JP2018051157A - Interdental cleaning tool - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an interdental cleaning tool that, even if a wire made of polyethylene and polyvinylidene fluoride, prevents resin from being defectively filled and that further can prevent the wire from falling out.SOLUTION: An interdental cleaning tool of the present invention includes: a pair of support pieces that are arranged with a prescribed space apart; a handle part that connects the pair of support pieces and that can be gripped by hand; and a wire that extends between the pair of support pieces and that has at least one multi-filament. Each multi-filament is formed by polyethylene or polyvinylidene fluoride. Each support piece is provided with a first face on the mutually opposing side and a second face on the side opposite from the first face. Both ends of the wire each penetrate the support pieces between the first and the second faces. The support pieces and the handle part are formed by polystyrene with melt mass flow rate not less than 7 g/10 min.SELECTED DRAWING: Figure 1

Description

  The present invention relates to an interdental cleaning tool.

  Conventionally, various interdental cleaning tools for removing plaque clogged between teeth have been proposed. For example, Patent Document 1 discloses an interdental cleaning tool in which a wire called a floss is arranged between support pieces arranged at a predetermined interval, and both support pieces are connected by a handle portion that can be gripped by a hand. Proposed. In such an interdental cleaning tool, various materials are used as the wire. Among them, polyethylene and polyvinylidene fluoride are preferably used because they have excellent strength and are easily inserted between the teeth.

JP 7-136193 A

  However, since polyethylene and polyvinylidene fluoride, especially polyethylene, are inferior in heat resistance compared to other materials such as nylon, there are the following problems. That is, when the support piece and the handle portion are injection-molded at a resin temperature of 220 ° C. or higher, which is usually set at the time of injection molding, there is a problem that the wire is melted. Therefore, when polyethylene or polyvinylidene fluoride is used as the material for the wire, it is necessary to lower the resin temperature at the time of injection (about 170 to 190 ° C.). However, when the resin temperature is lowered, there is a problem that the fluidity of the resin is not sufficiently obtained, and the resin is difficult to spread over the entire mold for molding the handle portion and the support piece. In particular, in the mold of the interdental cleaning tool, since the wire is arranged near the tip of the cavity corresponding to the support piece, the resin flow is blocked by the wire, and the resin reaches the tip of the cavity of the support piece. I found that there was a specific problem of being difficult. In this way, if the resin does not reach the tip of the cavity of the support piece sufficiently, the wire rod can be easily removed from the molded support piece, or a molding failure near the tip of the support piece occurs, but the fluidity of the resin is ensured. Therefore, when the temperature at the time of resin injection is increased, there is a problem that the wire is melted by heat and easily cut.

  The present invention has been made to solve this problem, and even when a wire made of polyethylene or polyvinylidene fluoride is used, it is possible to prevent poor filling of the resin and thus prevent the wire from being cut. The purpose is to provide a cleaning tool.

  An interdental cleaning tool according to the present invention is provided between a pair of support pieces arranged at a predetermined interval, a handle portion that connects the pair of support pieces and can be gripped by hand, and the pair of support pieces. A wire having at least one multifilament extending, wherein each multifilament is made of polyethylene or polyvinylidene fluoride, and each support piece has a first surface on a side facing each other, and the first surface And both ends of the wire rod penetrate the support pieces between the first surface and the second surface, respectively. It is formed of polystyrene having a melt mass flow rate of 7 g / 10 min or more.

  According to this configuration, the support piece and the handle portion are made of polystyrene having a melt mass flow rate of 7 g / 10 min or more. Therefore, even if the temperature at the time of the injection of polystyrene is low, the polystyrene can be spread over the entire mold that forms the support piece and the handle portion. In particular, in the cavity for molding the support piece, there is a possibility that the wire is arranged and hinders the flow of the resin. It is possible to sufficiently spread the resin to the tip of the support piece, and it is possible to prevent the wire rod from being melted and easily cut during use.

  Moreover, since the shrinkage | contraction after a shaping | molding is small for polystyrene, it can prevent that the cleaning tool main body shrink | contracts so that the distance between support pieces may become short after a shaping | molding, for example. Thereby, it can prevent that a wire becomes loose between support pieces.

  The interdental cleaning tool can be in various forms. For example, the handle portion can be connected to the pair of support pieces so as to extend in parallel with the extending direction of the wire.

