Floss tape, floss rolls, and floss picks

Abstract

To provide a floss tape having a multilayer structure. [Solution] A floss tape 1 having an elongated strip shape, comprising an inner layer 10 and an outer layer 20 wrapped around the outside of the inner layer, wherein the elastic modulus of the inner layer is greater than that of the outer layer, the hardness of the inner layer is greater than that of the outer layer, the volume of the inner layer in any length direction of the floss tape accounts for 10% to 60%, preferably 15% to 50%, more preferably 20% to 40%, of the total volume of the floss tape in the length direction, the inner layer contains a mixture of elastomer and plastic, the outer layer contains elastomer, the elastomer in the inner layer has the same type of repeating structural units as the elastomer in the outer layer, and preferably the elastomer in the inner layer is the same as the elastomer in the outer layer.

Description

Technical Field

[0003]

[0001] This application relates to the field of dental cleaning tools, and more particularly, to floss tapes, floss rolls made of such floss tapes, and floss picks made of such floss tapes. This application also relates to a method for manufacturing a floss tape.

Background Art

[0002] Existing floss tapes can be made of high-strength polymer multifilament materials (such as nylon 6 fibers or ultra-high molecular weight polyethylene fibers). Since the individual fibers of such multifilament materials are relatively thin, they are likely to cause a feeling of cutting the gums. This type of floss tape is also prone to problems of individual fiber breakage during use, further affecting the user experience. To solve the above problems, some floss tapes are made of soft polymer materials (such as polytetrafluoroethylene or elastomers) to reduce the problems of the feeling of cutting and breaking.

[0003] Due to safety concerns regarding perfluoroalkyl and polyfluoroalkyl substances, the production of polytetrafluoroethylene floss tapes is gradually decreasing. Elastomer floss tapes are prone to stretching, creating new problems. Specifically, in the manufacturing process of floss rolls and floss picks, the floss tape needs to be drawn from the spool. Then, in the case of floss rolls, the drawn floss tape is wound onto the core bobbin of the floss roll product. Elastomer floss tapes are stretched during this process. Therefore, when they move on to the next process, a large amount of residual tension remains in the floss tape. These tensions accumulate in the floss tape during the process of winding it onto the core bobbin. Since the length of floss tape wound onto the core bobbin of a floss roll can be as long as 40 meters, the tension accumulated in the floss tape can deform the core bobbin, making it impossible to remove it from the winding equipment, or it can directly crush the core bobbin, rendering it unusable. In the case of floss picks, these tensions automatically retract the floss tape when it breaks after one cycle of injection molding of the floss pick handle is completed, making it impossible for the device to grip the floss tape for the next cycle of floss pick handle injection molding. In this way, the originally continuous automated manufacturing process is interrupted. [Overview of the project]

[0004] To address the technical challenges described above, this application proposes a floss tape having a multilayer structure. Compared to a single-layer floss tape, the floss tape according to this application has very little elasticity in the longitudinal direction x (the definition of this direction is provided below), thereby preventing manufacturing interruptions or product defects caused by accumulated tension on the floss tape during the manufacturing process of floss rolls and floss picks. Furthermore, the floss tape according to this application is less susceptible to damage when inserted into narrow interdental gaps, resulting in a better user experience.

[0005] This application relates to a floss tape having an elongated strip shape and comprising an inner layer and an outer layer wrapped around the outside of the inner layer, wherein the modulus of elasticity of the inner layer is greater than that of the outer layer, the hardness of the inner layer is greater than that of the outer layer, the volume of the inner layer along any length direction of the floss tape accounts for 10% to 60%, preferably 15% to 50%, more preferably 20% to 40%, of the total volume of the floss tape in the said length direction, the inner layer comprises a mixture of elastomer and plastic, the outer layer comprises an elastomer, the elastomer in the inner layer has the same type of repeating structural units as the elastomer in the outer layer, and the elastomer in the inner layer preferably has the same type of repeating structural units as the elastomer in the outer layer We propose a floss tape characterized by being the same as the elastomer within the layer.

[0006] According to an optional embodiment, the outer layer includes a corrugated section, the height of the corrugated section being in the range of 40 μm to 200 μm, preferably in the range of 60 μm to 170 μm, more preferably in the range of 80 μm to 150 μm, the width of the corrugated section being in the range of 700 μm to 3000 μm, preferably in the range of 700 μm to 2000 μm, more preferably in the range of 1000 μm to 2000 μm, the thickness of the corrugated section being in the range of 20 μm to 120 μm, preferably in the range of 30 μm to 90 μm, more preferably in the range of 40 μm to 80 μm, the thickness of the corrugated section being uniform or non-uniform, and if the thickness of the corrugated section is non-uniform, the maximum value of the thickness of the corrugated section not exceeding 6 times the minimum value, preferably not exceeding 2 times the minimum value.

[0007] According to an optional embodiment, the corrugated section includes a first corrugated portion, the first corrugated portion includes continuously connected corrugated units, the shape of which the corrugated units are one or more of a triangle, an arc, a sine wave, a rectangle, and other polygons, and the transition portion has a rounded corner profile.

[0008] According to an optional embodiment, the first corrugated portion comprises 2 to 25 continuously connected corrugated units, preferably 5 to 10 continuously connected corrugated units, wherein the wavelength of the corrugated units is in the range of 60 μm to 800 μm, preferably in the range of 100 μm to 600 μm, more preferably in the range of 150 μm to 500 μm, and the amplitude of the corrugated units is in the range of 0 μm to 90 μm, preferably in the range of 3 μm to 80 μm, more preferably in the range of 5 μm to 70 μm.

[0009] According to an optional embodiment, the corrugated section includes a second corrugated portion, the second corrugated portion includes a secondary corrugated unit, the shape of which the secondary corrugated unit is one or more of a triangle, an arc, a sine wave, a rectangle, and other polygons, and has a rounded corner profile in the transition portion.

