ES2776230T3 - Lock and head for an oral care utensil and oral care utensil - Google Patents

Abstract

A tuft (16, 66) for an oral care implement (10) comprising a plurality of filaments (20), each filament (20) having a longitudinal axis and a cross-sectional area (22) intersecting extends in a plane substantially perpendicular to the longitudinal axis, the cross-sectional area (22) having four projections (24) and four channels (26), the projections (24) and channels (26) being arranged so as alternating, each channel (26) having a concave curvature (34) formed by adjacent and convergent projections (24), the concave curvature (34) having a radius (30), where the radius (30) of the concave curvature (34 ) of the channel (26) is in a range of about 0.025mm to about 0.10mm, characterized in that the tuft (16, 66) has a compaction factor in a range of 40% to 49%.

Description

DESCRIPTION

Tuft and head for an oral care tool and oral care tool

Field of the invention

The present disclosure relates to a tuft for an oral care implement, the tuft comprising a plurality of filaments having a longitudinal axis and a substantially cross-shaped cross-sectional area extending in a plane substantially perpendicular to the longitudinal axis. The present description also refers to a head for an oral care utensil and to an oral care utensil comprising said head.

Background of the invention

Tufts composed of a plurality of filaments for oral care utensils, such as manual and electric toothbrushes, are well known in the state of the art. Generally, the tufts are attached to a bristle holder of a head intended to be inserted into the oral cavity of a user. A grip handle is usually attached to the head, which handle is grasped by the user during brushing. The head is either permanently attached or can be repeatedly attached and detached from the handle.

To clean teeth effectively, adequate contact pressure must be provided between the free ends of the filaments and the teeth. Generally, the contact pressure depends on the bending stiffness and displacement of the filaments, while the bending stiffness of a single filament depends on its length and cross-sectional area. Typically longer filaments show lower flexural stiffness compared to shorter filaments. However, relatively fine filaments tend to bend outward easily and the relatively low flexural stiffness results in reduced efficiency in removing plaque from tooth surfaces, as well as lower interdental penetration and interdental penetration properties. cleaning capacity. To compensate for such a reduction in flexural stiffness of the longer filaments, the size of the cross-sectional area of a filament could be increased. However, relatively thick filaments can create an unpleasant brushing sensation and tend to damage the gums in the oral cavity. Furthermore, thicker filaments can show reduced flex recovery and the use of such filaments can give an impression of wear to the tuft pattern after a relatively short time of use.

Furthermore, filaments are also known in the state of the art that have a profile along their longitudinal extension that gives rise to a non-circular cross-sectional area, e.g. eg, a polygonal or cross-sectional area. These filaments should improve the cleaning properties of oral care utensils during normal use. In particular, the profiled edges should provide a stronger scraping action during a brushing process to improve the removal of plaque and other debris on tooth surfaces.

EP 2918 191 A1, which forms the basis for the two-part form of claim 1, discloses a head for an oral care implement comprising a mounting surface and at least one tuft mounted on the mounting surface. The tuft has a longitudinal axis and a cross-sectional area that extends in a plane that is perpendicular to the longitudinal axis. The tuft comprises a plurality of substantially cylindrical filaments. Each filament has a longitudinal axis and a cross-sectional area that extends in a plane that is perpendicular to the longitudinal axis. The cross-sectional area of each filament has a substantially non-circular shape.

JP 2005 185399 A describes a toothbrush comprising bundles of bristles, where the compaction factor is equal to or greater than 50%.

JP2004-202021 discloses a toothbrush comprising a bundle of bristles, the bundle being bristles composed of bristles having a star-shaped cross-sectional area including five channels and five projections, the channels and projections being arranged alternately .

Although toothbrushes that comprise these types of filaments clean the outer buccal aspect of the teeth adequately, they are generally not as well suited to provide adequate removal of plaque and debris in the interproximal regions and other hard-to-reach regions of the tooth. mouth, as penetration into the interdental spaces remains relatively difficult. In addition, during manufacturing processes and during brushing, the crosshair bristles / bristles can easily get caught in each other, resulting in a worn-out appearance of the toothbrush. Additionally, these filaments do not provide enough capillary effects to remove plaque and debris from tooth and gum surfaces during brushing.

An object of the present description is to provide a tuft and head for an oral care utensil that overcomes at least one of the above-mentioned drawbacks. Another object of the present description is to provide an oral care utensil comprising such a head.

Summary of the invention

According to one aspect, a tuft is provided for an oral care implement, the tuft comprising a plurality of filaments, each filament having a longitudinal axis and a substantially cross-shaped cross-sectional area extending in a plane substantially perpendicular to the axis. longitudinal, the cross-sectional area having four projections and four channels, the projections and channels being alternately arranged, each channel having a concave curvature formed by adjacent and converging projections, the concave curvature having a radius, in where the radius of the concave curvature of the channel is in the range of about 0.025mm to about 0.10mm, and the tuft has a compaction factor in the range of about 40% to about 49%.

According to one aspect, there is provided a head for an oral care implement comprising said tuft. According to one aspect, an oral care utensil is provided comprising said head.