  This type of interdental cleaning tool is used to operate the handle part while gripping the vicinity of the support piece, and to move the wire directly to the desired interdental space and then insert it between the teeth. It is easier to insert the wire between the teeth if it is not loose between the support pieces. On the other hand, since the interdental cleaning tool according to the present invention uses polystyrene that does not easily shrink after molding as described above, the distance between the support pieces can be prevented from being shortened after molding. Can be prevented from loosening. Therefore, the present invention is particularly preferably applied to an interdental cleaning tool in which the handle portion extends in parallel with the wire.

  In the interdental cleaning tool, the wire can be formed of a plurality of the multifilaments. In this case, the thickness of each multifilament forming the wire is usually reduced, but even in such a case, it is possible to prevent the wire from being melted by the heat of the injected resin, and the wire is cut. It becomes difficult.

  Each said interdental cleaning tool WHEREIN: Each said multifilament can be 100-250 denier. The thickness of the wire has an effect on the wire being cut under the influence of heat. In the present invention, even if the multifilament is thin as described above, the multifilament is difficult to break. On the other hand, if the multifilament is too thick, it is difficult to insert between the teeth. Therefore, when the thickness is as described above, the wire is easily inserted between the teeth.

  In each of the above interdental cleaning tools, each of the multifilaments is preferably formed of polyethylene. Specifically, when polyethylene is inferior in heat resistance compared to polyvinylidene fluoride, according to the present invention, the wire can be prevented from being melted by the heat of the injected resin, the wire becomes difficult to break, and the resin Since filling failure can also be prevented, the present invention is particularly preferably applied to an interdental cleaning tool having a multifilament formed of polyethylene.

  According to the interdental cleaning tool according to the present invention, even if a wire made of polyethylene or polyvinylidene fluoride is used, defective filling of the resin can be prevented, and eventually the wire can be prevented from being cut.

It is a front view of the interdental cleaning tool which concerns on this embodiment. It is the sectional view on the AA line of FIG. It is the BB sectional view taken on the line of FIG. It is a figure which shows the outline of the shaping | molding die which manufactures the interdental cleaning tool of FIG. It is a figure which shows a part of manufacturing method of the interdental cleaning tool of FIG. It is a top view which shows the other example of the interdental cleaning tool which concerns on this invention. It is a perspective view which shows the other example of the interdental cleaning tool which concerns on this invention. It is the front view (a) and bottom view (b) which show the interdental cleaning tool concerning Examples 1-4 and a comparative example. It is a photograph of the interdental cleaning tool which concerns on a reference example. It is a photograph of the interdental cleaning tool which concerns on Example 4. FIG.

  Hereinafter, an embodiment of an interdental cleaning tool according to the present invention will be described with reference to the drawings. 1 is a front view of an interdental cleaning tool according to the present embodiment, FIG. 2 is a cross-sectional view taken along line AA in FIG. 1, and FIG. 3 is a cross-sectional view taken along line BB in FIG. In the following description, for convenience of description, description will be made with reference to the direction in the drawing of FIG. As for the handle portion, the left side in FIG. 1 may be referred to as the front end side, and the right side may be referred to as the rear end side. However, the present invention is not limited by the definition of this direction.

<1. Overview of interdental cleaning tool>
As shown in FIG. 1, the interdental cleaning tool includes a resin cleaning tool main body 10 and a wire rod 3 attached to the cleaning tool main body 10 for removing dental plaque between teeth. . The cleaning tool main body 10 includes a handle portion 1 extending in a rod shape, and a pair of support pieces 21 and 22 protrude from the handle portion 1 at a predetermined interval. Here, the support piece protruding from the end portion of the handle portion 1 is referred to as a first support piece 21, and the support piece extending in parallel with the support piece is referred to as a second support piece 22. The wire rod 3 described above is disposed between the support pieces 21 and 22 and is disposed in parallel with the handle portion 1. Both ends of the wire 3 are connected to the support pieces 21 and 22, respectively. Hereinafter, each member will be described in detail.

