Dental floss band, dental floss roll and dental floss pick

Abstract

A dental floss band (1) is in the shape of a long and thin strip, comprises an inner lining layer (10) and an outer wrapping layer (20) wrapping the outer portion of the inner lining layer (10), and is characterized in that the elastic modulus of the inner lining layer (10) is larger than that of the outer wrapping layer (20); the hardness of the lining layer (10) is greater than that of the outer cladding layer (20); the volume of the lining layer (10) in any length direction of the dental floss band (1) accounts for 10%-60% of the total volume of the dental floss band (1) in the length direction, preferably 15%-50%, and more preferably 20%-40%; the inner liner (10) comprises a mixture of an elastomer and a plastic; the outer cladding (20) comprises an elastomer; the elastomer in the inner liner (10) has repeating structural units of the same type as the elastomer in the outer cladding (20), and the elastomer in the inner liner (10) is preferably the same as the elastomer in the outer cladding (20).

Description

Technical Field

[0001] The present invention relates to the field of dental cleaning tools, in particular to a dental floss tape, a dental floss roll formed by the dental floss tape, and a dental floss stick formed by the dental floss tape. The present invention also relates to a method for manufacturing the dental floss tape. Background Art

[0002] Existing dental floss tapes can be made of high-strength polymer multifilament materials (such as nylon 6 fibers or ultra-high molecular weight polyethylene fibers). The individual fibers in this multifilament material are relatively thin, which can easily cause the gums to feel cut. This type of dental floss tape is also prone to single fiber breakage during use, further affecting the user experience. In order to solve the above problems, some dental floss tapes are made of soft polymer materials (such as polytetrafluoroethylene or elastomers) to reduce the feeling of being cut and the problem of breakage.

[0003] Due to the safety issues of perfluorinated and polyfluoroalkyl substances, the production of dental floss tapes made of polytetrafluoroethylene is gradually decreasing. Dental floss tapes made of elastomers are easily stretched, which will cause new problems. Specifically, during the production process of dental floss rolls and dental floss sticks, the dental floss tape needs to be pulled out from the reel. For dental floss rolls, the pulled out dental floss tape will be wound onto the mandrel of the dental floss roll. The dental floss tape made of elastomer is in a stretched state during this process, so when entering the next process, a large amount of tension will remain on the dental floss tape. These tensions will accumulate on the dental floss tape during the process of winding the dental floss tape around the mandrel. Since the length of the dental floss tape wound on the mandrel of the dental floss roll can be up to 40 meters, the accumulated tension on the dental floss tape will cause the mandrel to deform and cannot be removed from the winding equipment, or even directly press the mandrel to collapse and cannot be used. For dental floss picks, these tensions will cause the dental floss tape to automatically retract when it is cut after one cycle of dental floss pick handle injection molding is completed, and it cannot be grasped by the equipment for the next cycle of dental floss pick handle injection molding production. In this way, the originally continuous automated production process will be interrupted. Summary of the invention

[0004] In order to solve the above technical problems, the present application proposes a dental floss tape with a multi-layer structure. Compared with a dental floss tape with a single-layer structure, the dental floss tape according to the present application has very little elasticity in the length direction x (the definition of this direction is described below), so that during the production process of dental floss rolls and dental floss sticks, there will be no production interruption or product defects due to the accumulation of tension on the dental floss tape. In addition, the dental floss tape according to the present application is not easily damaged when entering a narrow gap between teeth, bringing a better user experience.

[0005] The present application proposes a dental floss tape, which has a shape of an elongated strip and includes an inner lining layer and an outer covering layer wrapped around the inner lining layer, characterized in that the elastic modulus of the inner lining layer is greater than the elastic modulus of the outer covering layer; the hardness of the inner lining layer is greater than the hardness of the outer covering layer; the volume of the inner lining layer along any length direction of the dental floss tape accounts for 10%-60%, preferably 15%-50%, and more preferably 20%-40% of the total volume of the dental floss tape in the length direction; the inner lining layer contains a mixture of elastomer and plastic; the outer covering layer contains an elastomer; the elastomer in the inner lining layer has the same type of repeating structural units as the elastomer in the outer covering layer, and the elastomer in the inner lining layer is preferably the same as the elastomer in the outer covering layer.

[0006] According to an optional embodiment, the outer cladding includes a wavy segment; the height of the wavy segment is in the range of 40 to 200 μm, preferably in the range of 60 to 170 μm, and more preferably in the range of 80 to 150 μm; the width of the wavy segment is in the range of 700 to 3000 μm, preferably in the range of 700 to 2000 μm, and more preferably in the range of 1000 to 2000 μm; the thickness of the wavy segment is in the range of 20 to 120 μm, preferably in the range of 30 to 90 μm, and more preferably in the range of 40 to 80 μm; the thickness of the wavy segment is uniform or non-uniform; in the case where the thickness of the wavy segment is non-uniform, the maximum value of the thickness of the wavy segment does not exceed 6 times the minimum value, and preferably does not exceed 2 times the minimum value.

[0007] According to an optional embodiment, the wavy section includes a first wavy portion; the first wavy portion is composed of wavy units of one or more shapes of triangles, arcs, sinusoidal waves, rectangles and other polygons connected in sequence, and has a rounded contour at the turning part.

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

[0009] According to an optional embodiment, the wavy section includes a second wavy portion; the second wavy portion is composed of secondary wavy units having one or more of the shapes of triangle, arc, sinusoidal wave, rectangle and other polygons, and has a rounded contour at the turning portion.

