Method for manufacturing columnar structure

Abstract

In a first step S101, a columnar structure composed of a substance obtained by storing a substance in a glass tube (filling the glass tube with the substance) is formed. Next, in a second step S102, a drawn glass tube is removed by rapidly increasing stress. For example, it is effective to remove the glass tube by applying a rapid stress increase to the glass tube by applying a thermal shock to the glass tube using a difference in thermal conductivity and thermal expansion coefficient with the columnar structure. The glass tube can be broken and removed by rapidly increasing the stress.

Description

Method for producing a columnar structure

[0001] The present invention relates to a method for producing a columnar structure such as a wire.

[0002] There is a technique for producing a columnar structure such as a wire rod by placing a target substance in a glass tube to form a columnar structure made of the substance, and then heating and elongating the glass tube to reduce the diameter of the columnar structure together with the glass tube (glass wire drawing method). In this technique, the glass tube has conventionally been removed by a chemical treatment using an acid or alkaline solution containing hydrofluoric acid, thereby obtaining a columnar structure with a reduced diameter (Non-Patent Document 1).

[0003] H. Chiriac et al., "Amorphous glass-covered magnetic wires for sensing applications", Sensors Actuators A: Physical, vol. 59, pp. 243-251, 1997.

[0004] However, the above-mentioned method cannot be applied when the material constituting the columnar structure is not corrosion-resistant, and there is a problem that the materials to which the glass wire drawing method can be applied are limited. Furthermore, even for corrosion-resistant materials, the method of chemically dissolving the material has the problem of taking a long time to completely remove the glass, which lengthens the process time. Furthermore, there are problems such as the generation of acidic / alkaline waste liquid, which places a heavy burden on the environment, and the increase in man-hours and costs due to the need for neutralization treatment.

[0005] The present invention has been made to solve the above problems, and an object of the present invention is to provide a method by which a columnar structure can be produced industrially advantageously.

[0006] The method for manufacturing a columnar structure according to the present invention comprises a first step of filling a glass tube with a substance to form a columnar structure made of the substance, and a second step of physically removing the glass tube by applying a sudden increase in stress.

[0007] In one example of the above-described method for producing a columnar structure, the second step applies a sudden increase in stress to the glass tube by thermal shock.

[0008] In one example of the above-described method for producing a columnar structure, the second step involves irradiating the glass tube with light to cause a sudden increase in stress.

[0009] In one example of the method for producing the columnar structure, the glass tube is doped with a light absorbing material that absorbs light.

[0010] In one example of the method for producing the columnar structure, the glass tube contains a light absorbing material that absorbs light on the surface thereof.

[0011] In one configuration example of the above-described method for producing a columnar structure, the substance has electrical conductivity, and in the second step, a voltage is applied to the columnar structure to cause a sudden increase in stress in the glass tube.

[0012] In one example of the method for manufacturing a columnar structure, the columnar structure is a wire.

[0013] As described above, according to the present invention, the glass tube is physically removed by applying a sudden increase in stress, and therefore a method for producing a columnar structure with industrial advantages can be provided.

[0014] Fig. 1 is a flowchart illustrating a method for fabricating a columnar structure according to an embodiment of the present invention, and Fig. 2 is a photograph showing the glass tube actually used in the fabrication and the state after the glass tube has been filled with a substance and stretched.

[0015] A method for producing a columnar structure according to an embodiment of the present invention will be described below with reference to FIG.

[0016] First, in the first step S101, a substance is placed (filled) in a glass tube to form a columnar structure made of the placed substance. In this step, after the substance is placed in the glass tube, the glass tube can be heated and stretched to reduce the diameter of the glass tube and the columnar structure. The substance placed in the glass tube can be, for example, a solid or glass body. The substance placed in the glass tube can be, for example, a substance whose melting point is equal to or lower than the softening point of the glass material constituting the glass tube. In the case of such a substance, it is possible to apply a sudden increase in stress to the glass tube.

[0017] The substance to be contained can be a heat-curable liquid or a light-curable liquid. When such a liquid is contained, the substance (liquid) can be heated and cured to a solid when it is contained in the glass tube or when it is stretched. Furthermore, the substance (liquid) can be irradiated with light when it is contained in the glass tube or when it is stretched, thereby curing it to a solid.

[0018] Next, in the second step S102, the glass tube is physically removed by applying a sudden increase in stress. For example, applying a thermal shock to the glass tube by utilizing the difference in thermal conductivity and thermal expansion coefficient between the glass tube and the columnar structure is effective for removing the glass tube. The conditions for the thermal shock can be determined in advance by experiment, etc. By applying a sudden increase in stress, the glass tube can be broken and removed. The columnar structure can be a wire.