<2. Cleaning tool body>
The two support pieces 21 and 22 and the handle portion 1 constituting the cleaning tool main body 10 are integrally formed of polystyrene (hereinafter simply referred to as “resin”). In particular, the polystyrene used in this embodiment has a melt mass flow rate of 7 g / 10 min or more, preferably 8 g / 10 min or more, and preferably 9 g / 10 min or more. On the other hand, the upper limit of the melt mass flow rate of this polystyrene is preferably 17 g / 10 min or less, more preferably 16 g / 10 min or less, and still more preferably 14 g / 10 min. The melt mass flow rate is measured under the conditions (condition H) of a load of 5.00 kg and a temperature of 200 ° C. in accordance with JIS K7210.

  Each of the support pieces 21 and 22 is formed in a plate shape, and the names of the surfaces of the support pieces 21 and 22 will be described below with the front side 211 and the front side of the paper surface of FIG. 222, the right side of FIG. 1 is referred to as a right side 213 (first side), 223 (second side), and the left side is referred to as a left side 214 (second side), 224 (first side). And as shown in FIG. 2, the thickness of each support piece 21 and 22 is formed so that it may become small as it goes to the front-end | tip of each support piece 21 and 22 from the handle | steering-wheel part 1. As shown in FIG. Further, in each support piece 21, 22, the portion through which the wire 3 passes is near the tip of each support piece 21, 22, that is, the distance L from the tip is preferably within 4 mm, and more preferably within 3.2 mm. By making the thicknesses of the support pieces 21 and 22 and the locations where the wire 3 passes in this way, for example, when the resin for the handle portion 1 is injected from the handle portion 1 side, the support pieces 21 and 22 Since the temperature of the resin can be lowered when the resin reaches the vicinity of the tip, the problem that the wire 3 is melted and cut or damaged by the high temperature resin can be prevented. Note that the lower limit of the distance L is usually about 1 mm.

  Further, as shown in FIG. 3, the thickness of the first support piece 21 decreases as it goes from the left surface 214 to the right surface 213. On the other hand, the thickness of the second support piece 22 decreases as it goes from the right surface 223 to the left surface 224. That is, the thickness of each support piece 21, 22 becomes smaller toward the first surface side. By comprising in this way, it becomes easy to make the temperature of resin low as mentioned above, and it can prevent that the wire 3 is cut | disconnected or damaged with the heat | fever of the resin at the time of shaping | molding.

  Furthermore, the left surface 214 of the first support piece 21 and the right surface 223 of the second support piece 22 are respectively formed with small recesses (not shown) in which the ends of the wire 3 are disposed, and these recesses are formed. The end portion of the wire rod 3 protrudes from the location.

<3. Wire>
Next, the wire 3 will be described. The wire 3 is a bundle of one multifilament or a plurality of multifilaments 31. Below, especially the case where a wire is comprised with the some multifilament 31 is demonstrated. Each multifilament 31 is obtained by twisting a plurality of monofilaments formed of polyethylene. Since polyethylene has a small coefficient of friction, it has the advantage that it is easy to slip between teeth and scrape off plaque. The multifilament 31 may be a bundle of monofilaments that are not twisted. Besides polyethylene, for example, polyvinylidene fluoride can also be used. However, compared to polyvinylidene fluoride, polyethylene is inferior in heat resistance. With the interdental cleaning tool according to the present invention, the wire can be prevented from being melted by the heat of the injected resin, and the wire is less likely to be cut. In addition, since it is possible to prevent defective filling of the resin, the present invention is particularly preferably applied to an interdental cleaning tool having a multifilament 31 formed of polyethylene.

  Although the thickness of each multifilament 31 is not specifically limited, For example, it is preferable to set it as 100-250 denier, and it is more preferable that it is 100-160 denier. If this is smaller than 100 denier, the multifilament 31 may be detached from the support pieces 21 and 22, or the wire 3 may be cut by the heat of the resin. If it is larger than 250 denier, it is difficult to insert between the teeth. There is a possibility.

  Moreover, the number of the multifilaments 31 which comprise the wire 3 is not specifically limited, For example, it is preferable that it is multiple, and it is more preferable to use 3-5. When the number of the multifilaments 31 is one, it may be detached from each of the support pieces 21 and 22, and the effect of scraping off plaque may be reduced. In particular, when the number of the multifilaments 31 is three or more, the wire 3 is prevented from being detached, and the support pieces 21 and 22 are not easily detached, and the plaque scraping effect is improved. On the other hand, when the number is 7 or less, it becomes easy to enter between the teeth, and the operability is improved, and as a result, the effect of scraping off plaque can be improved.

