Toothbrush head and part thereof

Abstract

A portion (10) of a brush head, in particular a toothbrush head (12, 16), comprising: one or more bristle tufts (20) each consisting of a plurality of bristle filaments (22) connected to each other via a fusion ball (24); and a cleaning element holder (30) wherein the fused balls (24) are embedded in the material of the cleaning element holder (30) such that the one or more fused balls (24) are fully encapsulated and the bristle filaments (22) protrude from the front surface (31) of the cleaning element holder (30); wherein at least two fusion balls (24) are located at different levels in the cleaning element holder (30). Furthermore, a brushhead, in particular a toothbrush head (12, 16) comprising a portion (10) as disclosed herein, is disclosed.

Description

Technical Field

[0001] Modern brush heads, in particular toothbrush heads, exhibit a high degree of design flexibility. Several requirements, such as deep cleaning, sensitive cleaning, gum massage, cleaning teeth with braces, etc., require different brush heads including various arrangements of different types of cleaning elements. In addition, consumers also demand a good mouthfeel during brushing, which limits, for example, the size or thickness of the toothbrush head. Therefore, there is a need for an improved manufacturing method that allows a high degree of design flexibility in order to meet all the requirements of a modern toothbrush. For example, different cleaning elements, such as elastomeric cleaning elements and different types of bristle tufts, must be securely arranged together at one brush head. The present invention relates to a brush head or part thereof that shows a high variability of different types of cleaning elements. Background Art

[0002] Methods for producing brush heads or parts thereof are known in the prior art. Fusing the ends of bristle tufts to form a fused ball is an important step in most methods. The resulting fused ball not only connects the individual bristle filaments of one bristle tuft to each other, but also helps to securely mount the bristle tuft in the brush head. In particular, a fused ball that is larger than the bristle tuft can anchor the bristle tuft in the brush head.

[0003] One production method using such anchoring is the anchor-free tufting (AFT) method developed by Bart G. Boucherie. Thus, the bristle tufts are pushed through the holes of a perforated plate, and the ends of the tufts that are not intended for cleaning are fused by applying heat energy. The fused balls thus formed are larger than the holes so that the bristle tufts are stuck at the back side of the perforated plate. The fused balls can also be combined with the perforated plate, for example by applied heat energy or by ultrasonic welding; the perforated plate is then mounted together with the bristle tufts into the brush head (EP1142505B1). The uniform size, form and shape of the fused balls are not important for the AFT method.

[0004] In contrast, in the hot tufting method developed by Ulrich Zahoransky, the bristle tufts are arranged in the holes of the mold bar so that the fused balls can be used for overmolding by the plastic material. During the overmolding, the brush head is at least partially formed and the bristle tufts and the formed brush head are combined. Due to the fused balls that are larger than the bristle tufts themselves, undercuts are formed during the overmolding process so that the bristle tufts and the brush head are firmly combined. The hot tufting method can be used to meet the geometric requirements of the brush head to be formed.

[0005] There is a continuous demand in toothbrush manufacturing to further increase the flexibility of brush head design. Thus, different types of cleaning elements and different types of bristle tufts must be securely included in one brush head. Summary of the invention

[0006] According to one aspect, a brush head is provided, in particular a part of a toothbrush head, the part comprising:

[0007] - one or more bristle tufts, each consisting of a plurality of bristle filaments connected to one another via a fused ball at the end opposite to the end intended for cleaning;

[0008] - a cleaning element holder comprising a front surface, a rear surface and a thickness, wherein the one or more fused balls of the one or more bristle tufts are embedded in the material of the cleaning element holder such that the one or more fused balls are fully encapsulated and the bristle filaments protrude from the front surface of the cleaning element holder; and

[0009] At least two of the fused balls are located at different levels in the cleaning element holder.

[0010] According to another aspect, there is provided a brush head, in particular a toothbrush head, comprising parts of a brush head as disclosed herein.

[0011] According to another aspect, there is provided a (toothbrush head) brush head or a part thereof manufactured by the method as described herein. BRIEF DESCRIPTION OF THE DRAWINGS

[0012] Figure 1A An exemplary embodiment of a cleaning element holder 30 having a central protrusion 37 is shown in side view;

[0013] Figure 1B An exemplary embodiment of a cleaning element holder 30 having a central protrusion 37 and a central depression 35 is shown in cross-section;

[0014] Figure 1C An exemplary embodiment of a cleaning element holder 30 including bristle tufts 20 having a central protrusion 37 is shown in side view;

[0015] Figure 1D A cross-sectional view of an exemplary embodiment of a cleaning element holder 30 including bristle tufts 20 arranged to a bristle field 28 having a central protrusion 37 and a central recess 35 is shown;

[0016] Figure 2A , Figure 2B The gap 38 ( Figure 2A ) of a cross-sectional view of an exemplary embodiment of a cleaning element holder 30, the voids may be filled with elastomeric cleaning elements 40 ( Figure 2B );

[0017] Figure 2C , Figure 2DThe drive portion 44 ( Figure 2C ) is a cross-sectional view of an exemplary embodiment of a cleaning element holder 30, wherein the driving portion is securely connected to the cleaning element holder 30 via a cover 46 ( Figure 2D );

[0018] Figure 2E A cross-sectional view of an exemplary embodiment of a cleaning element holder 30 including a drive portion 44, elastomeric cleaning elements 40, and bristle tufts 20 is shown;

[0019] Figure 3 a)-i) show schematic diagrams of a method for producing a cleaning element holder 30;

[0020] Figure 4A , Figure 4B A manual toothbrush 14 ( Figure 4A ) and replacement brush heads 19 ( Figure 4B ) is a schematic cross-sectional view of

[0021] Figure 5 A top view of a perforated plate 60 including three dies for forming cleaning element holders 30 is shown. DETAILED DESCRIPTION

[0022] The following is a description of many embodiments of methods of producing a brush head or part thereof and a brush head or part thereof produced by the methods as disclosed herein. This description should be regarded as merely exemplary and does not describe every possible embodiment, since it would be impractical, if possible, to describe every possible embodiment, and it should be understood that any feature, characteristic, structure, component, step or methodology described herein may be deleted, combined with or replaced by any other feature, characteristic, structure, component, product step or methodology described herein, in whole or in part. In addition, a single feature or (sub)combination of features may be inventive, regardless of the combination of features provided in the claims, the corresponding part of this specification or the drawings.

[0023] The unit "cm" used herein means centimeter. The unit "mm" used herein means millimeter. The unit "μm" or "micrometer" used herein means micrometer. The unit "mil" used herein means one thousandth of an inch.

[0024] As used herein, the word "about" means + / - 10%.

[0025] As used herein, the word "comprise" and its variations are intended to be non-limiting, such that recitation of items in a list is not to the exclusion of other similar items that may also be useful in the materials, devices, and methods of the present invention. The term includes "consisting of" and "consisting essentially of."

[0026] As used herein, the words "includes" and variations thereof are intended to be non-limiting, such that recitation of items in a list is not to the exclusion of other similar items that may also be useful in the materials, apparatus, and methods of the present invention.

[0027] As used herein, the words "preferred", "preferably" and their variations such as "especially" and "particularly" refer to embodiments of the present invention that provide particular benefits under particular circumstances. However, other embodiments may also be preferred under the same or other circumstances. In addition, the recitation of one or more preferred embodiments does not imply that other embodiments are not useful, and is not intended to exclude other embodiments from the scope of the present invention.

[0028] The present invention provides a method for producing a brush head, specifically a toothbrush head or part thereof, the method comprising providing at least two bristle clusters comprising a plurality of bristle filaments, wherein at least two bristle clusters differ in at least one attribute. As used herein, the term "bristle cluster" is understood to be a bristle filament of a predefined length of any shape, form, size and / or arrangement. A bristle cluster can be formed by any geometric shape, form or arrangement produced by grouping individual bristle filaments. The standard shape given as an example is a circular bristle cluster, an elliptical bristle cluster, a sickle-shaped bristle cluster, a bristle cluster strip or a combination thereof. In addition, two or more bristle clusters can also be arranged into a cluster-in-cluster arrangement, wherein the shape of each single cluster can be the same or different and combined with the alternative scheme given above. For example, a circular cluster can be arranged in a circular cluster, or a circular cluster can be arranged in an elliptical cluster, or a strip cluster can be arranged in a circular cluster, etc. In a cluster-in-cluster arrangement, two clusters can be different in at least one attribute or can be the same about at least one attribute. At least two bristle clusters differing in at least one property are arranged in a perforated plate comprising a front surface, a rear surface, a thickness and one or more holes (preferably a plurality of holes), wherein the one or more holes (preferably a plurality of holes) are distributed in the perforated plate according to the desired bristle area of ​​the brush head or part thereof to be produced.

