阅读说明：本技术 用于口腔护理工具的头部和口腔护理工具 (Head for an oral care implement and oral care implement ) 是由 U·容尼克尔 于 2020-03-25 设计创作，主要内容包括：本发明公开了一种用于口腔护理工具的头部,该头部具有在近侧端部与远侧端部之间延伸的纵向长度延伸部、外部边缘以及内部部分。该头部包括至少两个第一类型的牙齿清洁组件和多个第二类型的牙齿清洁组件,该第一类型的牙齿清洁组件布置在头部的内部部分处,并且多个第二类型的牙齿清洁组件布置在头部的外部边缘处,从而包围第一类型的牙齿清洁组件。第一类型的牙齿清洁组件为包括多根长丝的第一类型的簇。该第一类型的簇被布置成基本上彼此平行。每个簇具有基本上矩形或椭圆形的横截面形状,该基本上矩形或椭圆形的横截面形状具有约4mm至约8mm的较长长度延伸部以及约1.5mm至约2.5mm的较短宽度延伸部,其中较长长度延伸部相对于头部的纵向长度延伸部限定角度α,该角度α为约25°至约60°。(A head for an oral care implement has a longitudinal length extension extending between a proximal end and a distal end, an outer edge, and an inner portion. The head comprises at least two tooth cleaning assemblies of a first type arranged at an inner portion of the head and a plurality of tooth cleaning assemblies of a second type arranged at an outer edge of the head, thereby enclosing the tooth cleaning assemblies of the first type. The first type of tooth cleaning elements are a first type of tufts comprising a plurality of filaments. The first type of clusters are arranged substantially parallel to each other. Each tuft has a substantially rectangular or oval cross-sectional shape with a longer length extension of about 4mm to about 8mm and a shorter width extension of about 1.5mm to about 2.5mm, wherein the longer length extension defines an angle a with respect to the longitudinal length extension of the head, the angle a being about 25 ° to about 60 °.)

1. A head (14) for an oral care implement (10), the head (14) having a longitudinal length extension (52) extending between a proximal end (41) and a distal end (40), an outer edge (98), and an inner portion (100), the head (14) comprising at least two tooth cleaning assemblies of a first type (16, 17) and a plurality of tooth cleaning assemblies of a second type (96),

the first type of tooth cleaning assembly (16, 17) is arranged at the inner portion (100) of the head (14), and

the plurality of tooth cleaning assemblies of the second type (96) being arranged at the outer edge (98) of the head (14) so as to enclose the tooth cleaning assemblies of the first type (16, 17),

the first type of tooth cleaning assembly (16, 17) is a first type of tuft (16, 17) comprising a plurality of filaments (20), the first type of tufts (16, 17) being arranged substantially parallel to each other, each tuft (16, 17) of the first type having a substantially rectangular or elliptical cross-sectional shape with a longer length extension (101) of about 4mm to about 8mm and a shorter width extension (103) of about 1.5mm to about 2.5mm, wherein the longer length extension (101) defines an angle a relative to the longitudinal length extension (52) of the head, the angle a being about 25 ° to about 60 °.

2. A head (14) according to claim 1, wherein the angle a is from about 30 ° to about 45 °, preferably from about 30 ° to about 35 °, further preferably from about 40 ° to about 45 °.

3. A head (14) according to claim 1 or 2, wherein the head (14) comprises at least three, preferably four, tufts (16, 17) of the first type.

4. A head (14) according to any of the preceding claims, wherein the second type of tooth cleaning elements (96) are tufts (96) of filaments, each tuft having a substantially circular cross-sectional area with a diameter of about 1.5mm to about 2mm, preferably about 1.6 mm.

5. A head (14) according to any of the preceding claims, wherein the second type of tooth cleaning assembly (96) is a tuft (96) comprising a plurality of tapered filaments, preferably the filaments of the second type of tuft (96) are longer than the filaments of the first type of tuft (16, 17).

6. A head (14) according to any of the preceding claims, wherein the filaments of at least one of the tufts of the first type (16) each have a longitudinal axis and a substantially cross-shaped cross-sectional area (22) extending in a plane substantially perpendicular to the longitudinal axis, the cross-shaped cross-sectional area (22) having four protrusions (24) and four channels (26), the protrusions (24) and channels (26) being arranged in an alternating manner.

7. A head (14) according to claim 6, wherein the at least one tuft (16) or tufts (16) of the first type comprising filaments having a cross-shaped cross-sectional area (22) are arranged in an alternating manner with at least one tuft (17) or tufts (17) of the first type comprising filaments having a substantially circular cross-sectional shape.

8. A head according to claim 6 or 7, wherein the at least one tuft (16) of the first type comprising filaments having the cruciform cross-sectional area (22) has a fill factor in the range of from about 40% to about 55%, preferably from about 45% to about 50%.

9. A head (14) according to any of claims 6 to 8, wherein each channel (26) has a concave curvature (34) formed by adjacent and converging protrusions (24), the concave curvature (34) having a radius (30) in the range of about 0.025mm to about 0.10mm, preferably about 0.03mm to about 0.08mm, still preferably about 0.04mm to about 0.06 mm.

10. A head (14) according to any of claims 6 to 9, wherein the cross-sectional area (22) of each filament (20) of the first type of tuft (16) has an outer diameter (28) in the range of from about 0.15mm to about 0.40mm, preferably from about 0.19mm to about 0.38mm, further preferably from about 0.22mm to about 0.35mm, even further preferably from about 0.24mm to about 0.31 mm.

11. A head (14) according to any of claims 6 to 10, wherein the cross-sectional area (22) of each filament (20) of the first type of tuft (16) has an outer diameter (28) and each channel (26) of filaments (20) of the first type of tuft (16) has a concave curvature (34) with a radius formed by adjacent and converging protrusions (24), and the ratio of the outer diameter (28) to the radius (30) of the concave curvature (34) of the channel (26) is in the range of about 2.5 to about 12, preferably about 2.7 to about 9.