  The number of monofilaments constituting the multifilament 31 is preferably 15 to 120, more preferably 30 to 100, and particularly preferably 50 to 100. This is due to the following reason. That is, when the number of monofilaments is small, the wire 3 is easily detached from the support pieces 21 and 22 or easily cut. Further, the resin (polystyrene) and the monofilament are not easily entangled, and the wire 3 is easily detached from the support pieces 21 and 22. On the other hand, if the number of monofilaments is large, it becomes difficult for the resin to enter between the monofilaments, and this also makes it easier for the wire 3 to come out of the support pieces 21 and 22. Therefore, by setting the number of monofilaments within the above range, it is possible to prevent the wire 3 from coming off.

  Moreover, as an upper limit of the number of twists per meter of the multifilament 31, it is preferable that it is 500 times or less. Specifically, it is preferably 300 times or less, more preferably 200 times or less, and particularly preferably 170 times or less. This is due to the following reason. That is, when the number of twists of the multifilament 31 is too large, as will be described later, it is difficult for the resin to enter between the monofilaments, and the support pieces 21 and 22 are easily removed. Therefore, when the number of twists is 500 times or less, the resin easily enters between the monofilaments, and the wire 3 can be prevented from coming off. In addition, the lower limit of the number of twists per 1 m of the multifilament 31 is not particularly limited as long as it is not twisted. From the viewpoint of, for example, 5 times or more is preferable.

  Furthermore, the multifilament 31 can contain a reinforcing material. Examples of the reinforcing agent include fibrous reinforcing materials such as glass fibers and amide fibers, granular reinforcing materials such as talc, plate-like reinforcing materials such as plate glass and mica, and the like.

<4. Connection of wire and support piece>
Then, the connection method of the wire 3 and each support piece 21 and 22 is demonstrated. As shown in FIG. 1, both ends of the wire 3 pass through the support pieces 21 and 22. More specifically, the left end portion of the wire 3 passes through the right surface 213 of the first support piece 21 and protrudes from the left surface 214, and the multifilaments 31 of the protruded wire 3 are heat-welded with each other to be integrated into a lump. 32 is formed. Similarly, the right end portion of the wire 3 passes through the left surface 224 of the second support piece 22 and protrudes from the right surface 223, and the multifilaments 31 of the protruded wire 3 are thermally welded together to form a lump 32. doing. These lumps 32 are larger than the outer diameter of the bundled multifilaments.

<5. Manufacturing method of interdental cleaning tool>
Next, the manufacturing method of the interdental cleaning tool comprised as mentioned above is demonstrated, referring FIG.4 and FIG.5.

  First, a mold 100 for injection molding as shown in FIG. 4 is prepared. The molding die 100 is provided with a plurality of cavities 101 for molding a plurality of cleaning tool bodies 10. In this mold, a gate 102 for injecting resin is provided in the handle portion 1. Although not shown, the mold 100 is provided with a plurality of resin passages branched from nozzles for discharging resin, so-called runners, and the resin is supplied from the nozzles to the respective gates 102 through the runners. Is done. In addition, the number of cavities 101 and the number of runners associated therewith are not particularly limited, and the length of the runners may vary depending on the arrangement of the cavities 101, and they are not all the same. And when performing injection molding, the wire 3 is arrange | positioned to a shaping | molding die. At this time, the wire 3 is disposed so as to extend between the portions corresponding to both the support pieces 21 and 22 of each cavity 101 over the plurality of cavities 101.

  Next, a resin for the cleaning tool body 10 is injected into the cavity 101. As described above, first, when the resin is injected, the resin reaches the gate 102 through the runner, and is injected into the cavity 101 from the gate 102. And since the said gate 102 is provided in the handle | steering-wheel part 1, when the injected resin reaches | attains the front-end | tip vicinity of each support piece 21 and 22 via a runner and the handle | steering-wheel part 1, it cools by the shaping | molding die 100. And the temperature is sufficiently lower than when injected. Therefore, it is possible to prevent the wire 3 from being melted by the temperature of the resin for the cleaning tool body. In other words, the wire 3 may be melted and cut by the high-temperature resin, but the gate 102 is separated from the support pieces 21 and 22 as described above, and the wire 3 is further near the tips of the support pieces 21 and 22. By arrange | positioning to, melting of the wire 3 can be prevented.