[0029] The perforated plate will be disclosed in more detail below. In one embodiment, the perforated plate comprises a front surface, a rear surface, a thickness and one or more holes (preferably a plurality of holes), wherein the holes may be grouped into more than one hole arrangement, wherein the more than one hole arrangement may be identical or different from each other, preferably identical or different with respect to the number of holes, the shape of the holes, the size of the holes, the distance between the holes and their combination. This means that the perforated plate may comprise a plurality of hole arrangements, wherein each arrangement corresponds to a desired bristle area of ​​a brush head to be produced or a portion thereof, preferably in a circular or elongated form, more preferably in the form of a head of a manual toothbrush or a head of a replacement brush head for an electric toothbrush. Alternatively, the perforated plate may comprise only one hole arrangement corresponding to the desired bristle area. Preferably, the perforated plate comprises the same hole arrangement, more preferably, the perforated plate comprises 4 identical hole arrangements. In addition, more than one perforated plate (e.g., two perforated plates) may be combined into a larger perforated plate. The number of holes in one arrangement may be in the range of 1 to 60 holes, preferably 10 to 60 holes, more preferably 15 to 40 holes, more preferably 15 to 35 holes, more preferably 15 to 30 holes. The distance between adjacent holes in one arrangement is in the range of 0.2 mm to 2.0 mm, preferably in the range of 0.4 mm to 1.8 mm, more preferably in the range of 0.5 mm to 1.2 mm. The distance between adjacent arrangements in one perforated plate is defined by the design and the molding process used, and may be at least 2 mm, in particular in the range of 2 mm to 40 mm.

[0030] The shape of the hole in the perforated plate corresponds to the shape of the bristle tuft that should be located in the corresponding hole. The bristle tuft can be manufactured in any form, wherein the form can be adapted according to the function of the tuft, the position of the tuft in the bristle area, the form of the cleaning element support and / or their combination. During the positioning of the bristle tuft in the hole of the perforated plate, the bristle tuft adapts the shape of the hole and can be fixed into this shape during further processing steps such as fusion. The suitable shape of the hole of the perforated plate is circular, semicircular, sickle-shaped, elliptical, elongated, angled, for example quadrilateral, trapezoid, pentagon, hexagon, heptagon, octagon or their mixture. All different shapes can be combined with each other, for example, a semicircular shape can be combined with a quadrilateral shape, or a trapezoidal shape can be combined with a sickle shape. The preferred hole of the perforated plate is circular, oval, semicircular, sickle-shaped, elongated or angled, more preferably circular or oval.

[0031] Additionally or alternatively, the size of the holes depends on the clusters to be integrated. Thus, the size of the holes may be about 0.6 mm 2 To about 40mm 2 The appropriate size of the hole for a round standard bristle tuft is 0.6 mm. 2 Up to 3mm 2 In the range of 1.0 mm, preferably 1.0 mm 2 Up to 2mm 2More preferably, about 1.5 mm 2 In addition or alternatively, the perforated plate may also include holes for bristle tufts having a plurality of the sizes of standard bristle tufts, specifically 2 to 25 bristle tufts, more specifically 2 to 15 bristle tufts, more specifically 5 to 10 bristle tufts. A preferred embodiment of a large tuft comprising more than one standard tuft size may be, for example, a block bristle tuft comprising a combination of about 5 to 15 bristle tufts. Thus, a preferred range of holes for block tufts may be about 8 mm. 2 To about 24mm 2 More preferably, about 8 mm 2 To about 16mm 2 within the range.

[0032] The perforated plate to be used in the method as disclosed herein can be made of any suitable material that is resistant to the method steps disclosed herein and can be formed. Heat-resistant materials are preferred because the perforated plate as disclosed herein is particularly used as a part of the mold. As used herein, suitable materials for the perforated plate are any heat-resistant material, specifically metals and metal alloys (such as steel, specifically stainless steel), heat-resistant plastics (specifically polytetrafluoroethylene (PTFE) or polyetheretherketone (PEEK)), ceramics or combinations thereof. The perforated plate can be produced by any method that allows the formation of high-precision parts, such as metal casting (especially aluminum casting), 3D printing, vitrification, pulsed electrochemical machining (PECM), molding. Depending on the manufacturing method used, the perforated plate can be a single component or a base component comprising several component parts. For example, the base component can be made of steel, including a cavity for the plug-in, including a hole arrangement as described above. Such an arrangement allows different bristle areas to be manufactured using one base component only by changing the hole arrangement. In addition, the hole arrangement that needs to have high quality and high precision can be produced independently of the base component.

[0033] In a preferred embodiment, the perforated plate may include an uneven front surface, preferably in the area of ​​the hole arrangement, more preferably wherein the front surface in the area of ​​the hole arrangement is a convex surface. Thus, the holes of one arrangement may be located at different levels of the perforated plate. For example, the front surface may include a protrusion located in the area of ​​at least one hole arrangement, or the front surface may include one or more protrusions located in the area of ​​each hole arrangement. In a preferred embodiment, the one or more protrusions in the front surface of the perforated plate are central protrusions. The central protrusion may include the area of ​​at least one hole of the perforated plate belonging to one bristle tuft arrangement and the area of ​​up to all holes. In addition or alternatively, the one or more protrusions (specifically the central protrusion) may cover at least 10% of the area of ​​the front surface, preferably at least 15% of the area of ​​the front surface, more preferably at least 20% of the front surface. The central protrusion may protrude from the front surface by about 0.2mm to about 0.6mm, preferably from about 0.3mm to about 0.5mm, more preferably from about 0.35mm to about 0.45mm, and even more preferably the central protrusion protrudes from the front surface by about 0.4mm.

[0034] According to the method as disclosed herein, the perforated plate as disclosed herein comprises through holes for the generation of bristle tufts, i.e. holes are generated as long as the plate is thick and the bristle tufts can be repositioned in the holes and at different distances from the front surface of the perforated plate. In addition, the perforated plate may also comprise blind holes, wherein the blind holes can be used for elastomeric cleaning elements.

[0035] A suitable thickness of the perforated plate may be in the range of 5 mm to 20 mm, preferably 6 mm to 14 mm. In addition, the perforated plate may comprise more than one layer, in particular wherein the more than one layer may consist of different materials. Suitable materials for the first layer comprising the front surface are heat-resistant and allow the formation of high-precision holes, such as stainless steel. Suitable materials for the second layer may be less heat-resistant, such as plastic materials. In addition, the perforated plate may also be combined with a stopper plate. Therefore, the rear surface of the perforated plate may be combined with such a stopper plate, wherein the stopper plate may comprise a flat surface or may comprise protrusions corresponding in form and shape to the hole arrangement. The stopper plate may be used, for example, to arrange the bristle tufts orthogonally in the holes, in particular for changing and / or repositioning the position of the bristle tufts in the holes of the perforated plate during different process steps.

[0036] At least one property of at least two bristle tufts that are different according to the method as disclosed herein is selected from the size of the bristle tufts, the form of the bristle tufts, the position of the bristle tufts in the perforated plate and / or in the desired bristle area of ​​the brush head to be produced, the material of the bristle filaments, the color of the bristle filaments, the diameter and / or cross-section of the bristle filaments, the shape of the bristle filaments, the additives present in the bristle filaments or a combination thereof.

[0037] As used herein, the term "bristle field" shall refer to an arrangement of more than one, preferably a plurality of bristle tufts. Thus, the term is used independently of the location of the arrangement, for example the bristle field may be arranged in a perforated plate, in a mold bar, in a portion of a brush head, in a brush head or in a toothbrush.

[0038] The bristle filaments may be monofilaments made of plastic material, for example. Suitable plastic materials for the bristle filaments may be polyamide (PA), in particular nylon, polyamide 6.6, polyamide 6.10 or polyamide 6.12, polybutylene terephthalate (PBT), polyethylene terephthalate (PET) or mixtures thereof.

[0039] The circumference of the bristle filaments can be substantially circular, or the circumference can include one or more recesses (such as X-band bristle filaments) or can vary along the long axis of the bristle filaments. The diameter of the circular bristle filaments can be in the range of about 4 mil (0.1016 mm) to about 9 mil (0,2286 mm), specifically in the range of about 4 mil (0.1016 mm) to about 7 mil (0.1778 mm), more specifically in the range of about 5 mil (0.127 mm) to about 6 mil (0.1524 mm), or any other range that is narrower and falls within the above-mentioned broader range, as if these narrower ranges are expressly stated herein.

[0040] In addition, ultrafine bristle filaments are used in toothbrushes relative to standard bristle filaments having diameters as given above. Ultrafine bristle filaments have a smaller diameter than standard bristle filaments and may behave like dental floss during normal brushing. The diameter of the ultrafine bristle filaments may range from about 2 mil (0.0508 mm) to about 4 mil (0.1016 mm), or any other range that is narrower and falls within the above-mentioned broader ranges, as if these narrower ranges are expressly stated herein. The manufacturing tolerance for bristle filament diameter is 10%.

[0041] In addition to bristle filaments with a substantially constant diameter, bristle filaments whose diameter decreases towards the end can also be used. These kinds of tapered bristle filaments are based on standard diameter bristle filaments whose ends are chemically tapered. Suitable tapered bristle filaments are provided by, for example, BBC (Korea).

[0042] In addition, bristle filaments including irregular diameters, i.e., including at least one recess, can be used. As understood herein, a "recess" in the circumference, diameter, cross-section and / or volume of a bristle filament should mean any recess, cavity, slot or other geometric recess that modifies the volume of the bristle filament. A bristle filament having at least one recess on its circumference may have one or more recesses along the circumference of the bristle filament. A suitable example of a bristle filament including at least one recess is an X-shaped bristle filament. The X-shaped bristle filament has four recesses and two lines of reflected symmetry, each line of reflected symmetry passing through two recesses positioned relative to each other. In addition, all four recesses may be identical. The angle of the X-shaped bristle filament may be in the range of about 40° to about 160°.

