Dental floss, dental floss continuum, and method for manufacturing dental floss continuum

Abstract

To provide a dental floss which is easier to handle due to a rigid portion while keeping cleaning properties.SOLUTION: A dental floss comprises: a floss part 11 which is obtained by twisting a plurality of filaments without binding; and a bound part 12 which is obtained by binding a plurality of filaments and provided continuously to the floss part 11. In the cross section of the bound part 12, the filaments are covered with an outline part.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to dental floss (interdental cleaning tool). [Background technology]

[0002] Dental floss is known as one means for cleaning the spaces between teeth (interdental spaces). As described in Patent Document 1 and Patent Document 2, dental floss is made of a number of thin thread-like fibers (filaments) bundled together to form a single thread. These bundled filaments pass between the teeth, entangling dirt between the teeth and cleaning the spaces. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Patent No. 5221280 [Patent Document 2] Japanese Patent Application Publication No. 8-117252 Summary of the Invention [Problem to be solved by the invention]

[0004] The invention disclosed in Patent Document 1 is able to increase rigidity by spirally winding a sheath yarn around a core yarn. However, some parts of the core yarn are pressed down by the sheath yarn, which reduces cleaning properties. In addition, the structure is complicated, which makes production time-consuming.

[0005] The invention disclosed in Patent Document 2 has bundling parts provided at predetermined intervals, and it is believed that these bundling parts have higher rigidity than other parts. However, it cannot be said that sufficient rigidity can be obtained.

[0006] In view of the above problems, the present invention aims to provide dental floss that is easy to handle due to its highly rigid portion while maintaining its cleaning properties. [Means for solving the problem]

[0007] One aspect of the present disclosure is a dental floss having a floss portion formed by twisting together multiple filaments without bundling them, and a bundling portion that is continuous with the floss portion and forms a bundling of multiple filaments, wherein the filaments are covered by an outer shell portion in cross section at the bundling portion.

[0008] Another aspect of the present disclosure is a continuous dental floss body having a plurality of the above-mentioned floss portions and the above-mentioned bundled portions arranged alternately.

[0009] Another aspect of the present disclosure is a method for producing a continuous dental floss body comprising a continuous dental floss, the method including a step of alternately forming heated and unheated portions on a raw yarn formed by twisting together a number of filaments, and when forming the heated portions, the raw yarn is heated without applying a pressing force to melt and weld the outer periphery of the raw yarn. Effect of the Invention

[0010] According to the present invention, it is possible to provide dental floss that is easy to handle due to its highly rigid portion while maintaining its cleaning properties. [Brief description of the drawings]

[0011] [Figure 1] FIG. 1 is a diagram showing the appearance of dental floss 10. As shown in FIG. [Diagram 2] FIG. 2 is a diagram illustrating the floss portion 11. As shown in FIG. [Diagram 3] FIG. 3 is a diagram illustrating an example of the filament 10a. [Figure 4] FIG. 4 is a diagram illustrating the binding portion 12. As shown in FIG. [Diagram 5] FIG. 5 is a diagram illustrating a method for evaluating the rigidity of the binding portion 12. As shown in FIG. [Figure 6] FIG. 6 is a diagram showing the external appearance of a continuous body of dental floss 20. As shown in FIG. [Figure 7]FIG. 7 is a diagram illustrating the roll 21. As shown in FIG. [Figure 8] FIG. 8 is a diagram illustrating an apparatus for producing the continuous dental floss 20. As shown in FIG. [Figure 9] FIG. 9 is a perspective view illustrating the welding device 31. As shown in FIG. [Figure 10] FIG. 10 is a diagram illustrating the welding device 31. As shown in FIG. [Figure 11] FIG. 11 is a diagram illustrating a structure for moving the welding device 31. As shown in FIG. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0012] 1. Dental floss Fig. 1 shows the appearance of one form of dental floss 10. As can be seen from Fig. 1, dental floss 10 is a string-like member overall, and has a floss portion 11 that is formed thick and contributes mainly to interdental cleaning, and a tied portion 12 that is a thin tied portion. Dental floss 10 in this embodiment represents a single-use piece of dental floss, with bound portions 12 extending continuously from both ends of floss portion 11. This will be explained in detail below.

[0013] 1.1.Floss section The floss portion 11 is a portion disposed between the teeth and has the function of trapping dirt, and is in the form of a thread formed by twisting together a number of filaments 10a, which are thin fibers. Fig. 2 shows a schematic cross section taken along the line AA in Fig. 1 (i.e., a cross section perpendicular to the direction in which the floss portion 11 and the fiber filaments 10a extend). As can be seen from Fig. 2, although the floss portion 11 has a number of filaments 10a twisted together, the filaments 10a are not joined together, and each filament 10a is configured to be able to move within a predetermined range within the plane (transverse section) shown in Fig. 2. This allows each filament 10a to trap dirt between the teeth and retain the trapped dirt between adjacent filaments 10a.