  Further, as shown in FIG. 2, the thickness of each support piece 21, 22 decreases as it goes from the handle portion 1 side to the wire rod 3 side, and further, as shown in FIG. 3, each support piece 21, 22. Since the thickness of the wire decreases toward the side where the wire 3 is exposed, the resin is easily cooled by the molding die in the process of the resin going from the gate 102 to the end portions of the support pieces 21 and 22. This also prevents the wire 3 from being melted by the resin.

  Thus, when the injection of the resin is completed, the plurality of cleaning tool main bodies 10 are taken out from the mold 100 after a predetermined time has elapsed. At this time, in each cleaning tool main body 10, the wire 3 is integrated in a state of being embedded in both support pieces 21 and 22. The plurality of cleaning tool main bodies 10 are connected by one wire 3. Therefore, as the next step, as shown in FIG. 5, the wire 3 is burned out on the left surface 214 side of the first support piece 21 and the right surface 223 side of the second support piece 22 of each cleaning tool body 10. The means 50 for burning out the wire 3 is not particularly limited, and can be burned out by a flame or a heated blade, irradiated by a heat ray such as far infrared rays, or by electric discharge. Thereby, the several interdental cleaning tool with which the wire 3 and the cleaning tool main body 10 were integrated is formed.

  As described above, when the wire 3 is burned out, a plurality of multifilaments 31 constituting the wire 3 are melted by heat and integrated to form a lump 32.

<6. Features>
As described above, according to the present embodiment, the following effects can be obtained.
(1) Since both the support pieces 21 and 22 and the handle portion 1 are made of polystyrene having a melt mass flow rate of 7 g / 10 min, even if the temperature at the time of injection is low, Polystyrene can be spread to 22 tips. In particular, since the wire 3 penetrates near the tips of the support pieces 21 and 22, there is a possibility that the flow of polystyrene may be hindered by the wire 3, but by using polystyrene as described above, Even if the temperature at the time of injection is low and the wire 3 is provided, polystyrene can be distributed to the tips of the support pieces 21 and 22. As a result, it is possible to prevent the wire 3 from being detached from the support pieces 21 and 22 and to prevent the wire 3 from being melted by the resin.

(2) Since polystyrene has a small shrinkage after molding, for example, the cleaning tool body 10 can be prevented from shrinking in a direction in which the distance between the support pieces 21 and 22 is shortened after molding. Thereby, it can prevent that the wire 3 loosens between the support pieces 21 and 22. In particular, the interdental cleaning tool of the type in which the handle portion 1 and the wire 3 are parallel as in the present embodiment is intended for the wire 3 by operating the handle portion 1 while gripping the vicinity of the support pieces 21 and 22. In many cases, the tooth is inserted between the teeth after being moved directly between the teeth. Therefore, it is easier to insert the wire 3 between the teeth if the wire 3 is not loosened between the support pieces 21 and 22. Therefore, in the interdental cleaning tool as in the present embodiment, it is particularly advantageous to form the cleaning tool body from polystyrene.

(3) Polystyrene can be spread between the multifilaments 31 constituting the wire 3 and the polystyrene and the multifilaments 31 can be firmly fixed. As a result, it is possible to prevent the wire 3 from coming off from the support pieces 21 and 22.

(4) A plurality of multifilaments 31 are integrated by thermal welding at both ends of the wire 3 protruding from the support pieces 21 and 22. Therefore, this integrated part becomes a lump 32 and serves as a retaining member, and the wire 3 can be prevented from being detached from the support pieces 21 and 22. Thus, by melting a plurality of multifilaments 31 to form a lump, for example, compared to melting a single monofilament to form a lump, the ends of the plurality of multifilaments 31 are connected to each other. Moreover, since the large lump 32 can be formed, the retaining effect can be further improved.

  Further, when the ends of two or more multifilaments 31 are melted to form a mass 32, the end of one multifilament 31 made of the same number of monofilaments as the total number of monofilaments constituting the two or more multifilaments 31 is used. As compared with the case where the lump is melted to form a lump, the retaining effect can be improved. That is, when increasing the number of monofilaments constituting the wire 3 and improving the scraping effect or the like, it is better to use two or more multifilaments 31 than when using a single multifilament 31. , The retaining effect can be improved.