[0043] The length of bristle filaments depends on the intended use. Typically, bristle filaments can have any suitable length for transportation, such as about 1300mm, and then cut into segments of desired length. The length of the bristle filaments in a toothbrush affects the bending force required to bend the bristle filaments. Therefore, the length of the bristle filaments can be used to achieve the different stiffness of the bristle filaments in the bristle area of ​​the brush head. The typical length of the bristle filaments for a brush (specifically a toothbrush) can be in the range of about 5mm to about 20mm, specifically in the range of about 6mm to about 15mm, more specifically in the range of about 7mm to about 12mm, or any narrower and other numerical ranges falling within the above-mentioned wider numerical ranges, just as these narrower numerical ranges are all clearly stated herein.

[0044] In addition, the bristle filament material may include additives, such as abrasives, coloring pigments, spices, etc., to provide indicator filaments. "Indicator filaments" as understood herein are any elements that are modified over time and / or used to indicate the state of the toothbrush. For example, the indicator element may change or wear its color over time and / or use. During use, the coloring on the outside of the material slowly fades to indicate the degree to which the bristle filaments are worn. Suitable additives for the bristle filaments of the bristle tufts are, for example, ultraviolet fluorescent (UV) brighteners, signal substances, such as indicator coloring pigments and / or abrasives. For example, abrasives such as kaolin and / or colored bristle filaments at the outer surface may be added.

[0045] Several bristle filaments are grouped to form a bristle tuft. As used herein, the term "bristle tuft" is understood to be a bristle filament of predefined length of any shape, form, size and / or arrangement. A bristle tuft can be formed by any geometric shape, form or arrangement produced by grouping individual bristle filaments. The standard shapes given as examples are circular bristle tufts, oval bristle tufts, sickle-shaped bristle tufts, bristle tuft strips, or a combination thereof. The filaments for forming a suitable number of bristle tufts can be, for example, in the range of about 10 to about 80 filaments, or in the range of about 15 to about 60 filaments, or in the range of about 20 to about 50 filaments, or in any narrower and other numerical ranges falling within the above-mentioned wider numerical ranges, as these narrower numerical ranges are clearly stated herein.

[0046] After at least two bristle tufts are arranged in a perforated plate, an energy source (specifically a thermal energy source) is arranged at a predetermined distance from the front surface of the perforated plate, so that the ends of the at least two bristle tufts and the energy source are arranged in non-contact. In addition, at least two bristle tufts are arranged in a fusion position, wherein the ends of at least two bristle tufts to be fused are arranged in the perforated plate and at different distances from the front surface, resulting in different distances between the ends of the bristle tufts and the energy source, wherein the distance is adjusted according to at least one property of the at least two bristle tufts. Due to the different distances, the ends of the bristle tufts will melt identically, although they provide at least one different property. As used herein, the term "identically melted" shall mean that the fusion process of at least two different bristle tufts is standardized so that fused balls of similar form and shape are formed within the same fusion time.

[0047] After arranging the at least two bristle tufts in the fusion position energy, heat energy is supplied from the energy source to the ends of the at least two bristle tufts, in particular until a fusion ball is formed at the ends of the at least two bristle tufts.

[0048] The bristle filaments of a bristle tuft are connected to each other at one end and form a fused ball. As used herein, the term "fused ball" should be understood as the molten filament material connecting the bristle filaments of a bristle tuft after the fusion process. The fused ball can have any shape or form, including but not limited to a plane, a plane with a recessed portion, a plane with a concave surface, a plane with a convex surface, a mushroom head, a dome-shaped head, or a combination thereof. The size of the fused ball is based on the requirements to be met. The two main requirements are to ensure that the cluster is firmly connected to the brush head (cluster retention) and that the individual filaments are firmly combined with each other according to government regulations (filament retention).

[0049] The formation of the fusion ball during the fusion process will now be described in more detail. As used herein, the term "fusion process" should be understood as the entire process of applying energy (specifically heat energy) from an energy source to the end of at least one bristle tuft so as to form a fusion ball at the end of the bristle tuft. A non-restrictive exemplary fusion process begins with applying energy to the end to be fused of the at least one bristle tuft. Thus, the ends of the bristle filaments soften, whereby the bristle filament ends of the bristle filaments located at the bristle tuft profile soften faster than the bristle filament ends of the bristle filaments located in the middle of the bristle tuft. Without being limited by theory, it is believed that the bristle filaments located in the middle of the bristle tuft are shielded by the bristle filaments located outside the bristle tuft to avoid being subjected to the energy applied by the energy source. After softening, the bristle filament material melts and begins to flow along the bristle filaments. Thus, the free space between the bristle filaments of a bristle tuft is filled with molten material. In addition, the molten material flows downward at the contour of the bristle tuft and the contour of the bristle tuft at the end of the bristle tuft increases, so that the protrusion is formed by the fused ball at the end of the bristle tuft. At this stage, the form of the fused ball can be described as a plane or concave plane with a central depression. If more heat energy is applied, more bristle tuft material melts and combines with the already formed fused ball. As a result, the form of the fused ball changes and the molten material accumulates at the end of the bristle tuft, thereby forming a convex plane. If more heat energy is applied, the material that previously flowed downward at the contour will also accumulate at the top of the end of the bristle tuft, and a mushroom head or dome-shaped fused ball will eventually be constructed. The fusion process can be interrupted at any time, specifically, when the form and shape of the fused ball meet the requirements of the further use of the bristle tuft. The fusion process as described herein can be performed by a horizontal or vertical arrangement of the perforated plate of the bristle tuft. The vertical arrangement may be preferred because the vapor or steam that may be generated during the fusion process can be removed and will not accumulate on the surface of the energy source. In addition, the energy source is not deformed during the fusion process.

[0050] According to the present disclosure, it is preferred to fuse at least until the ends of the bristle tufts are fully melted. As used herein, the term "fully melted" should be understood as applying energy (preferably thermal energy) to the ends of the bristle filaments until the material of the bristle filaments softens and melts, and the molten material forms any kind of fused ball as defined above.

[0051] The preferred form of the fused ball according to the invention is a plane, a plane with a depression, in particular a plane with a central depression, a concave plane, a slightly convex plane, a convex plane or a combination thereof. Preferably, the fused ball has the form of a plane. Thereby, the geometrical profile of the plane is defined by the geometrical profile of the bristle tufts, which is defined and fixed by the geometry and form of the holes in the perforated plate. For example, a circular bristle tuft will form a disc-shaped plane, an elliptical bristle tuft will form an elliptical plane, a sickle-shaped bristle tuft will form a sickle-shaped plane, and a bristle tuft strip will form a plane in the form of a strip.

[0052] In addition, the preferred profile of the plane is greater than the profile of the bristle tuft, so that the fused ball forms a protrusion at the end of the bristle tuft. Specifically, the ratio of the profile of the fused ball of the bristle tuft to the profile of the bristle tuft is at least 1.05:1, preferably at least 1.1:1, more preferably at least 1.2:1, more preferably at least 1.3:1. In subsequent processes, such as molding of the brush head or part thereof, the protrusion will form an undercut to firmly connect the bristle tuft to the brush head or part thereof.

[0053] The end of the bristle tuft opposite the fused ball represents the end intended to clean teeth. The ends of the bristles intended for cleaning can be cut to a special profile, can be tapered, can be rounded at the ends and can be polished to provide a safe and comfortable bristle tuft that will not harm the soft tissue in the oral cavity.

[0054] According to the method as disclosed herein, the distance between the energy source (specifically a thermal energy source) and the ends of the bristle tufts to be fused is adjusted according to the properties of the bristle tufts, such as the size of the bristle tufts, the form of the bristle tufts, the position of the bristle tufts in the perforated plate and / or in the desired bristle area of ​​the brush head to be produced, the material of the bristle filaments, the cross-section and / or diameter of the bristle filaments, the shape of the bristle filaments, the color of the bristle filaments, the additives present in the bristle filaments, or a combination thereof. All these properties affect the energy intake, specifically the thermal energy intake of the bristle tufts, and therefore the fusion process of each bristle tuft. Therefore, the ends of the bristle tufts are arranged at different distances from the energy source in order to standardize the fusion process again.

[0055] A suitable distance from an energy source (e.g., a thermal energy source) to the front surface of the perforated plate is in the range of 0.5 mm to 1 mm, preferably in the range of 0.5 mm to 4 mm. The bristle tufts protrude from the perforated plate, and the more the bristle tufts protrude from the perforated plate, the smaller the distance between the ends of the bristle tufts to be fused and the energy source.

[0056] As disclosed herein, properties affect the melting of bristle tufts and the formation of fused balls. For example, the position of the bristle tufts in the perforated plate and / or in the desired bristle zone of the brush head to be produced affects the fusion process. Without being bound by theory, it is believed that the bristle tufts arranged at the periphery of the bristle zone shield the bristle tufts arranged in the middle of the bristle zone. The more bristle tufts arranged around the object bristle tuft, the more thermal energy is shielded. Therefore, if all bristle tufts in the bristle zone should be fused at the same time and the fused balls should be similar, preferably formed substantially identically, the shielding effect can be balanced by reducing the distance between the ends of the bristle tufts and the energy source. For example, when multiple bristle tufts are arranged in the perforated plate, in the fusion position, the distance between the energy source and the ends of the bristle tufts of the bristle tufts arranged in the middle of the multiple bristle tufts is shorter than the distance between the energy source and the ends of the bristle tufts of the bristle tufts arranged in the periphery of the multiple bristle tufts, preferably, the distance between the energy source and the ends of the bristle tufts of the bristle tufts arranged in the center of the multiple bristle tufts is the shortest.