[0019] For example, in the second step S102, a sudden increase in stress can be imparted by irradiating the glass tube with light. A known laser, such as a continuous wave or pulsed laser, can be used as the light source for the irradiated light. For example, a sudden increase in stress can be imparted by irradiating the glass tube with a femtosecond laser or picosecond laser of a predetermined light intensity.

[0020] For example, by using a glass tube doped with a light-absorbing substance, a sudden increase in stress can be applied to the glass tube by irradiating it with light. Quartz glass, which is typically used as a material for glass tubes, does not have sufficient absorption for light with wavelengths from infrared to ultraviolet. In contrast, by constructing a glass tube from glass doped with iron or ytterbium, a sudden increase in stress can be applied to the glass tube by irradiating it with light of a wavelength absorbed by the added element or ion. The added element or ion can be added as long as the glass state can be maintained.

[0021] The light-absorbing material can be supplied to the glass tube from the material contained in the glass tube. For example, by selecting a material containing an element that has a stronger tendency to oxidize than the material that constitutes the glass tube, it is possible to ionize the element and add it to the glass.

[0022] The glass tube may also contain a light-absorbing substance on its surface. The light-absorbing substance is contained on the surface of the glass tube before the second step. For example, the light-absorbing substance may be attached to or impregnated into the glass tube in advance. Alternatively, the light-absorbing substance may be contained in the glass tube after the substance is filled. It is sufficient that the light-absorbing substance is contained before the second step is carried out. In the second step, a sudden increase in stress can be applied to the glass tube by irradiating light onto the glass tube containing the light-absorbing substance.

[0023] Furthermore, if the material contained in the glass tube is electrically conductive, a sudden increase in stress can be imparted to the glass tube by applying a voltage to the columnar structures in the second step. If the electrically conductive material contained in the glass tube is continuous within the glass tube, thermal expansion can be caused by instantaneously applying a large current thereto, thereby imparting a sudden increase in stress to glass, which has a relatively low thermal expansion coefficient. This application of a voltage to the columnar structures can be carried out in combination with the above-mentioned light irradiation.

[0024] [Examples] Hereinafter, the present invention will be described in more detail using examples.

[0025] In the first step, a glass tube with a diameter of 16 mm was filled with an aluminum alloy. The glass tube was then heated to a temperature above its softening point, and the aluminum ions of the filled aluminum alloy were impregnated as a light-absorbing material. The filled material was then stretched to a diameter of approximately 1.5 mm, forming a wire. The appearance of the glass tube after stretching is shown in Figure 2(a).

[0026] Then, in the second step, the glass tube containing the light-absorbing material was irradiated with light to create a thermal shock, causing a sudden increase in stress in the glass tube and removing it. For example, light was irradiated to the central region of the external appearance shown in Figure 2(a). This light irradiation immediately removed the glass tube, resulting in the state shown in Figure 2(b). Further light irradiation allowed the glass tube to be completely removed, as shown in the photograph in Figure 1(c).

[0027] As described above, according to the present invention, the glass tube is removed by applying a sudden increase in stress, and therefore, a method for producing a columnar structure with industrial advantages can be provided.

[0028] As a result of intensive research, the inventors have discovered that applying a sudden increase in stress to a glass tube can efficiently remove the glass tube. The inventors have discovered that this removal method allows glass to be removed by light irradiation without using a dissolving solution such as an acid or a base, and has the advantages of being quick, clean, resource-saving, space-saving, and cost-saving, and have arrived at the solution to the conventional problems in one fell swoop with the present invention.

[0029] It should be noted that the present invention is not limited to the embodiments described above, and it is clear that many modifications and combinations can be made by a person having ordinary knowledge in the art within the technical concept of the present invention.

Claims

1. A method for manufacturing a columnar structure comprising: a first step of filling a glass tube with a substance to form a columnar structure made of said substance; and a second step of physically removing said glass tube by applying a sudden increase in stress.

2. A method for producing a columnar structure according to claim 1, wherein the second step applies a sudden increase in stress to the glass tube by thermal shock.

3. A method for producing a columnar structure according to claim 2, wherein the second step involves irradiating the glass tube with light to cause a sudden increase in stress.

4. A method for producing a columnar structure according to claim 3, wherein the glass tube is doped with a light-absorbing material that absorbs the light.

5. A method for producing a columnar structure according to claim 3, wherein the glass tube contains a light-absorbing material on the surface thereof that absorbs the light.

6. A method for producing a columnar structure according to claim 1, wherein the substance is electrically conductive, and the second step applies a voltage to the columnar structure to cause a sudden increase in stress in the glass tube.

7. A method for producing a columnar structure according to any one of claims 1 to 6, wherein the columnar structure is a wire.

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