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

[0011] According to an optional embodiment, the maximum thickness of the lining layer is 50 μm; the ratio of the total width of the lining layer to the maximum thickness is greater than 20:1, preferably greater than 30:1; the thickness of the lining layer is uniform or non-uniform, and when the thickness of the lining layer is non-uniform, the thickness of the lining layer varies periodically, and the ratio of the distance extended by the lining layer in one cycle of thickness variation to the maximum thickness of the lining layer in the one cycle is greater than 5:1, preferably greater than 8:1.

[0012] According to an optional embodiment, the dental floss tape includes one or two guide sections; the guide sections are arranged at the edges of the outer covering; the guide sections include a connecting portion close to the outer covering and a guide portion away from the outer covering; the guide portion has a smoothly extending arc surface; the width of the guide section is in the range of 50 to 550 μm.

[0013] According to an optional embodiment, the inner lining layer comprises one or more of polyamide thermoplastic elastomers, polyether ester thermoplastic elastomers, polyolefin thermoplastic elastomers, thermoplastic polyurethane elastomers, and styrene block copolymer elastomers, preferably comprises polyamide thermoplastic elastomers or polyether ester thermoplastic elastomers, and more preferably comprises polyether ester thermoplastic elastomers; the elastomer content in the inner lining layer is not less than 20%, preferably not less than 30%; the outer layer comprises one or more of polyamide thermoplastic elastomers, polyether ester thermoplastic elastomers, polyolefin thermoplastic elastomers, thermoplastic polyurethane elastomers, and styrene block copolymer elastomers, preferably comprises polyamide thermoplastic elastomers or polyether ester thermoplastic elastomers, and more preferably comprises polyether ester thermoplastic elastomer; the Shore hardness of the outer layer is lower than 55HD.

[0014] According to an optional embodiment, the plastic in the inner lining layer comprises one or more of polyamide, olefin polymer, polyester polymer, polystyrene, acrylonitrile-styrene-butadiene copolymer resin and thermoplastic polyurethane, preferably comprises polyhexamethylene adipamide, polyhexamethylene sebacamide, polyhexamethylene dodecanoamide, polycaprolactam, polylaurolactam, polyethylene terephthalate, polybutylene terephthalate or polytrimethylene terephthalate, more preferably comprises polybutylene terephthalate; the elastic modulus of the plastic in the inner lining layer is greater than 1 GPa.

[0015] The present application also proposes a method for preparing a dental floss tape, characterized in that the method comprises: adding an outer layer composition containing an elastomer to a first extruder; adding an inner lining layer composition containing an elastomer and a plastic to a second extruder; melting the outer layer composition and the inner lining layer composition separately to generate a melt of the outer layer composition and a melt of the inner lining layer composition; feeding the melt of the outer layer composition into an outer layer material channel in an extrusion spinneret assembly; feeding the melt of the inner lining layer composition into an inner lining material channel in an extrusion spinneret assembly; merging the melt of the outer layer composition and the melt of the inner lining layer composition into a composite melt in the extrusion spinneret assembly; extruding the composite melt from the spinneret holes on a spinneret plate; pulling the extruded composite melt into cold water for quenching and solidification; drawing the solidified composite melt into a filamentous solid in hot water and in a dry heat oven in sequence; shaping the filamentous solid in a dry heat oven; winding one or more shaped filamentous solids on a reel for collection.

[0016] According to an optional embodiment, the volume ratio of the liner layer in the dental floss tape and the thickness of the dental floss tape are adjusted by adjusting the pump speeds of the first extruder and the second extruder.

[0017] The present application also proposes a dental floss roll, which includes a dental floss roll housing, a dental floss reel arranged in the dental floss roll housing, and the dental floss tape wound on the dental floss reel.

[0018] The present application also proposes a dental floss stick, which includes a dental floss stick holder and the dental floss tape connected between different ends of the dental floss stick holder.

[0019] The dental floss tape according to the present application has the following technical effects: On the basis of the outer layer having soft characteristics, the plastic material of the inner lining layer has sufficient strength, which can reduce the elasticity of the dental floss tape as a whole in the length direction x and the width direction y, so that the dental floss tape is not easily damaged when entering the narrow tooth gap, bringing a better use experience.

[0020] The outer layer of the dental floss tape has a shape that can enhance the cleaning effect of the dental floss tape. The combination of the inner lining layer, the outer lining layer, and the guide section of the dental floss tape makes the sliding resistance of the dental floss tape uniform and stable during the period of entering the tooth gap. In the case of a sudden change in the width of the tooth gap, the friction force acting on the outer lining layer will suddenly decrease, resulting in a sudden increase in the tension acting on the dental floss tape in the width direction. At this time, the inner lining layer will maintain the shape of the dental floss tape so that it will not be flattened due to the tension in the width direction, thereby preventing the phenomenon of the dental floss tape suddenly changing in shape due to the sudden change in the width of the tooth gap and damaging the gums.

[0021] The dental floss tape according to the present application has very little elasticity in the length direction x, so that during the production process of dental floss rolls and dental floss sticks, there will be no production interruption or product defects due to the accumulation of tension on the dental floss tape. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] The above and other aspects of the present application will be more fully understood from the detailed description below in conjunction with the following drawings. It should be noted that the scales of the drawings may be different for the purpose of clear description, but this will not affect the understanding of the present application.

[0023] Figure 1 is a three-dimensional diagram of a dental floss tape according to the present application.

[0024] Figure 2 yes Figure 1 Cross-section of a dental floss tape.