<7. Modification>
As mentioned above, although one Embodiment of this invention was described, this invention is not limited to the said embodiment, A various change is possible unless it deviates from the meaning. Note that the following modifications can be combined as appropriate.

  The handle portion and the support piece can be in various forms. For example, as shown in FIG. 6, the width (portion indicated by reference numeral 25) of the support pieces 21 and 22 can be increased on the right surface 213 side of the first support piece 21 and the left surface 214 side of the second support piece 22. it can. By doing so, the left and right widths of the support pieces 21 and 22 are increased, so that the support pieces 21 and 22 can be prevented from contracting so that the support pieces 21 and 22 approach each other, thereby preventing the wire from loosening. can do.

  For example, in the above-described embodiment, the handle portion 1 is connected to the both support pieces 21 and 22 so as to extend at right angles, but the configuration of the handle portion 1 is not particularly limited as long as it can be gripped by hand. For example, as shown in FIG. 6, the ends of both support pieces 21 and 22 are connected to each other and extend to the opposite side of both support pieces 21 and 22, that is, the cleaning tool body 10 is formed in a Y shape as a whole. It can also be formed.

  In the above embodiment, all the multifilaments 31 are thermally welded and integrated at both ends of the wire 3, but the present invention is not limited to this. For example, among all the multifilaments 31, two or more multifilaments 31 may be integrated by thermal welding. That is, it is only necessary that the multifilaments 31 are thermally welded so that there are a plurality of thermally welded masses 32. In addition to welding by heat, it is also possible to perform various weldings such as ultrasonic waves. Moreover, the aspect which fixed the both ends of the wire 3 to each support piece 21 and 22 without forming the lump 32 may be sufficient.

  The wire 3 may be simply a bundle of a plurality of multifilaments 31 or may be twisted. However, from the viewpoint of sufficiently intertwining the multifilament 31 and polystyrene, the number of twists of the wire 3 in which a plurality of multifilaments 31 are bundled is preferably 5 times or less per meter.

  In addition, the wire 3 can be coated with a medicine such as a refreshing agent, a powder flavor component, and a preventive or therapeutic agent for caries. In addition to being held on the wire 3 in a liquid state, such a drug can be fixed in a dry state at room temperature (for example, 25 ° C.).

  Examples of the present invention will be described below. However, the present invention is not limited to the following examples.

<A. Strength test>
The cutting strength of the wire was confirmed as follows. First, the interdental cleaning tool concerning four types of Examples and one type of comparative example was produced as follows. The shapes of these cleaning tool bodies are all the same, as shown in FIG.

(Material for cleaning tool body)
Example 1: Polystyrene (melt mass flow rate: 9 g / 10 min))
Example 2: Polystyrene (melt mass flow rate: 8 g / 10 min))
Example 3: Polystyrene (melt mass flow rate: 7 g / 10 min))
-Example 4: Polystyrene (melt mass flow rate: 16 g / 10 min))
Comparative example: polystyrene (melt mass flow rate: 5 g / 10 min))
The melt mass flow rate is measured under the conditions (condition H) under a load of 5.00 kg and a temperature of 200 ° C. in accordance with JIS K7210.

(wire)
Forty-five monofilaments made of polyethylene were twisted 150 times per meter to form 150 denier multifilaments, and four such multifilaments were used as the wire.

  The Example and comparative example which consist of the said cleaning tool main body and a wire were manufactured by the method shown in the said FIG.4 and FIG.5. Specifically, as shown in the above-described embodiment, lumps are formed at both ends of the wire passing through each support piece. Moreover, in injecting the polystyrene, the temperature was adjusted so that the polystyrene was sufficiently distributed to the tip of the support piece, and then the polystyrene was filled. A plurality of runners are connected to the nozzle for filling the polystyrene in the mold, and the polystyrene that has passed through each runner is filled into the cavity from the gate of the mold.

  The temperature of the resin refers to the temperature at the tip of the nozzle, and the length of the runner from the nozzle to the gate is approximately 60 to 80 mm.

