorded.

According to the device of the present invention, the sample is cut while sliding the cutting blade, and the contact portion between the blade and the sample changes every moment,
The most efficient cut can be made without deterioration of the blade.
Further, since the frictional resistance and the stress in the lateral direction are hardly applied, it is possible to accurately measure the cut resistance value.

[Example] Example 1 Two 20-count spun yarns made of aramid fiber and 5 plied yarns were used.
The cut resistance was measured by the cut resistance device shown in FIG.

A detector with a capacity of 50 kg was used, and the cutting blade was a cutter blade manufactured by NT Corp., and an attachment tool was used in which two blades were attached with the internal angle of 60 degrees.

The gripping plate of the sample was made of iron and had a slit with a width of 10 mm.

The cutting speed of the blade was 500 mm / min (constant speed).

When the above-mentioned work gloves were cut under these cutting conditions, a cutting resistance of 1.28 kg was exhibited.

Example 2 A work gloves made of a cotton thread having the same thickness as the aramid fiber thread of Example 1 was cut under the same conditions.

The cut resistance at that time was 0.33 kg, and the difference in performance depending on the material could be clearly confirmed.

Examples 3, 4 Using the same apparatus as used in Example 1, under the same conditions,
The cut resistance of the long rope was measured.

Set two cords and ropes at intervals of 3 to 5 mm,
The method of cutting two at the same time was adopted.

In the sample rope, the core portion was made of aramid filaments and the sheath portion was braided with nylon filaments and had a diameter of 3 mm (Example 3).
A 0% rope (Example 4) was prepared.

The cut resistance of these ropes was 14.6 kg in Example 3 and 7.5 kg in Example 4.

As a result, it has been found that the measuring device of the present invention can clearly measure the difference in performance depending on the material.

[Advantage of Invention] According to the present invention, even samples having various materials and structures
Accurate cut resistance can be measured with simple operation.

[Brief description of drawings]

 FIG. 1 is a schematic view of a cut resistance measuring device of the present invention. 1: Cut blade mounting tool 2: Sample holder 3: Compressive stress detector 11: Cut blade 22: Sample gripping plate 23: Slit

Claims (4)

[Scope of utility model registration request] 1. A sample having a vertically moving V-shaped cutting blade in which a flat blade is attached with the blade facing the outside of a V-shaped having an acute-angled apex, and a slit into which the cutting blade is fitted. A holder is provided so as to face each other, and the cutting blade cuts the sample by a detector provided on either the cutting blade side or the sample holding table side. A cut resistance measuring device characterized by detecting compressive stress applied at the time. 2. The cut resistance measuring device according to claim 1, wherein the apex of the V-shaped cutting blade has an inside angle of 30 to 90 degrees. 3. The sample holder has a sample slip stopper 2
The cut resistance measuring device according to claim (1), which comprises a sample holding plate and a frame for fixing the plate. 4. The cut resistance measuring device according to claim 1, wherein the V-shaped cutting blade is moved at a constant speed.