[0025] Figure 3 yes Figure 2 A partial enlarged schematic diagram of the dental floss tape.

[0026] Figure 4 It is a partially enlarged schematic diagram of a dental floss tape according to another embodiment of the present application, showing a wavy unit and a plurality of secondary wavy units superimposed thereon.

[0027] Figure 5 It is a partially enlarged schematic diagram of a dental floss tape according to another embodiment of the present application, showing a wavy unit and a plurality of secondary wavy units superimposed thereon.

[0028] Figure 6 It is a partially enlarged schematic diagram of a dental floss tape according to another embodiment of the present application, showing a wavy unit and a plurality of secondary wavy units superimposed thereon.

[0029] Figure 7 It is a partially enlarged schematic diagram of a dental floss tape according to another embodiment of the present application, showing a wavy unit and a plurality of secondary wavy units superimposed thereon.

[0030] Figure 8It is a partially enlarged schematic diagram of a dental floss 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.

[0031] Fig. 9 It is a partially enlarged schematic diagram of a dental floss 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.

[0032] Fig.10 It is a partially enlarged schematic diagram of a dental floss tape according to another embodiment of the present application.

[0033] Fig.11 is a flow chart of a method for preparing a dental floss tape according to the present application. DETAILED DESCRIPTION

[0034] The exemplary embodiments of the present application will be described in more detail below with reference to the accompanying drawings. Although the exemplary embodiments of the present application are shown in the accompanying 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. On the contrary, these embodiments are provided in order to enable a more thorough understanding of the present application and to fully convey the scope of the present application to those skilled in the art.

[0035] Figure 1 is a stereoscopic view of the dental floss tape 1 according to the first embodiment of the present application. In this article, the extension direction of the dental floss tape 1 is defined as the length direction x (ie, Figure 1 The direction of the arrow x in the figure is defined as the width direction y (i.e., Figure 1 The direction orthogonal to the length direction x and the width direction y is defined as the height direction z (i.e., Figure 1 The dental floss tape 1 has an elongated strip shape and includes an inner lining layer 10 and an outer layer 20 wrapped outside the inner lining layer 10. The outer layer 20 includes a corrugated section 21. The dental floss tape 1 may also include a guide section 30 arranged at the edge of the outer layer 20. The outer layer 20 may be composed of 65% by weight. 4068FG (polyether ester thermoplastic elastomer), 25 wt% 5556 (polyetherester thermoplastic elastomer), 5 wt% Multibase TM MB50-010 (DuPont's polyether ester thermoplastic elastomer-based lubricant masterbatch) and 5 wt% polyether ester thermoplastic elastomer 4068FG is made of white masterbatch for base material.

[0036] Figure 2 yes Figure 1The cross-sectional view of the dental floss tape 1. The maximum thickness of the inner lining layer 10 is 50 μm. The ratio of the total width of the inner lining layer 10 to the maximum thickness is greater than 20:1, preferably greater than 30:1. The inner lining layer 10 is wavy (undulating along the width direction y), and has a higher elastic modulus and hardness than the outer covering layer 20.

[0037] The inner liner 10 may include one or more of polyamide thermoplastic elastomer, polyether ester thermoplastic elastomer, polyolefin thermoplastic elastomer, thermoplastic polyurethane elastomer, and styrene block copolymer elastomer, preferably polyamide thermoplastic elastomer or polyether ester thermoplastic elastomer, and more preferably polyether ester thermoplastic elastomer. The polyether ester thermoplastic elastomer may be a commercially available product, such as Celanese's Resins, more specifically 4068FG, 5556, SC956, SC969, SC976 and SC988.

[0038] The elastomer content in the inner liner 10 is not less than 20%, preferably not less than 30%. In addition, the elastomer of the inner liner 10 has the same type of repeating structural unit as the elastomer of the outer cladding 20. The elastomer in the inner liner 10 is preferably the same as the elastomer in the outer cladding 20. In other words, the repeating structural unit of the elastomer long-chain molecule constituting the inner liner 10 has the same functional group as the repeating structural unit of the elastomer long-chain molecule constituting the outer cladding 20. For example, the elastomer in the outer cladding 20 is a polyether ester thermoplastic elastomer, and the repeating structural unit of its long-chain molecule contains ester group and ether bond functional group, then the elastomer in the inner liner 10 is also a polyether ester thermoplastic elastomer, and the repeating structural unit of its long-chain molecule also contains ester group and ether bond functional group. The number of ester group and ether bond functional group in the two cases does not need to be exactly the same, and the non-functional group structure between the ester group and the ether bond functional group can also be different. Functional group refers to a class of atoms or atomic groups in organic molecules that give compounds specific chemical properties. It is usually composed of a specific arrangement of atoms or bonds and is a core structural unit that determines the chemical reactivity and physical properties of the compound. The elastomer in the inner lining layer 10 is the same as the elastomer in the outer covering layer 20, which means that the repeating structural units of the long-chain molecules of the two elastomers not only contain the same functional groups, but also the number of functional groups in the two cases is the same, and the non-functional group structure between the functional groups is the same. For polymer materials, the "number of functional groups is the same" and "the same structure" referred to here are the same and the same in a statistical sense. In reality, the number of functional groups and the non-functional group structure between the functional groups can allow statistical deviations. For example, the elastomer in the inner lining layer 10 and the elastomer in the outer covering layer 20 are resins of the same brand from the same manufacturer but produced in different batches.