[0010] According to an optional embodiment, the second corrugated portion includes one or more secondary corrugated units superimposed on each corrugated unit of the first corrugated portion, wherein the wavelength of the secondary corrugated unit is in the range of 20 μm to 600 μm, preferably in the range of 30 μm to 400 μm, more preferably in the range of 40 μm to 200 μm, the amplitude of the secondary corrugated unit is in the range of 0 μm to 50 μm, preferably in the range of 1 μm to 25 μm, more preferably in the range of 2 μm to 15 μm, the wavelength of the secondary corrugated unit is smaller than the wavelength of the corrugated unit, the amplitude of the secondary corrugated unit is smaller than the amplitude of the corrugated unit, and the wavelength of the secondary corrugated unit is greater than 1 / 20 of the wavelength of the corrugated unit, preferably greater than 1 / 10, and more preferably greater than 1 / 6.

[0011] According to an optional embodiment, the maximum thickness of the inner layer is 50 μm, the ratio of the total width to the maximum thickness of the inner layer is greater than 20:1, preferably greater than 30:1, and the thickness of the inner layer is uniform or non-uniform. If the thickness of the inner layer is non-uniform, the thickness of the inner layer changes periodically, and the ratio of the distance the inner layer extends in one cycle of thickness variation to the maximum thickness of the inner layer in that cycle is greater than 5:1, preferably greater than 8:1.

[0012] According to an optional embodiment, the floss tape includes one or two guide sections, each guide section is positioned at the edge of the outer layer, and each guide section includes a connecting portion closer to the outer layer and a guide portion further away from the outer layer, the guide portion having a smoothly extending curved surface, and the width of the guide section is in the range of 50 μm to 550 μm.

[0013] According to an optional embodiment, the inner layer comprises one or more of polyamide-based thermoplastic elastomers, polyether-ester thermoplastic elastomers, polyolefin-based thermoplastic elastomers, thermoplastic polyurethane elastomers, and styrene-based block copolymer elastomers, preferably comprising a polyamide-based thermoplastic elastomer or a polyether-ester thermoplastic elastomer, more preferably comprising a polyether-ester thermoplastic elastomer, with an elastomer content of 20% by weight or more, preferably 30% by weight or more, and the outer layer comprises one or more of polyamide-based thermoplastic elastomers, polyether-ester thermoplastic elastomers, polyolefin-based thermoplastic elastomers, thermoplastic polyurethane elastomers, and styrene-based block copolymer elastomers, preferably comprising a polyamide-based thermoplastic elastomer or a polyether-ester thermoplastic elastomer, more preferably comprising a polyether-ester thermoplastic elastomer, and the Shore hardness of the outer layer is less than 55HD.

[0014] According to an optional embodiment, the plastic in the inner layer comprises one or more of polyamides, olefin polymers, polyesters, polystyrenes, acrylonitrile-styrene-butadiene copolymer resins, and thermoplastic polyurethanes, preferably polyhexamethylene adipamide, polyhexamethylene sebakamid, polyhexamethylene dodecanediamide, polycaprolactam, polylaurolactam, polyethylene terephthalate, polybutylene terephthalate, or polytrimethylene terephthalate, more preferably polybutylene terephthalate, and the elastic modulus of the plastic in the inner layer is greater than 1 GPa.

[0015] The present application also proposes a method for preparing a floss tape, comprising: adding an outer layer composition comprising an elastomer to a first extruder; adding an inner layer composition comprising an elastomer and a plastic to a second extruder; melting the outer layer composition and the inner layer composition, respectively, to produce a molten outer layer composition and a molten inner layer composition; feeding the molten outer layer composition into an outer layer material channel in an extruded spin pack; introducing the molten inner layer composition into an inner layer material channel in an extruded spin pack; merging the molten outer layer composition and the molten inner layer composition into a composite molten material in the extruded spin pack; extruding the composite molten material from a spinning hole on a spinneret; drawing the extruded composite molten material into cold water for quenching and solidification; continuously stretching the solidified composite molten material into a solid filament in hot water and a dry heat oven; setting the solid filament in another dry heat oven; and winding one or more heat-set solid filaments onto a spool for collection.

[0016] According to an optional embodiment, the volume ratio of the inner layer within the floss tape and the thickness of the floss tape are adjusted by adjusting the pump speeds of the first and second extruders.

[0017] This application also proposes a floss roll comprising a floss roll housing, a floss core bobbin disposed within the floss roll housing, and a floss tape wound around the floss core bobbin.

[0018] This application also proposes a floss pick comprising a floss pick frame and a floss tape connected between different ends of the floss pick frame.

[0019] The floss tape according to this application has the following technical effects: Based on the flexible properties of the outer layer, the inner layer plastic material has sufficient strength, which can reduce the overall elasticity of the floss tape in the length direction x and width direction y, and as a result the floss tape This makes it less susceptible to damage when entering narrow interdental spaces, resulting in a better user experience.

[0020] The shape of the outer layer of the floss tape can enhance its cleaning effect. The combination of the inner layer, outer layer, and guide section of the floss tape evens out and stabilizes the sliding resistance of the floss tape as it enters the interdental gap. When the width of the interdental gap changes abruptly, the frictional force acting on the outer layer decreases abruptly, and the tension acting on the floss tape along the width direction increases abruptly. At this time, the inner layer maintains the shape of the floss tape so as not to flatten due to the tension along the width direction, thereby preventing gingival damage caused by abrupt changes in the shape of the floss tape resulting from abrupt changes in the width of the interdental gap.

[0021] The floss tape according to this application has very little elasticity in the length direction x, and as a result, the accumulated tension on the floss tape during the manufacturing process of floss rolls and floss picks does not cause manufacturing interruptions or product defects.

