Interdental Cleaning Tools

Abstract

To provide an interdental cleaning tool which comprises a froth part having a portion different in thickness and easy to form.SOLUTION: An interdental cleaning tool comprises: a froth part including at least one multifilament. The froth part has a portion different in thickness by differentiating the degree of crimping along a length direction.SELECTED DRAWING: Figure 3

Description

[Technical field]

[0001] The present invention relates to an interdental cleaning tool. [Background technology]

[0002] Interdental cleaning tools that are inserted between teeth have been known for some time. Patent Document 1 discloses an interdental cleaning tool that includes a cleaning part that is made by winding and covering a wire around the outer circumferential surface of a core material. Patent Document 1 also describes that steps or gaps are provided between the wires to improve the cleaning ability of the cleaning part. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2014-68977 A Summary of the Invention [Problem to be solved by the invention]

[0004] However, the interdental cleaner described in Patent Document 1 still has room for improvement in terms of ease of forming unevenness such as the above-mentioned steps and gaps.

[0005] An object of the present invention is to provide an interdental cleaning tool having a floss portion with easily formable portions of different thicknesses. [Means for solving the problem]

[0006] The interdental cleaner according to a first aspect of the present invention comprises a floss portion including at least one multifilament, the floss portion having portions of different thicknesses due to the degree of crimping being varied in the length direction.

[0007] In one embodiment of the present invention, in the at least one multifilament, the degree of crimp is repeatedly increased and decreased in the length direction, so that thick portions and thin portions are alternately formed.

[0008] In one embodiment of the present invention, the floss portion is made of a plurality of multifilaments arranged in parallel without being twisted together, each of the plurality of multifilaments has a portion of different thickness by varying the degree of crimping in the length direction, and the difference between the maximum diameter and the minimum diameter of each of the plurality of multifilaments is 0.15 mm or less.

[0009] In one embodiment of the present invention, the floss portion is made of a plurality of multifilaments arranged in parallel without being twisted together, each of the plurality of multifilaments has a portion of different thickness by varying the degree of crimping in the length direction, and the difference between the maximum diameter and the minimum diameter of each of the plurality of multifilaments is 0.05 mm or more.

[0010] In one embodiment of the present invention, the floss portion is made of a plurality of twisted multifilaments, and the difference between the maximum and minimum diameters of the floss portion is 0.15 mm or less.

[0011] In one embodiment of the present invention, the floss portion is made of a plurality of twisted multifilaments, and the difference between the maximum and minimum diameters of the floss portion is 0.05 mm or more.

[0012] In one embodiment of the invention, the cleaning tool comprises a cleaning tool body including two supports between which the floss portion is supported. Effect of the Invention

[0013] According to the present invention, it is possible to provide an interdental cleaning tool having a floss portion having portions of different thicknesses that can be easily formed. [Brief description of the drawings]

[0014] [Figure 1] FIG. 1 is a diagram showing an interdental cleaner according to one embodiment of the present invention. [Diagram 2] FIG. 2 is a cross-sectional view taken along line II in FIG. [Diagram 3] 2 is an enlarged view of a portion of the floss part in FIG. 1 that is bridged between two support parts. FIG. [Figure 4] 2 is an enlarged view of a portion of the floss part in FIG. 1 that is fixed to a first support part. FIG. [Diagram 5] FIG. 2 is a schematic diagram showing a mold for producing the interdental cleaner of FIG. 1. [Figure 6] 2A to 2C are diagrams showing a part of a method for manufacturing the interdental cleaner of FIG. 1. [Figure 7] FIG. 2 is a diagram showing a modified example of the interdental cleaner shown in FIG. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0015] Hereinafter, an embodiment of an interdental cleaning tool according to the present invention will be described with reference to the drawings. The same reference numerals are used to designate the same components in each drawing.

[0016] Fig. 1 is a diagram showing an interdental cleaner 1 as one embodiment of the interdental cleaner according to the present invention. As shown in Fig. 1, the interdental cleaner 1 includes a cleaner body 10 and a floss portion 20. The floss portion 20 is a filament that is inserted between the teeth to remove plaque between the teeth. The cleaner body 10 holds the floss portion 20.