[0039] Specifically, the inner liner 10 comprises a mixture of elastomer and plastic. The elastic modulus of the plastic in the inner liner 10 is greater than 1GPa. The plastic in the inner liner 10 can include one or more of PA (polyamide), olefin polymers, polyester polymers, polystyrene, ABS (acrylonitrile-styrene-butadiene copolymer) resin and TPU (thermoplastic polyurethane), and optionally present thermoplastic elastomer. Preferably, the plastic in the inner liner 10 can include nylon 66 (polyhexamethylene adipamide), nylon 610 (polyhexamethylene sebacamide), nylon 612 (polydodecane diamide hexamethylene diamine), nylon 6 (polycaprolactam), nylon 12 (polylaurolactam), PET (polyethylene terephthalate), PBT (polybutylene terephthalate) or PTT (polypropylene terephthalate). More preferably, the plastic in the inner liner 10 can include PBT. The PBT may be a commercially available product, such as DHKD03 of Xinguang Synthetic Fiber Co., Ltd., PBT B2520 of BASF, PBT L2100 of Sinopec Yizheng Chemical Fiber, PBT 1200 211D / 211M of Changchun Chemical, spinning-grade PBT of Hengli Chemical Fiber, and the like.

[0040] It is understood that the lining layer 10 can be flat. In addition, the volume of the lining layer 10 along any length direction of the dental floss tape 1 accounts for 10%-60%, preferably 15%-50%, and more preferably 20%-40% of the total volume of the dental floss tape 1 in the length direction.

[0041] The outer layer 20 may include one or more of a polyamide-based thermoplastic elastomer, a polyetherester thermoplastic elastomer, a polyolefin-based thermoplastic elastomer, a thermoplastic polyurethane elastomer, and a styrene-based block copolymer elastomer. Preferably, the outer layer 20 may include a polyamide-based thermoplastic elastomer or a polyetherester thermoplastic elastomer. More preferably, the outer layer 20 may include a polyetherester thermoplastic elastomer.

[0042] Specifically, the Shore hardness of the outer cover 20 is lower than 55 HD.

[0043] Thus, the dental floss tape 1 according to the present application maintains the softness of the outer layer 20, and reduces the elasticity of the dental floss tape in the length direction x by means of the plastic material of the inner lining layer 10, so that during the production process of the dental floss roll and the dental floss stick, the production interruption or product defect will not be caused by the accumulation of tension on the dental floss tape. At the same time, the inner lining layer 10 has sufficient strength, so that the dental floss tape is not easily damaged when entering the narrow gap between teeth, bringing a better user experience.

[0044] The material constituting the guide section 30 may be the same as that of the outer cladding 20 .

[0045] The corrugated section 21 of the outer cladding 20 has a thickness h1 of 70 μm, a height h3 of 100 μm, and a width h2 of 1600 μm.

[0046] The guide section 30 is disposed 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 away from the corrugated section 21. The width h8 of the guide section 30 is about 120 μm. The guide portion 301 has a smoothly extending arc surface.

[0047] Figure 3 yes Figure 2 A partially enlarged schematic diagram of the dental floss tape 1, for the sake of clarity, the lining layer 10 is omitted, and the outer layer 20 is simplified as a line segment (although it actually has a certain thickness) to facilitate the description of its shape. The wavy section 21 of the outer layer 20 includes a first wavy portion 210 and a second wavy portion 211. The first wavy portion 210 includes a plurality of wavy units connected in sequence (one wavy unit is shown in the figure). The shape of the wavy unit is triangular. The second wavy portion 211 includes one or more secondary wavy units superimposed on the wavy unit of the first wavy portion 210 (two secondary wavy units are shown in the figure). The shape of the secondary wavy unit is a sine wave. Specifically, a secondary wavy unit is superimposed on half of the wavy unit. The wavelength h4 of the wavy unit is greater than the wavelength h5 of the secondary wavy unit. The amplitude h7 of each wavy unit of the first wavy portion 210 is greater than the amplitude h6 of each secondary wavy unit of the second wavy portion 211. Specifically, the wavelength h4 of the corrugated unit is about 260 μm, the amplitude h7 is about 15 μm, and has a rounded corner profile at the turning point. The wavelength h5 of the secondary corrugated unit is about 168 μm, and the amplitude h6 is about 6 μm.

[0048] The wavy section 21 formed by superimposing the first wavy section 210 and the second wavy section 211 can increase the roughness and cleaning power of the dental floss tape without affecting the compressibility and the ability to enter the gaps between teeth of the dental floss tape. The wavelength h4 and amplitude h7 of the wavy unit of the first wavy section 210 are relatively large, and constitute the basic structure of the wavy section 21 to give the dental floss tape good compressibility and the ability to enter the gaps between teeth. The wavelength h5 and amplitude h6 of the secondary wavy unit of the second wavy section 211 are relatively small, and mainly play the role of increasing the roughness of the dental floss tape, which can improve the cleaning power of the dental floss tape.

[0049] It can be understood that, in order to achieve the above technical effect, the travel direction of the secondary wavy units of the second wavy portion 211 changes along the contour direction of the first wavy portion 210 .

[0050] It can be understood that in order to achieve the above technical effects, the thickness of the corrugated section 21 can be uniform or non-uniform. In the latter case, the maximum value of the thickness of the corrugated section 21 does not exceed 6 times the minimum value, preferably does not exceed 2 times. The thickness h1 of the corrugated section 21 can be in the range of 20 to 120 μm, preferably in the range of 30 to 90 μm, and more preferably in the range of 40 to 80 μm. The width h2 of the corrugated section 21 can be in the range of 700 to 3000 μm, preferably in the range of 700 to 2000 μm, and more preferably in the range of 1000 to 2000 μm. The height h3 of the corrugated section 21 can be in the range of 40 to 200 μm, preferably in the range of 60 to 170 μm, and more preferably in the range of 80 to 150 μm.

