Classifications

• • A—HUMAN NECESSITIES
  • A46—BRUSHWARE
  • A46B—BRUSHES
  • A46B3/00—Brushes characterised by the way in which the bristles are fixed or joined in or on the brush body or carrier
  • A46B3/06—Brushes characterised by the way in which the bristles are fixed or joined in or on the brush body or carrier by welding together bristles made of metal wires or plastic materials
• • A—HUMAN NECESSITIES
  • A46—BRUSHWARE
  • A46D—MANUFACTURE OF BRUSHES
  • A46D3/00—Preparing, i.e. Manufacturing brush bodies
  • A46D3/005—Preparing, i.e. Manufacturing brush bodies by moulding or casting a body around bristles or tufts of bristles
• • A—HUMAN NECESSITIES
  • A46—BRUSHWARE
  • A46D—MANUFACTURE OF BRUSHES
  • A46D3/00—Preparing, i.e. Manufacturing brush bodies
  • A46D3/04—Machines for inserting or fixing bristles in bodies
• • A—HUMAN NECESSITIES
  • A46—BRUSHWARE
  • A46B—BRUSHES
  • A46B2200/00—Brushes characterized by their functions, uses or applications
  • A46B2200/10—For human or animal care
  • A46B2200/1066—Toothbrush for cleaning the teeth or dentures

Definitions

• a brush head in particular a toothbrush head and a method for its production are described herein.
• Said brush head has a plurality of cleaning elements, at least two different types of cleaning elements and/or at least two distinctive cleaning elements of the same type which are fastened by one of their ends in the brush head.
• the fastened ends comprise thickenings which are produced by melting and optionally reshaping with a punching tool.
• Anchor using and anchor-free methods are known in order to fasten cleaning elements, such as bristle tufts, in a bristle carrier or the brush head of a toothbrush.
• the anchor-free or hot-tufting methods fasten the cleaning elements in the brush head by means of a forming technique.
• the bristle tufts are melted at their ends to form thickenings in order to increase the pull- out resistance of the tufts.
• These thickenings can be over-molded with a plastic material to form a bristle carrier or a brush head, or the thickenings can be cast in a bristle carrier or a brush head mechanically by other forming techniques. Theoretically these methods allow to generate bristle fields with different properties in different areas.
• a method for producing a brush head in particular a toothbrush head is described, in which at least two different types of cleaning elements or at least two distinctive cleaning elements of the same type or a combination thereof are embedded at one of their ends at least partially in a bristle carrier, comprising placing the free ends which are not intended to be embedded in the bristle carrier in a carrier part for holding ;applying different amounts of heat to the ends to be embedded in the bristle carrier of each of the at least two different types of cleaning elements or the at least two distinctive cleaning elements of the same type or a combination thereof by reflecting the heat supplied partially from the carrier part and/or absorbing the heat supplied partially by the carrier part.
• a device for producing a brush head in particular a toothbrush head, is described in which at least two different types of cleaning elements or at least two distinctive cleaning elements of the same type or a combination thereof are embedded at one of their ends at least partially in a bristle carrier, wherein said ends are molten by heat before embedding comprising a holding unit for holding the free ends which are not intended to be embedded and a heat source for applying heat to the ends to be embedded, wherein the carrier part reflects and/or absorbs differently the heat that is applied with respect to the at least two different types of cleaning elements or at least two distinctive cleaning elements of the same type or a combination thereof.
• a brush head in particular a toothbrush head, is described which is produced using the method and/or the device described herein.