[0017] <Cleaning tool body 10> The cleaning tool body 10 of this embodiment includes a rod-shaped handle portion 11 that can be gripped by a user, and two rod-shaped support portions 12, 13 protruding from the handle portion 11. In the interdental cleaning tool 1 of this embodiment, the floss portion 20 is disposed between the two support portions 12, 13 of the cleaning tool body 10. In other words, both ends of the floss portion 20 are fixed to the two support portions 12, 13.

[0018] The handle portion 11 of the present embodiment includes a portion that extends substantially linearly and a portion that is connected to the linear portion and curves and tapers, but the shape of the handle portion 11 is not particularly limited.

[0019] The two support parts 12 and 13 in this embodiment are provided at one end side of the rod-shaped handle part 11 in the longitudinal direction, protruding from the handle part 11 in a direction substantially perpendicular to the longitudinal direction of the handle part 11. The two support parts 12 and 13 in this embodiment are provided at different positions in the longitudinal direction of the handle part 11, protruding in parallel with each other. Furthermore, the two support parts 12 and 13 in this embodiment are arranged facing each other in the longitudinal direction of the handle part 11. Hereinafter, for convenience of explanation, one support part 12 located at the end side of the longitudinal direction of the handle part 11 will be described as a "first support part 12", and one support part 13 located at the center side of the longitudinal direction of the handle part 11 will be described as a "second support part 13". In addition, when the first support part 12 and the second support part 13 are not particularly distinguished from each other, they will be simply described as "support parts 12 and 13".

[0020] FIG. 2 is a cross-sectional view taken along line II in FIG. 1. As shown in FIGS. 1 and 2, the first support 12 of this embodiment has a plate shape in which the direction facing the second support 13 is the width direction (the left-right direction in FIG. 1, the direction perpendicular to the paper surface in FIG. 2), and the direction perpendicular to the extension direction (the up-down direction in FIG. 1 and FIG. 2) and the width direction of the first support 12 is the thickness direction (the direction perpendicular to the paper surface in FIG. 1, the left-right direction in FIG. 2). As shown in FIG. 2, the thickness of the first support 12 in the thickness direction of this embodiment is gradually thinner from the base end side connected to the handle part 11 in the extension direction toward the tip side on the opposite side. However, the thickness of the first support 12 in the thickness direction may be uniform in the extension direction, and the configuration is not particularly limited. In addition, the first support 12 of this embodiment has a rectangular cross-sectional shape in a cross-sectional view perpendicular to the extension direction, but is not limited to this configuration. The cross-sectional shape of the first support portion 12 in a cross-sectional view perpendicular to the extending direction may be, for example, a circle or other shape.

[0021] 1 and 2, the end of the floss portion 20 in the longitudinal direction is fixed to the first support portion 12 in a state where it is inserted into a through hole 12b that passes through the first support portion 12 in the width direction. This will be described in detail later (see FIG. 4).

[0022] In addition, the configuration of the second support part 13 in this embodiment is similar to the configuration of the first support part 12. Therefore, in this embodiment, only the details of the configuration of the first support part 12 will be described, and the details of the configuration of the second support part 13 will not be described.

[0023] The cleaning tool body 10 of this embodiment can be made from a synthetic resin such as polypropylene, polystyrene, polyethylene, ABS, polycarbonate, or polybutylene terephthalate.

[0024] <Floss Section 20> As shown in FIG. 1 and FIG. 2, the floss part 20 includes at least one multifilament 21. That is, the floss part 20 is a filament-like body in which one or more multifilaments 21 are bundled together. As shown in FIG. 2, the floss part 20 of this embodiment is composed of four multifilaments 21, but the number is not particularly limited. Therefore, the number of multifilaments 21 constituting the floss part 20 may be only one. However, as in this embodiment, the floss part 20 is preferably composed of a plurality of multifilaments 21. In this way, the effect of scraping off plaque can be improved. In addition, by bundling the plurality of multifilaments 21 so as to interact with each other, the floss part 20 is less likely to fall off from the respective support parts 12, 13, and separation from the respective support parts 12, 13 is suppressed. However, if the number of multifilaments 21 is too large, the floss part 20 is less easily inserted between teeth. Therefore, it is preferable that the number of multifilaments 21 constituting the floss part 20 is, for example, seven or less.