12. A head (14) according to any of claims 6 to 11, wherein each protrusion (24) of the cross-sectional area (22) of a filament (20) of the first type of tuft (16) is endlessly rounded, thereby forming a bend having a diameter (42), and the bent diameter (42) of the protrusion (24) is in the range of about 0.01mm to about 0.04mm, preferably in the range of about 0.018mm to about 0.026 mm.

13. A head (14) according to claim 12, wherein the ratio of the diameter (42) of the bend of the protrusion (24) to the radius (30) of the bend (34) of the channel (26) is from about 0.2 to about 1.5, preferably from about 0.3 to about 1.0, further preferably from about 0.5 to about 0.7.

14. A head (14) according to any of the preceding claims, wherein each filament (20) of the first type of tuft (16) comprises along its longitudinal axis a substantially cylindrical portion and a tapered portion, the tapered portion tapering towards the free end of the filament.

15. An oral care implement (10) comprising a head (14) according to any preceding claim and a handle (12), preferably the head (14) is repeatedly attachable to and detachable from the handle (12).

Technical Field

The present disclosure relates to a head for an oral care implement, the head comprising at least two tooth cleaning assemblies of a first type and a plurality of tooth cleaning assemblies of a second type. Each of the tooth cleaning elements of the first type is a tuft of the first type having a substantially rectangular or elliptical cross-sectional shape, which is surrounded by tooth cleaning elements of the second type. The present disclosure also relates to an oral care implement comprising such a head.

Background

Tufts composed of a plurality of filaments for oral care implements, such as manual and electric toothbrushes, are well known in the art. Generally, the tufts are attached to a bristle carrier intended for a head inserted into a user's mouth. A grip handle is typically attached to the head, the handle being held by the user during brushing. The head is permanently connected to the handle or is repeatedly attachable to and detachable from the handle.

To effectively clean the teeth, such brush heads include tufts of multiple filaments that generally have a circular or slightly oval cross-sectional shape. However, such tufts have limited cleansing and cream foaming capabilities during brushing. In addition, standard tufts do not provide sufficient capillary effect to remove plaque and debris from the tooth and gum surfaces during brushing. However, in order to achieve good cleaning results, plaque must be reached through the tufts/filaments, then must be destroyed and finally removed.

Furthermore, toothbrushes are known which have relatively large tuft sizes. While toothbrushes comprising this type of tuft assemblies can provide relatively good foam formation and polishing during brushing, they can produce an unpleasant brushing sensation when used with brushing techniques, i.e., when subjected to horizontal back and forth motions along the tooth line. Such toothbrushes are inadequate for users with sensitive gums. Therefore, there is a need for a toothbrush which ensures a sufficient cleaning effect while providing a good feeling on the gums during brushing.

It is an object of the present disclosure to provide a head for an oral care implement that overcomes at least one of the above-mentioned deficiencies. It is another object of the present disclosure to provide an oral care implement comprising such a head.

Disclosure of Invention

According to one aspect, there is provided a head for an oral care implement, the head having a longitudinal length extension extending between a proximal end and a distal end, an outer edge, an inner portion, the head comprising at least two tooth cleaning assemblies of a first type and a plurality of tooth cleaning assemblies of a second type, the tooth cleaning assemblies of the first type being arranged at the inner portion of the head and the plurality of tooth cleaning assemblies of the second type being arranged at the outer edge of the head so as to enclose the tooth cleaning assemblies of the first type, the tooth cleaning assemblies of the first type being tufts of the first type comprising a plurality of filaments, the tufts of the first type being arranged substantially parallel to each other, each tuft having a substantially rectangular or oval cross-sectional shape with a longer length extension of about 4mm to about 8mm and a shorter width extension of about 1.5mm to about 2.5mm Wherein the longer length extension defines an angle a relative to the longitudinal length extension of the head, the angle a being about 25 ° to about 60 °.

According to one aspect, an oral care implement is provided that includes such a head, which is preferably repeatedly attachable to and detachable from a handle.

Drawings

The invention is described in more detail below with reference to various embodiments and the accompanying drawings, in which:

fig. 1 shows a schematic perspective top view of an exemplary embodiment of an oral care implement including a head according to the present disclosure;

FIG. 2 shows a schematic cross-sectional view of one filament of the first type of tuft shown in FIG. 1;

FIG. 3 shows a schematic cross-sectional view of a filament according to the prior art;

FIG. 4 shows a schematic cross-sectional view of a tuft comprising cross-shaped filaments according to the present disclosure;

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

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

FIG. 7 shows a graph comparing the brushing results of a tuft comprising cross-shaped filaments according to the present disclosure with the brushing results of tufts according to two comparative example embodiments;

FIG. 8 shows a graph comparing the "pulp absorption quality" of a tuft comprising cruciform filaments according to the present disclosure with the "pulp absorption quality" of a tuft according to two comparative example embodiments;

FIG. 9 shows a graph comparing the "pulp absorption rate" of a tuft comprising cruciform filaments according to the present disclosure with the "pulp absorption rate" of a tuft according to two comparative example embodiments;

FIG. 10 shows a schematic cross-sectional view of a diamond shaped filament according to the prior art;

FIG. 11 illustrates a graph comparing the gum massaging effect of a cross-shaped filament according to the present disclosure with the gum massaging effect of a round filament of the head; and

FIG. 12 shows a cluster configuration of the head that produces the data of FIG. 11.

Detailed Description

A head for an oral care implement has a longitudinal length extension extending between a proximal end and a distal end, the distal end being opposite the proximal end. The proximal end is defined as the end closest to the handle. The handle can be permanently attached to the handle or can be repeatedly attached to and detached from the handle. The head includes an outer edge surrounding an inner portion. At least two tooth cleaning assemblies of a first type are arranged at an inner portion of the head. These first type of tooth cleaning elements are tufts of filaments and are surrounded by a plurality of second type of tooth cleaning elements arranged along the outer edge.