[0014] Length of floss part 11 L F There is no particular limit to the size, but a size of around 50mm to 200mm is easy to use as dental floss. The number of filaments 10a constituting the floss portion 11 is not particularly limited, but is preferably about 1000 to 3000. If the number is less than 1000, the cleaning function of the floss portion 11 may not be sufficient, and if the number is more than 3000, it becomes difficult to move the floss portion 11 between the teeth. The thickness of the floss portion varies depending on the number of filaments 10a that make up the floss portion 11, but because the filaments 10a of the floss portion 11 have a high degree of freedom of movement as shown in Figure 2, the thickness of the floss portion 11 falls within a certain range but is not constant. In the dental floss 10 of this embodiment, there is no element that holds down the filaments 10a in the floss portion 11, so it has high cleanability.

[0015] The filaments 10a constituting the floss 11 are not particularly limited, but may be, for example, resins such as polyester, nylon, polyethylene, polypropylene, polyurethane, polyvinyl chloride, rayon, acetate, etc., or a combination of two or more of these. Among them, a filament having a composite cross-sectional shape in which a plurality of materials occupy respective regions in the cross section of the filament is preferable. An explanatory diagram is shown in FIG.

[0016] Fig. 3 is an enlarged schematic cross-section (cross-section perpendicular to the longitudinal direction) of one filament 10a. As can be seen from Fig. 3, this filament 10a has radial portions 10b extending from the center in four directions perpendicular to each other in the cross-section, and filled portions 10c between adjacent radial portions 10b. In this embodiment, the radial portions 10b are made of nylon, and the filled portions 10c are made of polyester. Filaments of this type have edges and gaps between portions 10b and 10c, which are advantageous in entangling and retaining dirt.

[0017] The thickness of the filament is not particularly limited, but a thickness of about 1 μm to 50 μm maintains a balance between the strength and cleaning properties required for dental floss, and is easy to function.

[0018] 1.2. Binding part 1, the binding portion 12 is disposed so as to extend from both ends in the longitudinal direction of the floss portion 11. For example, the binding portion 12 is inserted between the teeth to be used as a portion for introducing the dental floss 10 between the teeth, and then the binding portion 12 is moved, for example by pulling, while keeping the dental floss 10 between the teeth, to place the floss portion 11 between the teeth. This allows the floss portion 11 to clean between the teeth.

[0019] The bound portion 12 is also in the form of a thread formed by twisting together a plurality of filaments 10a, which are thin fibers. The filaments 10a and the number of filaments 10a used to form the bound portion 12 are the same as those of the floss portion 11. Therefore, as will be described later, the floss portion 11 and the bound portion 12 of the dental floss 10 are made of the same continuous raw yarn, and the raw yarn is processed in the longitudinal direction to separate the floss portion 11 and the bound portion 12.

[0020] FIG. 4 is a schematic diagram of a cross section taken along the line BB in FIG. 1 (i.e., a cross section perpendicular to the direction in which the bundled portion 12 and the fiber filaments 10a extend). As can be seen from FIG. 4, the bundled portion 12 has a plurality of filaments 10a twisted together, and the outer periphery of the bundled portion 12 has a continuous outer shell portion 12a formed around the entire circumference in the cross section. Inside the outer shell portion 12a, the filaments 10a are arranged more densely than the floss portion 11, and the filaments 10a are bundled by the outer shell portion 12a. Here, the outer shell portion 12a is formed by welding and joining the filaments 10a arranged on the outer periphery of the twisted filaments 10a, as described later. That is, in this embodiment, the outer shell portion 12a is derived from the filaments 10a.

[0021] It is preferable that the outer shell 12a covers the outer periphery of the binding part 12 without any gaps, but it is not necessary that there be no gaps at all, and some degree of gap is permissible.

[0022] Length of binding section 12 L S There is no particular limit to the length, but a length of about 50 mm to 100 mm is easy to handle in terms of introducing and gripping the dental floss. The filaments 10a constituting the bundled portion 12 are made of the same raw yarn as the floss portion 11 as described above, and therefore can be considered to be the same as the floss portion 11. However, the shape of the filaments 10a may change due to processing, and the individual filaments 10a in the bundled portion 12 do not have a fixed shape. The cross-sectional shape of the binding part 12 is preferably small in flatness, and most preferably close to a circle. This can prevent a decrease in rigidity. Specifically, it is preferable that the ratio X / Y of the maximum width X (e.g., X in FIG. 4) to the minimum width Y (e.g., Y in FIG. 4) of the cross section is 0.7 to 1.3. The dimensions of X and Y (diameter if the cross section is circular) are preferably 0.3 mm to 0.7 mm, which allows for easy insertion between teeth while maintaining rigidity.