[0051] It can be understood that no matter whether the thickness of the corrugated section 21 is uniform or not, the thickness of the lining layer 10 may be non-uniform.

[0052] It can be understood that in order to achieve the above technical effects, the first wavy portion 210 of the wavy section 21 can have 2 to 25 wavy units, preferably 5 to 10 wavy units. The wavelength h4 of the wavy units of the first wavy portion 210 of the wavy section 21 can be in the range of 60 to 800 μm, preferably in the range of 100 to 600 μm, and more preferably in the range of 150 to 500 μm. The amplitude h7 of the wavy units of the first wavy portion 210 of the wavy section 21 can be in the range of 0 to 90 μm, preferably in the range of 3 to 80 μm, and more preferably in the range of 5 to 70 μm.

[0053] It can be understood that in order to achieve the above technical effects, the wavelength h5 of the secondary wavy unit of the second wavy portion 211 of the wavy section 21 can be in the range of 20 to 600 μm, preferably in the range of 30 to 400 μm, and more preferably in the range of 40 to 200 μm. The amplitude h6 of the secondary wavy unit of the second wavy portion 211 of the wavy section 21 can be in the range of 0 to 50 μm, preferably in the range of 1 to 25 μm, and more preferably in the range of 2 to 15 μm.

[0054] It can be understood that, in order to achieve the above technical effects, the wavelength h5 of the secondary corrugated unit is greater than 1 / 20 of the wavelength h4 of the corrugated unit, preferably greater than 1 / 10, and more preferably greater than 1 / 6.

[0055] It is understood that, although not shown in the figure, the dental floss tape according to the present application may also include a coating applied on its surface. The coating may be made of the following substances: lubricants, stripping agents, abrasives, whitening agents, active agents, olfactory stimulants, salivating agents, sensory stimulants, essential oils, spices, antibacterial agents or antiviral agents.

[0056] Figure 4 1 is a partially enlarged schematic diagram of a dental floss tape 1 according to another embodiment of the present application. For the sake of clarity, the inner lining layer 10 is omitted, and the outer covering layer 20 is simplified to a line segment (although it actually has a certain thickness) to facilitate description of its shape. Figure 3 compared to, Figure 4 The shape of the corrugated unit of the first corrugated portion 210 is still triangular, while the shape of the secondary corrugated unit of the second corrugated portion 211 is also changed to triangular, and two secondary corrugated units are superimposed on half of the corrugated unit.

[0057] Figure 5 1 is a partially enlarged schematic diagram of a dental floss tape 1 according to another embodiment of the present application. For the sake of clarity, the inner lining layer 10 is omitted, and the outer covering layer 20 is simplified to a line segment (although it actually has a certain thickness) to facilitate description of its shape. Figure 3 compared to, Figure 5 The shape of the corrugated unit of the first corrugated portion 210 is still triangular, while the shape of the secondary corrugated unit of the second corrugated portion 211 becomes a sine wave, and two secondary corrugated units are superimposed on half of the corrugated unit.

[0058] Figure 6 1 is a partially enlarged schematic diagram of a dental floss tape 1 according to another embodiment of the present application. For the sake of clarity, the inner lining layer 10 is omitted, and the outer covering layer 20 is simplified to a line segment (although it actually has a certain thickness) to facilitate description of its shape. Figure 3 compared to, Figure 6 The shape of the corrugated unit of the first corrugated portion 210 becomes a sine wave, and the shape of the secondary corrugated unit of the second corrugated portion 211 is still a sine wave, but three secondary corrugated units are superimposed on half of the corrugated unit.

[0059] Figure 7 1 is a partially enlarged schematic diagram of a dental floss tape 1 according to another embodiment of the present application. For the sake of clarity, the inner lining layer 10 is omitted, and the outer covering layer 20 is simplified to a line segment (although it actually has a certain thickness) to facilitate description of its shape. Figure 3 compared to, Figure 7 The shape of the corrugated unit of the first corrugated portion 210 becomes a rectangle, and the shape of the secondary corrugated unit of the second corrugated portion 211 also becomes a rectangle, and 2.5 secondary corrugated units are superimposed on half of the corrugated unit.

[0060] It can be understood that in order to achieve the above-mentioned technical effects, the first wavy portion 210 of the wavy unit having the above-mentioned shape (such as triangle, circular arc, sine wave, rectangle, other polygons, etc.) and the second wavy portion 211 of the secondary wavy unit having the above-mentioned shape (such as triangle, circular arc, sine wave, rectangle, other polygons, etc.) can be arbitrarily combined and are all within the scope of protection of the present application.

[0061] Figure 8 1 is a partially enlarged schematic diagram of a dental floss tape 1 according to another embodiment of the present application. For the sake of clarity, the inner lining layer 10 is omitted, and the outer covering layer 20 is simplified to a line segment (although it actually has a certain thickness) to facilitate description of its shape. Figure 3 compared to, Figure 8 The shape of the corrugated unit of the first corrugated portion 210 is changed into an arc shape, and the shape of the secondary corrugated unit of the second corrugated portion 211 is changed into a sine wave shape. In addition, Fig. 9 A straight section 212 is connected between two corrugated units of the first corrugated portion 210 .

