JP7252708B2 - Method for manufacturing interdental cleaning tool and base - Google Patents

Description

The present invention relates to an interdental cleaning tool.

Conventionally, an interdental cleaning tool for cleaning between teeth is known. For example, Patent Literature 1 discloses an interdental cleaning tool that includes a base made of a composite material containing a synthetic resin and a fibrous material, and a cleaning portion made of an elastomer. The base has a shaft having a shape that allows it to be inserted between teeth, and a grip that has a shape that allows it to be gripped with fingers. Patent Literature 1 describes that the rigidity (buckling strength) of the shaft portion is increased by blending a fibrous material into a synthetic resin. Further, when polypropylene is used as the synthetic resin, it is preferable that the fiber material is blended in an amount of 15% to 35% by weight, and when polybutylene terephthalate is used as the synthetic resin, the fiber material is blended in an amount of 12% to 35% by weight. It is described that it is preferable to be Specifically, it describes the use of polypropylene to which glass fibers, glass balls, or talc is added as a fibrous material, and the use of polybutylene terephthalate to which glass fiber is added as a fibrous material. It is

WO2013/176297

In the interdental cleaning tool as described in Patent Document 1, the buckling strength of the shaft portion is enhanced by blending a fibrous material with a synthetic resin such as polypropylene, but the shaft portion is not easily buckled. When it occurs, it becomes easy to be divided (easily torn) at that part. If the shaft is cut off during cleaning between the teeth with the interdental cleaning tool, there is a concern that the fragments may remain between the teeth.

SUMMARY OF THE INVENTION An object of the present invention is to provide an interdental cleaning tool capable of securing the buckling strength of the shaft and suppressing the division of the shaft when the shaft is buckled, and a method of manufacturing the same. That is.

As a result of intensive studies to solve the above problems, the present inventors found that by blending carbon fibers having a bending strength greater than the bending strength of glass fibers into synthetic resins, the fibrous materials can be added to the synthetic resins. It is possible to secure the buckling strength of the shaft while reducing the compounding amount. ) can be improved.

The present invention has been made based on the above viewpoints. Specifically, the present invention is an interdental cleaner, which includes a base having a shaft having a shape that can be inserted between the teeth, and the base is a composite material containing synthetic resin and carbon fiber. Provided is an interdental cleaner made of a material, wherein the content of the carbon fiber in the composite material is 5% by weight or more and 10% by weight or less.

In this interdental cleaning tool, the composite material forming the base contains 5% by weight or more and 10% by weight or less of carbon fiber having a relatively high bending strength. When buckling occurs in the portion, division of the shaft portion is suppressed. Specifically, when the carbon fiber content in the composite material is 5% by weight or more, the buckling strength of the shaft portion is effectively ensured. The carbon fiber content is 10% by weight or less, that is, the synthetic resin content in the composite material is increased, thereby increasing the toughness of the shaft portion.

Further, it is preferable that the synthetic resin is polypropylene.

In this way, the toughness of the shaft portion is effectively increased, so even if the shaft portion is buckled, the division of the shaft portion at that portion is more reliably suppressed.

Further, the present invention provides a method for manufacturing a base having a shaft portion having a shape that can be inserted between teeth, the composite material containing a synthetic resin and carbon fiber, wherein the content of the carbon fiber is is 5% by weight or more and 10% by weight or less, and a molding step of molding the base by filling the composite material in a mold having a space corresponding to the base. , provides a method of manufacturing a base.

In this manufacturing method, since the content of carbon fiber in the composite material filled in the mold in the molding process is 5% by weight or more and 10% by weight or less, the buckling strength is ensured and even if buckling occurs, A base having a shaft that is difficult to break even if there is one is manufactured. Furthermore, the fluidity of the composite material filled in the mold increases compared to when the carbon fiber content is more than 10% by weight. Therefore, the manufacturing efficiency of the base is improved.

Further, in the method for manufacturing the base, in the preparing step, a solid material containing the synthetic resin and the carbon fiber is prepared as the composite material, and in the molding step, the solid material is melted and placed in the mold. It is preferable to fill the

In this way, in the preparation process, a solid material (for example, a pellet-like material) in which the amount of carbon fiber blended with respect to the synthetic resin is adjusted in advance is prepared. Variation in carbon fiber content in the material is suppressed.