The first type of clusters are arranged substantially parallel to each other. Each tuft extends from the mounting surface of the head in a substantially straight and perpendicular manner. The tuft has a length extension and a cross-sectional area extending substantially perpendicular to the length extension. The cross-sectional area has a rectangular or oval shape defining a longer length extension of about 4mm to about 8mm and a shorter width extension of about 1.5mm to about 2.5 mm. Alternatively, the length extension may be about 5mm to about 7mm or about 6mm to about 7mm or about 6.8mm and the width extension about 2 mm. The longer length extension defines an angle a relative to the longitudinal length extension of the head, the angle a being about 25 ° to about 60 °, or about 30 ° to about 45 °, or about 30 ° to about 35 °, or about 40 ° to about 45 °, or 35 °, or 45 °. The head may comprise at least three, preferably four, tufts of the first type.

Consumer testing has shown that such tuft patterns are perceived as very gentle in the mouth during brushing, while delivering improved cleaning performance, as compared to conventional toothbrushes (so-called "sensitive toothbrushes") having bristle patterns/structures that are perceived as soft. Toothbrushes according to the present disclosure are suitable for users with gingival sensitivity while delivering sufficient cleaning to deliver good oral health in the mouth.

Sensitive toothbrushes (i.e., toothbrushes having relatively thin filaments or filaments comprising tapered free ends) often face the challenge of combining soft filaments with some stability during use. Replacing the standard filament delivery overall softer toothbrush in a conventional toothbrush with a softer filament having a smaller diameter, but the toothbrush can easily collapse after a certain time of use because consumers typically do not automatically apply less brushing force on sensitive toothbrushes. However, "collapsed" toothbrushes (defined as toothbrushes with filaments that flex significantly) do not deliver the desired cleaning performance.

To overcome this drawback, the head according to the invention comprises tufts of the first type having a relatively large elongated, i.e. substantially rectangular or elliptical, cross-sectional shape. Such a first type of cluster may be defined as a "block cluster". The tufts of the first type are arranged in the middle or inner region/portion of the head, allowing for a higher filament density, as compared to conventional toothbrushes consisting of a large number of individual tufts having a relatively small diameter of about 1.5mm to about 2.5 mm. The high filament density at the interior portion of the head according to the present disclosure allows for a thorough polishing and slurry foaming effect as compared to conventional prior art toothbrushes.

The filaments of the first type of tuft may have a diameter of about 0.127mm (5 mils). Despite the use of relatively thin filaments (e.g., about 0.127mm), collapse of the toothbrush can be prevented in the event of relatively high compressive forces being applied to the tufts during brushing, as such forces can be absorbed and equally distributed by the large number of filaments of the first type of tufts according to the present disclosure. The first type of tufts have increased stability so as to prevent the tufts from spreading widely, while providing increased tooth cleaning efficiency. After brushing, and particularly after a longer period of time, it appears that a less used toothbrush provides greater consumer acceptance.

The first type of tufts (the longer length extensions are oriented at an angle a of about 25 ° to about 60 °, or about 30 ° to about 45 °, or about 30 ° to about 35 °, or about 40 ° to about 45 °, or 35 °, or 45 ° relative to the length extensions of the head, and the tufts are arranged substantially parallel to each other) are specifically arranged to allow for a smooth gliding effect when the toothbrush is moved in a back and forth scrubbing motion along the tooth lines. The overlap of the diagonal orientation of the first type of tufts and the corresponding tufts (when moving the toothbrush in a back and forth brushing motion) ensures that there is substantially no interruption in brushing force and load intake. With this arrangement, it is ensured that the toothbrush slides continuously along the teeth. At the same time, continuous sliding delivers gentle in-mouth perception. A common tuft arrangement comprising a large number of individual tufts provides a coarser in-mouth perception compared to a toothbrush according to the present disclosure, since an individual tuft causes a peak in brushing force when jumping from one tooth to the next, thereby hitting the latter. The head according to the present disclosure not only provides the aforementioned benefits when applying a scrubbing motion, but also provides a scrubbing motion when the head moves from the gums to the teeth.

While toothbrushes comprising tufts of the conventional type clean the outer buccal surfaces of teeth adequately, they are generally not well suited to provide adequate removal of plaque and debris from the interproximal and other hard to reach oral areas, as penetration into the interdental spaces is still relatively difficult. In particular, they are not well suited for adequately cleaning the gingival margin where plaque typically begins to grow. Therefore, in order to achieve and maintain good oral health, and prevent gingivitis, it is important to gently clean along the gum line, in particular along the gap between the teeth and the periodontal tissue (the so-called gingival sulcus), without causing irritation or recession of the gums. It is known that lack of good removal of plaque in the gingival sulcus can lead to gingivitis, i.e. inflammation of the gingival tissue.

To overcome these disadvantages, a second type of tooth cleaning element may be tufts of filaments, each tuft having a substantially circular cross-sectional area of about 1.5mm to about 2mm, or about 1.6mm in diameter. To further maximize mild in-mouth perception and mild cleansing effect, the filaments of the second type of tufts can be tapered filaments that contact the relatively sensitive gum line during brushing. The filaments of the second type of tuft may be longer than the filaments of the first type of tuft, thereby further improving access to the gingival sulcus.

Alternatively, the second type of tooth cleaning assembly may also be an elastomeric cleaning assembly. The elastomeric component may be made of a TPE material and/or may have the shape of an elastomeric wall extending along the length extension of the head. Such elastomeric walls can provide a polishing effect on the outer tooth surfaces and can more completely remove tooth staining. Alternatively, the elastomeric component may have the shape of a rubber nub or finger for stimulating and massaging the gums.

To even further maximize cleaning performance and mild in-mouth feel, the head may comprise at least one tuft of the first type, wherein the tuft is comprised of cross-shaped filaments, while at least one other tuft of the first type may comprise cylindrical filaments having a relatively small diameter, e.g., about 0.127mm (5 mils). Cruciform filaments may be combined with soft round filaments to enhance cleaning performance by virtue of the cruciform filaments while providing a density to the bristle field by using relatively thin round filaments. In other words, the at least one tuft or plurality of tufts of the first type comprising filaments having a cross-shaped cross-sectional area may be arranged in an alternating manner with the at least one tuft or plurality of tufts of the first type comprising filaments having a substantially circular cross-sectional shape.