[0057] Similar effects are also shown with respect to the size of the bristle tufts or the form of the bristle tufts. In larger bristle tufts, the central filaments are shielded from energy during the fusion process. The effect is also affected by the form of the bristle tufts, as the shielding effect of round bristle tufts is greater than that of elongated strip bristle tufts. Without being bound by theory, it is believed that the formation of a central depression in the plane during the formation of the fused ball is based on the shielding of the inner bristle filaments by the outer bristle filaments. Therefore, larger bristle tufts and / or bristle tufts with larger cross-sections are arranged at a smaller distance from the energy source than smaller bristle tufts and / or bristle tufts with smaller cross-sections. According to the method as disclosed herein, in the fusion position, the distance between the energy source and the bristle tuft end of the bristle tuft decreases with the increasing cross-section of the bristle tuft.

[0058] In addition or alternatively, the fusion process is also affected by the properties of the bristle filaments, such as the material, diameter, cross-section, shape, color of the bristle filaments or the presence of further additives in the bristle filaments. For example, in the fusion position, the distance between the energy source (particularly the thermal energy source) and the end of the bristle tuft is adjusted according to the material of the bristle tuft, wherein preferably, the distance for a bristle tuft comprising bristle filaments made of polyamide (PA), particularly nylon, polyamide 6.6, polyamide 6.10, or polyamide 6.12 is greater than the distance for a bristle tuft comprising filaments made of polybutylene terephthalate (PBT) or polyethylene terephthalate (PET).

[0059] Additionally or alternatively, the fusing process is also slightly affected by the color of the bristle filaments. For example, the distance between the energy source and the end of the bristle tuft of a bristle tuft comprising green bristle filaments may be selected to be greater than the distance between the energy source and the end of the bristle tuft of a bristle tuft comprising filaments of any other color.

[0060] In addition or alternatively, the fusion process may also be affected by the size of the bristle filaments, specifically the diameter and / or cross-section of the bristle filaments. Without being bound by theory, it is believed that, for example, smaller bristle filaments melt faster than larger bristle filaments, and / or X-shaped bristle filaments melt faster than round filaments. For example, according to the method disclosed herein, in the fusion position, the distance between the energy source (specifically a thermal energy source) and the end of the bristle tuft of a bristle tuft including bristle filaments with smaller diameters and / or cross-sections may be greater than the distance between the energy source and the end of the bristle tuft of a bristle filament including bristle filaments with larger diameters and / or cross-sections, preferably wherein the distance may decrease with increasing bristle filament diameter and / or cross-section, more preferably wherein the distance may decrease when the bristle filament diameter is from about 2 mil (0.0508 mm) to about 9 mil (0,2286 mm). Additionally or alternatively, in the fused position, the distance between the energy source and the tuft ends of bristle tufts comprising bristle filaments having an X-shaped diameter may be greater than the distance between the energy source and the tuft ends of bristle tufts comprising bristle filaments having a circular diameter.

[0061] Another property that can affect the fusion process and therefore the fusion position of the bristle tuft is the presence or absence of an additive in the bristle filaments. The additive can slow down and / or speed up the fusion process by absorbing or reflecting thermal energy during the use process. For example, in the fusion position, the distance between the energy source (e.g., a thermal energy source) and the end of the bristle tuft including bristle filaments containing an additive (e.g., clay or titanium dioxide) is shorter than the distance between the energy source and the end of the bristle tuft including filaments without the additive.

[0062] The effects of all the properties of the bristle tufts and bristle filaments as disclosed above may compensate for each other or may enhance each other. For example, a bristle tuft with a smaller cross section located in the middle of the bristle zone may undergo a fusion process similar to a bristle tuft with a larger cross section located outside the bristle zone. Therefore, according to the method as disclosed herein, all the properties of the bristle tuft are taken into account by adjusting the distance from the end of the bristle tuft to the energy source. Preferably, the effects of some properties are evaluated to be greater than the effects of other properties. In a preferred embodiment of the method as disclosed herein, the distance between the end of the bristle tuft and the energy source (e.g., a thermal energy source) is adjusted according to the size and / or cross section of the bristle tuft, the position of the bristle tuft in the bristle zone, or a combination thereof, and more preferably the distance between the end of the bristle tuft and the energy source (e.g., a thermal energy source) is adjusted according to the position of the bristle tuft in the bristle zone.

[0063] Any suitable energy source capable of producing the required amount of energy can be used for the fusion process as disclosed herein. For example, a thermal energy source can be used, the thermal energy source being a heater, preferably a convection heater, a thermal radiation heater, an infrared radiation lamp, etc. Alternatively, the heater can be a heating plate, more preferably, wherein the heating plate is at least partially made of a conductive material for emitting thermal radiation when an electric current flows through the conductive material. Suitable heating sources are disclosed, for example, in WO2015 / 094991A1, which is incorporated herein by reference. For example, the thermal energy source may include a heating plate, which is at least partially made of a conductive material for emitting thermal radiation when an electric current flows through the conductive material. The heating plate may be structured so that at least two heating sections each including a conductive material are formed, the at least two heating sections are separated from each other by at least one separation section arranged to at least emit less thermal radiation than the heating section, and each heating section has a heating surface on the heating side of the heating plate, wherein each of the heating surfaces has a thickness of about 0.25 mm. 2 To about 250mm 2 In particular, at least one of the heating surfaces has an area of ​​less than 100 mm 2 area.

[0064] The heating surface may be heated to such an extent that the heat radiation is sufficient to melt the ends of the bristle tufts arranged at a specific distance in the emission direction. During the fusion process, the distance between the ends of the bristle tufts and the heating surface may be in the range of about 0.05 mm to about 5 mm, preferably in the range of about 0.1 mm to about 2 mm, and adjusted according to the properties of the bristle tufts as disclosed herein. The temperature of the heating surface may be in the range of about 500 degrees Celsius to about 800 degrees Celsius, and the application time of the heat energy from the heat energy source during fusion may be in the range of 1 second to 15 seconds, preferably 2 seconds to 12 seconds, more preferably 3 seconds to 10 seconds, more preferably 4 seconds to 8 seconds, more preferably 5 seconds to 7 seconds. A suitable heat energy flow (Φ) is from the heat energy source to at least two bristle tuft ends located in the perforated plate, wherein the temperature in ° C measured with an emissivity of 0,88 is in the range of 500°C to 1000°C, preferably 600°C to 900°C, more preferably 650°C to 850°C.

[0065] The heating surface of the heating section of the heating plate may be made of an electrically conductive material having a higher electrical resistance than the electrically conductive material forming at least one separation section at least partially adjoining the heating section. For example, this may be a layer of electrically conductive material at the location of the heating section which is thinner than the layer thickness of the electrically conductive material at least partially forming the separation section and / or this may be an electrically conductive material having a higher resistivity than the electrically conductive material at least partially forming the separation area for realizing the heating section. When sufficient current flows through the heating section (i.e. a current of typically up to 200 Amperes), sufficient heat radiation will be emitted. The layer thickness of the conductive material forming the heating section may be, for example, about or below 1.0 mm, in particular below 900 μm, below 800 μm, below 700 μm, below 600 μm, below 500 μm, below 400 μm, below 300 μm, below 200 μm, or below 100 μm, preferably in the range of 250 μm to 750 μm or in the range of about 400 μm to about 600 μm. The layer thickness of the conductive material in the separation section may be above 1.0 mm, in particular above 1.5 mm, above 2.0 mm, above 3.0 mm, above 4.0 mm, above 5.0 mm, or above 10 mm.

[0066] As a heating zone, a structured part of the heating plate is understood in this context to include an electrically conductive material, which structured part has a heating surface on the heating side of the heating plate, which heating surface tends to emit a higher amount of thermal radiation than surface areas of a separated section at least partially adjoining the respective at least two heating zones, in particular because the heating zone comprises an electrically conductive material having a higher electrical resistance than the electrically conductive material in adjacent (i.e. adjoining) areas of the heating plate, or because the heating zone is embedded in an insulating material.

[0067] Electrical resistivity, ρ (also known as resistivity, specific resistance, or volume resistivity) quantifies how strongly a given material opposes the flow of electric current. Low resistivity indicates a material that readily allows charge to move. For example, 18% chromium / 8% nickel austenitic stainless steel has a resistivity of ρ steel =6.9.10 -7 Ωm, the resistivity of copper is ρ copper =1.68·10 -8 Ωm, the resistivity of PET (polyethylene terephthalate) is ρ PET =1.0·10 21 Ωm (all values ​​are given for a temperature of 20°C). Resistivity is a material property. The resistance R of a piece of resistive material having a length l and a cross-sectional area A that resists the flow of current in the direction of the length between its two ends is given by R=ρ·l / A. Thus, the resistance of a piece of uniform material of a given length can be increased by reducing its cross-sectional area, as is generally known.