• Figure 1 shows a schematic side view of a toothbrush with a bristle field comprising a multiplicity of bristle tufts as cleaning elements which are anchored in an injection-molded bristle carrier in a hot-tufting process
• Figures 2A, 2B show a schematic sectional view of a carrier part for retaining the bristle tufts during the production process; insertion of the bristle tufts into the carrier part is shown in Figure 2A, and the bristle tufts already in place are shown in Figure 2B
• Figure 3 shows a schematic sectional view illustrating the melting and thickening of the ends of the bristle tufts prior to the injection process;
• Figure 4A shows a schematic, perspective illustration of the bristle tufts situated in the carrier part, which shows the positioning of the bristle tufts according to the subsequent arrangement thereof on the brush head;
• Figure 4B shows, in a partial detail view, an enlarged sectional view of the bristle tuft
• Figure 5 A shows a schematic, perspective illustration of the melting, through application of infrared radiation to the ends of the bristle tufts to be embedded, wherein the infrared radiation device is shown in a working position;
• Figure 5B shows, in a partial detail view, an enlarged sectional view of the bristle tuft in the carrier part according to Figure 5 A;
• Figure 6 A shows a sectional view of the melting, wherein different bristle tufts are
• Figure 6B shows a top view to a bristle field being placed in a carrier part having absorbing and less absorbing surfaces;
• Figure 7 A shows a sectional view of the melting, wherein different bristle tufts are
• Figure 7B shows a top view to a bristle field being placed in a carrier part having relfecting and less reflecting surfaces
• Figure 8A shows a schematic, perspective illustration of the mechanical reshaping by means of a punching tool of the melted end sections of the bristle tufts situated in the carrier part
• Figure 8B shows a partial view, in an enlarged illustration, of a bristle tuft and the reshaping of the melted end section thereof by means of a section of the punching tool
• Figure 9 shows a schematic, perspective illustration of the finished reshaped end sections of the bristle tufts situated in the carrier part.
• the brush head and the method for the production thereof as disclosed herein, as well as an improved tool for the production of said brush head allow design flexibility, for example, in the positioning of cleaning elements and allows providing of different types of cleaning elements, including cleaning elements made from differing materials.
• An improved brush head may comprise, for example, a compact form and is efficient to produce, despite the complex design of the bristle field thereof, having, for example, differently designed cleaning elements.
• a method for producing such a brush head, in particular such a toothbrush head is shown, wherein different cleaning elements, in particular bristle tufts, are fused and over-molded at one of their ends using a plastic material.
• “Different cleaning elements” as used herein shall be understood as two different types of cleaning elements or two distinctive cleaning elements of the same type or a combination thereof.
• "Different types of cleaning elements” as used herein shall be understood as cleaning elements differing at least in the material they are made from.
• An example for different types of cleaning elements may be bristles made of different materials or bristles and elastomeric elements.
• An elastomeric element may be for example, a strip, a nub, a pin, a fin, a wall, a bar, a gutter, a curve, a circle, a lamella, a textured element, a polishing element such as, for example, a polishing cup, a sponge element or a tongue cleaning element or a combination thereof.
• elastomeric elements Materials which may be used to form elastomeric elements are for example rubber, polypropylene (PP) or thermoplastic elastomers (TPE) the latter having a Shore A hardness in the range of about 10 to about 70 or in the range of about 20 to about 50 or in the range of about 30 to about 45 or a mixture thereof.
• "Distinctive cleaning elements of the same type" as used herein shall be understood as cleaning elements which are made of the same material, but which are distinguishable from each other in at least one other property. Examples for these other properties in which the distinctive cleaning elements of the same type may differ are e.g. size, composition, form, outer shape or surface appearance.
• An example for distinctive cleaning elements of the same type may be bristle tufts having different tuft diameters or having different tuft geometries, or bristles being tapered or crimpled compared to unmodified bristles.
• the cleaning elements may be held by at least one carrier part which has hole-shaped retaining recesses, in which the cleaning elements may be arranged.
• the position of the cleaning elements in the carrier part corresponds to the desired relative arrangement thereof with respect to one another on the brush head.
• said carrier part may form a wall of the mold cavities, in which the ends of the cleaning elements extending out from the carrier part can be over-molded in a multi-component process. Owing to the use of the carrier part as part of the injection mold, the positioning of the ends of the cleaning elements to be over-molded as well as the opening and closing of the injection mold can be executed very simply and efficiently.
• the side of the carrier part facing the ends to be over-molded may form a negative mold for the cleaning-element-side or bristle-side surface of the bristle carrier of the brush head.
• the carrier part may be a carrier plate having through holes for holding the cleaning elements or a mold bar having blind holes for holding the cleaning elements. While the cleaning elements are embedded into the bristle carrier a part of the brush head, the complete brush head or only the bristle carrier itself may be molded. That means the term "bristle carrier” as used herein means the part of a brush, in particular a toothbrush in which the cleaning elements are mounted or from which the cleaning elements protrude with their free ends.