[0023] 1.3. Effects of dental floss The dental floss 10 described above has high rigidity, particularly at the binding portion 12, and is able to suppress a decrease in rigidity due to the influence of saliva in the oral cavity. This is believed to be because the outer shell 12a of the binding portion 12 increases the strength and suppresses the penetration of saliva into the binding portion 12. By being able to maintain high rigidity at the binding portion 12, the dental floss 10 becomes easier to handle. For example, buckling is unlikely to occur when inserting (introducing) the dental floss 10 between teeth, making it easier to insert, and easier to handle by pinching it between fingers. In addition, the surface of the outer shell 12a is smoother than the surface formed by bonding the filaments 10a without the outer shell 12, and therefore friction can be reduced when inserting the outer shell 12a between the teeth, making it easier to insert from that standpoint, and it also feels smooth and pleasant to the touch when touched by the fingers.

[0024] The inventors compared the rigidity of the binding portion 12 of the dental floss 10 of the present disclosure with that of a conventional product. Specifically, the results are as follows. As shown in Figure 5, the portion of the bound portion 12 of the dental floss 10 30 mm from the end was held between the fingers, and the end face of the bound portion 12 was pressed against an electronic balance with a non-slip sheet in between. The reading (g) on ​​the electronic balance just before buckling occurred was then read. On the other hand, the same test was also conducted on the bound portion of the conventional (commercially available) dental floss with a bound portion. As a result, the dental floss of the present disclosure weighed 9.0 g, while the two commercially available products weighed 1.3 g and 4.2 g, respectively. Furthermore, when the cross-sectional shape of the binding part of the commercially available products was checked, a part corresponding to the outer shell part of the present disclosure was not formed.

[0025] 2. Dental floss continuous body, roll body The dental floss 10 described so far is a single-use dental floss, but dental floss is often provided in a continuous body (continuous dental floss body) in which multiple dental flosses are connected together for multiple uses. The continuous dental floss body is then wound around a bobbin and manufactured as a roll. It may then be further divided into smaller pieces and placed in a floss holder that fits in one hand for sale. Figure 6 shows a continuous dental floss body 20, and Figure 7 shows a roll body 21.

[0026] As shown in Fig. 6, in dental floss continuous body 20, multiple dental flosses 10 are connected in the length direction to form one continuous piece. At this time, multiple dental flosses 10 are connected together by the shape of the bundling parts 12. Therefore, a user can obtain a single use amount of dental floss 10 by cutting bundling part 12. As shown in FIG. 7, the continuous dental floss 20 is wound around a bobbin 21a to form a roll 21.

[0027] 3. Manufacturing method of dental floss continuum As described above, a single-use portion of dental floss 10 is obtained by a user by cutting it from the continuous dental floss body 20, so here, a method for manufacturing the continuous dental floss body and the roll will be described. An explanatory diagram is shown in FIG. 8.

[0028] A raw yarn 30a formed by twisting together a plurality of filaments 10a is wound and unwound from a raw yarn roll body 30. The unwound raw yarn 30a is inserted into a welding device 31, where a bound portion 12 is formed. Tension adjusting devices 32 such as tension rollers are disposed before and after the welding device 31, respectively, to adjust the tension of the raw yarn 30a in the welding device 31. When the bonding device 31 forms the bound portion 12, the raw thread 30a becomes the continuous dental floss body 20, which is then wound around the bobbin 21a to form the roll body 21. The unwinding of the raw thread 30a, the application of tension, and the winding of the continuous dental floss body 20 around the bobbin 21a are performed by the servo motor 33 attached to the bobbin 21a being driven to rotate the bobbin 21a.

[0029] Of the above steps, the formation of the bound portion 12 by the welding device 31 will be described in detail. Fig. 9 to Fig. 11 are diagrams for explanation. Fig. 9 is an external perspective view of the welding device 31, Fig. 10 is a diagram showing a scene in which the original yarn 30a is placed in the welding device 31, and Fig. 11 is a diagram for explaining the operation of the welding device 31.