INDUSTRIAL APPLICABILITY As described above, according to the present invention, there is provided an interdental cleaning tool capable of securing the buckling strength of the shaft portion and suppressing the splitting of the shaft portion when the shaft portion is buckled. A manufacturing method can be provided.

1 is a front view of an interdental cleaning tool according to one embodiment of the present invention; FIG. It is a figure which shows the outline of the formation process of a base. 1 is a schematic diagram of a solid composite material containing synthetic resin and carbon fibers (long fibers). FIG. 1 is a schematic diagram of a solid composite material containing synthetic resin and carbon fibers (short fibers); FIG. 2 is a table showing the composition of each example and each comparative example.

An interdental cleaning tool 1 according to one embodiment of the present invention will be described with reference to FIGS. 1 to 4. FIG.

As shown in FIG. 1 , the interdental cleaner 1 comprises a base 10 and preferably further comprises a cleaning portion 40 . The base 10 has a shaft portion 20 and a grip portion 30 .

The shaft portion 20 has a shape that extends linearly along a specific direction (horizontal direction in FIG. 1) and that can be inserted between the teeth. A cross section of the shaft portion 20 in a plane perpendicular to the axial direction of the shaft portion 20 (horizontal direction in FIG. 1) is circular. The cross section may be elliptical, polygonal, or the like. In this embodiment, the shaft portion 20 is formed in a columnar shape with an outer diameter that gradually decreases from the base end portion toward the tip end of the shaft portion.

The grip portion 30 extends along the axial direction of the shaft portion 20 so as to be separated from the base end portion of the shaft portion 20, and has a shape that can be gripped with fingers. The grip portion 30 is formed flat. As shown in FIG. 1 , the gripping portions 30 of the interdental cleaners 1 are connected by connecting pieces 32 .

The base 10 is made of a composite material including a synthetic resin 61 (see FIGS. 3 and 4) and carbon fibers 62, 63 (see FIGS. 3 and 4). As the synthetic resin 61, polypropylene, polyethylene, ABS, polybutylene terephthalate, polycarbonate, polyethylene terephthalate, polystyrene, polyacetal, etc. are preferably used. In this embodiment, polypropylene is used as the synthetic resin 61 . As carbon fibers, long fibers 62 having a fiber length of about 1 to 8 mm (see FIG. 3) or short fibers 63 having a fiber length of about 0.1 to 1 mm (see FIG. 4) are used. The content of the carbon fibers 62, 63 in the composite material is preferably set to 5% by weight or more and 10% by weight or less. In addition, the carbon fibers 62 are normally about 0.5 to 2 mm in the molded base 10, and the carbon fibers 63 are normally about 0.01 to 4 mm in the molded base 10. Also, the bending elastic modulus of the carbon fibers 62 and 63 (see FIGS. 3 and 4) is about 4 to 20 GPa.

Here, a method for manufacturing the base 10 described above will be described. This manufacturing method includes a preparation process and a molding process.

In the preparation step, the composite material (the content of the carbon fibers 62, 63 is 5% by weight or more and 10% by weight or less) is prepared. Specifically, in this step, a solid (pellet-like) P (see FIGS. 3 and 4) containing a synthetic resin 61 and carbon fibers 62 and 63 is prepared as a composite material. The solid P is formed in, for example, a columnar shape, a spherical shape, or a quadrangular prism. However, from the viewpoint of preventing clogging when the solid P is put into a tank for melting the solid P, it is preferable that the solid P is formed in a cylindrical shape. The long fibers 62 are held by the synthetic resin 61 in a posture in which the longitudinal direction of the fibers is parallel to the axial direction of the cylinder.

In the molding step, as shown in FIG. 2 , the base 10 is molded by filling a mold 50 having a space corresponding to the base 10 while melting the solid P.

Next, the cleaning section 40 will be described. The cleaning part 40 is a part for cleaning between teeth, and is made of a resin material having a hardness lower than that of the base part 10 . Specifically, a styrene-based elastomer is used as the resin material. However, silicon, olefin elastomer, polyester elastomer, or the like may be used as the resin material. In this embodiment, the cleaning unit 40 includes a cleaning unit main body 42 that covers a part of the outer peripheral surface of the shaft 20 (a portion including the tip of the shaft 20), and each projecting from the outer peripheral surface of the cleaning unit main body 42. and a plurality of brush portions 44 having a shape that Note that the cleaning unit 40 may be omitted.