[0022] The aforementioned and other aspects of this application will be better understood from the following detailed description in conjunction with the accompanying drawings. Note that the proportions of the drawings may differ for clarity but will not affect the understanding of this application. [Brief explanation of the drawing]

[0023] [Figure 1] This is a perspective view of the floss tape according to this application. [Figure 2] Figure 1 is a cross-sectional view of the floss tape. [Figure 3] Figure 2 is a schematic diagram of a partially enlarged section of the floss tape. [Figure 4]A partial enlarged schematic view of a frost tape according to another embodiment of the present application, showing one wavy unit and a plurality of secondary wavy units superimposed thereon. [Figure 5] A partial enlarged schematic view of a frost tape according to another embodiment of the present application, showing one wavy unit and a plurality of secondary wavy units superimposed thereon. [Figure 6] A partial enlarged schematic view of a frost tape according to another embodiment of the present application, showing one wavy unit and a plurality of secondary wavy units superimposed thereon. [Figure 7] A partial enlarged schematic view of a frost tape according to another embodiment of the present application, showing one wavy unit and a plurality of secondary wavy units superimposed thereon. [Figure 8] A partial enlarged schematic view of a frost tape according to another embodiment of the present application, showing two wavy units of the same shape and a plurality of secondary wavy units superimposed thereon. [Figure 9] A partial enlarged schematic view of a frost tape according to another embodiment of the present application, showing two wavy units of different shapes and a plurality of secondary wavy units superimposed thereon. [Figure 10] A partial enlarged schematic view of a frost tape according to another embodiment of the present application. [Figure 11] A flowchart of a method for preparing a frost tape according to the present application.

Embodiments for Carrying out the Invention

[0024] Typical embodiments of the present application will be described in more detail below with reference to the accompanying drawings. Although typical embodiments of the present application are shown in the drawings, it should be understood that the present application can be implemented in various forms and should not be limited by the embodiments described herein. In contrast, these embodiments are provided to enable a more complete understanding of the present application and to convey the scope of the present application to those skilled in the art.

[0025] Figure 1 is a perspective view of a floss tape 1 according to a first embodiment of this application. In this specification, the extending direction of the floss tape 1 is defined as the length direction x (i.e., the direction of the arrow x in Figure 1), the direction perpendicular to one side edge of the floss tape from the other side edge is defined as the width direction y (i.e., the direction of the arrow y in Figure 1), and the direction perpendicular to the length direction x and the width direction y is, The height direction z (i.e., the direction of the arrow z in Figure 1) is defined. Floss tape 1 is in the shape of an elongated strip and has an inner layer 10 and an outer layer 20 wrapped around the outside of the inner layer 10. The outer layer 20 includes a corrugated section 21. Floss tape 1 may also include a guide section 30 positioned at the edge of the outer layer 20. The outer layer 20 can be made from 65 wt% Hytrel® 4068FG (polyether-ester thermoplastic elastomer), 25 wt% Hytrel® 5556 (polyether-ester thermoplastic elastomer), 5 wt% Multibase® MB50-010 (DuPont's lubricant masterbatch based on polyether-ester thermoplastic elastomer), and a white masterbatch based on 5 wt% polyether-ester thermoplastic elastomer Hytrel® 4068FG.

[0026] Figure 2 is a cross-sectional view of the floss tape 1 shown in Figure 1. The maximum thickness of the inner layer 10 is 50 μm. The ratio of the total width to the maximum thickness of the inner layer 10 is greater than 20:1, preferably greater than 30:1. The inner layer 10 is corrugated (with undulations along the width direction y), and both its modulus of elasticity and hardness are higher than those of the outer layer 20.

[0027] The inner layer 10 may contain one or more of the following: polyamide thermoplastic elastomers, polyether-ester thermoplastic elastomers, polyolefin thermoplastic elastomers, thermoplastic polyurethane elastomers, and styrene-based block copolymer elastomers, preferably containing a polyamide thermoplastic elastomer or a polyether-ester thermoplastic elastomer, and more preferably containing a polyether-ester thermoplastic elastomer. The polyether-ester thermoplastic elastomer may be a commercially available product, for example, Hytrel® resin from Celanese, more specifically Hytrel® 4068FG, Hytrel® 5556, Hytrel® SC956, Hytrel® SC969, Hytrel® SC976, and Hytrel® SC988.

[0028] The elastomer content in the inner layer 10 is 20% by weight or more, preferably 30% by weight or more. Furthermore, the elastomer in the inner layer 10 has the same type of repeating structural units as the elastomer in the outer layer 20. Preferably, the elastomer in the inner layer 10 is the same as the elastomer in the outer layer 20. In other words, the repeating structural units of the long-chain elastomer molecules constituting the inner layer 10 have the same functional groups as the repeating structural units of the long-chain elastomer molecules constituting the outer layer 20. For example, if the elastomer in the outer layer 20 is a polyether-ester thermoplastic elastomer and its long-chain molecular repeating structural units contain ester and ether groups, then the elastomer in the inner layer 10 is also a polyether-ester thermoplastic elastomer, and its long-chain molecular repeating structural units also contain ester and ether groups. The number of ester and ether groups in the two cases does not need to be exactly the same, and the non-functional group structures between the ester and ether groups may also differ. A functional group refers to a class of atoms or groups of atoms in an organic molecule that confer specific chemical properties to a compound. Functional groups typically consist of a specific arrangement of atoms or bonds and are core structural units that determine the chemical reactivity and physical properties of a compound. For the elastomer in the inner layer 10 to be identical to the elastomer in the outer layer 20 means that not only do the repeating structural units of the long-chain molecules of the two elastomers contain the same functional groups, but the number of functional groups in both cases is also the same, as is the non-functional group structure between the functional groups. In the case of polymer materials, "same number of functional groups" and "same structure" as used here mean the same in a statistical sense, and the actual number of functional groups and the non-functional group structure between functional groups can allow for statistical deviations. For example, the elastomer in the inner layer 10 and the elastomer in the outer layer 20 may be the same grade of resin from the same manufacturer, but from different production batches.