[0025] In addition, the floss portion 20 of this embodiment has multiple (four in this embodiment) multifilaments 21 arranged in parallel without being twisted together. More specifically, the multiple multifilaments 21 constituting the floss portion 20 of this embodiment are arranged in parallel so as to be aligned in a straight line in the extension direction of the support portions 12, 13 (the vertical direction in Figures 1 and 2) in a cross-sectional view (see Figure 2) perpendicular to the longitudinal direction A of the floss portion 20. However, the configuration of the floss portion 20 is not limited to this configuration. The floss portion 20 may also have a configuration in which multiple multifilaments 21 are twisted together.

[0026] The thickness of each multifilament 21 is not particularly limited, but when the multifilaments 21 are arranged in parallel without being twisted as in the present embodiment, the thickness of each multifilament 21 is preferably, for example, 1.7 mm to 2.0 mm. The thickness of each multifilament 21 is preferably 1300 dtex to 1450 dtex, and more preferably 1330 dtex to 1400 dtex. Although details will be described later, at least one multifilament 21 constituting the floss portion 20 has a portion having a different thickness by varying the degree of crimping in the length direction (see Figs. 3 and 4). When the floss portion 20 is constituted by twisting a plurality of multifilaments 21 together, the thickness of each multifilament 21 may be set so that the thickness of the entire floss portion 20 is, for example, 1.7 mm to 2.0 mm.

[0027] Furthermore, each multifilament 21 may be formed by twisting together a plurality of monofilaments made of, for example, polyethylene. The material of the monofilaments constituting the multifilament 21 is not limited to polyethylene, and may be, for example, nylon, Teflon (registered trademark), vinylon, polyethylene terephthalate, polybutylene terephthalate, polyacrylonitrile, polystyrene, polypropylene, etc. Also, the plurality of monofilaments constituting one multifilament 21 may be formed from different forming materials. Furthermore, the multifilament 21 is not limited to a configuration in which a plurality of monofilaments are twisted together, and may be a configuration in which a plurality of monofilaments are bundled together without being twisted.

[0028] The number of monofilaments constituting each multifilament 21 is preferably 15 to 120, more preferably 30 to 100, and particularly preferably 50 to 100. If the number of monofilaments is too small, the synthetic resin material of the injection-molded cleaning tool body 10 and the monofilaments are difficult to entangle, and the floss part 20 is likely to fall off from each of the supports 12 and 13. If the number of monofilaments is too small, the floss part 20 is likely to break. On the other hand, if the number of monofilaments is too large, the synthetic resin material of the injection-molded cleaning tool body 10 does not sufficiently penetrate between the monofilaments, and the floss part 20 is likely to fall off from each of the supports 12 and 13. Therefore, the number of monofilaments constituting each multifilament 21 is preferably within the above range.

[0029] Furthermore, when each multifilament 21 is configured by twisting a plurality of monofilaments together, the number of twists per meter of each multifilament 21 is preferably 500 or less. Specifically, it is preferably 300 or less, more preferably 200 or less, and particularly preferably 170 or less. If the number of twists of the multifilament 21 is too large, the synthetic resin material of the cleaning tool body 10, which is injection molded, does not sufficiently penetrate between the monofilaments, and the floss portion 20 is likely to fall off from each of the support portions 12, 13. Therefore, it is preferable that the number of twists per meter of each multifilament 21 is within the above range.

[0030] There is no particular lower limit to the number of twists per meter of each multifilament 21. As described above, each multifilament 21 may be formed by bundling a plurality of monofilaments without twisting them.

[0031] Furthermore, a reinforcing material can be contained in the multifilament 21. Examples of the reinforcing material include fibrous reinforcing materials such as glass fiber and amide fiber, granular reinforcing materials such as talc, and plate-like reinforcing materials such as plate-like glass and mica.

[0032] Next, details of floss portion 20 will be described with reference to Fig. 3. Fig. 3 is an enlarged view of a portion of floss portion 20 in Fig. 1 that is disposed between supports 12, 13.

[0033] As shown in FIG. 3, the floss portion 20 has portions of different thicknesses due to the degree of crimping being different in the longitudinal direction A. More specifically, the floss portion 20 has both portions with a small degree of crimping and portions with a large degree of crimping and portions with a large degree of crimping at different positions in the longitudinal direction A. The difference in "degree of crimping" can be confirmed, for example, by comparing the extension length of the monofilament contained per unit length in the longitudinal direction A in each of the thin and thick portions. The extension length of the monofilament contained per unit length in the longitudinal direction A is relatively short in the thin portions with a small degree of crimping and is relatively long in the thick portions with a large degree of crimping.