[0062] Fig. 9 1 is a partially enlarged schematic diagram of a dental floss tape 1 according to another embodiment of the present application. For the sake of clarity, the inner lining layer 10 is omitted, and the outer covering layer 20 is simplified to a line segment (although it actually has a certain thickness) to facilitate description of its shape. Figure 8 compared to, Fig. 9 The first wavy portion 210 is formed by sequentially connecting a triangular wavy unit and a sinusoidal wavy unit. The secondary wavy unit superimposed on the triangular wavy unit of the second wavy portion 211 is in a triangular shape, while the secondary wavy unit superimposed on the sinusoidal wavy unit is in a sinusoidal shape. In addition, Fig. 9 No straight section 212 is provided between the first wavy portions 210 .

[0063] Fig.10 FIG. 1 is a partially enlarged schematic diagram of a dental floss tape according to another embodiment of the present application. Fig.10 In the embodiment, the thickness of the lining layer 10 is non-uniform.

[0064] The following describes the process of dental floss tape entering the gap between teeth based on the embodiment of the present application. When the dental floss tape 1 slides on the occlusal surface of the teeth, the guide section 30 of the dental floss tape 1 will be stuck in the gap opening, thereby generating feedback to the object pulling the dental floss tape (such as a hand, a dental floss roll, or a dental floss stick). In this way, the user of the dental floss tape 1 can clearly sense the position of the dental floss tape 1, and then change the direction of the force applied to the dental floss tape 1. After the direction of the force applied to the dental floss tape 1 is changed from parallel to the occlusal surface of the teeth to perpendicular to the occlusal surface of the teeth, the dental floss tape 1 reciprocates on the gap opening under the action of the combined force, so that the outer layer 20 extends from the gap opening into the gap along the width direction y. When the dental floss tape 1 reciprocates in the tooth gap along the width direction y, the wavy section 21 of the outer layer 20 contacts the surface of the tooth gap, so that food residues in the tooth gap and dental plaque on the tooth surface are squeezed into the gap formed by the first wavy portion 210 and the second wavy portion 211 of the wavy section 21, and are thereby brought out of the tooth gap as the dental floss tape moves.

[0065] The dental floss tape according to the present application has the following technical effects: On the basis of the outer layer 20 having soft characteristics, the plastic material of the inner lining layer 10 has sufficient strength, which can reduce the elasticity of the dental floss tape as a whole in the length direction x and the width direction y, so that the dental floss tape is not easily damaged when entering the narrow tooth gap, bringing a better user experience.

[0066] The outer layer 20 of the dental floss tape 1 has a shape that can enhance the cleaning effect of the dental floss tape 1. The combination of the inner lining layer 10, the outer lining layer 20 and the guide section 30 of the dental floss tape 1 makes the sliding resistance of the dental floss tape 1 uniform and stable during the period of entering the interdental space. In the case of a sudden change in the interdental width, the friction force acting on the outer lining layer 20 will suddenly decrease, resulting in a sudden increase in the tension acting on the dental floss tape 1 along the width direction y. At this time, the inner lining layer 10 will maintain the shape of the dental floss tape 1 so that it will not be flattened due to the tension along the width direction y, thereby preventing the phenomenon of the dental floss tape 1 suddenly changing in shape due to the sudden change in the interdental width and damaging the gums.

[0067] The present application also includes a dental floss roll and a dental floss stick formed by the dental floss tape 1. The dental floss tape 1 according to the present application has very little elasticity in the length direction x, so that during the production process of the dental floss roll and the dental floss stick, there will be no production interruption or product defects due to the accumulation of tension on the dental floss tape 1.

[0068] The following describes an experiment on the breakage rate of dental floss tape when passing through simulated interdental spaces, including the following steps:

[0069] Step 1: Fix the two ends of the dental floss tape on the two arms of the bow-shaped tooling respectively, so that the length of the dental floss tape between the two fixed points is about 4 cm;

[0070] Step 2: Connect the tooling to the handheld handle;

[0071] Step 3: Adjust the distance between the two round heads of the double-round micrometer to 30 μm, use the gap between the two round heads as the simulated tooth gap, and fix the micrometer on the table;

[0072] Step 4: Hold the handle with one hand and apply pressure vertically downward to the dental floss tape fixed on the tooling, so that the dental floss tape passes through the gap between the two round heads of the micrometer screw;

[0073] Step 5: Hold the handle with one hand, apply tension vertically upward to the dental floss tape that has passed through the gap, select a dental floss tape from a different area from the dental floss tape used to pass through the gap between the two round heads in step 4, and make the dental floss tape pass through the gap between the two round heads of the micrometer screw;

[0074] Step 6: Record whether the dental floss tape is damaged.

[0075] Replace the dental floss sample with a new one and repeat the above test six times to calculate the probability of the dental floss being damaged when passing through the gap between the two round heads of the screw micrometer, i.e., the damage rate.

[0076] The following describes an experiment for evaluating the tensile breaking force and elongation under 1 Newton tension of dental floss tape, comprising the following steps:

[0077] Step 1: Install the pneumatic rope clamp on the Instron 5965 universal material testing machine and adjust the load to zero;

[0078] Step 2: Take a dental floss tape longer than 30 cm and install it on the pneumatic rope clamp. Control the effective sample length to 20 cm and adjust the gauge length to zero.

[0079] Step 3: Stretch the dental floss tape at a rate of 10 inches per minute until it breaks.

[0080] Step 4: Record the load at which the dental floss tape breaks and the elongation of the dental floss tape when the tensile load is 1 Newton.