Brief description of the drawings

The invention is described in more detail below, referring to various embodiments and figures, where:

Fig. 1 shows a schematic perspective view of an oral care appliance having tufts comprising a plurality of filaments according to the present disclosure;

Fig. 2 shows a schematic cross-sectional view of a tuft filament as shown in Fig. 1; Fig. 3 shows a schematic cross-sectional view of a filament according to the state of the art; Fig. 4 shows a schematic cross-sectional view of an illustrative embodiment of a tuft;

Fig. 5 shows a schematic cross-sectional view of a tuft according to a first comparative illustrative embodiment;

Fig. 6 shows a schematic cross-sectional view of a tuft according to a second comparative illustrative embodiment;

Fig. 7 shows a diagram in which the brushing results of a tuft comprising filaments according to Fig. 2 are compared with the results of tuft brushing according to two comparative illustrative embodiments;

Fig. 8 shows a diagram in which an "aqueous suspension absorption mass" of a strand comprising filaments according to Fig. 2 is compared with an "aqueous suspension absorption mass" of strands according to two illustrative embodiments. comparative;

Fig. 9 shows a diagram in which the "absorption rate of an aqueous suspension" of a strand comprising filaments according to Fig. 2 is compared with the "absorption rate of an aqueous suspension" of strands according to two illustrative embodiments comparative; and

Fig. 10 shows a schematic cross-sectional view of a diamond-shaped filament according to the state of the art.

Detailed description of the invention

The tuft according to the present description comprises a plurality of filaments. Each filament of said tuft has a longitudinal axis that is defined by the main length of the filament. From now on the extension of the filament along its longitudinal axis can also be referred to as "longitudinal extension of the filament". The filament has a cross-sectional area that extends in a plane that is substantially perpendicular to the longitudinal axis. The shape of said cross-sectional area is cross-shaped. The cross sectional area comprises four projections and four channels wherein the projections and channels are arranged alternately. Two adjacent projections, that is, two lateral edges close to said projections, converge at the bottom of a channel and define a "converging region". Proximate projections converge in said converging region so that a concave curvature is formed, that is, with an inwardly curved radius formed at the bottom of the channel.

The radius of the concave curvature of the channel is in a range from about 0.025mm to about 0.10mm, or from about 0.03mm to about 0.08mm, or from 0.04mm to about 0.06mm. A radius with this range is relatively large compared to standard cross-shaped filaments (see Fig. 3 and its description below).

Conventional cross-shaped filaments (eg, as shown in Fig. 3 and described in more detail below) have been observed in the past to have the disadvantage that these types of filaments can easily snag each other, both during manufacturing and brushing. However, it has been surprisingly discovered that the specific geometry / contour of the outer surface of the filament according to the present disclosure allows for improved manufacturability, as there is a significantly less probability of the filaments snagging when a plurality of said filaments filaments combine to form a tuft during a so-called "pick-up process."

Furthermore, due to the relatively large radius at the bottom of the channel, the filament is provided with greater stability and therefore less damage to the filament occurs during the brush manufacturing process, e.g. For example, when the filaments are collected and secured to the brush head mounting surface during a hot stapling or tufting process. In the past it has been observed that a relatively high number of conventional cross-shaped filaments are damaged during the collection process, in particular the protrusions can become detached from the filament, or the filament is attached in the convergent region at the bottom of a channel . The attached filaments can provide relatively sharp edges that can damage / injure oral tissue during brushing.

Furthermore, due to the specific geometry of the concave radius of curvature, the channels can facilitate that the filaments can be compacted within a tuft with less density, that is, with a lower compaction factor. This can cause even more toothpaste / toothpaste to retain / adhere to the filaments for a longer period of time during a tooth brushing process. In addition, the lower density of the strand can prevent toothpaste from spreading, which can lead to an improved overall brushing process. In other words, the toothpaste can be better received in the canals and, on cleaning contact with the teeth, delivered directly, thereby achieving a greater polishing effect that is desirable, in particular to remove tooth discoloration.

The tuft according to the present disclosure has a compaction factor in a range from about 40% to about 49%, or from about 45% to about 49%, or about 49%. Surprisingly it has been found that cross-shaped filaments having a concave channel radius of curvature in a range of about 0.025mm to about 0.10mm can allow for this relatively low compaction factor of the filaments within the tuft, since gaps between two adjacent filaments can be maximized. In the context of this description, the term "compaction factor" is defined as the total sum of the cross-sectional areas of the filaments in the tuft hole divided by the cross-sectional area of the tuft hole. In embodiments where anchors such as staples are used, to mount the tuft in the tuft hole, the area of the anchoring means is excluded from the cross sectional area of the tuft hole. A compaction factor of about 40% to about 49%, or from about 45% to about 49%, or about 49% opens a specific void volume within the tuft while the filaments continue to contact each other at along a part of the outer lateral surface. The empty volume can supply more toothpaste to the tooth brushing process, and the toothpaste can interact with the teeth for a longer period of time, helping to enhance the effects of tooth brushing. Furthermore, the void volume, i.e. the space between the filaments, allows for greater uptake of loose plaque due to improved capillary action.

In other words, a relatively low compaction factor within a range of about 40% to about 49%, or about 45% to about 49%, or about 49% can provide improved brushing efficiency, that is, better removal of plaque and debris from the surface of the teeth and gums due to improved capillary effects. These capillary effects can allow the toothpaste to flow to the tip / free end of the filaments, thus making it easier for the toothpaste to reach the teeth and gums during brushing. At the same time, the uptake of plaque and debris from the surface of the teeth and gums is improved.