A cruciform filament is defined as a filament having a longitudinal axis and a substantially cruciform cross-sectional area extending in a plane substantially perpendicular to the longitudinal axis. The cross-shaped cross-sectional area has four protrusions and four channels arranged in an alternating manner. The longitudinal axis of the filament is defined by the main extension of the filament. Hereinafter, the extension of the filament along its longitudinal axis may also be referred to as "longitudinal extension of the filament".

The filaments comprising at least one tuft of the first type of cruciform filament may be provided with a lower fill factor in the range of about 40% to about 55%, or in the range of about 45% to about 50%. In the context of the present disclosure, the term "fill factor" is defined as the 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 an anchor (such as a nail) is used to install the tuft within the tuft hole, a region of the anchoring device is excluded from the cross-sectional area of the tuft hole.

A fill factor of about 40% to about 55%, or about 45% to about 50%, or about 49% may exhibit a particular void volume within a tuft, yet the filaments still contact each other along a portion of the outer lateral surface. The void volume can deliver more toothpaste to the brushing process and the toothpaste can interact with the teeth for a longer period of time, which helps improve brushing. Furthermore, the void volume (i.e. the space between the filaments) obtains an increased absorption of loose plaque due to improved capillary action. In other words, such a low fill factor may result in more dentifrice/toothpaste remaining at/adhering to the filaments for a longer period of time during the brushing process. In addition, the lower cluster density avoids dentifrice spreading, which can lead to an improved overall brushing process. Toothpaste is better contained in the channel and is delivered directly in contact with the teeth during cleaning, thereby achieving a greater polishing effect, which is desirable, particularly for removing tooth discoloration. At the same time, however, a greater number of filaments are provided within the tuft due to the large cross-sectional area of the overall tuft, enabling improved brushing force and load pick-up, thereby reducing tuft splay.

In other words, a relatively low fill factor in the range of about 40% to about 55%, or about 45% to about 50%, or about 49% can provide improved brushing efficacy, i.e., better removal of plaque and debris from the surfaces of the teeth and gums due to improved capillary effect. These capillary effects may enable the dentifrice to flow towards the tip/free end of the filament, and thus, may enable the dentifrice to be used more for teeth and gums during brushing. At the same time, improved plaque and debris absorption from the tooth and gum surfaces.

In addition, due to the cruciform geometry of the filaments, each individual filament is stiffer than a round filament when made from the same amount of material. However, due to the low fill factor in the range of about 40% to about 55%, or about 45% to about 50%, or about 49%, the stiffness of the overall tuft made of cross-shaped filaments is reduced compared to a tuft of round filaments. Surprisingly, it has been found that such tufts provide an improved sensory experience, i.e. a softer feel within the oral cavity during brushing, while providing increased cleaning efficacy. The protrusions of the cruciform filaments can easily enter the gingival sulcus and other hard to reach areas, e.g. interproximal tooth surfaces, scrape on the surface to loosen plaque, and due to the improved capillary effect of the entire tuft, better plaque removal can be achieved. Due to the specific shape, the cruciform filaments may penetrate deeper into the gingival sulcus and interproximal areas. Furthermore, the relatively low fill factor of the first type of tufts enables the individual cross-shaped filaments to better conform to the contour of the gum line and gingival sulcus.

Tests have shown that a head for an oral care implement comprising a cruciform filament according to the present disclosure provides excellent cleaning performance (see fig. 7-9 and 11 in conjunction with the description below).

In addition, tests that simulate wear during consumer use show that such brush heads additionally show less wear than heads comprising tufts of cruciform filaments only. The tests set up to simulate "wear" were as follows: the toothbrush was run through a program totaling 36.000 brushing cycles, 9.000 cycles each at 0, +45, -45, and 0 between the head and the row of teeth. During these cycles, a 7.5% blend solution of Med toothpaste was dripped onto the brush head. The load on the brushhead is set to 4N. The first 9.000 cycles at an angle of 0 are defined as moving in a straight line at a length of 30mm, whereas the next three 9.000 cycles at +45, -45 and 0 are defined as moving in a figure-of-eight at a width of 22mm and a length of 40 mm. The maximum penetration depth of the filaments into the row of teeth was set at 7 mm.

Each channel of the cross-shaped filaments of at least one of the first type of tuft may have a concave curve formed by adjacent and converging protrusions. The concave curve may have a radius in a range of about 0.025mm to about 0.10mm, or about 0.03mm to about 0.08mm, or about 0.04mm to about 0.06 mm. In other words, the lateral edges of two adjacent protrusions, i.e. two adjacent sides of said protrusions, may converge at the bottom of the channel and define a "convergence zone". Adjacent projections may converge in the convergence region in a concavely curved manner (i.e., with an inwardly curved radius) formed at the bottom of the channel. The radii in such ranges are relatively large compared to standard cruciform filaments (see fig. 3 and as described further below).

It has been observed in the past that conventional cruciform filaments (e.g., as shown in fig. 5 and described further below) have the following disadvantages: these types of filaments can be easily trapped between each other during manufacturing and brushing. However, it has surprisingly been found that the specific geometry/profile of the outer surface of the filaments according to the present disclosure allows for improved manufacturability, since the probability of a filament being trapped is significantly reduced when combining a plurality of said filaments to form one tuft during the so-called "pick-up process".

In addition, the filaments provide increased stability due to the larger radius at the bottom of the channel, and therefore less filament damage occurs during the toothbrush manufacturing process, such as when the filaments are picked up and secured on the mounting surface of the brush head during a stapling or hot tufting process. In the past, it has been observed that a relatively large number of conventional cruciform filaments are damaged during the pick-up process, in particular the protrusions may detach from the filaments or the filaments are cut in a converging region at the bottom of the channel. The severed filaments can provide relatively sharp edges, which can damage/injure oral tissue during brushing.