[0081] Replace the dental floss tape sample with a new one and repeat the above test ten times to calculate the average load when the dental floss tape breaks, i.e. the tensile breaking force. Calculate the average elongation of the dental floss tape under a tensile load of 1 Newton, i.e. the elongation under a tension of 1 Newton. The elongation under a tension of 1 Newton can indicate the elasticity of the dental floss tape. The higher the elongation under a tension of 1 Newton, the greater the elasticity of the dental floss tape.

[0082] The dental floss tape of the above embodiment (ie, Example 1 in the following table) was tested and compared with other dental floss tapes in the prior art. The results are shown in Tables 1-3 below.

[0083] Table 1 Test results of various dental floss tapes

[0084]

[0085] Table 2 Dimensions of various dental floss tapes

[0086]

[0087] Table 3 Dimensions of various dental floss tapes

[0088]

[0089] The numbers in brackets in Table 3 are the parameters of the secondary wavy unit of Comparative Document 1.

[0090] In Table 1, “breakage rate” refers to the ratio of the number of times the dental floss tape was broken after entering and exiting the simulated interdental space to the total number of times the dental floss tape entered and exited the interdental space.

[0091] In Table 1, "elongation under 1 Newton tension" refers to the ratio of the elongated length of the dental floss tape when subjected to 1 Newton force to the original length.

[0092] According to Table 1, when the inner lining layer contains PBT, the elongation under 1 Newton tension of the dental floss tape is significantly lower than the elongation under 1 Newton tension when the inner lining layer does not contain PBT, that is, the elasticity of the monofilament is reduced. When the inner lining layer only contains PBT but does not contain polyester or ether ester elastomer, the breakage rate of the dental floss tape is relatively high. After adding polyester or polyester elastomer to the inner lining layer, the breakage rate of the dental floss tape can be significantly reduced. It can be seen from the tensile breaking force of the dental floss tape that the reduction in the breakage rate of the dental floss tape is not due to the increase in the tensile breaking force of the dental floss tape.

[0093] Fig.11 1 is a flow chart of a method for preparing a dental floss tape according to the present application. The method comprises the following steps:

[0094] S101: adding an outer coating composition containing an elastomer into a first extruder;

[0095] S102: adding an inner liner composition comprising an elastomer and a plastic into a second extruder;

[0096] S103: melting the outer cladding composition and the inner lining composition respectively to generate a melt of the outer cladding composition and a melt of the inner lining composition;

[0097] S104: feeding the melt of the outer cladding composition into an outer cladding material channel in an extrusion spinneret assembly;

[0098] S105: The melt of the lining layer composition enters the lining layer material channel in the extrusion spinneret assembly;

[0099] S106: combining the melt of the outer cladding layer composition and the melt of the inner lining layer composition into a composite melt in an extrusion spinneret assembly;

[0100] S107: extruding the composite melt from the spinneret holes on the spinneret;

[0101] S108: pulling the extruded composite melt into cold water for quenching and solidification;

[0102] S109: drawing the solidified composite melt into a filamentous solid in hot water and in a dry heat oven in sequence;

[0103] S110: shaping the filamentous solid in a dry heat oven;

[0104] S111: Winding one or more shaped filamentous solids onto a reel for collection.

[0105] In the above method, the volume ratio of the liner layer in the dental floss tape and the thickness of the dental floss tape are adjusted by adjusting the pump speeds of the first extruder and the second extruder.

[0106] In the above method, the extending direction of the filamentous solid is the length direction x defined herein.

[0107] The foregoing description of the embodiments has been provided for illustrative and descriptive purposes. It is not intended to be exhaustive or to limit the embodiments to the variants described. Many modifications and variations will be apparent to those skilled in the art. The embodiments are selected and described in order to best illustrate the principles and practical applications, so that those skilled in the art can understand the embodiments in their various embodiments and various modifications suitable for their intended use. Within the framework of the embodiments, the above-mentioned components and features can be combined between the different embodiments described.

Claims

1. A dental floss tape (1), which has a shape of an elongated strip and comprises an inner lining layer (10) and an outer covering layer (20) wrapped outside the inner lining layer (10), It is characterized in that The elastic modulus of the inner lining layer (10) is greater than the elastic modulus of the outer covering layer (20); The hardness of the inner lining layer (10) is greater than the hardness of the outer covering layer (20); The volume of the lining layer (10) along any length direction of the dental floss tape (1) accounts for 10%-60% of the total volume of the dental floss tape (1) in the length direction, preferably 15%-50%, and more preferably 20%-40%; The inner lining layer (10) comprises a mixture of elastomer and plastic; The outer layer (20) comprises an elastomer; The elastomer in the inner lining layer (10) has the same type of repeating structural units as the elastomer in the outer cladding layer (20), and the elastomer in the inner lining layer (10) is preferably the same as the elastomer in the outer cladding layer (20).

2. The dental floss tape (1) according to claim 1, wherein: The outer cladding (20) comprises a corrugated section (21); The height of the corrugated section (21) is in the range of 40 to 200 μm, preferably in the range of 60 to 170 μm, more preferably in the range of 80 to 150 μm; The width of the corrugated section (21) is in the range of 700 to 3000 μm, preferably in the range of 700 to 2000 μm, more preferably in the range of 1000 to 2000 μm; The thickness of the corrugated section (21) is in the range of 20 to 120 μm, preferably in the range of 30 to 90 μm, more preferably in the range of 40 to 80 μm; The thickness of the corrugated section (21) is uniform or non-uniform; In the case where the thickness of the corrugated section (21) is non-uniform, the maximum value of the thickness of the corrugated section (21) does not exceed 6 times the minimum value, and preferably does not exceed 2 times the minimum value.