[0030] 9, the welding device 31 has a first heating plate 31a and a second heating plate 31b, which are two separable plate-like members. The first heating plate 31a and the second heating plate 31b are plate-like members made of metal, and are configured to be heated by having a heater inside. The first heating plate 31a and the second heating plate 31b can be overlapped with the plate surface 31aa and the plate surface 31ba facing each other, and can be separated from each other. The opposing plate surfaces 31aa and 31ba are provided with grooves 31ab and 31bb along the direction in which the raw yarn 30a moves. As a result, when the first heating plate 31a and the second heating plate 31b are overlapped, a through hole H is formed between the first heating plate 31a and the second heating plate 31b, as shown in Figs. As described above, the first heating plate 31a and the second heating plate 31b can be heated, and the inside of the through hole H can be made into a high-temperature space by this heating.

[0031] The through hole H is configured so that the tensioned yarn 30a can be placed inside the through hole H without being pressed by the first heating plate 31a and the second heating plate 31b. Most preferably, the yarn 30a can be placed inside the through hole H without touching the surfaces of the grooves 31ab and 31bb. Specifically, the through hole H can have a diameter about four times the diameter of the bound portion to be formed. The through hole H is not limited to a hole having a circular cross section, and may have another cross section shape, such as a square.

[0032] 8 and 10, the yarn 30a is placed in the through-hole H with the first heating plate 31a and the second heating plate 31b overlapping each other, and the yarn 30a is held for a predetermined time (several seconds) to form the bound portion 12. At this time, as described above, the yarn 30a is tensioned and thinned in a small, flat state, and is heated without being pressed by the first heating plate 31a and the second heating plate 31b, and most preferably without touching the surfaces of the grooves 31ab and 31bb, so that the outer periphery of the yarn 30a is welded with little flattening in cross section, and the outer shell 12a can be efficiently formed.

[0033] Since the dental floss continuous body 20 has the floss portion 11 and the bundling portion 12 arranged in this order, it is necessary to provide a portion that is not heated by the welding device 31 (a portion in which the raw yarn 30a remains) in order to provide the floss portion 11. At this time, the heating by the welding device 31 must be stopped, so the first heating plate 31a and the second heating plate 31b are separated and separated from the raw yarn 30a. Figure 11 is a diagram illustrating a structure 34 for achieving this separation.

[0034] The structure 34 has a first link mechanism 35 and a second link mechanism 36. The first link mechanism 35 is a link mechanism for moving the first heating plate 31a, and the second link mechanism 36 is a link mechanism for moving the second heating plate 31b. The first link mechanism 35 includes a first link 35a and a second link 35b. One end of the first link 35a is connected to the rotation shaft O1, and the other end is rotatably connected to one end of the second link 35b, and the other end of the second link 35b is connected to the first heating plate 31a. The second link mechanism 36 includes a first link 36a and a second link 36b. One end of the first link 36a is connected to the rotation shaft O2, and the other end is rotatably connected to one end of the second link 36b, and the other end of the second link 36b is connected to the second heating plate 31b.

[0035] According to the structure 34, when the first links 35a, 36a rotate around the respective rotation axes O1, O2, the first heating plate 31a and the second heating plate 31b move away from each other in an arcuate trajectory while maintaining their posture via the second links 35b, 36b. As a result, the first heating plate 31a and the second heating plate 31b are separated from each other and are separated from the yarn 30a. According to this structure 34, the first heating plate 31a and the second heating plate 31b can be moved in both the x and y directions which are perpendicular to each other, and the first heating plate 31a and the second heating plate 31b can be moved efficiently to eliminate the effect of heat on the raw yarn 30a. [Explanation of symbols]

[0036] 10. Dental floss 10a filament 11 Floss Section 12 Binding section 12a Outer shell 20 Dental Floss Continuum 21 Roll body 30 Raw yarn roll body 30a yarn 31 Welding equipment

Claims

1. a floss portion formed by twisting together a plurality of filaments without bundling; a bundling portion which is continuous with the floss portion and in which a plurality of filaments are bound together; In a cross section of the bundled portion, the plurality of filaments are covered by an outer shell portion, The outer shell portion is formed by melting and bonding a part of the filaments. Dental floss.

2. 2. A continuous dental floss body comprising a continuous piece of dental floss according to claim 1, the floss portions and the bundled portions being arranged alternately in a plurality of positions.

3. A method for producing the dental floss continuum according to claim 2, comprising: The method includes a step of alternately forming heated and unheated portions on a raw yarn formed by twisting together the plurality of filaments, When forming the heated portion, the raw yarn is heated without applying a pressing force to the raw yarn because the raw yarn does not come into contact with a heat source member for heating, and the outer periphery of the raw yarn is melted and welded. A method for manufacturing a dental floss web.

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