Surprisingly it has been found that this void volume can be achieved by using cross-shaped filaments having a concave radius of curvature of the channel in a range of about 0.025mm to about 0.10mm. It has been discovered that it is important that the filaments clear an empty area while still being in contact with each other. To produce a toothbrush that meets regulatory requirements and is appreciated by the consumer with respect to overall appearance, a high compaction factor is typically required (approximately 70% to approximately 80% for round filaments; approximately 80% for diamond-shaped filaments; approximately 89% for trilobed filaments). Relative to toothbrushes made by a stapling process, a compaction factor of less than about 70% results in insufficiently compressed filaments within the tuft hole, thereby providing insufficient tuft retention. Accordingly, the regulatory requirements are not met in the case that round filaments are provided with a compaction factor less than about 70%. For hot tuft insertion toothbrushes, a compaction factor of less than about 70% would allow molten plastic to enter the strand during the overmolding process as the pressure of the melt pushes the strands of the strand through. one side until the filaments are in contact with each other. In this way, so-called multi-points are formed that can injure / damage the gums, thus giving rise to unsafe products. In addition to the regulatory and safety aspects, a low compaction strand of round filaments would have a 'wild' appearance and destroyed and would not be accepted by consumers. However, with the use of cross-shaped filaments having a concave radius of curvature of the channel in a range of about 0.025mm to about 0.10mm, a low compaction factor can be achieved for compliant and safe products with an appearance. generally acceptable, while providing improved cleaning properties.

As shown in Fig. 7 and explained in greater detail below, a tuft comprising a plurality of filaments in accordance with the present disclosure provides improved plaque removal from the buccal, lingual, occlusal, and interdental surfaces, as well as throughout. along the gum line, compared to a conventional or circular cross-shaped tuft of filaments.

Furthermore, due to the specific cross-shaped geometry of the filament, each individual filament is stiffer than a circular-shaped filament, when made from the same amount of material. However, due to the low compaction factor in a range of about 40% to about 49%, or about 45% to about 49%, or about 49%, the stiffness of the total tuft made of cross-shaped filaments having a concave radius of curvature of the channel in a range of about 0.025mm to about 0.10mm is reduced compared to a tuft of circular shaped filaments. Surprisingly, it has been found that this lock provides a better sensory experience, that is, a softer feeling inside the mouth during brushing while providing greater cleaning efficiency.

The cross-sectional area of each filament has an outer diameter. In the context of the present description, the outer diameter is defined by the length of a straight line that passes through the center of the cross-sectional area of the filament and whose end points are on the outermost circumference of the cross-sectional area. In other words, the cross-sectional area has an imaginary outer circumference in the shape of a circle (that is, an outer wrapping circle), and the outer diameter is defined as the longest straight line segment of the circle that passes through the center of the circle.

The outer diameter can be in a range of about 0.15mm to about 0.40mm, or about 0.19mm to about 0.38mm, or the outer diameter can be in a range of about 0.22mm. to about 0.35mm, or from about 0.24mm to about 0.31mm.

The ratio of the outer diameter to the radius of curvature of the channel may be in a range of about 2.5 to about 12. Alternatively, the ratio of the outer diameter to the radius of curvature of the channel may be in a range of about 2 , 7 to about 9.

Surprisingly, it has been found that this filament geometry provides even better cleaning performance, while maintaining the comfort of the brush in the mouth. Furthermore, this geometry has been found to further help reduce the wear aspect of the filament / tuft since there is an even less chance of the filaments getting caught during brushing. Furthermore, the manufacturability of such filaments during a toothbrush manufacturing process is further improved.

Each projection of the cross-sectional area of the filament can be rounded thereby forming a curvature. Said curvature can have a diameter. The diameter of the curvature of the projection may be in a range of about 0.01mm to about 0.04mm, or in a range of about 0.018mm to about 0.026mm.

The ratio of the diameter of the curvature of the projection to the radius of the curvature of the channel can be in a range of about 0.2 to about 1.5, or about 0.3 to about 1.0, or about 0 .5 to about 0.7. Said ratio is relatively low compared to the standard cross-shaped filaments according to the state of the art (see Fig. 3 and its description below). In other words, the radius of the concave curvature of the channel is relatively large with respect to the diameter of the curvature of the projection, that is, with respect to the widthwise extension of the projection or, in other words, the diameter of the curvature of the The overhang can be relatively fine compared to the radius of the concave curvature of the channel. The relatively large radius provides greater stability to the relatively thin projections. Therefore, there is less chance that the filaments / projections are damaged or relatively fine projections break during the brush manufacturing process, particularly when the filaments are collected. In other words, the manufacturability of such filaments during a toothbrush manufacturing process is further improved.

Furthermore, surprisingly, it has been found that this geometry of the filament provides even more improved cleaning performance while maintaining the comfort of the brush in the mouth. Furthermore, it has been found that this geometry helps to further reduce the wear aspect of the filament / tuft since there is an even lower likelihood of the filaments getting caught during brushing.