(Test method)
Autograph AGS-X (manufactured by Shimadzu Corporation) was used for the test. The wire rods of Examples 1 to 4 and the comparative example were fixed so as to be horizontal with the lower jig and so that the cleaning tool main body was not buried in the lower jig. The long side of the 2.5 mm L-shaped hexagon wrench was fixed to the upper jig, and the height was adjusted so that the shorter side of the L-shaped hexagon wrench was caught by the wire. A tensile test was performed from this state, and the maximum point until the wire broke was regarded as the thread breakage strength and evaluated. The test conditions are as follows.
・ Load cell: 500N
・ Tensile speed: 100 mm / min

(Evaluation)
The evaluation criteria for thread break strength according to the above test method were set as follows.
-4: 29 N or more (can be used repeatedly several times until the wire 3 is cut without being cut during one use)
* 3: 24N or more and less than 29N (It does not break during one use and can easily clean all teeth)
-2: 19N or more and less than 24N (The wire rod is hardly cut during use, and all the teeth can be sufficiently cleaned.)
-Less than 1: 19N (wires often break during use)

The results are as follows.
Example 1: 4 (temperature of the resin at the tip of the nozzle: 180 ° C.)
Example 2: 3 (temperature of the resin at the tip of the nozzle: 190 ° C.)
Example 3: 2 (the temperature of the resin at the tip of the nozzle: 205 ° C.)
Example 4: 4 (the temperature of the resin at the tip of the nozzle: 180 ° C.)
Comparative example: 1 (resin temperature at the nozzle tip: 230 ° C.)

  From the above, Examples 1 to 4 using polystyrene having a melt mass flow rate of 7 g / 10 min or more as the main body of the cleaning tool show higher thread breakage strength than the comparative example, and a strength that can sufficiently clean the teeth is obtained. It was. In addition, it was found that the higher the melt mass flow rate, the more the polystyrene reaches the tip of the support piece even when the temperature of the polystyrene is lowered. On the other hand, in the comparative example, unless the temperature is raised to 230 ° C., polystyrene does not reach the tip of the support piece, so the temperature of the resin when reaching the wire is high, and the wire may be melted. It is considered that the strength is low.

  Therefore, the interdental cleaning tool according to Examples 1 to 4 can prevent the polystyrene from being cut around the support piece even when the polystyrene is sufficiently spread to the tip of the support piece and a polyethylene wire is used. It turns out that it can withstand enough.

<B. Loose wire due to shrinkage of resin material>
Subsequently, as a reference example, the cleaning tool main body shown in FIG. 8 was made of polypropylene in the same mold as when Examples 1 to 4 and a comparative example were made. When the distance between support of a reference example was confirmed using the one-shot 3D shape measuring device VR3000 (made by Keyence Corporation), the distance between the support pieces after molding was 18.182 mm. As a result, it was found that, for example, loosening of the wire as shown in FIG. 9 occurred.

  On the other hand, when the distance between the support pieces in Example 4 was confirmed, the distance between the support pieces after molding was 18.445 mm. And as shown in FIG. 10, the looseness of the wire was not able to be confirmed. Furthermore, also in the interdental cleaning tool of Examples 1-3, the distance between support pieces was larger than that of the reference example. Therefore, it was found that when polystyrene is used for the cleaning tool body, the wire rod does not loosen due to less shrinkage after molding.

1 Handle portion 21, 22 Support piece 3 Wire 31 Multifilament

Claims (4)

A pair of support pieces arranged at a predetermined interval;
A handle portion that connects the pair of support pieces and can be gripped by hand
A wire having at least one multifilament extending between the pair of support pieces;
With
Each of the multifilaments is formed of polyethylene or polyvinylidene fluoride,
Each of the support pieces has a first surface facing each other and a second surface opposite to the first surface,
Both ends of the wire rod penetrate the support pieces between the first surface and the second surface, respectively.
The said support piece and the handle | steering-wheel part are interdental cleaning tools currently formed with the polystyrene whose melt mass flow rate is 7 g / 10min or more.   The interdental cleaning tool according to claim 1, wherein the handle portion is connected to the pair of support pieces so as to extend in parallel with a direction in which the wire extends.   The interdental cleaning tool according to claim 1 or 2, wherein the wire is formed of a plurality of the multifilaments.   The interdental cleaning tool according to any one of claims 1 to 3, wherein each multifilament is 100 to 250 denier.