[0068] Perfect isolator materials do not exist, however, "conductive material" shall mean a material with a resistivity lower than ρ = 1.0 Ωm (specifically, the limit may be set to be lower than ρ = 1.0·10 -1 Ωm), and “isolation material” shall mean a material with a resistivity higher than ρ=1.0 Ωm (specifically, the limit may be set to be higher than ρ=1.0·10 3 Ωm). Metals (which allow free electron flow) such as steel, copper, silver, gold, iron, and metal alloys are good conductive materials. Other conductive materials include amorphous carbon, conductive ceramics such as ITO, and conductive polymers such as PEDOT:PSS. Particularly suitable conductive materials within the scope of the present disclosure are those conductors that are thermally stable at the above-mentioned temperatures of about 500 degrees Celsius to about 800 degrees Celsius.

[0069] Within the meaning of the present disclosure, many metals such as steel, copper, aluminum, silver, many metal alloys (including iron-based alloys or copper-based alloys such as brass, bronze or beryllium copper (ASTM B194, B196, B197), etc.) are thermally stable (i.e., do not significantly deform or melt or otherwise degrade so that the material can be used for an industrially reasonable period of time). Good isolator materials are glass, paper, dry wood, Teflon, PET, hard rubber, rubbery polymers, isolating ceramics such as alumina or stearates, and many plastics, etc.

[0070] The passage of electric current through a conductor releases thermal energy through a process known as resistive heating (or Ohmic heating or Joule heating). The resistive heating results in the emission of thermal radiation (specifically infrared radiation) that is absorbed by the ends of the filaments in sufficient amounts to melt the thermoplastic material at the exposed ends of the bristle tufts and form a fused ball structure, as has been discussed in detail above. The fusing of the ends of the bristle tufts as disclosed herein can be performed horizontally (i.e., the tufts are arranged substantially parallel to the direction of the earth's gravity), but can also be performed vertically (i.e., where the tufts are substantially inclined relative to the direction of the earth's gravity, specifically where the tufts are arranged substantially perpendicular to the direction of the earth's gravity). Vertical fusion will be particularly possible if the applied thermal energy is suitable for the individual properties of the bristle tufts as disclosed herein. The molten bristle tuft ends melt very quickly and also solidify very quickly when the source of thermal radiation is removed so that substantially no "nose" of dripping plastic melt is generated. Fusion techniques that apply more thermal energy than is required to form the fused ball heat, for example, the entire environment, making it almost impossible to avoid at least the generation of the nose during vertical fusion. Due to the limited heating of the ends of the bristle tufts as disclosed herein, the volume of the molten material is smaller than in a normal fusion process, and the surface tension of the molten material is therefore higher and effectively reduces the generation of a nose or even dripping material. In addition, the heating process can be further optimized in terms of cost by using different heating sections so that the heating surface selectively emits different amounts of thermal radiation during operation of the device. The area of ​​the heating surface of each heating section can be approximately 0.25 mm 2 To about 250mm 2 In the range of about 0.5 mm 2 To about 100mm 2 The upper limit may be smaller, such as about 90 mm. 2 , 80mm 2 , 70mm 2 、60mm 2 , 50mm 2 , 40mm 2 , 30mm 2 , 20mm 2 , 10mm 2 , 5mm 2 , 4mm 2 , 3mm 2 , or 2mm 2 The diameter of a typical cylindrical tuft, such as that used in many current toothbrushes, may be in the range of about 0.5 mm to about 2.5 mm, specifically in the range of about 1.0 mm to about 2.0 mm, and further specifically in the range of about 1.3 mm to about 1.8 mm. For example, a circular tuft having a diameter of 1 mm has a diameter of about 0.785 mm. 2Some toothbrushes include large-sized single tufts, such as the Oral-B A toothbrush having an area of ​​about 28 mm at its front end 2 (It can be considered that 30mm 2 Obviously, even larger single bristle tufts (50 mm is an appropriate upper limit) can be envisioned. 2 The bristle tufts are arranged at a certain distance from each other, otherwise they will form a single tuft with densely arranged filaments. The bristle tufts are arranged at a certain distance to allow the free filament ends of the final toothbrush to move when a force is applied against the tooth surface. The typical distance between adjacent tufts of the tuft area of ​​the toothbrush can be in the range of about 0.2mm to about 5.0mm, specifically in the range of about 0.5mm to about 2.0mm. In some current toothbrushes, a distance between adjacent tufts of about 0.8mm to about 1.6mm is used.

[0071] Higher heat emission of the heated surface can be achieved by an average profile roughness Ra on the heated surface that is different from the average profile roughness Ra on the adjacent surface made of the conductive material of the separation section. Typical values ​​of the average profile roughness of the heated surface are Ra ≥ 20 μm, specifically Ra ≥ 25 μm (an upper limit of Ra ≤ 200 μm, specifically Ra ≤ 200 μm, and further specifically Ra ≤ 50 μm can be adopted). Typical values ​​of the average profile roughness of the surface of the separation section are Ra ≤ 10 μm, specifically Ra ≤ 5 μm, further specifically Ra ≤ 2.0 μm. A typical polished surface has an average profile roughness of Ra ≤ 1.0 μm (where fine grinding results in an average profile roughness of Ra ≤ 0.2 μm).

[0072] The heating surface may be a non-planar surface, for example may be concavely formed, so that the heat radiation will be more focused than a planar heating surface. Generally speaking, the heating plate may be made of a sintered material, in particular a laser sintered material, in particular an electrically conductive material, although the heating plate may also comprise an insulating material.

[0073] After forming the fused ball, at least two bristle tufts are transferred to a subsequent process position, wherein the distance from the bottom edge of the fused ball of at least one bristle tuft in the subsequent process position to the front surface of the perforated plate is different from the distance from the bottom edge of the fused ball of the bristle tuft in the fusion position to the front surface of the perforated plate, wherein the subsequent process position may be, for example, a molding position. Preferably, the distance between the bottom edge of the fused ball in the fusion position and the front surface of the perforated plate of at least one bristle tuft is greater than or less than (preferably greater than) the distance between the bottom edge of the fused ball in the subsequent process position and the front surface of the perforated plate of at least one bristle tuft. As used herein, the term "bottom edge of the fused ball" should be understood as a position at the bristle filaments in the bristle tuft, where the modification of the bristle filament material caused by energy, specifically thermal energy applied during the fusion process (i.e., softening or melting of the material of the bristle filaments) ends.

[0074] This means that after the fusion process, the position of the bristle tuft in the perforated plate can be revised again, and wherein the position of the bristle tuft is adjusted according to the requirement of subsequent process.For example, the distance between the bottom edge of the fusion ball in the fusion position and the front surface of the perforated plate of at least one bristle tuft is greater than or less than the distance between the bottom edge of the fusion ball in the subsequent process position and the front surface of the perforated plate of at least one bristle tuft.For example, subsequent process can be the overmolding of fusion ball to form a brush head at least in part.If the subsequent process position is adjusted according to the molding process, the larger distance between the bottom edge of the fusion ball and the front surface of the perforated plate can be advantageous, so that more materials are flowed around the fusion ball and the bristle tuft is more closely fixed in the brush head to be formed.In addition or alternatively, the smaller distance between the bottom edge of the fusion ball and the front surface of the perforated plate can be advantageous, so that a small brush head and / or the free space in the brush head above the fusion ball is generated.Described free space may be required to include other features of brush head, such as the transmission or coupling element required for the brush head of an elastomer cleaning element or an electric toothbrush. A suitable distance between the bottom edge of the bristle tuft end of at least two bristle tufts in the molded position and the front surface of the perforated plate is in the range of 0.2 to 3 mm, preferably 0.3 to 2.5 mm, more preferably 0.4 to 2 mm, more preferably 0.5 to 1.5 mm, more preferably 0.6 to 1.2 mm.

[0075] Other subsequent process steps (such as review or inspection steps and / or molding steps) for setting the elastomeric cleaning elements into the perforated plate may optionally be included in the method as disclosed herein. Suitable review or inspection steps may include inspecting and confirming the correct number, diameter and / or color of the filaments in the individual holes of the perforated plate; inspecting and confirming the correct position of the bristle tufts and / or elastomeric elements in the holes of the perforated plate; inspecting the presence and quality of the fused balls of the bristle tufts, and / or combinations thereof. The quality inspection of the fused balls may include displacing the fused balls from the perforated plate so that the fused balls can be visually inspected by looking down, looking up and looking sideways, thereby checking the form and size of the fused balls and whether all filaments are completely included. Finally, the bristle tufts are arranged in a molding position, wherein the distance between the bottom edge of the fused ball and the front surface of the perforated plate is adjusted according to the requirements of the subsequent molding process, wherein according to the method as disclosed herein, the molding position of at least one bristle tuft is different from the fusion position of the bristle tuft.

[0076] After the bristle tufts are arranged in the molding position, the fused balls of at least two bristle tufts are overmolded by a plastic material, thereby forming a brush head or a portion thereof. Thus, a mold is formed in which the perforated plate forms a part of the mold. The mold is formed so that the fused balls are located in a hollow portion formed by the mold without contacting any inner surface of the mold, so that the fused balls can be embedded in the material to be fully injected when the brush head or a portion thereof is formed. Suitable materials for forming the brush head or a portion thereof are hard plastic materials. The Shore D hardness of a "hard plastic" material as understood herein can be in the range of about 30 to about 90, specifically in the range of about 40 to about 80, more specifically in the range of about 50 to about 80, and even more specifically in the range of about 65 to about 75. Suitable materials that can be used as the hard plastic material may be, for example, polypropylene (PP), polyethylene (PE), polyoxymethylene (POM), polyethylene terephthalate (PET), polyamide (PA), or a blend or mixture comprising polypropylene (PP), polyethylene (PE), polyoxymethylene (POM), polyethylene terephthalate (PET) or polyamide (PA).