In addition, surprisingly, it has been found that due to the specific geometry of the radii of the concave bends, the filaments within a tuft can be better filled with a relatively low fill factor (i.e., in the range of about 40% to about 55%, or in the range of about 45% to about 50%) because the gap between two adjacent filaments can be maximized. It has been found that it is important that the filaments exhibit specific interstitial regions while still being in contact with each other. To produce a toothbrush that meets regulatory requirements and is understood by the consumer as to overall appearance, a very high fill factor is typically required (about 70% to about 80% for round filaments; about 80% for diamond filaments; about 89% for trilobal filaments). With toothbrushes made by the binding process, a fill factor of less than about 70% results in insufficiently compressed filaments within the tuft holes, and thus provides insufficient tuft retention. Thus, the regulatory requirements are not met in case round filaments are provided with a fill factor below about 70%. For hot tufted toothbrushes, a fill factor of less than about 70% will allow the plastic melt to enter the tuft during the overmolding process, as the pressure of the melt pushes the filaments of the tuft to one side until the filaments contact each other. So called multi-cusps are formed, which may damage/damage the gums and thus lead to an unsafe product. In addition to regulatory and safety aspects, the low-filled clusters of round filaments will have a "wild-type" and damaged appearance, and will not be accepted by consumers. However, with the use of a cross-shaped filament having a concave curvature of the channel with a radius in the range of about 0.025mm to about 0.10mm, a low fill factor can be achieved for a compliant and safe product with an acceptable overall appearance while providing improved cleaning characteristics.

Each protrusion of the cross-shaped cross-sectional area comprises two outer lateral edges along the longitudinal extension of the filament. These lateral edges can create relatively high concentrated stresses on the tooth surface to disrupt and remove plaque. The outer edge may provide a scraping effect, allowing plaque and other debris to more effectively loosen. Due to the relatively large radius of the concave curvature at the bottom of the channel, the protrusions provide increased stiffness/stability to make it easier/effective to loosen/remove plaque from the tooth surface. The channels can then trap the plaque that is destroyed and can be removed from the teeth. As shown in fig. 7 and explained further below, tufts comprising a plurality of filaments according to the present disclosure provide improved plaque removal from buccal, lingual, occlusal and interdental surfaces as well as along the gum line, as compared to tufts of round or conventional cruciform filaments.

The cross-shaped cross-sectional area of each filament of the first type of tuft may have an outer diameter. In the context of the present disclosure, the outer diameter is defined by the length of a straight line passing through the center of the filament cross-sectional region, and its endpoints are located on the outermost circumference of the cross-sectional region. In other words, the cruciform cross-sectional area has an imaginary outer circumference in the form of a circle (i.e., an outer envelope circle), and the outer diameter is defined as the longest straight line segment of the circle passing through the center of the circle.

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

The ratio of the outer diameter to the radius of curvature of the channel may be in the 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 the range of about 2.7 to about 9.

Surprisingly, it has been found that such filament geometries provide even further improved cleaning performance while maintaining tooth brushing comfort in the oral cavity. Furthermore, it has been found that such geometries even more contribute to the appearance of reduced filament/tuft wear, as the likelihood of filaments being trapped during brushing is even less. In addition, the manufacturability of such filaments during the toothbrush manufacturing process is further improved.

Each protrusion of the cruciform cross-sectional area of a filament of a tuft of the first type may be rounded at the end, thereby forming a bend. The bend may have a diameter. The diameter of the curvature of the protrusion may be in the range of about 0.01mm to about 0.04mm, or in the range of about 0.018mm to about 0.026 mm.

The ratio of the diameter of the curvature of the protrusion to the radius of the curvature of the channel may be in the 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. The ratio is relatively low compared to a standard cross-shaped filament according to the prior art (see fig. 3 and as described further below). In other words, the radius of the concave curvature of the channel may be relatively large with respect to the diameter of the curvature of the protrusion, i.e. with respect to the width extension of the protrusion, or in other words, the diameter of the curvature of the protrusion may be relatively thin compared to the radius of the concave curvature of the channel. The relatively large radius provides a relatively thin protrusion with increased stability. Thus, there is less likelihood of the filament/protrusion being damaged or the relatively thin protrusion breaking away during the toothbrush manufacturing process, particularly when the filament is picked up. In other words, the manufacturability of such filaments during the toothbrush manufacturing process is further improved.

Additionally, surprisingly, it has been found that such filament geometries provide even further improved cleaning performance while maintaining tooth brushing comfort in the oral cavity. Furthermore, it has been found that such geometries also help to reduce the appearance of filament/tuft fraying, as the filaments are even less likely to be trapped during brushing.

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

The protrusions of the cross-shaped filaments may taper radially in an outward direction, i.e. in a direction away from the center of the cross-sectional area and towards the outer circumference. Such conical protrusions may also ensure access to narrow spaces and other hard to reach areas, and may be able to penetrate/enter even deeper and effectively into the interdental areas. Because the cross-shaped filaments have a higher bending stiffness than round filaments made of the same amount of material, the higher bending stiffness may force the protrusions of the filaments to slide more easily into the interdental areas.

The protrusions may taper radially outward at an angle in the range of about 6 ° to about 25 ° or at an angle in the range of about 8 ° to about 20 °. Surprisingly, it has been found that such tapering allows optimum interdental penetration characteristics to be obtained. In addition, such filaments can be more easily bundled in a tuft without trapping the contours of adjacent filaments.

The filaments of the first type of tuft may be substantially cylindrical filaments, i.e. the filaments may have a substantially cylindrical outer lateral surface. In other words, the shape and size of the cross-sectional area of the filament along its longitudinal axis may not substantially change, i.e. the shape and size of the cross-sectional area may be substantially constant over the longitudinal extension of the filament. In the context of the present disclosure, the term "outer lateral surface of a filament" refers to any outer face or surface of the filament on its side. This type of filament may provide increased bending stiffness compared to tapered filaments. Higher bending stiffness may further facilitate penetration of the filaments into the interdental spaces/spaces. In addition, cylindrical filaments typically wear slowly, which can provide longer filament life.

The cylindrical filaments may have a substantially end-rounded tip/free end to provide mild cleansing properties. The rounded tip prevents the gums from being injured during brushing. In the context of the present disclosure, a filament with a rounded end still falls within the definition of a substantially cylindrical filament.