3. The dental floss tape (1) according to claim 1 or 2, wherein: The corrugated section (21) comprises a first corrugated portion (210); The first wavy portion (210) is composed of wavy units having one or more shapes of triangle, arc, sinusoidal, rectangular and other polygons connected in sequence, and has a rounded contour at the turning part.

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

5. The dental floss tape (1) according to claim 4, wherein: The corrugated section (21) comprises a second corrugated portion (211); The second wavy portion (211) is composed of secondary wavy units having one or more shapes of triangle, arc, sinusoidal wave, rectangle and other polygons, and has a rounded contour at the turning portion.

6. The dental floss tape (1) according to claim 5, wherein: 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-shaped unit is in the range of 20 to 600 μm, preferably in the range of 30 to 400 μm, more preferably in the range of 40 to 200 μm; The amplitude of the secondary wavy unit is in the range of 0 to 50 μm, preferably in the range of 1 to 25 μm, more preferably in the range of 2 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; The wavelength of the secondary corrugated unit is greater than 1 / 20, preferably greater than 1 / 10, and more preferably greater than 1 / 6 of the wavelength of the corrugated unit.

7. The dental floss tape (1) according to claim 1, wherein: The maximum thickness of the lining layer (10) is 50 μm; The ratio of the total width to the maximum thickness of the lining layer (10) is greater than 20:1, preferably greater than 30:1; The thickness of the lining layer (10) is uniform or non-uniform, When the thickness of the lining layer (10) is non-uniform, the thickness of the lining layer (10) varies periodically, and the ratio of the distance the lining layer (10) extends in one cycle of thickness variation to the maximum thickness of the lining layer (10) in the one cycle is greater than 5:1, preferably greater than 8:

1.

8. The dental floss tape (1) according to claim 1, wherein: The dental floss tape (1) comprises one or two guide sections (30); The guide section (30) is arranged at the edge of the outer cladding (20); The guide section (30) comprises a connecting portion (300) close to the outer cladding (20) and a guiding portion (301) away from the outer cladding (20); The guide portion (301) has a smoothly extending arc surface; The width of the guide section (30) is in the range of 50 to 550 μm.

9. The dental floss tape (1) according to claim 1, wherein: The inner lining layer (10) comprises one or more of a polyamide thermoplastic elastomer, a polyether ester thermoplastic elastomer, a polyolefin thermoplastic elastomer, a thermoplastic polyurethane elastomer, and a styrene block copolymer elastomer, preferably a polyamide thermoplastic elastomer or a polyether ester thermoplastic elastomer, and more preferably a polyether ester thermoplastic elastomer; The elastomer content in the inner lining layer (10) is not less than 20%, preferably not less than 30%; The outer layer (20) comprises one or more of polyamide thermoplastic elastomer, polyether ester thermoplastic elastomer, polyolefin thermoplastic elastomer, thermoplastic polyurethane elastomer, and styrene block copolymer elastomer, preferably polyamide thermoplastic elastomer or polyether ester thermoplastic elastomer, more preferably polyether ester thermoplastic elastomer; The outer cladding layer (20) has a Shore hardness lower than 55 HD.

10. The dental floss tape (1) according to claim 9, wherein the plastic in the inner lining layer (10) comprises one or more of polyamide, olefin polymer, polyester polymer, polystyrene, acrylonitrile-styrene-butadiene copolymer resin and thermoplastic polyurethane, preferably comprises polyhexamethylene adipamide, polyhexamethylene sebacamide, polyhexamethylene dodecanoamide, polycaprolactam, polylaurolactam, polyethylene terephthalate, polybutylene terephthalate or polytrimethylene terephthalate, more preferably comprises polybutylene terephthalate; The elastic modulus of the plastic in the inner lining layer (10) is greater than 1 GPa.

11. A method for preparing the dental floss tape according to any one of claims 1 to 10, characterized in that: The method comprises: adding an overcladding composition comprising an elastomer to a first extruder; adding an innerliner composition comprising an elastomer and a plastic to a second extruder; Melting the outer cladding composition and the inner lining composition separately to generate a melt of the outer cladding composition and a melt of the inner lining composition; feeding a melt of the outer cladding composition into an outer cladding material passage in an extrusion spinneret assembly; passing a melt of the liner composition into a liner material passage in an extrusion spinneret assembly; The melt of the outer covering layer composition and the melt of the inner lining layer composition are combined into a composite melt in an extrusion spinneret assembly; Extruding the composite melt from the spinneret holes on the spinneret; The extruded composite melt is drawn into cold water for quenching and solidification; The solidified composite melt is sequentially drawn into a filamentous solid in hot water and in a dry heat oven; The filamentous solid is shaped in a dry heat oven; One or more shaped filamentary solids are wound onto a reel for collection.

12. The method according to claim 11, wherein the volume ratio of the liner layer in the dental floss tape and the thickness of the dental floss tape are adjusted by adjusting the pump speeds of the first extruder and the second extruder.

13. A dental floss roll, comprising a dental floss roll housing, a dental floss reel arranged in the dental floss roll housing, and a dental floss tape (1) according to any one of claims 1 to 10 wound around the dental floss reel.

14. A dental floss stick, comprising a dental floss stick holder, and a dental floss tape (1) according to any one of claims 1 to 10 connected between different ends of the dental floss stick holder.

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