[0029] Specifically, the inner layer 10 contains a mixture of elastomer and plastic. The elastic modulus of the plastic is greater than 1 GPa. The plastic in the inner layer 10 may include one or more of PA (polyamide), olefin polymer, polyester, polystyrene, ABS (acrylonitrile-styrene-butadiene copolymer), and TPU (thermoplastic polyurethane), as well as optionally existing thermoplastic elastomers. Preferably, the plastic in the inner layer 10 may include nylon 66 (polyhexamethylene adipamide), nylon 610 (polyhexamethylene sebamid), nylon 612 (polyhexamethylene dodecanediamide), nylon 6 (polycaprolactam), nylon 12 (polylaurolactam), PET (polyethylene terephthalate), PBT (polybutylene terephthalate), or PTT (polytrimethylene terephthalate). More preferably, the plastic in the inner layer 10 may include PBT. PBT may be a commercially available product such as DHKD03 from Shinkong Synthetic Fibers Corp., PBT B2520 from BASF, PBT L2100 from Sinopec Yizheng Chemical Fibre, PBT 1200 211D / 211M from Chang Chun Plastics, or spinning-grade PBT from Hengli Chemical Fibre.

[0030] It can be understood that the inner layer 10 may be flat. Furthermore, the volume of the inner layer 10 along any length direction of the floss tape 1 accounts for 10% to 60%, preferably 15% to 50%, and more preferably 20% to 40%, of the total volume of the floss tape 1 in that length direction.

[0031] The outer layer 20 may contain one or more of the following: polyamide-based thermoplastic elastomer, polyether-ester thermoplastic elastomer, polyolefin-based thermoplastic elastomer, thermoplastic polyurethane elastomer, and styrene-based block copolymer elastomer. Preferably, the outer layer 20 may contain a polyamide-based thermoplastic elastomer or a polyether-ester thermoplastic elastomer. More preferably, the outer layer 20 may contain a polyether-ester thermoplastic elastomer.

[0032] Specifically, the Shore hardness of the outer layer 20 is less than 55HD.

[0033] Thus, the floss tape 1 according to this application maintains the flexible properties of the outer layer 20 while using the plastic material of the inner layer 10 to reduce the overall elasticity of the floss tape in the longitudinal direction x. Therefore, during the manufacturing process of floss rolls and floss picks, the accumulation of tension on the floss tape will not cause manufacturing interruptions or product defects. At the same time, since the inner layer 10 has sufficient strength, the floss tape is less likely to be damaged when it enters narrow interdental gaps, resulting in a better user experience.

[0034] The material constituting the guide section 30 may be the same as that of the outer layer 20.

[0035] The thickness h1 of the corrugated section 21 of the outer layer 20 is 70 μm, the height h3 is 100 μm, and the width h2 is 1600 μm.

[0036] The guide section 30 is positioned at the edge of the corrugated section 21 and includes a connecting portion 300 close to the corrugated section 21 and a guide portion 301 further away from the corrugated section 21. The width h8 of the guide section 30 is approximately 120 μm. The guide portion 301 has a smoothly extending curved surface.

[0037] Figure 3 is a partially enlarged schematic diagram of the floss tape 1 of Figure 2. For clarity, the inner layer 10 is omitted, and the outer layer 20 is simplified as a line segment (although it actually has a specific thickness) to facilitate the description of its shape. The corrugated section 21 of the outer layer 20 includes a first corrugated portion 210 and a second corrugated portion 211. The first corrugated portion 210 is continuously connected It contains multiple corrugated units (one corrugated unit is shown in the figure). The shape of the corrugated units is triangular. The second corrugated portion 211 contains one or more secondary corrugated units superimposed on the corrugated units of the first corrugated portion 210 (two secondary corrugated units are shown in the figure). The shape of the secondary corrugated units is sinusoidal. Specifically, one secondary corrugated unit is superimposed on half of the corrugated unit. The wavelength h4 of the corrugated unit is greater than the wavelength h5 of the secondary corrugated unit. The amplitude h7 of each corrugated unit in the first corrugated portion 210 is greater than the amplitude h6 of each secondary corrugated unit in the second corrugated portion 211. Specifically, the wavelength h4 of the corrugated unit is approximately 260 μm, the amplitude h7 is approximately 15 μm, and it has a rounded corner profile at the transition. The wavelength h5 of the secondary corrugated unit is approximately 168 μm, and the amplitude h6 is approximately 6 μm.

[0038] By overlapping the first wavy portion 210 and the second wavy portion 211 to form a wavy section 21, the roughness and cleaning power of the floss tape can be increased without affecting the compressibility and penetration into interdental gaps of the floss tape. The wavelength h4 and amplitude h7 of the wavy unit of the first wavy portion 210 are larger, constituting the basic structure of the wavy section 21 that provides the floss tape with good compressibility and penetration into interdental gaps. The wavelength h5 and amplitude h6 of the secondary wavy unit of the second wavy portion 211 are smaller, primarily serving to increase the surface roughness of the floss tape and improve the cleaning power of the floss tape.

[0039] To achieve the above technical effects, it can be understood that the direction of propagation of the secondary corrugated units of the second corrugated portion 211 changes along the contour direction of the first corrugated portion 210.