Alternatively, the filaments of the first type of tuft may comprise along their longitudinal axis a substantially cylindrical portion and a tapered portion, the tapered portion tapering longitudinally towards the free ends of the filaments, and the cylindrical portion having a cross-sectional area according to the present disclosure. In other words, the filaments of the first type of tuft may be tapered filaments having a pointed tip. The tapered filaments can achieve optimal penetration into the region between two teeth and into the gingival pocket during brushing and can therefore provide improved cleaning properties. The tapered filament may have an overall length extending over the mounting surface of the head 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 measured from the tip of the filament. The tip may be needle-shaped and may include a split end or a feathered end. The tapered portion may be produced by a chemical and/or mechanical tapering process.

The filaments of the first and/or second type of tufts may be made of polyamide (e.g., nylon) with or without an abrasive such as kaolin clay, polybutylene terephthalate (PBT) with or without an abrasive such as kaolin clay, and/or a polyamide indicator material (e.g., nylon indicator material) that is colored at the outer surface. With the filaments used over time, the coloration on the polyamide indicator material may slowly fade indicating the extent to which the filaments are worn.

The filaments of the first and/or second type of tuft may comprise at least two segments of different materials. At least one segment may comprise a thermoplastic elastomer material (TPE), and at least one segment may comprise a polyamide (e.g., nylon) with or without an abrasive such as kaolin clay, polybutylene terephthalate (PBT) with or without an abrasive such as kaolin clay, or a polyamide indicator material (e.g., nylon indicator material) colored at the outer surface. These at least two segments may be arranged in a side-by-side or core-sheath configuration, which may result in a reduced stiffness of the overall filament. Having an inner/core segment comprising a harder material (e.g. polyamide or PBT) and having an outer/sheath segment surrounding the core segment and comprising a softer material (e.g. TPE) a core-sheath type structure may provide filaments with a relatively soft outer lateral surface, which may lead to mild cleansing properties.

The filaments of the first and/or second type of tuft may comprise a component selected from the group consisting of: fluoride, zinc, strontium salts, flavors, silica, pyrophosphate, hydrogen peroxide, potassium nitrate, or combinations thereof. For example, fluoride may provide a mineralisation effect and may therefore prevent tooth decay. Zinc can enhance the immune system of the user. The hydrogen peroxide can bleach/whiten teeth. Silica can have an abrasive effect to more effectively remove plaque and debris. Pyrophosphate salts inhibit the formation of new plaque, calculus and calculus along the gum line. The pyrophosphate-containing filaments provide a long lasting protection against inflammation of the gums and oral mucosa.

If a plurality of such filaments are bundled together to form a tuft, they may be arranged as follows: the filaments at the outer lateral surface of the tufts can contain pyrophosphate to inhibit the formation of plaque, tartar, and calculus along the gum line, whereas the filaments disposed in the center of the tufts can contain fluoride to mineralize the teeth during the brushing process.

At least one of the above listed components may be coated onto the sheath, i.e. onto the outer segments of the filament. In other words, at least some of the filaments of the tuft may comprise a core-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 core-shell structures can allow one or more components to be applied directly to the teeth in relatively high concentrations, i.e., one or more components can be in direct contact with the teeth during brushing.

Alternatively, at least one of the components listed above may be co-extruded with the TPE, polyamide (e.g., nylon), and/or PBT. Such embodiments may allow for the gradual application of one or more components to the teeth as the filament material slowly wears during use.

An oral care implement according to the present disclosure can be a toothbrush comprising a handle and a head. The head extends from and is repeatedly attachable to and detachable from the handle, or the head may be non-detachably connected to the handle. The toothbrush may be an electric toothbrush or a manual toothbrush.

A head for an oral care implement according to the present disclosure can include a bristle carrier provided with tuft holes (e.g., blind-end holes). A tuft according to the present disclosure may be secured/anchored in the tuft hole by a stapling process/anchor tufting method. This means that the filaments of the tuft are bent/folded in a substantially U-shaped manner around an anchor, for example a cable bolt or anchor plate, for example made of metal. The filament is pushed into the tuft hole with the anchor such that the anchor penetrates into the opposing side wall of the tuft hole, thereby anchoring/fixing/securing the filament to the bristle carrier. The anchor may be secured in the opposing sidewall by positive frictional engagement. In the case of a tuft hole being a blind-ended hole, the anchor holds the filament against the bottom of the hole. In other words, the anchor may be positioned above the U-shaped bend in a substantially vertical manner. Since the filaments of the tuft are bent around the anchor in a substantially U-shaped configuration, the first and second branches of each filament extend from the bristle carrier in the direction of the filament. The type of filaments that can be used/adapted in the binding process is also referred to as "double-sided filaments". Heads for oral care implements manufactured by a binding process may be provided in a relatively cost and time efficient manner. To enable the provision of a first type of tuft comprising a relatively large cross-sectional area, a plurality of smaller tuft holes may be provided at a minimum spacing next to each other so that a larger overall tuft may be formed.

Alternatively, the tufts may be attached/secured to the head using a hot tufting process. A method of manufacturing a head of an oral care implement may comprise the steps of: first, a tuft can be formed by providing a desired amount of filaments according to the present disclosure. Second, the tuft can be placed into the mold cavity such that the end of the filament that should be attached to the head extends into the cavity. Third, the head or oral care implement body including the head and handle may be formed around the ends of the filaments extending into the mold cavity by an injection molding process, thereby anchoring the tufts in the head. Alternatively, the tufts may be anchored by forming a first portion of the head (a so-called "sealing plate") around the ends of the filaments extending into the mold cavity using an injection molding process before the remainder of the oral care implement can be formed. Before starting the injection molding process, the end of the at least one tuft that extends into the mold cavity may optionally be melted or fusion bonded to join the filaments together in the melt or spheres so that the melt or spheres are located within the cavity. The tufts may be held in the mold cavity by a molding bar having blind holes that correspond to the desired locations of the tufts on the finished head of the oral care implement. In other words, the filaments of the tufts attached to the head using the hot-tufting process may not be doubled at intermediate portions along their length and may not be mounted in the head by using anchors/staples. The tufts may be mounted on the head using a tufting process without anchors. The hot-tufting process allows complex tuft geometries to be obtained. For example, the tufts may have a particular topography/geometry at their free ends (i.e., at their upper top surfaces), which may be shaped to best accommodate the contours of the teeth and further enhance interproximal penetration. For example, the topography may be chamfered or rounded in one or both directions, sharp, or may form straight lines, concave surfaces, or convex surfaces.