The diameter of the curvature of the projection may range from about 6% to about 15% or from about 8% to about 12% of the outer diameter of the filament. Surprisingly, it has been found that these filaments can conform to the contour of the teeth even better and penetrate the interdental spaces more easily to remove plaque and debris more completely.

Each projection of the cross-sectional area comprises two outer side edges along the longitudinal extent of the filament. These side edges can place relatively high concentrated stress on tooth surfaces to break up and remove plaque. The outer edges can provide a scraping effect for plaque and other debris to be removed more effectively. Due to the relatively large radius of the concave curvature at the bottom of the canal, the projections are provided with greater rigidity / stability to loosen / remove plaque from tooth surfaces more easily / efficiently. The channels can then capture the broken plaque and move it away from the teeth.

The projections of the cross-shaped filament may taper radially in an outward direction, that is, in a direction away from the center of the cross-sectional area and toward the outer circumference. Such conical projections can ensure access to narrow spaces and other hard-to-reach regions and can penetrate / enter interdental regions even more deeply and efficiently. Since the bending stiffness of a cross-shaped filament is higher compared to a circular-shaped filament made from the same amount of material, the higher bending stiffness can force the protrusions of the filament to slide towards the edges. interdental regions more easily.

The projections may taper radially outward at an angle in a range of about 6 ° to about 25 ° or at an angle in a range of about 8 ° to about 20 °. Surprisingly it has been found that this narrowing allows for optimal interdental penetration properties. In addition, this filament can more easily be bundled into a tuft without being caught in the contours of adjacent filaments.

The filament can be a substantially cylindrical filament, that is, the filament can have a substantially cylindrical outer side surface. In other words, the shape and size of the cross-sectional area of the filament along its longitudinal axis may not vary substantially, that is, the shape and size of the cross-sectional area may be substantially constant throughout the longitudinal extent. of the filament. In the context of this description, the term "outer lateral surface of a filament" means any outer face or surface of the filament at its sides. This type of filament can provide higher flexural stiffness compared to tapered filaments. Greater bending stiffness can facilitate the filament to penetrate interdental gaps / spaces. Also, cylindrical filaments generally wear out slowly, which can provide longer filament life.

The cylindrical filament may have a substantially rounded free end / tip to provide mild cleaning properties. Tips with rounded ends can prevent gums from being damaged during brushing. Within the context of this description, rounded-ended filaments would still come under the definition of a substantially cylindrical filament.

Alternatively, the filament may comprise, along its longitudinal axis, a substantially cylindrical part and a conical part, the conical part tapers in the longitudinal direction towards a free end of the filament, and the cylindrical part has an area of cross section according to the present description. In other words, the filament can be a tapered filament having a pointed tip. Tapered filaments can achieve optimal penetration in areas between two teeth, as well as in gingival cavities during brushing, and can provide improved cleaning properties. The tapered filament may have an overall length that extends over the mounting surface in a range of about 8mm to about 16mm, optionally about 12.5mm, and a tapered portion in a range of about 5mm to about 10mm. mm measured from the tip of the filament. The pointed tip may be needle-shaped, may comprise a split or feather-shaped end. The conical part can be produced by a chemical and / or mechanical sharpening process.

The filament can be made of polyamide, e.g. g., nylon, with or without an abrasive such as kaolin clay, polybutylene terephthalate (PBT), with or without an abrasive such as kaolin, and / or a polyamide indicator material, e.g. eg nylon indicator material, colored on the outer surface. The coloration in the polyamide indicator material may slowly fade as the filament is used over time to indicate the degree of wear of the filament.

The filament can comprise at least two segments of different materials. At least one segment can comprise a thermoplastic elastomeric material (TPE) and at least one segment can comprise polyamide, e.g. eg, nylon, with or without an abrasive such as kaolin, polybutylene terephthalate (PBT), with or without an abrasive such as kaolin clay, or a polyamide indicator material, e.g. eg nylon indicator material, colored on the outer surface. These at least two segments can be arranged in a parallel structure or in a core and sheath structure which can result in reduced stiffness of the overall filament. A core and shell structure with an inner / core segment comprising a harder material, e.g. g., polyamide or PBT, and with an outer / sheath segment surrounding the core segment and comprising a softer material, for example TPE, can provide the filament with a relatively smooth outer side surface that can result in properties gentle cleansers.

The filament can comprise a component selected from fluoride, zinc, strontium salts, flavor, silica, pyrophosphate, hydrogen peroxide, potassium nitrate, or combinations thereof. For example, fluoride can provide a mineralization effect, and thus can prevent tooth decay. Zinc can boost the user's immune system. Hydrogen peroxide can lighten / whiten teeth. Silica can have an abrasive effect to remove dental plaque and debris more effectively. Pyrophosphate can inhibit the formation of new plaque, tartar, and dental stones along the gum line. A filament comprising pyrophosphate can offer long-lasting protection against inflammation of the gums and mucous membrane of the mouth.

If a plurality of these filaments are bundled together to form a tuft, they may be arranged so that the strands on the outer lateral surface of the tuft can comprise pyrophosphate to inhibit the formation of plaque, tartar, and dental calculi along the line of the gums while the filaments arranged in the center of the lock can comprise fluoride to mineralize the teeth during a brushing process.