As described above, in the interdental cleaner 1 of the present embodiment, the composite material forming the base 10 contains 5% by weight or more and 10% by weight or less of the carbon fibers 62 and 63 having relatively high bending strength. Therefore, the buckling strength of the shaft portion 20 is ensured, and furthermore, the division of the shaft portion 20 when buckling occurs in the shaft portion 20 is suppressed. Specifically, when the content of the carbon fibers 62, 63 in the composite material is 5% by weight or more, the buckling strength of the shaft portion 20 is effectively secured, and the content of the carbon fibers 62, 63 is 10% by weight. By increasing the content of the synthetic resin 61 in the composite material, the toughness of the shaft portion 20 is increased.

Further, since polypropylene is used as the synthetic resin 61, the toughness of the shaft portion 20 is effectively increased. Therefore, even if buckling occurs in the shaft portion 20, the division of the shaft portion 20 at that portion is more reliably suppressed.

Since the content of the carbon fibers 62 and 63 in the composite material is 5% by weight or more and 10% by weight or less, compared to the case where the content of the fiber material such as carbon fiber or glass fiber is more than 10% by weight, In the molding process, the fluidity of the composite material filled in the mold 50 is increased. Therefore, the manufacturing efficiency of the base 10 is improved.

In addition, in the preparation step, the solid material P including the synthetic resin 61 and the carbon fibers 62 and 63 is prepared as the composite material. Variation in the contents of 62 and 63 is suppressed.

It should be noted that the above-described embodiments disclosed this time should be considered as examples and not restrictive in all respects. The scope of the present invention is indicated by the scope of the claims rather than the description of the above-described embodiments, and includes all modifications within the meaning and scope equivalent to the scope of the claims.

For example, the composite material may contain both long fibers 62 and short fibers 63 as carbon fibers.

Also, the axial direction of the shaft portion 20 may intersect the longitudinal direction of the grip portion 30 . Also, the shaft portion 20 may be curved.

Four types of examples and two types of comparative examples were prepared for the interdental cleaning tool 1 of the above embodiment. The composition of each example and each comparative example is as shown in FIG. Specifically, in each example and comparative example, a composite material solid containing a synthetic resin (polypropylene) and a fiber material (carbon fiber or glass fiber) (Example 1: polypropylene and 5% by weight of long fibers 62 Example 2: Solid containing polypropylene and 10% by weight of long fibers 62, Example 3: Solid containing polypropylene and 5% by weight of short fibers 63, Example 4: Polypropylene and 10 Solids containing 63% by weight of short fibers, Comparative Example 1: Solids containing polypropylene and 5% by weight of glass fibers, Comparative Example 2: Solids containing polypropylene and 10% by weight of glass fibers) were prepared. Then, the base portion 10 was formed by filling the space (the space corresponding to the base portion 10) in the mold 50 with the solid matter while being melted. Then, an interdental cleaning tool was produced by providing a cleaning part 40 with a styrene-based elastomer to the base part 10 .

In any of Examples 1 to 4, as compared with Comparative Examples 1 and 2, when the shaft portion is buckled, it is difficult to break at that portion, and the mold 50 is filled. The fluidity of the composite material was also excellent. Also, the insertability of the cleaning part 40 between the front teeth and back teeth was excellent.

1 Interdental Cleaning Tool 10 Base 20 Shaft 30 Grip 40 Cleaning Part 42 Cleaning Part Body 44 Brush Part 50 Mold 61 Synthetic Resin 62 Long Fiber 63 Short Fiber P Solid Matter

Claims (4)

An interdental cleaner,
including a base having a shaft having a shape that can be inserted between the teeth;
The base is formed of a composite material made of synthetic resin and carbon fibers having a fiber length of 1 to 8 mm,
The interdental cleaner, wherein the content of the carbon fiber in the composite material is 5% by weight or more and 10% by weight or less. The interdental cleaning tool according to claim 1,
The interdental cleaner, wherein the synthetic resin is polypropylene. A method for manufacturing a base having a shaft having a shape that can be inserted between teeth,
A preparation step of preparing a composite material composed of a synthetic resin and carbon fibers having a fiber length of 1 to 8 mm , wherein the content of the carbon fibers is 5% by weight or more and 10% by weight or less;
and a molding step of molding the base by filling the composite material in a mold having a space corresponding to the base. In the method of manufacturing a base according to claim 3,
In the preparation step, a solid material containing the synthetic resin and the carbon fiber is prepared as the composite material,
In the molding step, the method of manufacturing a base portion includes filling the mold while melting the solid matter.

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