[0077] The brush head may include additional elements, such as chemical release elements or elastomeric elements. "Chemical release elements" as understood herein are any elements that release chemicals after contact with water and / or saliva during use and / or mechanically affected by the bristle filaments during brushing. Suitable chemical release elements are, for example, pads or reservoirs filled with or including chemically active substances. Suitable chemically active substances that can be released can be, for example, anti-allergic chemicals, analgesic chemicals, wound healing chemicals, anti-inflammatory chemicals, flavoring components, anti-tartar chemicals, whitening chemicals, antibacterial agents, anti-corrosion chemicals or mixtures thereof.

[0078] As understood herein, "elastomeric element" is any cleaning element that is not a bristle filament or a bristle tuft. The elastomeric element can be formed, for example, by a soft plastic material. The Shore A hardness of the "soft plastic" material as understood herein can be in the range of about 10 to about 80, specifically in the range of about 20 to about 70, more specifically in the range of about 30 to about 60, even more specifically in the range of about 30 to about 40. The Shore A hardness of the soft plastic material is suitable for the geometry of the elastomeric element. Compared with thicker elements, thinner geometric elements can be made of materials with greater Shore A hardness, and vice versa. The selection of soft plastic material also depends on the length of the formed element. In principle, longer geometric elements can be made of soft plastic materials with greater Shore A hardness compared with shorter elements. Suitable materials that can be used as soft plastic materials can be, for example, rubber, thermoplastic elastomer (TPE), polyethylene (PE), polypropylene (PP), polyoxymethylene (POM) or their blends or mixtures. Materials exhibiting elastomeric properties, such as TPE are preferably used as the soft plastic material herein. The soft plastic material can have any geometric form, such as knobs, pins, fins, walls, rods, grooves, bends, round pieces, sheets, textured elements, polishing elements such as, for example, polishing cups, or tongue scraping elements, or combinations thereof.

[0079] Elastomeric element can be produced before bristle tuft and / or can be provided with bristle tuft, and can be overmolded by the material for forming brush head or its part.In addition or alternatively, brush head or its part can comprise hole, and this hole is filled with elastomeric material in subsequent process step so that elastomeric element is formed.Preferably, the elastomeric element included in bristle zone is produced and / or provided before bristle tuft and / or with bristle tuft.In addition or alternatively, the elastomeric element (for example, the element that is intended to clean gum line or tongue) positioned at the profile of brush head and / or back side is preferably produced and / or provided after bristle zone.Independent of the process step used, physical connection is established between elastomeric element and brush head.Toothbrush can be for example manual toothbrush or replacement brush for electric toothbrush, and this electric toothbrush comprises brush head, handle and the neck that brush head and handle are connected to each other providing one or more cleaning elements as disclosed herein, and wherein this one or more cleaning elements can comprise one or more elastomeric elements and one or more bristle tuft. The method disclosed herein allows a high degree of design flexibility and makes the handling of non-bristle tuft cleaning elements as easy as bristle tuft cleaning elements. The handling of elastomeric elements is generally challenging due to the fact that elastomeric elements are difficult to grip, can be strongly affected by electrostatic forces, and are difficult to handle due to their elastomeric properties. If the elastomeric elements are formed directly in the perforated plate, these handling problems are reduced. By the method disclosed herein, bristle tuft cleaning elements and elastomeric elements are handled in a similar manner, thereby making toothbrush manufacturing more efficient. In addition or alternatively, the present method can also easily handle advanced filament types, such as ultra-thin filaments that are chemically or mechanically tapered in anchor-independent manufacturing techniques.

[0080] After the expected cleaning elements are all placed in the perforated plate, a mold cavity is formed, which includes a perforated plate as the first half mold and at least one second half mold. The plastic material forming the brush head or its part is then injected into the mold cavity. Thus, the fused ball of the one or more bristle tufts and the optional elastomeric element are overmolded by molten plastic material. Thus, the fused ball is embedded in the plastic material and forms an undercut so that the bristle tuft is fixed to resist tension. For example, the molten material of the cleaning element support can flow around the tuft end of the bristle tuft to form a ball or plate, or any geometric protrusion of the elastomeric element can be embedded in the molten material forming the brush head or its part. Preferably, the part formed by the molten material is a cleaning element support. The cleaning element support includes a front surface, a rear surface and a thickness, wherein the cleaning element support is at least thick enough to embed the one or more fused balls fully in the cleaning element support. The suitable thickness of the cleaning element support can be in the range of about 2.0mm to 4.0mm, preferably in the range of 2.2mm to 4.0mm, more preferably in the range of 2.5mm to 3.5mm. The bristle filaments protrude from the front surface of the cleaning element support, and at least two fused balls are preferably located at different levels in the cleaning element support. The cleaning element support can be made of any suitable plastic material, specifically any plastic material that can be processed in a molten state. Suitable materials include polyethylene (PE), polypropylene (PP), polyoxymethylene (POM), thermoplastic elastomer (TPE) or blends or mixtures thereof, wherein different materials exhibit different advantages and are selected accordingly. For example, polyoxymethylene is a harder material that exhibits higher resistance during use, but is more difficult to handle during injection molding; in contrast, polypropylene is less hard and less durable, but is also less expensive and easier to handle during injection molding. In the present invention, the material of the cleaning element support is preferably made of polypropylene.

[0081] The cleaning element support may also include an edge at the periphery of the rear surface. This means that the cleaning element support may also include a central depression in the rear surface, preferably in the range of 0.1mm to 3mm, more preferably in the range of 0.5mm to 2.5mm, more preferably in the range of 1mm to 2mm, more preferably in the range of 1.5 to 1.8mm. The central depression may cover at least 70% of the area of ​​the rear surface, preferably at least 80% of the area of ​​the rear surface, more preferably at least 85% of the area of ​​the rear surface, more preferably at least 90% of the area of ​​the rear surface, more preferably 90% to 98% of the area of ​​the rear surface. For example, the drive portion may be located in the first central depression. In addition, the cleaning element support may also include a second central depression in the rear surface, wherein the optional second central depression is preferably in the range of 0.1mm to 2mm, more preferably in the range of 0.1mm to 1.6mm, more preferably in the range of 0.2mm to 0.8mm. The second recessed portion (particularly the second central recessed portion) may cover at least 30% of the area of ​​the first recessed portion, preferably at least 40% of the area of ​​the first recessed portion, more preferably 40% to 50% of the area of ​​the first recessed portion. For example, a distribution channel or a soft plastic material layer for soft plastic cleaning elements may be located in the second central recessed portion.

[0082] In addition or alternatively, the cover can be located inside the edge and can cover the recessed portion of the cleaning element support, wherein the surface of the cover preferably forms a plane surface with the edge of the cleaning element support. The cover can be produced separately or can be directly formed on the cleaning element support, for example, by injection molding. For example, the material of the cover may include polyethylene (PE), polypropylene (PP), polyoxymethylene (POM), thermoplastic elastomer (TPE) or their blends or mixtures. The material can be molten and can be directly injected into the cleaning element support. Preferably, the material of the cover can be the same as the material used for the cleaning element support. If both materials are the same, the best bonding between the cleaning element support and the cover is achieved. Preferably, polypropylene (PP) is used as the material of the cover. In an alternative preferred embodiment, the elastomer cleaning element and the cover are made of the same material, specifically made of thermoplastic elastomer (TPE). The color of the material of the cover can be the same or different from the color of the material of the cleaning element support.

[0083] In addition or alternatively, the cleaning element support may include one or more slots suitable for receiving one or more elastomeric elements. The slot may have any geometric form and shape, and the form and shape of the one or more slots may be adjusted according to the form and shape of the elastomeric element. If more elastomeric elements are included in the cleaning element support, the elastomeric elements may be identical to each other or may be different in form and shape. If more elastomeric elements made of the same material are included in the cleaning element support, the rear surface of the cleaning element support may include a distribution channel, which connects the one or more slots to each other so that the elastomeric material can be distributed on the cleaning element support and all elastomeric elements can be produced in a process step. This means that the elastomeric elements are connected to each other via the elastomeric material located in the distribution channel. In contrast, different elastomeric elements may be produced independently of each other. Suitable materials that can be used for elastomeric elements include a blend of rubber, thermoplastic elastomer (TPE) or their mixture, preferably using thermoplastic elastomer (TPE) material.

[0084] The cleaning element support including bristle tufts and optional elastomeric elements represents the central part, i.e. the cleaning part of the toothbrush head. The cleaning element support may be included in the toothbrush head of the replacement brush head for an electric toothbrush, or may be included in the toothbrush head of a manual toothbrush. For example, the cleaning element support may be placed in a mold and may be overmolded by a molten plastic material, thereby forming a toothbrush, a replacement brush head for an electric toothbrush, or a part thereof. This means that a brush head, specifically a toothbrush head or a part thereof, and a toothbrush including the brush head or a part thereof, preferably produced by a method as disclosed herein, can be used to manufacture a replacement brush for any kind of manual toothbrush or any kind of electric toothbrush. Therefore, the present disclosure also provides a brush, specifically comprising a toothbrush of a cleaning element support providing a cleaning element as disclosed herein.