[0040] To achieve the above technical effects, it is understood that the thickness of the corrugated section 21 may be uniform or non-uniform. If non-uniform, the maximum thickness of the corrugated section 21 shall not exceed 6 times the minimum thickness, preferably not exceeding 2 times. The thickness h1 of the corrugated section 21 may be in the range of 20 μm to 120 μm, preferably in the range of 30 μm to 90 μm, and more preferably in the range of 40 μm to 80 μm. The width h2 of the corrugated section 21 may be in the range of 700 μm to 3000 μm, preferably in the range of 700 μm to 2000 μm, and more preferably in the range of 1000 μm to 2000 μm. The height h3 of the corrugated section 21 may be in the range of 40 μm to 200 μm, preferably in the range of 60 μm to 170 μm, and more preferably in the range of 80 μm to 150 μm.

[0041] It can be understood that the thickness of the inner layer 10 may be non-uniform, regardless of whether the thickness of the corrugated section 21 is uniform or not.

[0042] To achieve the above technical effects, it can be understood that the first corrugated portion 210 of the corrugated section 21 may have 2 to 25 corrugated units, preferably 5 to 10 corrugated units. The wavelength h4 of the corrugated units of the first corrugated portion 210 of the corrugated section 21 may be in the range of 60 μm to 800 μm, preferably in the range of 100 μm to 600 μm, and more preferably in the range of 150 μm to 500 μm. The amplitude h7 of the corrugated units of the first corrugated portion 210 of the corrugated section 21 may be in the range of 0 to 90 μm, preferably in the range of 3 μm to 80 μm, and more preferably in the range of 5 μm to 70 μm.

[0043] To achieve the above technical effects, it can be understood that the wavelength h5 of the secondary wave unit of the second wave portion 211 of the wave section 21 may be in the range of 20 μm to 600 μm, preferably in the range of 30 μm to 400 μm, and more preferably in the range of 40 μm to 200 μm. The amplitude h6 of the secondary wave unit of the second wave portion 211 of the wave section 21 may be in the range of 0 to 50 μm, preferably in the range of 1 μm to 25 μm, and more preferably in the range of 2 μm to 15 μm.

[0044] To achieve the above technical effects, it can be understood that the wavelength h5 of the secondary wave unit is greater than 1 / 20, preferably greater than 1 / 10, and more preferably greater than 1 / 6, of the wavelength h4 of the wave unit.

[0045] Although not shown in the figures, it can be understood that the floss tape according to this application may also include a coating applied to its surface. The coating may be made of substances such as lubricants, strippers, abrasives, whitening agents, activators, olfactory stimulants, salivary secretion agents, sensory stimulants, essential oils, fragrances, antimicrobial agents, or antiviral agents.

[0046] Figure 4 is a partially enlarged schematic diagram of the floss tape 1 according to another embodiment of the present application. For clarity, the inner layer 10 is omitted, and the outer layer 20 is simplified as a line segment (although it actually has a specific thickness) to facilitate the description of its shape. Compared to Figure 3, the shape of the corrugated unit of the first corrugated portion 210 in Figure 4 is still triangular, but the shape of the secondary corrugated unit of the second corrugated portion 211 is also triangular, with the two secondary corrugated units overlapping half of the corrugated unit.

[0047] Figure 5 is a partially enlarged schematic view of Floss Tape 1 according to another embodiment of the present application. For clarity, the inner layer 10 is omitted, and the outer layer 20 is simplified as a line segment (although it actually has a specific thickness) to facilitate the description of its shape. Compared to Figure 3, the shape of the corrugated units of the first corrugated portion 210 in Figure 5 is still triangular, but the shape of the secondary corrugated units of the second corrugated portion 211 is sinusoidal, with the two secondary corrugated units superimposed on half of the corrugated unit.

[0048] Figure 6 is a partially enlarged schematic diagram of the floss tape 1 according to another embodiment of the present application. For clarity, the inner layer 10 is omitted, and the outer layer 20 is simplified as a line segment (although it actually has a specific thickness) to facilitate the description of its shape. Compared to Figure 3, the shape of the corrugated units of the first corrugated portion 210 in Figure 6 is sinusoidal, and the shape of the secondary corrugated units of the second corrugated portion 211 is still sinusoidal, but three secondary corrugated units are superimposed on half of the corrugated unit.

[0049] Figure 7 is a partially enlarged schematic diagram of the floss tape 1 according to another embodiment of the present application. For clarity, the inner layer 10 is omitted, and the outer layer 20 is simplified as a line segment (although it actually has a specific thickness) to facilitate the description of its shape. Compared with Figure 3, the shape of the corrugated unit of the first corrugated portion 210 in Figure 7 is rectangular, and the shape of the secondary corrugated unit of the second corrugated portion 211 is also rectangular, with 2.5 secondary corrugated units overlapping half of the corrugated unit.

[0050] To achieve the above technical effects, a first corrugated portion 210 having corrugated units of the above shapes (e.g., triangles, arcs, sine waves, rectangles, other polygons, etc.) and a second corrugated portion 211 having secondary corrugated units of the above shapes (e.g., triangles, arcs, sine waves, rectangles, other polygons, etc.) can be arbitrarily combined, and it can be understood that all of these are within the scope of protection of this application.

[0051] Figure 8 is a partially enlarged schematic diagram of the floss tape 1 according to another embodiment of the present application. For clarity, the inner layer 10 is omitted, and the outer layer 20 is simplified as a line segment (although it actually has a specific thickness) to facilitate the description of its shape. Compared to Figure 3, the shape of the corrugated units of the first corrugated portion 210 in Figure 8 is an arc, and the shape of the secondary corrugated units of the second corrugated portion 211 is a sine wave. Also, a straight section 212 is connected between the two corrugated units of the first corrugated portion 210 in Figure 8.