[0034] The floss part 20 has parts of different thicknesses, which improves both the ease of insertion between teeth and the ease of cleaning between teeth. Specifically, the floss part 20 has relatively thin parts, which improves the ease of insertion between teeth. Furthermore, the floss part 20 has relatively thick parts, which makes it easier for the floss part 20 to come into close contact with the side of teeth between teeth, which improves cleaning. Furthermore, plaque is easily trapped in the steps and recesses formed by the thick and thin parts. Therefore, in this respect as well, the cleaning ability of the floss part 20 can be improved.

[0035] Here, in the floss portion 20, the different thicknesses are realized by varying the degree of crimping. In this way, by using the degree of crimping to vary the thickness, the floss portion 20 can easily have different thicknesses.

[0036] More specifically, the floss portion 20 of this embodiment is composed of a plurality of multifilaments 21. The floss portion 20 of this embodiment is composed of a plurality of multifilaments 21 arranged in parallel, each of which has a portion of different thickness due to the degree of crimping being different in the length direction A. That is, in this embodiment, each multifilament 21 constituting the floss portion 20 is configured to have a different degree of crimping in the length direction A. In this embodiment, a plurality of multifilaments 21 having different degrees of crimping in the length direction A are arranged in parallel, and thus the floss portion 20 as a whole has portions of different thickness due to the degree of crimping being different in the length direction A.

[0037] However, as described above, the floss portion 20 may be formed by twisting together a plurality of multifilaments 21 having different degrees of crimping in the length direction A. In other words, by twisting together a plurality of multifilaments 21 having different degrees of crimping in the length direction A, the floss portion 20 as a whole may have portions having different thicknesses by varying the degree of crimping in the length direction A.

[0038] Each of the multiple multifilaments 21 constituting the floss portion 20 only needs to have a portion with a different degree of crimp in the length direction A, and the positions in the length direction A of the portions with a large degree of crimp and the portions with a small degree of crimp may be different or the same among the multiple multifilaments 21. In other words, the portion with a large degree of crimp in the length direction A of one multifilament 21 may be disposed adjacent to the portion with a small degree of crimp in the length direction A of another multifilament 21 (see FIG. 3) or may be twisted together.

[0039] In this embodiment, each multifilament 21 is partially subjected to a bulking process such as false twisting in the longitudinal direction A. This causes each multifilament 21 to have portions with different degrees of crimp in the longitudinal direction A. As a result, each multifilament 21 has portions with different thicknesses in the longitudinal direction A.

[0040] In addition, the bulking process applied to each multifilament 21 may be performed using a processing method other than the above-mentioned false twist processing, such as twisting, heat setting, untwisting, rubbing, pushing, shaping, air injection, and composite crimping.

[0041] In addition, the floss portion 20 of this embodiment is configured by arranging multiple multifilaments 21 in parallel, each having a different degree of crimp in the length direction A, but as described above, the floss portion 20 may be formed by twisting multiple multifilaments 21 in parallel, each having a different degree of crimp in the length direction A. Also, the degree of crimp in the length direction A of the floss portion 20 may be made different after multiple multifilaments 21 having a uniform degree of crimp in the length direction A are arranged in parallel or twisted together.

[0042] As shown in Figure 3, in each multifilament 21 of the floss portion 20 of this embodiment, the degree of crimp is repeatedly increased and decreased in the longitudinal direction A, so that thick and thin portions are alternately formed. This configuration can further improve the ease of insertion between teeth and the ease of cleaning between teeth. Hereinafter, for the sake of convenience, of the thick and thin portions alternately formed in the longitudinal direction A, the thin portions will be referred to as "thin diameter portions 31" and the thick portions will be referred to as "thick diameter portions 32."