The following is a non-limiting discussion of exemplary embodiments of oral care implements and components thereof according to the present disclosure, wherein reference is made to the accompanying drawings.

Fig. 1 shows a schematic perspective top view of an exemplary embodiment of an oral care implement 10, which may be a manual or electric toothbrush 10, including a handle 12 and a head 14 extending longitudinally from the handle 12. The head 14 has a proximal end 41 that is proximal to the handle 12 and a distal end 40 that is furthest from the handle 12 (i.e., opposite the proximal end 41). Head 14 may have a substantially oval shape with a longitudinal length extension 52 and a width extension substantially perpendicular to length extension 52. Two tufts 16 of the first type comprising a plurality of cross-shaped filaments 20 and two tufts 17 of the first type comprising a plurality of round filaments having a diameter of about 0.127mm (5 mils) are arranged in an alternating manner at the inner portion 100 of the head 14.

The first type of tufts 16,17 are arranged substantially parallel to each other. Each tuft 16,17 has a substantially rectangular or oval cross-sectional shape with a longer length extension 101 of about 6.5mm to about 7mm and a shorter width extension 103 of about 1.8mm to about 2.2mm, wherein the longer length extension 101 defines an angle a with respect to the longitudinal length extension 52 of the head 14, the angle a being about 30 ° to about 45 °. The spacing 105 between the parallel tufts 16,17 can be about 0.5mm to about 0.8mm to enable a smooth gliding effect from one tuft to the other during brushing. Two additional elongated tufts 97 are adjacent tufts 16,17 at the distal end 40 and the proximal end 42 of the head 14, respectively. Tuft 97 has a substantially rectangular or oval cross-sectional shape with a longer extension 107 of about 3mm to about 3.5 mm.

A plurality of tooth cleaning assemblies of the second type 96 are arranged at an outer edge 98 of the head 14 so as to surround the tooth cleaning assemblies of the first type 16,17 and the tufts 97. The plurality of tufts 96 of the second type comprise a plurality of tapered filaments having a diameter of about 0.127mm (5 mils) or 0.1524(6 mils).

Tufts 16,17,96,97 can extend in a substantially perpendicular manner from mounting surface 18 of head 14.

The first type of cluster 16 may have a fill factor in the range of about 40% to about 55%, or about 45% to about 50%, or about 49%. The "fill factor" is defined as the sum of the cross-sectional areas 22 of the filaments 20 divided by the cross-sectional area of the tuft hole.

As shown in fig. 1, the first type of tuft 16 comprises a plurality of end-rounded cross-shaped filaments 20, one of which is shown in fig. 2. Alternatively, the filament 20 may be a tapered filament comprising a substantially cylindrical portion and a tapered portion along the longitudinal axis. The tapered portion tapers towards the free end of the filament 20 and the cylindrical portion has a cross-sectional area 22 according to the present disclosure.

Fig. 2 shows a schematic cross-sectional view of a filament 20 of a tuft 16. The filaments 20 have a longitudinal axis and a substantially cruciform cross-sectional region 22 extending in a plane substantially perpendicular to the longitudinal axis. The cruciform cross-sectional area 22 has four protrusions 24 and four channels 26. The protrusions 24 and channels 26 are arranged in an alternating manner. Each projection 24 tapers in an outward direction at an angle β in the range of about 6 ° to about 25 °, or about 8 ° to about 20 °.

The cross-sectional region 22 has an outer diameter 28 passing through the center 36 of the cross-sectional region 22 of the filament. The end point of outer diameter 28 is located on the outermost circumference 38 of cross-sectional region 22. The outer diameter 28 has a length extension in a range of about 0.15mm to about 0.40mm, or about 0.19mm to about 0.38mm, about 0.22mm to about 0.35mm, or about 0.24mm to about 0.31 mm.

Each channel 26 has a concave curvature 34, i.e., the curvature curves inwardly toward a center 36 of the cross-sectional area 22. A concave curve 34 is formed at the bottom of each channel 26 by two adjacent and converging protrusions 24. The concave curve 34 has a radius 30 in a range of about 0.025mm to about 0.10mm, or about 0.03mm to about 0.08mm, or about 0.04mm to about 0.06 mm.

The ratio of the outer diameter 28 to the radius 30 of the concave curve 34 may be in the range of about 2.5 to about 12, or about 2.7 to about 9.

Each protrusion 24 is rounded at its end to form a bend having a particular diameter 42. The diameter 42 may also be defined as a width extension 42 extending between two opposing lateral edges 44 of the tab 24. 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 in the 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.

In addition, the terminal circular diameter 42 of the protrusions 24 is defined in a range of about 6% to about 15%, or about 8% to about 12%, of the outer diameter 28 of the filament 20. For example, the diameter 42 of the terminal circle of the protrusion 24 may be in the range of about 0.01mm to about 0.04mm, or in the range of about 0.018mm to about 0.026 mm.

Fig. 3 shows a schematic cross-sectional view of a cross-shaped filament 54 according to the prior art. Filaments 54 include the following dimensions:

outer diameter 56: 0.295mm

Radius of concave curve 58 of the channel: 0.01mm

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

Taper of protrusion α: 15 degree

Diameter of curvature 62 of the projection: 0.04mm

Ratio of diameter 62 to radius 58: 4

Inner diameter 64: 0.1 mm.