[0052] Figure 9 is a partially enlarged schematic diagram of Floss Tape 1 according to another embodiment of the present application. For clarity, the inner layer 10 is omitted, and the outer layer 20 is simplified as a line segment (although it actually has a specific thickness) to facilitate the description of its shape. Compared with Figure 8, the first corrugated portion 210 in Figure 9 is formed by continuously connecting triangular corrugated units and sinusoidal corrugated units. In the case of the second corrugated portion 211, the shape of the secondary corrugated unit superimposed on the triangular corrugated unit is triangular, and the shape of the secondary corrugated unit superimposed on the sinusoidal corrugated unit is sinusoidal. Also in Figure 9, the straight section 212 is not provided between the first corrugated portions 210.

[0053] Figure 10 is a partially enlarged schematic diagram of a floss tape according to another embodiment of the present application. In the embodiment of Figure 10, the thickness of the inner layer 10 is non-uniform.

[0054] The process of inserting the floss tape into the interdental space is described below based on embodiments of this application. As the floss tape 1 slides over the occlusal surface of the tooth, the guide section 30 of the floss tape 1 is fitted into the interdental space opening, thereby generating feedback to the object pulling the floss tape (hand, floss roll, floss pick, etc.). In this way, the user of the floss tape 1 can clearly grasp the position of the floss tape 1 and then change the direction of the force applied to the floss tape 1. After the direction of the force applied to the floss tape 1 is changed from parallel to the occlusal surface of the tooth to perpendicular to the occlusal surface of the tooth, the floss tape 1 reciprocates over the interdental space opening under the combined force, and as a result, the outer layer 20 extends into the interdental space from the interdental space opening along the width direction y. As the floss tape 1 moves back and forth along the width direction y in the interdental gap, the wavy section 21 of the outer layer 20 comes into contact with the surface of the interdental gap. As a result, food debris in the interdental gap and plaque on the tooth surface are pushed into the grooves formed together by the first wavy portion 210 and the second wavy portion 211 of the wavy section 21, and are thereby removed from the interdental gap as the floss tape moves.

[0055] The floss tape according to this application has the following technical effects: Based on the flexible properties of the outer layer 20, the plastic material of the inner layer 10 has sufficient strength, which can reduce the overall elasticity of the floss tape in the length direction x and width direction y. As a result, the floss tape is less likely to be damaged when inserted into narrow interdental gaps, resulting in a better user experience.

[0056] The shape of the outer layer 20 of the floss tape 1 can enhance the cleaning effect of the floss tape 1. The combination of the inner layer 10, the outer layer 20, and the guide section 30 of the floss tape 1 makes the sliding resistance of the floss tape 1 uniform and stable as it enters the interdental gap. When the width of the interdental gap changes abruptly, the frictional force acting on the outer layer 20 decreases abruptly, and the tension acting on the floss tape 1 along the width direction y increases abruptly. At this time, the inner layer 10 maintains the shape of the floss tape 1 so as not to become flat due to the tension along the width direction y, thereby preventing gingival damage caused by abrupt changes in the shape of the floss tape 1 due to abrupt changes in the width of the interdental gap.

[0057] Furthermore, this application includes a floss roll made of floss tape 1 and a floss pick made of floss tape. The floss tape 1 according to this application has very little elasticity in the length direction x, and as a result, the accumulated tension on the floss tape 1 during the manufacturing process of the floss roll and floss pick does not cause manufacturing interruptions or product defects.

[0058] An experiment concerning the damage rate of floss tape when passing through simulated interdental gaps is described below, and includes the following steps.

[0059] Step 1: Secure the two ends of the floss tape to the two arms of the arch-shaped fixing device, respectively, so that the length of the floss tape between the two fixing points is approximately 4 cm.

[0060] Step 2: Connect the fastener to the handheld handle.

[0061] Step 3: Adjust the gap between the two round heads of the double round head micrometer to 30 μm, use the gap between the two round heads as a simulated interdental gap, and fix the micrometer on the table.

[0062] Step 4: Hold the handle with one hand and apply downward force perpendicular to the floss tape secured to the fixture, so that the floss tape passes through the gap between the two round heads of the micrometer.

[0063] Step 5: Holding the handle with one hand, apply tension vertically upward to the floss tape that has passed through the gap, and select a different area of ​​the floss tape than the one used in Step 4 to pass through the gap between the two round heads of the micrometer.

[0064] Step 6: Record whether the floss tape is damaged.

[0065] Replace the sample with a new floss tape and repeat the above test six times to calculate the probability of damage occurring when the floss tape passes through the gap between the two round heads of the micrometer, i.e., the damage rate.

[0066] An experiment to evaluate the tensile breaking force and elongation of the floss tape at a tension of 1 Newton is described below, and includes the following steps.

[0067] Step 1: Attach the pneumatic cord and yarn grip to the Instron 5965 universal material testing machine and set the load to zero.

[0068] Step 2: Take a floss tape longer than 30 cm, attach it to the pneumatic cord and yarn grip, control the effective sample length to 20 cm, and eliminate displacement.

[0069] Step 3: Stretch the floss tape at a speed of 10 inches / minute until it breaks.

[0070] Step 4: Record the load at which the floss tape breaks, and the elongation of the floss tape when the tensile load is 1 Newton.

[0071] Replace the sample with a new floss tape and repeat the above test 10 times to calculate the average load at which the floss tape breaks, i.e., the tensile breaking force. Calculate the average elongation of the floss tape under a 1 Newton tensile load, i.e., the elongation under 1 Newton tension. The elongation under 1 Newton tension can indicate the magnitude of the floss tape's elasticity. The higher the elongation under 1 Newton tension, the greater the elasticity of the floss tape.

[0072] Experiments were conducted using the floss tape of the above embodiment (i.e., Example 1 in the table below) and compared with other conventional floss tapes. The results are shown in Tables 1 to 3 below.