[0043] As shown in FIG. 3, each multifilament 21 of the floss portion 20 has a plurality of thick-diameter portions 32 at different positions in the length direction A. As shown in FIG. 3, in each multifilament 21, the length of each thick-diameter portion 32 in the length direction A may be uniform or different. Also, as shown in FIG. 3, in each multifilament 21, the maximum diameter of each thick-diameter portion 32 may be uniform or different. The maximum diameter of each thick-diameter portion 32 means the maximum linear distance between two points on the outer edge in a cross-sectional view perpendicular to the length direction A. For example, when the cross-sectional shape of the thick-diameter portion 32 in a cross-sectional view perpendicular to the length direction A is approximately circular, the maximum diameter of the thick-diameter portion 32 is the diameter of the circle. Furthermore, as shown in FIG. 3, in each multifilament 21, the distance between two adjacent thick-diameter portions 32 may be different depending on the position in the length direction A.

[0044] Here, in the case where the floss portion 20 is made of a plurality of multifilaments 21 arranged in parallel without being twisted together as in the present embodiment, the difference between the maximum diameter Dmax and the minimum diameter Dmin of each multifilament 21 having a portion with a different degree of crimping in the length direction A is preferably 0.15 mm or less, more preferably 0.11 mm or less. If the difference between the maximum diameter Dmax and the minimum diameter Dmin of each multifilament 21 is greater than 0.15 mm, at least one of the insertability and cleanability is likely to decrease. If the minimum diameter Dmin is set within a desired range to maintain insertability, the maximum diameter Dmax is likely to be too large for the gap between teeth, and cleanability is likely to decrease. On the other hand, if the maximum diameter Dmax is set within a desired range to maintain cleanability, the minimum diameter Dmin is likely to be easily broken during insertion, and insertability is likely to decrease. For the above reasons, the difference between the maximum diameter Dmax and the minimum diameter Dmin of each multifilament 21 is preferably within the above range.

[0045] In addition, as in this embodiment, when the floss portion 20 is made of a plurality of multifilaments 21 arranged in parallel without being twisted, the difference between the maximum diameter Dmax and the minimum diameter Dmin of each multifilament 21 having a portion with a different degree of crimping in the length direction A is preferably 0.05 mm or more, more preferably 0.09 mm or more. If the difference between the maximum diameter Dmax and the minimum diameter Dmin of each multifilament 21 is smaller than 0.05 mm, at least one of the insertability and cleanability is likely to decrease. If the minimum diameter Dmin is set to a desired range in order to maintain the insertability, the maximum diameter Dmax is likely to be too small for the gap between the teeth, and the cleanability is likely to decrease. On the other hand, if the maximum diameter Dmax is set to a desired range in order to maintain the cleanability, the minimum diameter Dmin is likely to be too thick, and the insertability is likely to decrease. For the above reasons, the difference between the maximum diameter Dmax and the minimum diameter Dmin of each multifilament 21 is preferably set to the above range.

[0046] In addition, when the floss portion 20 is made up of multiple twisted multifilaments 21, for the same reasons as above, the difference between the maximum and minimum diameters of the entire floss portion 20 may be set within the above numerical range.

[0047] Next, referring to FIG. 4, the details of the portion of the floss part 20 fixed to the first support part 12 will be described. FIG. 4 is an enlarged view of the portion of the floss part 20 fixed to the first support part 12 in FIG. 1. For convenience of explanation, in FIG. 4, the position of the first support part 12 is indicated by a two-dot chain line. In addition, in FIG. 4, the position of the through hole 12b provided in the first support part 12 is also indicated by a two-dot chain line. However, the first support part 12 of this embodiment is injection molded by filling the resin so as to cover the periphery of one end part of the floss part 20. Therefore, the through hole 12b of this embodiment is actually a hole that follows the outer shape of the floss part 20. That is, in FIG. 4, the position of the through hole 12b is indicated by a two-dot chain line for convenience, but the through hole 12b shown in FIG. 4 is different from the actual shape.

[0048] 4, floss portion 20 has a portion at each end in longitudinal direction A that penetrates first support portion 12 and has a different thickness in longitudinal direction A. More specifically, floss portion 20 of this embodiment has a thin diameter portion 31 and a thick diameter portion 32 at each end in longitudinal direction A. Each end of floss portion 20 in longitudinal direction A has thin diameter portion 31 and thick diameter portion 32 that is located outside thin diameter portion 31 in longitudinal direction A and is thicker than thin diameter portion 31.

[0049] Each of the ends of the floss part 20 in the longitudinal direction A may have at least one set of the thin diameter portion 31 and the thick diameter portion 32 specified by the positional relationship described above, but may have multiple sets. Specifically, one end of the floss part 20 in the longitudinal direction A shown in FIG. 4 has multiple sets of the thin diameter portion 31 and the thick diameter portion 32 specified by the positional relationship described above.