[0085] A detailed description of several exemplary embodiments will be given below. It should be noted that all features described in the present disclosure, whether they are disclosed in the more general embodiments described above or in the exemplary embodiments of the device or method described below, or even they may be described in the context of a specific embodiment, are of course disclosed as individual features that can be combined with all other disclosed features, as long as this will not conflict with the purpose and scope of the present disclosure. Specifically, all features disclosed for any one of the devices or a part thereof or disclosed together with the method may also be combined with other parts or a part thereof of the device (if applicable) and / or applied to other parts or a part thereof of the device, and vice versa.

[0086] Figure 1AAn exemplary embodiment of a cleaning element holder 30 is shown. The cleaning element holder 30 comprises a front surface 31, a rear surface 32 and a thickness T. Suitable thicknesses of the cleaning element holder 30 as disclosed herein are in the range of 2.5 mm to 3.5 mm. The cleaning element holder 30 shown in FIG. 1 is a disk, but non-circular shapes are also possible. The cleaning element holder 30 comprises at least one protrusion 37, wherein the protrusion 37 is centrally located at the front surface 31. The central protrusion 37 covers at least 10% of the entire front surface 31, preferably 15% of the entire front surface 31, and more preferably 20% of the entire front surface. The size of the central protrusion 37 in % of the entire front surface 31 depends on the cluster design. The central protrusion 37 protrudes from the front surface 31 by about 0.4 mm. The central protrusion 37 preferably terminates between two clusters, but in certain embodiments, the central protrusion 37 may also terminate in one or more clusters.

[0087] Figure 1B Another exemplary embodiment of a cleaning element holder 30 comprising a front surface 31, a rear surface 32 and a thickness T is shown. Suitable thicknesses for cleaning element holders 30 as disclosed herein are in the range of 2.5 mm to 3.5 mm. Cleaning element holder 30 comprises at least one protrusion 37 centrally located at the front surface 31, and a central recess at the rear surface 32. The central recess 35 covers at least 70% of the rear surface 32 so that an edge 34 is formed in the periphery. The edge 34 may be about 0.6 mm to 1.2 mm thick, but smaller edges are also possible, as long as an edge that is stable during manufacturing is formed. The central protrusion 37 covers at least 10% of the entire front surface 31, preferably 15% of the entire front surface 31, and more preferably 20% of the entire front surface.

[0088] Figure 1C An exemplary embodiment of a portion 10 of a brush head is shown. The portion 10 shown in the side view comprises a cleaning element holder 30 having a front surface 31 and a rear surface 32 and a plurality of bristle tufts 20. Seven bristle tufts 20 can be seen, each of which comprises a plurality of filaments 22. The bristle tufts 20 protrude from the front surface 31 of the cleaning element holder 30, and the ends 26 of the filaments 22 intended for cleaning are rounded at the ends to ensure economical use. A fused ball (not shown) is formed at the opposite ends of the filaments 22, which is embedded in the cleaning element holder 30. The portion 10 of the brush head also comprises two elastomeric cleaning elements 40 made of thermoplastic elastomer (TPE).

[0089] Figure 1DA cross-sectional view of another exemplary embodiment of a portion 10 of a brush head is shown, the brush head comprising a cleaning element holder 30 and a plurality of bristle tufts 20 forming a bristle zone 28. Three different types of bristle tufts 20 (20a, 20b, 20c) are shown, which may differ in the number, color, length and / or material of individual filaments. The bristle tuft 20c is a cluster-in-cluster embodiment, wherein the inner center cluster protrudes from the peripheral cluster. The cleaning element holder 30 comprises at least one protrusion 37 centrally located at the front surface 31, and a central recess at the rear surface 32. The bristle tuft 20 protrudes from the front surface 31 of the cleaning element holder 30, and the end 26 of the filaments forming the bristle tuft 20 intended for cleaning is rounded at the end to ensure economical use. A fused ball 24 is formed at the opposite ends of the bristle tuft 20, which is firmly embedded in the cleaning element holder 30. The rear surface 32 of the cleaning element holder 30 includes a central recess 35, wherein the central recess 35 covers at least 70% of the rear surface 32 so that an edge 34 is formed in the periphery. The edge 34 may be about 0.6 mm thick, but smaller edges are also possible, as long as an edge that is stable during the manufacturing process is formed. The front surface 31 includes a central protrusion 37, wherein the area of ​​the cleaning element holder covered by the protrusion 37 is smaller than the area of ​​the cleaning element holder covered by the recess 35, so that the protrusion 37 is not recognizable by the user of the brush head. The protrusion 37 may cover at least 10% of the front surface 31 and may help to locally increase the thickness T of the cleaning element holder 30. The standard thickness T of the cleaning element holder 30 in the periphery is in the range of 2.5 mm to 3.5 mm, wherein the central recess 35 may reduce the thickness by about 1.5 mm. Therefore, it may be advantageous to increase the thickness T again by the protrusion 37 at the front surface 31. The increase in thickness T through the protrusion 37 may be about 0.4 mm, and may help embed the bristle tuft 20 firmly in the middle of the cleaning element holder 30 .

[0090] Figure 2A A cross-sectional view of an exemplary embodiment of a cleaning element holder 30 including a void 38 that can be filled with cleaning elements is shown. The front surface 31 of the cleaning element holder 30 includes a central protrusion 37 that covers at least 20% of the front surface 31. The rear surface 32 of the cleaning element holder 30 includes a central recess 35 that covers at least 70% of the rear surface 32 so that an edge 34 is formed in the periphery. A second recess 36 is shown in the middle of the central recess 35 that covers about 10% of the rear surface 32. Figure 2AThe cleaning element holder 30 shown is a disk, but non-circular shapes are possible. The rear surface 32 also includes a network of grooves 39 connected to each other and located in the area of ​​the recessed portion 35. The grooves 39 can form any network suitable for connecting the voids 38 so that at each end of the grooves 39, a void 38 is located in the cleaning element holder 30 that can be filled with cleaning elements. Figure 2B Shows Figure 2A The cleaning element holder 30 is shown with the voids 38 filled with elastomeric cleaning elements 40. The elastomeric material for the elastomeric cleaning elements 40 is added to the grooves 39 and distributed over the network so that the elastomeric connections 39a are formed therein and all the elastomeric cleaning elements 40 are formed together. Thus, the elastomeric cleaning elements 40 are connected to each other at the rear surface 32 of the cleaning element holder 30 via the elastomeric connections 39a.

[0091] Figure 2C A cross-sectional view of an exemplary embodiment of a cleaning element holder 30 is shown, which includes a central recess 35 at the rear surface 32 and a central protrusion 37 at the front surface 31. A drive portion 44 is placed in the central recess. Figure 2D Shows that already Figure 2C , wherein the driving portion 44 is mounted to the cleaning element holder 30 via a cover 46. The cover 46 is located inside the central recess 35, wherein the rear surface 47 of the cover 46 forms a plane surface with the edge 34. The material of the cover 46 is selected from polyethylene (PE), polypropylene (PP), polyoxymethylene (POM) or a blend or mixture thereof, preferably the material of the cover 46 is the same as the material of the cleaning element holder 30, and the cover 46 is directly formed into the recess 35 of the cleaning element holder 30 by injection molding. Therefore, the cover 46 and the cleaning element holder 30 are connected to each other and the driving portion 44 is firmly mounted. The color of the cover 46 is preferably different from the color of the cleaning element holder 30.

[0092] Figure 2CA cross-sectional view of an exemplary embodiment of a cleaning element holder 30 is shown, which includes a central recess 35 at the rear surface 32 and a central protrusion 37 at the front surface 31. The standard thickness T of the cleaning element holder 30 in the periphery is in the range of 2.5 mm to 3.5 mm, wherein the central recess 35 reduces the thickness by about 1.5 mm. The driving portion 44 is placed in the central recess and covered by a cover 46. The cover 46 is located inside the central recess 35, wherein the rear surface 47 of the cover 46 forms a planar surface with the edge 34. The cover 46 is preferably made of the same material as the cleaning element holder 30, and the cover 46 is formed by direct injection molding into the recess 35 of the cleaning element holder 30. Several bristle tufts 20 and elastomeric cleaning elements 40 protrude from the front surface 31 of the cleaning element holder. Seven bristle tufts 20 can be seen, wherein each bristle tuft 20 is different from the other bristle tufts 20 in at least one attribute. For example, the bristle tufts 20a and 20b differ in the position of the bristle tufts 20 in the cleaning element holder 30. The central bristle tuft 20c includes more bristle filaments and is a cluster-in-cluster embodiment including an inner cluster protruding from a peripheral cluster. In addition, the bristle filaments of the bristle tufts 20a, 20b, 20c may also differ in the material, color or size of the bristle tufts. The elastomeric cleaning element 40 is made of a thermoplastic elastomer (TPE).