[0073] [Table 1]

[0074] The formulations of the outer and inner layer materials in Table 1 are given as weight ratios. For example, 65 / 25 / 5 / 5 indicates that the proportions of the four components are 65% by weight, 25% by weight, 5% by weight, and 5% by weight, respectively.

[0075] [Table 2]

[0076] [Table 3]

[0077] The numbers in parentheses in Table 3 are the parameters of the secondary corrugated unit in Comparative Example 1. In this specification, when the thickness of the inner layer fluctuates periodically, "inner layer unit width" specifically refers to the distance the inner layer extends over one cycle of thickness fluctuation.

[0078] In Table 1, "damage rate" refers to the ratio of the number of times the floss tape was damaged after entering and exiting the simulated interdental space to the total number of times it entered and exited the interdental space.

[0079] In Table 1, "elongation by 1 Newton" refers to the ratio of the elongation length of the floss tape to its original length when subjected to a force of 1 Newton.

[0080] As can be seen from Table 1, when the inner layer contains PBT, the elongation of the floss tape under 1 Newton elongation is significantly reduced compared to an inner layer without PBT, i.e., the elasticity of the monofilament decreases. When the inner layer contains only PBT and does not contain polyester or polyether-ester thermoplastic elastomer, the damage rate of the floss tape is relatively high. After adding polyester or polyether-ester thermoplastic elastomer to the inner layer, the damage rate of the floss tape can be significantly reduced. From the tensile breaking force of the floss tape, it can be seen that the decrease in the damage rate of the floss tape is not caused by an increase in the tensile breaking force of the floss tape.

[0081] Figure 11 is a flowchart of the method for preparing floss tape according to this application. The method includes the following steps:

[0082] S101: Add to the first extruder an outer layer composition containing elastomer.

[0083] S102: The inner layer composition, including the elastomer and plastic, is added to the second extruder.

[0084] S103: The outer layer composition and the inner layer composition are melted, respectively, in order to produce a molten outer layer composition and a molten inner layer composition.

[0085] S104: The molten outer layer composition is sent into the outer layer material channel in the extrusion spin pack.

[0086] S105: The molten inner layer composition is placed into the inner layer material channel in the extrusion spin pack.

[0087] S106: The molten outer layer composition and the molten inner layer composition are combined into a composite molten material in an extrusion spin pack.

[0088] S107: The composite molten material is extruded from the spinning hole on the spinneret.

[0089] S108: The extruded composite molten material is drawn into cold water for rapid cooling and solidification.

[0090] S109: The solidified composite molten material is continuously stretched into a solid filament in high-temperature water and a dry-heat oven.

[0091] S110: Place the solid filament in a separate dry oven.

[0092] S111: Wind one or more heat-set solid filaments onto a spool for collection.

[0093] In the method described above, the volume ratio of the inner layer within the floss tape and the thickness of the floss tape are adjusted by adjusting the pump speeds of the first and second extruders.

[0094] In the method described above, the direction of extension of the solid filament is the longitudinal direction x as defined herein.

[0095] The above description of embodiments is provided for illustrative and explanatory purposes only. It is not intended to be exhaustive or to limit the embodiments to the exact form disclosed. Many modifications and variations will be apparent to those skilled in the art. These embodiments have been selected and described to best illustrate the principles and practical applications, thereby enabling other those skilled in the art to understand the various embodiments and modifications suitable for the specific application intended. Within the framework of the embodiments, the components and features described above can be combined between the different embodiments described.

Claims

1. A floss tape (1) having an elongated strip shape, comprising an inner layer (10) and an outer layer (20) wrapped around the outside of the inner layer (10), The modulus of elasticity of the inner layer (10) is greater than that of the outer layer (20). The hardness of the inner layer (10) is greater than the hardness of the outer layer (20). The volume of the inner layer (10) in any longitudinal direction of the floss tape (1) accounts for 10% to 60%, preferably 15% to 50%, and more preferably 20% to 40%, of the total volume of the floss tape (1) in that longitudinal direction. The inner layer (10) comprises a mixture of elastomer and plastic. The outer layer (20) includes an elastomer, Floss tape (1), characterized in that the elastomer in the inner layer (10) has the same type of repeating structural units as the elastomer in the outer layer (20), and preferably the elastomer in the inner layer (10) is the same as the elastomer in the outer layer (20).

2. The outer layer (20) comprises a corrugated section (21), The height of the wavy section (21) is in the range of 40 μm to 200 μm, preferably in the range of 60 μm to 170 μm, and more preferably in the range of 80 μm to 150 μm. The width of the wavy section (21) is in the range of 700 μm to 3000 μm, preferably in the range of 700 μm to 2000 μm, and more preferably in the range of 1000 μm to 2000 μm. The thickness of the corrugated section (21) is in the range of 20 μm to 120 μm, preferably in the range of 30 μm to 90 μm, and more preferably in the range of 40 μm to 80 μm. The thickness of the corrugated section (21) is uniform or non-uniform. If the thickness of the corrugated section (21) is non-uniform, the maximum thickness of the corrugated section (21) does not exceed six times the minimum thickness, preferably not exceeding twice the minimum thickness, according to claim 1.

3. The corrugated section (21) comprises a first corrugated portion (210), The floss tape (1) according to claim 2, wherein the first wavy portion (210) comprises wavy units having one or more shapes from triangles, arcs, sine waves, rectangles, and other polygons, and the folded portion has a rounded corner profile.

4. The first corrugated portion (210) comprises 2 to 25 corrugated units connected in a continuous manner, preferably 5 to 10 corrugated units connected in a continuous manner. The wavelength of the aforementioned wave-like unit is in the range of 60 μm to 800 μm, preferably in the range of 100 μm to 600 μm, and more preferably in the range of 150 μm to 500 μm. The floss tape (1) according to claim 3, wherein the amplitude of the wavy unit is in the range of 0 μm to 90 μm, preferably in the range of 3 μm to 80 μm, and more preferably in the range of 5 μm to 70 μm.