[0050] As shown in FIG. 4, the first support 12 has a pull-out restricting portion 12a that abuts against a step or tapered portion (step 40 in this embodiment) between the thin-diameter portion 31 and the thick-diameter portion 32 of each multifilament 21 of the floss portion 20 and restricts the floss portion 20 from being pulled out inward in the longitudinal direction A. In other words, the pull-out restricting portion 12a of the first support 12 is a portion that interferes with the thick-diameter portion 32 of each multifilament 21 of the floss portion 20 in the longitudinal direction A. The cleaning tool body 10 of this embodiment is integrally molded with the floss portion 20, as described later. In this case, the pull-out restricting portion 12a of this embodiment is formed by a part of the first support 12 that is located inside in the longitudinal direction A with respect to the step 40 at the end of each multifilament 21 of the floss portion 20 in the longitudinal direction A.

[0051] In this manner, the pull-out restricting portion 12a in this embodiment is formed from a part of the first support portion 12 which is an injection molded product, but is not limited to this configuration. The configuration of the pull-out restricting portion 12a is not particularly limited as long as it interferes with the step or tapered portion between the small diameter portion 31 and the large diameter portion 32 of the floss portion 20 and restricts the floss portion 20 from being pulled out inward in the longitudinal direction A.

[0052] The interdental cleaner 1 is used by inserting the floss portion 20 between the teeth and moving it back and forth in the longitudinal direction A. Therefore, by providing the first support portion 12 with the pull-out restricting portion 12a, it is possible to prevent the floss portion 20 from being pulled out of the first support portion 12 when the user uses the interdental cleaner 1.

[0053] In this embodiment, the pull-out restricting portion 12a is configured to abut and interfere with the step portion 40 between the thin diameter portion 31 and the thick diameter portion 32, but is not limited to this configuration. For example, when the outer diameter gradually decreases from the outer side to the inner side in the length direction A from the maximum diameter position of the thick diameter portion 32 to the minimum diameter position of the thin diameter portion 31, the pull-out restricting portion 12a may be configured to abut and interfere with the tapered portion between the maximum diameter position of the thick diameter portion 32 and the minimum diameter position of the thin diameter portion 31. However, as in this embodiment, it is preferable to provide a step portion 40 in the floss portion 20 and to configure the pull-out restricting portion 12a to abut against the step portion 40. In this way, the pull-out strength of the floss portion 20 can be further increased.

[0054] As shown in FIG. 4, one end of each multifilament 21 of the floss portion 20 in the length direction A of the present embodiment extends within the through hole 12b of the first support portion 12, and the above-mentioned pull-out restricting portion 12a is formed by the inner surface of this through hole 12b. The cleaning tool body 10 of the present embodiment is integrally molded with the floss portion 20, as described below. More specifically, the first support portion 12 is formed by filling the periphery of both ends of the floss portion 20 with a molding resin and solidifying it. Therefore, in the completed interdental cleaning tool 1, one end of each multifilament 21 of the floss portion 20 in the length direction A of the present embodiment extends within the through hole 12b formed in the first support portion 12. The pull-out restricting portion 12a of the present embodiment described above is composed of a restricting wall 12b1 formed on the inner surface of the through hole 12b, which is located on the inside in the longitudinal direction A of the stepped portion 40 at the end of the longitudinal direction A of each multifilament 21 of the floss portion 20 and faces the stepped portion 40 on the outside in the longitudinal direction A. The restricting wall 12b1 abuts against the stepped portion 40 to restrict the floss portion 20 from being pulled outward in the longitudinal direction A.

[0055] From the viewpoint of preventing the floss portion 20 from being pulled out of the first support portion 12, the thin diameter portion 31 and the thick diameter portion 32 only need to have different thicknesses that form a step or tapered portion, and it is not necessary to use the degree of crimp to make the thicknesses different. However, the thin diameter portion 31 and the thick diameter portion 32 can be easily formed by using the degree of crimp to make the thicknesses different at both ends of the length direction A of the floss portion 20, together with the portion of the floss portion 20 that is bridged between the two support portions 12, 13.