• the bristle carrier may be a part of the brush head, a part to be mounted into the brush head or the brush head itself. If the bristle carrier or a part of the brush head are molded the cleaning elements can be transported from a first injection-molding station in which at least said part of a bristle carrier and/or a brush head is injection-molded to a second injection-molding station, in which at least another part of a bristle carrier and/or a brush head is injection-molded. Further steps of transportation to additional injection-molding stations in which additional parts of the bristle-carrier and/or the brush head can be injection-molded are also applicable to the method as described herein. Additionally, the cleaning elements may be located in the at least one carrier part during transportation.
• the carrier part in which the cleaning elements are arranged, may also be used for handling and/or transporting of the cleaning elements in or between the different process steps.
• the cleaning elements may be transported from the thermal treatment for melting the ends of the cleaning elements to form thickenings to one or more injection molds to form the brush head.
• the thickenings at the cast ends of the cleaning elements are formed in order to increase the pull- out resistance of the cleaning elements from the bristle carrier.
• Said thickenings may be produced by thermal melting of the ends.
• the ends which are melted are the ends to be over-molded, i.e. said ends are not the ends used for cleaning the teeth.
• the ends intended for cleaning the teeth i.e. the free ends, are located at the opposite end of the cleaning element than the ends intended to be over-molded.
• Heat may be applied to the cleaning elements, either individually or in groups, thereby reshaping the ends into a thickening. Generally, this can be carried out by means of various types of energy flows in the form of mass flows and/or radiation.
• the ends to be thickened may be applied to a targeted flow of hot gas or to infrared radiation individually or in groups, in order to be melted thermally.
• the corresponding amount of heat may be controlled individually, that is to say independently of one another, for at least two different cleaning elements, in order to achieve an individual melting and/or reshaping of the ends of the at least two different cleaning elements. Therefore the heat applied is reflected and/or absorbed partially and selectively by the carrier part.
• By reflecting the heat supplied to one of the at least two different cleaning elements a bigger amount of heat impacts on the end of the cleaning element.
• by absorbing the heat supplied partially a smaller amount of heat impacts on the end of the cleaning element.
• the carrier part may be coated with a heat-reflective and/or heat-absorbing material.
• One carrier part may be coated with both heat reflective and heat-absorbing material in order to increase the difference in the amount of heat supplied.
• only a heat reflective or a heat absorbing coating may be supplied to the carrier part.
• the cleaning elements can have varying amounts of heat applied to individually or optionally in groups while they are being held in the manner in which they are intended to be cast in the brush head. This reduces also additional handling measures, such as for example grip changes or reinsertion of the cleaning elements into different carrier parts.
• the amount of heat may be controlled with respect to at least one property in which the at least two different cleaning elements are distinguishable from each other.
• Said property may be, for example, the material, the color, the composition, the thickness, the outer shape, the softening temperature, the position and/or the distance of the different cleaning elements relative to the heat source, the position relative to the adjacent cleaning element or a combination thereof.
• a thicker cleaning element and/or one having a higher softening temperature needs a bigger amount of heat to melt than a thinner cleaning element and/or one having a lower softening temperature.
• a cleaning element being positioned nearer to the heat source needs less impact of heat than one which is positioned farer away from the heat source.
• the reshaping of the ends of the cleaning elements can be carried out solely by applying the heat, for example infrared radiation, and using the effects of gravity. Thereby, the cleaning elements with their ends to be melted are positioned pointing upward, such that a melted end section naturally flows downward, thus resulting in a mushroom-shaped or drop-shaped thickening.
• a punching tool can be used to create the thickening. Said punching tool may be driven against the melted ends of the cleaning elements in order to reshape the heated ends accordingly.
• the punching tool can have various punching surfaces, for example structured or curved surfaces.
• the shapes of the punching tool may be adapted in each case to one cleaning element or group of cleaning elements, and which only reshape individually the one cleaning element or one group of cleaning elements, respectively.
• Various punching surfaces of the punching tool may be adjustable with respect to one another, in particular to be capable of being positioned in various planes with respect to one another. This makes it possible to create a punching tool pad of different punching surfaces which are positioned raised in relief-like manner at various heights, in order to enable reshaping of the ends of the cleaning elements, which ends are positioned at different heights.
• the cleaning elements may be over-molded with a plastic material, thereby forming at least the bristle carrier.
• the brush head, a part of the brush head or a complete toothbrush is formed during this over-molding step.
• a device for carrying out the method as described above.
• Said device comprises at least a carrier part for holding the free ends which are not intended to be embedded and a heat source for applying heat to the ends to be embedded.