5. The corrugated section (21) comprises a second corrugated portion (211), The floss tape (1) according to claim 4, wherein the second corrugated portion (211) comprises secondary corrugated units having one or more shapes from a triangle, an arc, a sine wave, a rectangle, and other polygons, and the folded portion has a rounded corner profile.

6. The second corrugated portion (211) comprises one or more secondary corrugated units superimposed on each corrugated unit of the first corrugated portion (210), The wavelength of the secondary wave unit is in the range of 20 μm to 600 μm, preferably in the range of 30 μm to 400 μm, and more preferably in the range of 40 μm to 200 μm. The amplitude of the secondary wave unit is in the range of 0 μm to 50 μm, preferably in the range of 1 μm to 25 μm, and more preferably in the range of 2 μm to 15 μm. The wavelength of the secondary wave unit is smaller than the wavelength of the wave unit. The amplitude of the secondary wave unit is smaller than the amplitude of the wave unit. The floss tape (1) according to claim 5, wherein the wavelength of the secondary wave unit is greater than 1 / 20, preferably greater than 1 / 10, and more preferably greater than 1 / 6 of the wavelength of the wave unit.

7. The maximum thickness of the inner layer (10) is 50 μm. The ratio of the total width to the maximum thickness of the inner layer (10) is greater than 20:1, preferably greater than 30:

1. The floss tape (1) according to claim 1, wherein the thickness of the inner layer (10) is uniform.

8. The maximum thickness of the inner layer (10) is 50 μm. The ratio of the total width to the maximum thickness of the inner layer (10) is greater than 20:1, preferably greater than 30:

1. The floss tape (1) according to claim 1, wherein the thickness of the inner layer (10) is non-uniform.

9. The thickness of the inner layer (10) changes periodically. The floss tape (1) according to claim 8, wherein the ratio of the distance the inner layer (10) extends during the thickness variation of one cycle to the maximum thickness of the inner layer (10) during one cycle is greater than 5:1, preferably greater than 8:

1.

10. The floss tape (1) comprises one or two guide sections (30), The guide section (30) is positioned at the edge of the outer layer (20), The guide section (30) comprises a connecting portion (300) close to the outer layer (20) and a guide portion (301) far from the outer layer (20), The guide portion (301) has a smoothly extending curved surface, The floss tape (1) according to claim 1, wherein the width of the guide section (30) is in the range of 50 μm to 550 μm.

11. The inner layer (10) comprises one or more of the following: polyamide thermoplastic elastomer, polyether-ester thermoplastic elastomer, polyolefin thermoplastic elastomer, thermoplastic polyurethane elastomer, and styrene block copolymer elastomer, preferably comprising a polyamide thermoplastic elastomer or a polyether-ester thermoplastic elastomer, and more preferably comprising a polyether-ester thermoplastic elastomer. The elastomer content in the inner layer (10) is 20% by weight or more, preferably 30% by weight or more. The outer layer (20) comprises one or more of the following: polyamide thermoplastic elastomer, polyether-ester thermoplastic elastomer, polyolefin thermoplastic elastomer, thermoplastic polyurethane elastomer, and styrene block copolymer elastomer, preferably comprising a polyamide thermoplastic elastomer or a polyether-ester thermoplastic elastomer, and more preferably comprising a polyether-ester thermoplastic elastomer. The floss tape (1) according to claim 1, wherein the Shore hardness of the outer layer (20) is less than 55 HD.

12. The plastic in the inner layer (10) comprises one or more of polyamides, olefin polymers, polyester polymers, polystyrenes, acrylonitrile-styrene-butadiene copolymer resins, and thermoplastic polyurethanes, preferably comprising polyhexamethylene adipamide, polyhexamethylene sebakamid, polyhexamethylene dodecanediamide, polycaprolactam, polylaurolactam, polyethylene terephthalate, polybutylene terephthalate, or polytrimethylene terephthalate, more preferably comprising polybutylene terephthalate. The floss tape (1) according to claim 11, wherein the elastic modulus of the plastic in the inner layer (10) is greater than 1 GPa.

13. A method for preparing a floss tape according to any one of claims 1 to 12, Adding an outer layer composition containing an elastomer to the first extruder, Adding an inner layer composition containing elastomer and plastic to a second extruder, To produce a molten outer layer composition and a molten inner layer composition, the outer layer composition and the inner layer composition are melted, respectively. The molten material of the outer layer composition is sent into the outer layer material channel in the extrusion spin pack. Sending the molten material of the inner layer composition into the inner layer material channel in the extrusion spin pack, The process involves combining the molten material of the outer layer composition and the molten material of the inner layer composition into a composite molten material within the extrusion spin pack, The process involves extruding the composite molten material from the spinning hole on the spinneret, The extruded composite molten material is drawn into cold water for rapid cooling and solidification, The solidified composite molten material is continuously stretched in high-temperature water and a dry-heat oven to become a solid filament. The solid filament is set in a dry heat oven, A method comprising winding one or more heat-set solid filaments onto a spool for collection.

14. The method according to claim 13, wherein the volume ratio of the inner layer within the floss tape and the thickness of the floss tape are adjusted by adjusting the pump speeds of the first extruder and the second extruder.

15. A floss roll comprising a floss roll housing, a dental floss core bobbin disposed within the floss roll housing, and a floss tape (1) according to any one of claims 1 to 12 wound around the dental floss core bobbin.

16. A floss pick comprising a floss pick holder and a floss tape (1) according to any one of claims 1 to 12 connected between different ends of the floss pick holder.

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