[0056] As shown in Fig. 4, the floss portion 20 of this embodiment is made up of a plurality of multifilaments 21 that are arranged in parallel without being twisted together. The thin diameter portion 31 and the thick diameter portion 32 at both ends of the floss portion 20 are formed by both ends in the length direction A of at least one of the plurality of multifilaments 21 (all of the multifilaments 21 in this embodiment). In particular, by configuring both ends of all of the multifilaments 21 to have a thin diameter portion 31 and a thick diameter portion 32 as in this embodiment, the pull-out strength of each multifilament 21 from the first support portion 12 is increased, and the pull-out strength of the entire floss portion 20 from the first support portion 12 can be further increased.

[0057] As described above, the floss portion 20 may be made up of a plurality of twisted multifilaments 21. In such a case, the thin diameter portion 31 and the thick diameter portion 32 at both ends of the floss portion 20 may be made up of both ends in the length direction A of the entire floss portion 20 in which the plurality of twisted multifilaments 21 are twisted together.

[0058] 4, the floss portion 20 of this embodiment passes through the through hole 12b of the first support portion 12, and a retaining portion 20a is formed at its end so as not to enter the through hole 12b. By providing such a retaining portion 20a, the floss portion 20 can be further prevented from being pulled out.

[0059] In addition, in this embodiment, the relationship between one end of the floss part 20 in the longitudinal direction A and the first support part 12 has been explained with reference to Figure 4, but the relationship between the other end of the floss part 20 in the longitudinal direction A and the second support part 13 is also similar.

[0060] Next, a method for manufacturing the interdental cleaner 1 of this embodiment will be described with reference to Figs.

[0061] First, a mold 100 for injection molding as shown in FIG. 5 is prepared. The mold 100 has a plurality of cavities 101 for molding a plurality of cleaning tool bodies 10. In the mold, a gate 102 for injecting resin is provided in the handle portion 11. Although not shown, the mold 100 has a plurality of resin passages (runners) branching from a nozzle for discharging resin. The resin is supplied from the nozzle to each gate 102 through each runner. The number of cavities 101 and the number of runners associated therewith are not particularly limited. The length of the runner can be appropriately changed depending on the arrangement of the cavities 101. Then, when performing injection molding, a plurality of wires 103 that will become the floss portion 20 are arranged in the mold. At this time, the plurality of wires 103 are arranged so as to extend across the plurality of cavities 101 between the portions corresponding to the two support portions 12 and 13 of each cavity 101.

[0062] Next, resin for the cleaning tool body 10 is injected into the cavity 101. As described above, when the resin is injected, it first reaches the gate 102 via the runner, and is then injected into the cavity 101 from the gate 102.

[0063] After the injection of the resin is completed, the cleaning tool main body 10 is removed from the mold 100 after a predetermined time has elapsed. At this time, in each cleaning tool main body 10, the multiple wires 103 that will become the floss part 20 are embedded in both support parts 12 and 13 and integrated together. In other words, the two support parts 12 and 13 are injection molded products that are injection molded with both ends of the floss part 20 embedded. In addition, the multiple cleaning tool main bodies 10 are connected by the multiple wires 103. Therefore, in the next step, as shown in FIG. 6, the multiple wires 103 are burned off on the left side of the first support part 12 and the right side of the second support part 13 of each cleaning tool main body 10. The burn-off means 50 for burning off the multiple wires 103 is not particularly limited, but can be burned off by a flame or a heated blade, by irradiation of heat rays such as far infrared rays, or by electrical discharge, for example. When the wires 103 are burned off in this manner, the multifilaments 21 constituting the wires 103 are melted by the heat and integrated into a mass, forming the retaining portion 20a. In this manner, the interdental cleaning tool 1 is formed.

[0064] Next, the outline and results of the sensory test for the interdental cleaner 1 of this embodiment will be described. In this sensory test, four types of multifilaments 21 having portions with different thicknesses depending on the degree of crimping were prepared. The four types of interdental cleaners 1 prepared by arranging six of each of these four types of multifilaments 21 in parallel were used by 19 monitors, who evaluated the ease of insertion on a five-point scale (easy to insert (5), somewhat easy to insert (4), neither (3), somewhat difficult to insert (2), difficult to insert (1)). In addition, the monitors evaluated the cleaning performance on a five-point scale (high (5), somewhat high (4), neither (3), somewhat low (2), low (1)).