At least one of the components listed above can be coated on a wrap, that is, on an outer segment of a filament. In other words, at least some of the strand filaments may comprise a core and sheath structure wherein the inner / core segment may comprise TPE, polyamide, or PBT, and the outer / sheath segment may comprise at least one of the components listed above. Such a core and shell structure can make the component (s) directly available to the teeth in a relatively high concentration, that is, the component (s) can be in direct contact with the teeth while brushing.

Alternatively, at least one of the components listed above can be coextruded with TPE, polyamide, e.g. eg, nylon and / or PBT. These embodiments can make the component (s) gradually available to the teeth as the filament material slowly wears out during use.

A plurality of filaments according to any of the embodiments described above are grouped together to form a tuft that can be attached to an oral care implement. The oral care utensil can be a toothbrush comprising a handle and a head. The head extends from the handle and can be either repeatedly attachable to, and detachable from, the handle or the head can be non-detachably connected to the handle. The toothbrush can be an electric or manual toothbrush.

The head may comprise a bristle holder having a substantially circular or oval shape. This bristle holder can be provided for an electric toothbrush that can effect a rotational oscillating motion. The bristle holder of an electric toothbrush can be actuated to rotate around an axis of motion and move axially along it, wherein said axis of motion may extend substantially perpendicular to the plane defined by the upper upper surface of the holder. sows. One or more tufts comprising a plurality of filaments according to the present description can be attached to the bristle holder. Such tuft (s) may allow filament protrusions to penetrate interdental regions and hard-to-reach regions more easily during head rotational oscillation movement which can provide improved head cleaning properties. Plaque and other debris can be dislodged by the oscillating action of filaments that are substantially perpendicular to tooth surfaces, while the rotary motion can clean plaque and other debris by dragging them.

The at least one tuft attached to the head for an oral care implement may have a longitudinal axis and a cross-sectional area that extends in a plane that is perpendicular to said longitudinal axis. The plurality of filaments can be arranged so that the cross-sectional area of the tuft has an enlarged shape of the respective shape of each individual strand that makes up the tuft. In other words, the tuft is an enlarged version of its filaments, that is, the cross-sectional area shape of the tuft may have substantially the same cross-sectional area as each individual strand, but larger in size. The shape of the cross-sectional area of the tuft may correspond to the shape of the cross-sectional area of its filaments. In the context of this description, the term "cross-sectional area having an enlarged shape" means a cross-sectional area comprising the same shape, but with a larger size. In other words, the type of shape can be the same but the size of the cross-sectional area is different, that is, larger. Any gaps, irregularities, embossments or grooves that may be present between two adjacent individual filaments on the outer circumference of the cross-sectional area of the tuft do not contribute to the substantial shape of said cross-sectional area and therefore do not have to be had. consider.

Such a lock can provide better cleaning properties. As described above, the specific shape / geometry of the individual filaments have specific cleaning properties that differ from the properties of regular filaments with a conventional or circular cross-sectional area. These specific cleaning properties can be enhanced by arranging the filaments to have a total tuft cross-sectional shape that is a scaled-down version of the cross-sectional shape of each individual filament. Furthermore, since the specific geometry of each single filament may be generally not visible to the user, the tuft according to the present description can communicate the respective geometry to the user, and therefore the corresponding cleaning properties of the filaments. that make up said lock.

Since the filaments and the tuft, respectively, each have a cross-sectional area with a non-circular shape, the filaments, as well as the total tuft, can provide flexural stiffness properties. anisotropic during a brushing process. In case of applying a given contact pressure to the free end of the strands / tuft, the amount of deflection / displacement of the strands / tuft depends on the diameter / radius of the strands / tuft. The smaller the diameter / radius, the greater the deflection / displacement of the free end of the filaments / tuft, and vice versa, the larger the diameter / radius, the smaller the deflection / displacement of the free end of the filaments / of the strand. The tuft can be arranged on the head mounting surface so that the superior flexural stiffness is provided in a direction where higher cleaning forces may be needed. Lower bending stiffness can be provided in a direction where gentler cleaning forces or a massaging effect may be needed.

A head for an oral care utensil according to the present disclosure may comprise a bristle holder which is provided with at least one tuft hole, e.g. eg, a knockout hole. A tuft comprising a plurality of filaments according to the present disclosure can be fixed / anchored in said tuft hole by a stapling process / tuft anchoring method. This means that the strands of the tuft bend / kink around an anchor, e.g. ex. an anchor wire or anchor plate, for example made of metal, in a substantially U-shaped manner. The filaments together with the anchor are pushed into the tuft hole so that the anchor penetrates the opposite side walls of the tuft hole thereby anchoring / fixing / holding the filaments to the bristle holder. The anchor can be attached to opposite side walls by positive and frictional coupling. In case the tuft hole is a blind hole, the anchor holds the filaments against the bottom of the hole. That is, the anchor may be bent over the U-shaped bend in a substantially perpendicular manner. Since the strand filaments are bent around the anchor in a substantially U-shaped configuration, a first end and a second end of each strand extend from the bristle holder in a direction of the strand. The types of filaments that can / are suitable for use in a stapling process are also called "double-sided filaments". Heads for oral care implements that are manufactured by a stapling process can be provided relatively cheaply and quickly. Due to the improved geometry of the filament according to the present disclosure, fewer filaments are damaged, e.g. eg, bonding, when the filaments are collected and attached to the brush head mounting surface during the stapling process. Also, fewer filaments are caught on the outer surface of an adjacent filament when a plurality of filaments are collected to form a tuft.