• the heat source may be for example, an infrared radiation device.
• the carrier part in which the different cleaning elements are arranged reflects the heat partially.
• the carrier part may be coated with, may comprise or may consist of a reflected material.
• a suitable reflective material may be polished metal, such as steel, aluminum, silver or a combination thereof.
• the carrier part in which the different cleaning elements are arranged absorbs the heat partially.
• the carrier part may be coated with, may comprise or may consist of an absorbing material.
• the material of the carrier part should provide an absorption peak in the range of the wavelength of the infrared radiation used.
• a suitable absorbing material may be a rough dark surface or a water covered surface.
• the heat which is absorbed by the carrier part may be dissipated by cooling the carrier part at least selectively.
• a brush head for example a toothbrush head having bristle tufts comprising at least two different cleaning elements being melted individually according to the special requirement of each cleaning element as described above.
• the ends providing the thickenings are over-molded to form the carrier part or the brush head. If the carrier part is formed by over- molding the carrier part can be embedded into the brush head by fastening it into a recess at the brush head using ultrasonic welding, gluing and/or clipping. All features, whether described in combination or individually and which are described with respect to the method are also applicable to the resulting brush head as far as they have a structural impact to the brush head.
• the toothbrush 1 shown in Figure 1 comprises a shaft-like handle 2, which is connected to a brush head 4 via a neck piece 3.
• the brush head 4 comprises a bristle carrier 5 joined to the neck piece 3 which supports a field 6 of cleaning elements 7, which comprises a multiplicity of cleaning elements 7.
• the cleaning elements 7 are bristle tufts.
• other cleaning elements 7 could be provided, for example in the form of elastomeric elements.
• the toothbrush 1 is designed as a manual toothbrush; however, a motor-driven toothbrush could also have a correspondingly designed brush head.
• each tuft can comprise a multiplicity of bristles that are combined to form the tuft.
• the bristle tufts are cut to the desired lengths, the free ends of the bristle tufts optionally being tapered, spliced or rounded off as desired. Every treatment to the bristle tufts can be performed on the finished toothbrush 1 or can also be effected before the bristle tufts are mounted to the brush head 4.
• Figures 2 to 9 show the fusing of the cleaning elements 7 before they are fastened in the bristle carrier 5.
• the process will be described for bristle tufts as an example for cleaning elements 7. All features described with respect to bristle tufts can be also applied to other cleaning elements 7.
• a carrier part 8 which may form a part of the injection mold for injection molding the bristle carrier 5 or the brush head 4 later on.
• the carrier part 8 comprises a multiplicity of receptacle recesses 9, which are designed in the form of a through-hole or a blind-hole and which accommodate the corresponding bristle tuft 7 with an accurately fitting.
• the receptacle recesses 9 may be arranged in a grid pattern that corresponds to the desired positioning of the bristle tufts 7 on the brush head 4. As shown in Figure 2B, the bristle tufts 7 protrude by a certain length beyond the carrier part 8, such that the ends of the bristle tufts 7 can be positioned in a mold cavity of an injection mold, in order to be over-molded with plastic therein. In order to achieve increased resistance of the bristle tufts 7 against being pulled from the bristle carrier 5, the ends of the bristle tufts 7 to be embedded are first reshaped through application of heat energy— for example using infrared radiation 32— in order to form thickenings 10, as shown in Figure 3.
• heat energy for example using infrared radiation 32
• the ends of the bristle tufts 7 to be melted protruding from the carrier part 8 are first melted through application of infrared radiation 32.
• Figures 4A and 4B show the initial state, in which the bristle tufts 7 are positioned in the carrier part 8, in the arrangement according to the bristle field 6 to be created.
• Figure 4B shows a sectional view of the bristle field 6 before the thickenings 10 are formed at the ends to be melted.
• the ends to be melted of the bristle-tufts 7 are arranged in different planes so that the tuft ends to be melted define a three-dimensional arrangement.
• the ends to be metled of bristle tufts 7 of a center row 35 are positioned higher than the ends to be melted of bristle tufts of rows 36, 37 lying on the outside. If all bristle tufts comprise bristles of an identical length the three-dimensional arrangement of the ends to be melted is identical to the three-dimensional arrangement of the ends of the bristles intended to clean.