[0065] [Table 1] shows the median diameter, maximum diameter, and minimum diameter of the multifilament 21 used in each of the four types of interdental cleaners 1 as examples. [Table 1] also shows the results of sensory tests on the insertability and cleaning ability of each of the four types of interdental cleaners 1 as examples.

[0066] In addition, the "median diameter value" of multifilament 21 in [Table 1] refers to the average value of the diameter of a 25 cm yarn bundle measured at 10 points with a micrometer under a load of 4.9 N (500 gf) and with a twist of 1 turn / cm.

[0067] In addition, the results of the sensory test on ease of insertion and cleaning in [Table 1] show the most common rating among the five floors of evaluations by 19 monitors.

[0068] [Table 1]

[0069] As shown in [Table 1], it can be seen that the interdental cleaners 1 of Examples 1 to 4 all provide high insertability and cleaning performance. In particular, it can be seen that by setting the difference between the maximum diameter Dmax and the minimum diameter Dmin of each multifilament 21 used in the interdental cleaner 1 to 0.05 mm to 0.15 mm, or even 0.09 mm to 0.11 mm, it is possible to achieve both insertability and cleaning performance at a very high level. Note that, in the above test, an interdental cleaner 1 in which six of each of the four types of multifilaments 21 were arranged in parallel was used, but similar results were obtained even when the number of strands arranged in parallel was changed.

[0070] Finally, a pull-out test from the support part 12 was conducted using the interdental cleaners 1 of Examples 1 to 4, which are the same as those in [Table 1]. That is, a test was conducted to pull out one end of each of six multifilaments 21, each having a thin diameter portion 31 and a thick diameter portion 32, from the support part 12. [Table 2] shows the test results. As shown in [Table 2], it can be seen that the interdental cleaners 1 of Examples 1 to 4 all have high thread pull-out strength. In particular, it can be seen that Examples 2 to 4 have a thread pull-out strength of more than 9 kgf. Therefore, it is particularly preferable that the difference between the maximum diameter Dmax and the minimum diameter Dmin of each multifilament 21 of the interdental cleaner 1 is 0.09 mm or more.

[0071] [Table 2]

[0072] The interdental cleaner 1 according to the present invention is not limited to the configuration of the embodiment described above, and various modifications and alterations are possible without departing from the scope of the claims. For example, in the interdental cleaner 1 of the embodiment described above, the length direction A of the floss portion 20 extends substantially parallel to the longitudinal direction of the handle portion 11, but the present invention is not limited to this configuration. As in an interdental cleaner 201 as a modified example shown in Fig. 7, the length direction A of the floss portion 20 may extend in a direction intersecting the longitudinal direction of the handle portion 211 (a direction substantially perpendicular in Fig. 7). [Industrial Applicability]

[0073] The present invention relates to an interdental cleaning tool. [Explanation of symbols]

[0074] 1, 201: Interdental cleaning tool 10: Cleaning tool body 11, 211: Handle part 12: First support part (support part) 12a: Withdrawal control part 12b: Through hole 12b1: Regulatory wall 13:Second support part (support part) 20: Floss section 20a: Anti-slip part 21: Multifilament 31: Thin section 32: Thick diameter part 40: Step 50: Burning off method 100: Molding mold 101: Cavity 102: Gate 103: Wire rod A: Length of the floss Dmax: Maximum diameter of floss part Dmin: Minimum diameter of floss part

Claims

1. A floss portion including at least one multifilament, The floss portion has a portion having a different thickness due to the degree of crimping being different in the length direction, The floss portion is made of a plurality of multifilaments arranged in parallel without being twisted together, Each of the plurality of multifilaments has a portion having a different thickness by varying the degree of crimp in the length direction, the difference between the maximum diameter and the minimum diameter of each of the plurality of multifilaments is 0.05 mm to 0.15 mm; The interdental cleaning tool, wherein each of the plurality of multifilaments has a thickness of 1.7 mm to 2.0 mm.

2. The interdental cleaning tool according to claim 1 , wherein the at least one multifilament has thick and thin portions alternately formed by repeating large and small degrees of crimping in the length direction.

3. 3. The interdental cleaner according to claim 1, further comprising a cleaning tool body including two support parts between which the floss part is supported.

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