Alternatively, the at least one strand may be attached / attached to the head by a hot tuft insertion process. A method of manufacturing the head of an oral care utensil may comprise the following steps: First, the at least one tuft may be formed by providing a desired quantity of filaments according to the present disclosure. Second, the tuft can be placed in a mold cavity, so that the ends of the filaments intended to be attached to the head extend into said cavity. Third, the head or an oral care utensil body comprising the head and handle can be shaped around the ends of the filaments that extend into the mold cavity by an injection molding process, thereby anchoring the at least one strand on the head. Alternatively, the tuft can be anchored by forming a first head part (the so-called "sealing plate") around the ends of the filaments that extend into the mold cavity by an injection molding process before it can be formed. the remaining part of the oral care utensil. Before starting the injection molding process, the ends of the at least one strand that extend into the mold cavity can be fused or fused together to bond the filaments together into a fused mass or ball, the masses being arranged or balls fused within the cavity. The at least one strand can be held in place in the mold cavity by a mold bar having blind holes corresponding to the desired position of the strand in the finished head of the oral care implement. In other words, the strands of the at least one tuft attached to the head by a hot tuft insertion process may not be bent at an intermediate portion along their length and may not be mounted to the head using an anchor / staple. The at least one tuft can be mounted to the head by an anchorless tuft insertion process. A hot tuft manufacturing process allows for complex tuft geometries. For example, the tuft may have a specific topography / geometry at its free end, that is, at its upper surface, which may be shaped to optimally fit the contour of the teeth and further enhance interdental penetration. For example, the topography may be beveled or rounded in one or two directions, it may be pointed, or it may be linear, concave, or convex. Due to the improved geometry of the filament according to the present disclosure, fewer filaments are damaged, e.g. eg, bonding, when the filaments are collected and fixed to the brush head mounting surface during the hot tuft insertion process. Also, fewer filaments are caught on the outer surface of an adjacent filament when a plurality of filaments are collected to form a tuft.

The following is a non-limiting explanation of illustrative embodiments of oral care utensils and their parts according to the present description, where reference is made to the figures.

Fig. 1 shows a top to bottom perspective view of an oral care utensil 10, which could be a manual or electric toothbrush 10, comprising a handle 12 and a head 14 extending from the handle 12 at a longitudinal direction. Head 14 has a proximal end 41 near handle 12 and a distal end 40 further from handle 12, that is, opposite proximal end 41. Head 14 may be substantially in the shape of an oval with a longitudinal extension 52 and a extension 51 of width substantially perpendicular to the longitudinal extension 52. A plurality of tufts 16 having a plurality of filaments 20 in accordance with the present disclosure may be attached to head 14 by a hot tuft insertion or stapling process. Tufts 16 may extend from a mounting surface 18 of head 14 in a substantially orthogonal manner.

The tufts 16, as illustrated in Fig. 1, comprise a plurality of rounded-ended filaments 20, one of which is shown in Fig. 2. Alternatively, the filaments 20 may be tapered filaments comprising, a along the longitudinal axis, a substantially cylindrical part and a tapered part. The tapered portion tapers toward the free end of the filament 20, and the cylindrical portion has a cross-sectional area 22 according to the present disclosure. The plurality of filaments 20 are arranged so that tufts 16 have a cross-sectional area 32 with an enlarged shape of the shape of each individual strand 20. In other words, the shape of the cross-sectional area 32 of tufts 16 corresponds to the shape of the cross-sectional area 22 of each individual filament 20. The tufts 16 may have a compaction factor in a range from about 40% to about 49%, or from about 45% to about 49%, or about 49%. The "compaction factor" is defined as the total sum of the cross-sectional areas 22 of the filaments 20 divided by the cross-sectional area of the tuft hole.

Fig. 2 shows a schematic cross-sectional view of a filament 20 according to the present description. Each filament 20 has a longitudinal axis and a substantially cross-shaped cross-sectional area 22 extending in a plane substantially perpendicular to the longitudinal axis. The cross-sectional area 22 has four projections 24 and four channels 26. The projections 24 and channels 26 are arranged alternately. Each projection 24 tapers in an outward direction at an angle α in a range of about 6 ° to about 25 °, or about 8 ° to about 20 °.

Cross-sectional area 22 has an outer diameter 28 that passes through the center 36 of cross-sectional area 22 of the filament. The end points of the outer diameter 28 are on the outermost circumference 38 of the cross-sectional area 22. The outer diameter 28 has a longitudinal extension in a range from about 0.15mm to about 0.40mm, from about 0.19mm to about 0.38mm, from about 0.22mm to about 0.35mm, or from about 0.24mm to about 0.31mm.

In addition, each channel 26 has a concave curvature 34, that is, a curvature curved inwardly towards the center 36 of the cross-sectional area 22. The concave curvature 34 is formed at the bottom of each channel 26 by two adjacent and converging projections 24. The concave curvature 34 has a radius 30 that is in a range from about 0.025mm to about 0.10mm, or from about 0.03mm to about 0.08mm, or from about 0.04mm to about 0.06mm. mm.