[0093] Figure 3 An illustrative method that may be used to produce a cleaning element holder 30 as disclosed herein is shown. Figure 3 A shows a side view of a perforated plate 60 including a front surface 61, a rear surface 62, a thickness D and a plurality of holes 70, wherein the plurality of holes 70 are shaped and distributed in the perforated plate 60 according to the desired bristle area 28 of the brush head to be produced. The thickness D is suitable for the bristle to be placed in the holes 70 ( Figure 3 B) of the length of the bristle tufts 20. Thus, the perforated plate 60 is thick enough so that the filaments 22 of the bristle tufts 20 are stabilized and protected during the manufacturing steps, but thin enough so that the bristle tufts 20 can still be handled. A suitable thickness D of the perforated plate 60 is 6 mm to 14 mm. The holes 70 are adapted to the size and shape of the bristle tufts 20 to be placed therein. For example, the bristle tuft 20a is larger than the bristle tuft 20b, so the holes 70 are different accordingly.

[0094] exist Figure 3In C, the perforated plate 60 is rotated 90°. The bristle tufts 20 protrude from the perforated plate 60 on both sides. One end 26 of the bristle tuft 20 is intended for cleaning and is therefore rounded at the end and includes a smooth surface. The opposite end 23 of the bristle tuft 20 is intended for fusing. The fusing of the end 23 is performed by a heat energy source 80 close to the end 23. Due to the different properties of the bristle tufts 20a, 20b, the ends 23 melt differently, i.e., different amounts of heat energy are required to melt. For example, the bristle tuft 20a is significantly larger than the bristle tuft 20b, so that the bristle tuft 20a requires more heat energy to melt. Therefore, the distance between the end 23 of the bristle tuft 20a and the heat energy source 80 is smaller than the distance between the end 23 of the bristle tuft 20b and the heat energy source 80. If heat energy is applied, the end 23 melts and forms a fused ball 24 ( Figure 3 d), these fused balls are similar to each other due to the different distances from the heat energy source 80. Thus, the distance from the bottom edge 25 of the fused ball 24 of the first bristle tuft 20a to the front surface 61 is different from the distance from the bottom edge 25 of the fused ball 24 of the second bristle tuft 20b to the front surface 61. For example, the bristle tuft 20b located in the middle of the bristle area is shielded from the heat energy source 80 by its adjacent bristle tufts 20. Therefore, the bristle tuft 20b is arranged closer to the heat energy source 80.

[0095] After the fused balls 24 are formed, the bristle tufts 20 are arranged in the perforated plate 60 according to the arrangement of the bristle tufts 20 in the bristle area 28 to be produced. Figure 3 e). This means that during fusion, the distance between the fused ball 24 and the perforated plate 60 can be different for subsequent process steps such as molding. The position of the bristle tufts 20 in the perforated plate 60 in the molding position is based on the position of the ends 26 intended for cleaning in the bristle area 28. The perforated plate 60 represents a part of the mold and together with the second mold half 82 provides a mold for the cleaning element holder 30. The molten material, for example polyethylene, is then filled into the mold and the cleaning element holder 30 ( Figure 3 f), in which the fused balls 24 are embedded in the material of the cleaning element holder 30 and are thus securely mounted thereto.

[0096] Figure 3 g to Figure 3 h shows an alternative embodiment, wherein the drive portion 44 is further integrated into the cleaning element holder 30. Thus, the drive portion 44 is partially placed in the mold so that the molten polyethylene material surrounds the fused ball 24 and a portion of the drive portion 44. Figure 3 FIG. 1 shows an alternative embodiment in which the perforated plate 60 comprises a central depression 63. The central depression 63 will form the central protrusion 37 in the cleaning element holder 30 to be formed.

[0097] Figure 4AA schematic cross-sectional view of a manual toothbrush 14 is shown comprising a handle 13 and a head 12, wherein the head 12 comprises a cleaning element holder 30 as disclosed herein. The cleaning element holder 30 comprises a number of bristle tufts 20, wherein the bristle tufts 20 are each secured in the cleaning element holder 30 by a fused ball 24 and projecting therefrom an end 26 intended for cleaning.

[0098] Figure 4B A schematic cross-sectional view of a replacement brush head 19 for an electric toothbrush is shown, comprising a neck 17 and a head 16. The head 16 comprises a cleaning element holder 30 as disclosed herein, as well as a drive portion 44 and a gear connection 18. The cleaning element holder 30 comprises a number of bristle tufts 20, wherein the bristle tufts 20 are each secured in the cleaning element holder 30 by a fused ball 24 and projecting therefrom an end 26 intended for cleaning.

[0099] Figure 5 A schematic top view of the front surface 61 of a perforated plate 60 comprising three arrangements 65 of holes 70 is shown. The arrangements 65 are separated from each other by a distance of at least 2 mm. The holes 70 in the arrangement 65 correspond to the bristle zone 28 to be formed and are positioned according to the bristle zone. Different sizes and shapes of the holes 70 are possible, for example, elongated holes 70a, oval holes 70b, circular holes 70c, arc holes 70d or trapezoidal holes 70e are shown, but other shapes or sizes may also be present depending on the bristle tufts that should be used. The perforated plate 60 also includes some blind holes 64 that are suitable for receiving other cleaning elements such as elastomeric cleaning elements. More than or less than the three arrangements 65 shown may be present in one perforated plate 60. Two or more perforated plates 60 may be combined into a larger overall.

[0100] The dimensions and values ​​disclosed herein are not to be understood as being strictly limited to the exact numerical values ​​cited. Instead, unless otherwise indicated, each such dimension is intended to represent the stated value and a functionally equivalent range around that value. For example, a dimension disclosed as "40 mm" is intended to mean "about 40 mm".

Claims

1. A part (10) of a brush head, in particular a part (10) of a toothbrush head (12, 16), comprising: - one or more bristle tufts (20), each consisting of a plurality of bristle filaments (22) connected to one another via a fusion ball (24) at the end opposite to the end (26) intended for cleaning; - a cleaning element holder (30), said cleaning element holder comprising a front surface (31), a rear surface (32) and a thickness (T), wherein one or more fused balls (24) of said one or more bristle tufts (20) are embedded in the material of said cleaning element holder (30) such that said one or more fused balls (24) are completely encapsulated and said bristle filaments (22) protrude from said front surface (31) of said cleaning element holder (30); and - wherein at least two fused balls (24) are located at different levels in the cleaning element holder (30), - wherein the cleaning element holder (30) further comprises a central depression (35) in the rear surface (32), preferably in the range of 0.1 mm to 3 mm, more preferably in the range of 0.5 mm to 2.5 mm, more preferably in the range of 1.0 mm to 2.0 mm, more preferably in the range of 1.5 mm to 1.8 mm, - wherein the driving portion (44) is located in said central recess (35).

2. A portion (10) of a brush head according to the preceding claim, wherein the cleaning element holder (30) further comprises an edge (34) at the periphery of the rear surface (32), preferably in the range of 0.2 mm to 3.0 mm, more preferably in the range of 0.3 mm to 2.5 mm, more preferably in the range of 0.4 mm to 1.5 mm, more preferably in the range of 0.6 to 1.2 mm.

3. A portion (10) of a brush head according to the preceding claim, wherein the cleaning element holder (30) further comprises a second central recess (36) in the rear surface (32), preferably in the range of 0.1 mm to 2 mm, more preferably in the range of 0.1 mm to 1.6 mm, more preferably in the range of 0.2 mm to 0.8 mm.

4. The portion (10) of a brush head according to any one of the preceding claims, wherein the cleaning element holder (30) comprises one or more voids (38) adapted to receive one or more elastomeric elements (40).

5. A portion (10) of a brush head according to the preceding claim, wherein the rear surface (32) comprises at least one groove (39) connecting the one or more voids (38) to each other, preferably a regular network of grooves (39) connected to each other, more preferably an X-shaped network of grooves (39) connected to each other.

6. A portion (10) of a brush head according to any one of the preceding claims 4 and 5, wherein one or more elastomeric elements (40) are located in the one or more gaps (38), and preferably wherein the one or more elastomeric elements (40) are connected to each other via an elastomeric material located in the at least one groove (39).

7. A portion (10) of a brush head according to the preceding claim, wherein the material of the one or more elastomeric elements (40) is selected from rubber, thermoplastic elastomer (TPE) or blends or mixtures thereof, preferably wherein the material is a thermoplastic elastomer (TPE).

8. A portion (10) of a brush head according to any one of the preceding claims, wherein the thickness (T) of the cleaning element holder (30) is in the range of 2.0 mm to 4.0 mm, preferably in the range of 2.2 mm to 4.0 mm, more preferably in the range of 2.5 mm to 3.5 mm.

9. The portion (10) of a brush head according to any one of the preceding claims 2 to 8, wherein a cover (46) is located inside the edge (34), wherein a rear surface (47) of the cover (46) forms a planar surface with the edge (34).

10. The portion (10) of a brush head according to the preceding claim, wherein the cover (46) has a color different from the color of the cleaning element holder (30).

11. A part (10) of a brush head according to any one of the preceding two claims, wherein the material of the covering part (46) is selected from polyethylene (PE), polypropylene (PP), polyoxymethylene (POM) or a blend or mixture thereof, preferably wherein the material of the covering part (46) is polypropylene (PP), more preferably wherein the material of the covering part (46) is the material used for the cleaning element holder (30).

12. A part (10) of a brush head according to any one of the preceding claims, wherein the material of the cleaning element holder (30) is selected from polyethylene (PE), polypropylene (PP), polyoxymethylene (POM) or blends or mixtures thereof, preferably wherein the material of the cleaning element holder (30) is polypropylene (PP).

13. A brush head, in particular a toothbrush head (12, 16), comprising a portion (10) according to any one of the preceding claims.

Images