Fig. 4 shows a schematic cross-sectional view of a tuft 66 having cross-shaped filaments 68 according to the present disclosure (exemplary embodiment 1). Cluster 66 has a fill factor of about 49%. The filaments 68 of tuft 66 have the following dimensions:

outer diameter 28: 0.309mm

Radius of concave curve 30: 0.06mm

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

Taper of protrusion α: 10 degree

Diameter 42 of curvature of projection 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 round filaments 74 according to the prior art. The filaments 74 have a diameter of about 0.178mm (7 mils). Such clusters 72 have a fill factor of about 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. Such clusters 76 have a fill factor of about 58% (comparative example 3).

Comparative experiment

Manipulator testing：

The tuft 66 according to fig. 4 comprising a plurality of filaments 68 (tuft diameter: 1.7mm) (exemplary embodiment 1), the tuft 72 according to fig. 5 comprising a plurality of filaments 74 (tuft diameter: 1.7mm) (comparative example 2) and the tuft 76 according to fig. 6 comprising a plurality of filaments 54 (tuft diameter: 1.7mm) (comparative example 3) were compared with respect to their plaque replacement removal efficacy on an artificial tooth (typodont).

The brushing test was performed using a robotic system KUKA 3 under the following conditions (see table 1):

TABLE 1

Fig. 7 shows the amount (%) of plaque replacement removal of exemplary embodiment 1, comparative example 2, and comparative example 3, respectively, relative to all of tooth surface 78, buccal surface 80, lingual surface 82, lingual and buccal surfaces 84, occlusal surface 86, gum line 88, and interdental surface 90.

As clearly shown in FIG. 7, exemplary embodiment 1 provides significantly improved plaque removal characteristics relative to all of tooth surface 78, buccal surface 80, lingual surface 82, lingual and buccal surfaces 84, occlusal surface 86, gum line 88 and interdental surface 90, as compared to comparative examples 2 and 3. The most significant improvement in cleaning performance occurred on occlusal surface 86 with 22% and 9% improvement, respectively.

Slurry absorption test：

Fig. 8 shows a graph comparing the "pulp absorption quality" of a tuft comprising cross-shaped filaments according to the present disclosure (exemplary embodiment 4) with the "pulp absorption quality" of a tuft comprising diamond-shaped filaments (see fig. 10) and having a fill factor of about 80% (comparative example 5) and the "pulp absorption quality" of a tuft 72 according to comparative example 2 having a fill factor of about 77%.

The filaments of exemplary embodiment 4 have the following dimensions:

outer diameter: 0.269mm

Radius of concave curve of channel: 0.05mm

Ratio of outer diameter to radius of concave curve: 5.38

Taper of protrusion α: at an angle of 14 °

Diameter of curvature of the protrusion: 0.029mm

Ratio of the diameter of the curve of the protrusion to the radius of the concave curve of the channel: 0.58

Inner diameter: 0.102mm

The filaments of comparative example 5 had the following dimensions (see fig. 12):

longer diagonal length 92: 0.29mm

Shorter diagonal length 94: 0.214 mm.

Fig. 9 shows a graph comparing the "pulp absorption rate" of exemplary embodiment 4 with the "pulp absorption rates" of comparative examples 2 and 5.

Description of the test:

the brush head comprising tufts according to exemplary embodiment 4 and comparative examples 2 and 5 was held in a horizontal position with the filaments pointing down. A bowl of toothpaste slurry (toothpaste: water 1:3) is placed under the brush head with a scale. The scale is used to measure the amount of slurry in the bowl. At the start of the test, the toothbrush was moved down at 100mm/s and immersed into the slurry to a depth of 2 mm. The toothbrush was then held in the toothpaste slurry for 5 seconds and pulled out again at 100 mm/min. The force in the vertical direction is measured over time.

FIGS. 8 and 9 clearly show that exemplary embodiment 4 provides significantly improved "slurry absorption" in terms of mass and speed as compared to comparative examples 2 and 5. The increased void volume within the clusters of exemplary embodiment 4 can improve capillary action. This results in increased absorption of the toothpaste (slurry), allowing the toothpaste to interact/assist in the brushing process for longer periods of time. The tufts of exemplary embodiment 4 can absorb more than about 50% of the toothpaste slurry at a higher absorption rate of about 50%, which results in improved tooth cleaning. In other words, the specific void volume within the tufts of exemplary embodiment 4 also enables increased absorption of loose plaque, in addition to delivering more toothpaste to the brushing process. This results in overall improved clinical performance of a toothbrush including a head having a tuft configuration according to the present disclosure.

Fig. 11 shows a graph comparing the "perceived gum massaging" characteristics of a cross-shaped filament with the "perceived gum massaging" characteristics of a round filament. As shown, brush heads 202, 204 comprising cruciform filaments having a lower stiffness (cN/mm2) (x-axis) achieve a higher level of gum massaging intensity (y-axis) than brush heads 206, 208 having round filaments. In other words, the brush heads 202, 204 provide improved gum massaging/feel due to the particular configuration of the cross-shaped filaments.

The arrangement of the tufts of brush heads 202 and 204 is shown in figure 12. The tuft configuration of brush heads 202 and 204 is as follows:

	brush head 202	Brush head 204
			Fill factor	55％	49％
Diameter of the tuft	1.7mm	1.7mm
			Outer diameter 28 of the filament	0.30mm	0.38mm

The tuft configuration of the brush heads 206 and 208 is apparent from figure 12 in conjunction with tables 2 and 3. All clusters have a diameter of 1.7 mm.

Table 2: tuft configuration for toothbrush 206

Table 3: tuft configuration for toothbrush 206

In the context of this disclosure, the term "substantially" refers to an arrangement of components or features that, while in theory would be expected to exhibit exact correspondence or behavior, may in fact render something somewhat less precise. Also, the term represents the extent to which: quantitative values, measurement values, or other related representations may vary from the stated reference without resulting in a change in the basic function of the subject matter at issue.

The dimensions and values disclosed herein are not to be understood as being strictly limited to the exact numerical values recited. Rather, unless otherwise specified, each such dimension is intended to mean both the recited value and a functionally equivalent range surrounding that value. For example, a dimension disclosed as "40 mm" is intended to mean "about 40 mm".