The ratio of outside diameter 28 to radius 30 of concave curvature 34 is in a range of about 2.5 to about 12, or about 2.7 to about 9.

Each projection 24 has a rounded end, thereby forming a curvature with a specific diameter 42. Said diameter 42 can also be defined as the extension 42 of width extending between two opposite side edges 44. The ratio of the diameter 42 of the curvature of the boss 24 to the radius 30 of the curvature 34 of the channel 26 is in a range of about 0.2 to about 1.5, or about 0.3 to about 1.0, or from about 0.5 to about 0.7.

Furthermore, the diameter 42 is defined in a range of about 6% to about 15%, or from about 8% to about 12% of the outer diameter 28 of the filament 20. For example, the diameter 42 may be in a range from about 0.01mm to about 0.04mm, or in a range from about 0.018mm to about 0.026mm.

Fig. 3 shows a schematic cross-sectional view of a cross-shaped filament 54 according to the state of the art. Filament 54 comprises the following dimensions:

Outer diameter 56: 0.295mm

Radius 58 of the concave curvature of the channel: 0.01 mm

Ratio of outer diameter 56 to radius 58 of concave curvature: 29.5

Angle a of taper of the projections: 15 °

Flange bend diameter 62: 0.04mm

Ratio of diameter 62 to radius 58: 4

Inside diameter 64: 0.1mm

Fig. 4 shows a schematic cross-sectional view of an illustrative embodiment 1 of a tuft 66 according to the present disclosure. Tuft 66 has a compaction factor of approximately 49%. The filaments 68 of the tuft 66 have the following dimensions:

Outer diameter 28: 0.309mm

Concave Bend Radius 30: 0.06mm

Ratio of outer diameter 28 to radius 30 of concave curvature: 5.15

Angle a of taper of the projections: 10 °

Boss 42 Curvature Diameter 42: 0.04mm

Ratio of diameter 42 to radius 30: 0.67

Inner diameter 70: 0.12 mm.

Fig. 5 shows a schematic cross-sectional view of a tuft 72 comprising a plurality of circular filaments 74 according to the state of the art. The diameter of the filaments 74 is approximately 0.178mm (7 mil). Said tuft 72 has a compaction factor of approximately 77% (Comparative Example 2).

Fig. 6 shows a schematic cross-sectional view of a tuft 76 comprising a plurality of filaments 54 according to Fig. 3. This tuft 76 has a compaction factor of about 58% (Comparative Example 3).

Comparison experiments

Robot tests:

The tuft 66 (tuft diameter: 1.7mm) according to Fig. 4, comprising a plurality of filaments 68 (illustrative embodiment 1), the tuft 72 (tuft diameter: 1.7mm) according to Fig. 5 , comprising a plurality of filaments 74 (Comparative Example 2), and the tuft 76 (diameter of the tuft: 1.7 mm) according to Fig. 6 comprising a plurality of filaments 54 (Comparative Example 3) were compared with respect to its efficacy in removing a plaque substitute on artificial teeth (anatomical denture models).

The brushing tests were performed using a KUKA 3 robotic system under the following conditions (see Table 1):

Table 1

Fig. 7 shows the amount of plaque substitute removal in% of Comparative Example 1, Comparative Example 2 and Comparative Example 3, each with respect to all tooth surfaces 78, buccal surfaces 80, lingual surfaces 82, lingual surfaces 84 and buccal, occlusal surfaces 86, gum line 88 and interdental surfaces 90.

Fig. 7 clearly shows that Illustrative Embodiment 1 provides significantly improved plaque removal properties over all tooth surfaces 78, buccal surfaces 80, lingual surfaces 82, lingual and buccal surfaces 84, occlusal surfaces 86, line 88 of the gums and interdental surfaces 90 compared to Comparative Examples 2 and 3. The most significant improvement in cleaning performance occurred on occlusal surfaces 86 with an improvement of 22% and 9%, respectively.

Aqueous suspension absorption tests:

Fig. 8 shows a diagram in which "an aqueous suspension absorption mass" of a tuft (diameter of the tuft: 1.7 mm) comprising filaments according to the present description and having a compaction factor of about 46% (Embodiment Example 4) is compared to a "water suspension absorption mass" of a strand (strand diameter: 1.7 mm) comprising diamond-shaped filaments (see Fig. 10) and having a factor compaction of about 80% (Comparative Example 5), and with an "aqueous suspension absorption mass" of the tuft 72 according to Comparative Example 2.

The filaments of illustrative embodiment 4 have the following dimensions:

Outer diameter: 0.269mm

Channel concave bend radius: 0.05mm

Ratio of outside diameter to radius of concave curvature: 5.38

Angle a of taper of the projections: 14 °

Boss bend diameter: 0.029mm

Ratio of the diameter of the curvature of the projection to the radius of the concave curvature of the channel: 0.58 Inner diameter: 0.102 mm

The filaments of Comparative Example 5 have the following dimensions (Fig. 10):

Longest diagonal length 92: 0.29 mm

Shortest diagonal length 94: 0.214 mm

Fig. 9 shows a diagram in which the "absorption rate of an aqueous suspension" of Illustrative Embodiment 4 is compared with the "absorption rate of an aqueous suspension" of Comparative Examples 2 and 5.

Trial description:

Brush heads comprising tufts according to Illustrative Embodiment 4 and Comparative Examples 2 and 5 were set in a horizontal position with the filaments pointing downward. A container of aqueous toothpaste suspension (toothpaste: water = 1: 3) with a scale was placed directly below the brush heads. The scale was used to measure the amount of aqueous suspension in the container. When the test was started, the brushes were lowered to 100 mm / s and dipped to a depth of 2 mm in the aqueous suspension. The brushes were then held for 5 s in the aqueous toothpaste suspension and pulled out again at 100 mm / min. The force in the vertical direction was measured over time.

Figs. 8 and 9 clearly show that Illustrative Embodiment 4 provides improved "slurry absorption" in terms of mass and speed compared to Comparative Examples 2 and 5. The increased void volume within the tuft of Illustrative Embodiment 4 allows for an action enhanced capillary. This leads to greater absorption of toothpaste (aqueous suspension) so that the toothpaste interacts / contributes longer to the tooth brushing process. The tuft of illustrative embodiment 4 can absorb approximately 50% more aqueous toothpaste suspension with an absorption rate of approximately 50% higher, resulting in improved dental cleaning effects. In other words, in addition to supplying more toothpaste to the tooth brushing process, the specific void volume within the tuft of illustrative embodiment 4 also allows for greater uptake of detached plaque. This results in improved clinical performance of a toothbrush comprising a tuft according to the present disclosure.

Claims (15)

i. A tuft (16, 66) for an oral care implement (10) comprising a plurality of filaments (20), each filament (20) having a longitudinal axis and a cross-sectional area (22) intersecting extends in a plane substantially perpendicular to the longitudinal axis, the cross-sectional area (22) having four projections (24) and four channels (26), the projections (24) and channels (26) being arranged so alternating, each channel (26) having a concave curvature (34) formed by adjacent and convergent projections (24), the concave curvature (34) having a radius (30), where the radius (30) of the concave curvature (34 ) of the channel (26) is in a range of about 0.025mm to about 0.10mm, characterized in that the tuft (16, 66) has a compaction factor in a range of 40% to 49%. 2. A tuft (16, 66) according to claim 1, wherein the radius (30) of the concave curvature (34) of the channel (26) is in a range of about 0.03mm to about 0.08mm , preferably from about 0.04mm to about 0.06mm. 3. A tuft (16, 66) according to claim 1 or 2, wherein the compaction factor is in a range of about 45% to about 49%. A tuft (16, 66) according to any of the preceding claims, wherein the cross-sectional area (22) of each filament (20) has an outer diameter (28) in a range from about 0.15mm to about 0.40mm, preferably from about 0.19mm to about 0.38mm, more preferably from about 0.22mm to about 0.35mm, even more preferably from about 0.24mm to about 0.31mm. 5. A tuft (16, 66) according to any preceding claim, wherein the cross-sectional area (22) of each filament (20) has an outer diameter (28) and the ratio of the outer diameter (28) to The radius (30) of the concave curvature (34) of the channel (26) is in a range of about 2.5 to about 12, preferably about 2.7 to about 9. A tuft (16, 66) according to any preceding claim, wherein each projection (24) of the cross-sectional area (22) has a rounded end, thereby forming a curvature, the curvature having a diameter (42 ), and the diameter (42) of the curvature of the projection (24) is in a range of about 0.01mm to about 0.04, preferably in a range of about 0.018mm to about 0.026. A tuft (16, 66) according to any preceding claim, wherein each protrusion (24) of the cross-sectional area (22) has a rounded end, thereby forming a curvature, the curvature having a diameter (42 ), and the ratio of the diameter (42) of the curvature of the projection (24) to the radius (30) of the curvature (34) of the channel (26) is from about 0.2 to about 1.5. A tuft (16, 66) according to claim 7, wherein the ratio of the diameter (42) of the curvature of the protrusion (24) to the radius (30) of the curvature (34) of the channel (26) is approximately 0.3 to about 1.0, preferably about 0.5 to about 0.7. A tuft (16, 66) according to any of the preceding claims, wherein each protrusion (24) of the cross-sectional area (22) of each filament (20) tapers in an outward direction. A tuft (16, 66) according to claim 9, wherein each protrusion (24) tapers in the outward direction at an angle defined in a range of about 6 ° to about 25 °. A lock (16, 66) according to claim 9 or 10, wherein each protrusion (24) tapers in the outward direction at an angle defined in a range of about 8 ° to about 20 °. 12. A tuft (16, 66) according to any preceding claim, wherein the tuft (16, 66) has a longitudinal axis and a cross-sectional area (32) extending in a plane that is perpendicular to the longitudinal axis. , and the plurality of filaments (20) are arranged such that the cross-sectional area (32) of the tuft (16, 66) has an enlarged shape with respect to the shape of the cross-sectional area (22) of each filament (twenty). A tuft (16, 66) according to any of the preceding claims, wherein each filament (20) comprises, along its longitudinal axis, a substantially cylindrical portion and a tapered portion, where the tapered portion narrows towards a free end of the filament and the cylindrical part has a cross-sectional area (22) according to any of the preceding claims. A head (14) for an oral care implement (10) comprising a lock (16, 66) according to any one of the preceding claims. 15. An oral care implement (10) comprising a head (14) according to claim 14.