• a three-dimensional arrangement of the ends of the bristle tufts intended to clean might be helpful to improve overall or special cleaning performance. For example interdental cleaning performance might be improved by having bristle tuft ends intended to clean which protrude wider from the brush head in the periphery than the bristle tuft ends intended to clean arranged in the center of the brush head.
• the length of the bristles may also differ between different bristle tufts so that a three-dimensional arrangement of the bristle tuft ends to be melted differs from the three-dimensional arrangement of the bristle tuft ends intended to clean.
• a flat profile of the ends intended to clean may be formed, wherein the length of the bristles tufts differs from each other. This might by used to create different bending strength, although the same kind of bristle is used for several bristle tufts.
• the carrier part 8 is coated with an absorbing material or comprises an absorbing surface 33.
• the absorbing surface 33 is a rough dark surface.
• the surface 341 of the rows 36, 37 lying on the outside is made of a less absorbing material like a metal. If now heat 32 is supplied to the bristle tufts 7, for example from an infrared radiation device 11 as shown in Figures 5 A and 5B equal thickenings 10 can be formed.
• the ends of the bristle tufts 7 are melted by the application of heat 32 to the extent that drop-shaped thickenings 10 form due to the effects of gravity and surface tension.
• the bristle tufts 7 are arranged in an essentially vertical orientation with the ends to be melted pointing upwards when the heat. Due to the change of the absorbing properties of the carrier part 8 the melting process works independently from the arrangement of the bristle tuft 7. Thus, equal thickenings 10 can also be achieved using inclined bristle tufts 7.
• bristle tufts 7 are shown which are arranged in a common plane. Although the ends of the bristle tufts 7 are arranged at an equal distance to the infrared radiation device 11 different amounts of heat 32 are needed to produce equal thickenings 10. Different cleaning elements, namely bristle tufts 71 and 72 are arranged which differ at least in their tuft diameter from each other. The bristle tuft 72 comprises a thicker diameter than the bristle tuft 71 so that more heat is needed to melt the bristle tuft 72 than to melt the bristle tuft 71.
• Fig. 6 A shows a sectional view of the bristle tufts 71 and 72 being arranged in the carrier part 8.
• the environment surrounding the bristle tufts 71 may comprise an absorbing surface 33 and the environment surrounding the bristle tufts 72 may comprise a less absorbing surface 341 compared to the absorbing surface 33.
• the absorbing surface 33 may be a dark rough surface and the less absorbing surface 341 may be a metal surface.
• Fig. 6B shows a top view onto the bristle carrier 5.
• the heat 32 supplied to the bristle tufts 71 is absorbed selectively at the surface 33 and does not show and impact to the ends of the bristle tufts 71.
• the heat 32 supplied to bristle tufts 71 is reduced compared to the heat 32 supplied to the bristle tufts 72 which is at least partially reflected at the surface 341.
• less heat of the heat 32 supplied shows an impact to the ends of the bristle tufts 71 so that an equal melting of bristle tufts 71 and 72 differing at least in their tuft diameter can be achieved and equal thickenings 10 are formed.
• Fig. 7 shows another embodiment of a carrier part 8 which is used to form equal thickenings 10.
• Fig. 7 A shows a sectional view of the bristle tufts 71 and 72 being arranged in the carrier part 8.
• the environment surrounding the bristle tufts 72 may comprise a reflecting surface 38 and the environment surrounding the bristle tufts 71 may comprise a less reflecting surface 342 compared to the absorbing surface 38.
• the reflecting surface 38 may be made of aluminum or a polished metal and the less reflecting surface 342 may be for example a rough metal surface.
• Fig. 7B shows a top view onto the bristle carrier 5.
• the heat 32 supplied to the bristle tufts 72 is reflected at the surface 38 and reapplied to the end of the bristle tuft 72.
• the heat 32 supplied to bristle tufts 72 is increased compared to the heat 32 supplied to the bristle tufts 71 which is not or at least less reflected at the surface 342.
• reflective surfaces 38 selectively at the surface of the carrier part 8, an equal melting of bristle tufts 71 and 72 differing at least in their tuft diameter can be achieved and equal thickenings 10 are formed.
• a mechanical reshaping of the melted thickenings 10 can be performed.
• a punching tool 13 is used which is moved up against the still-soft, malleable thickenings 10, in order to shape said thickenings 10 in the desired manner.
• a flat, disk-shaped thickening 10 is generated in such a way that a flat punching tool 13 is pressed on the front side against the ends of the tufts 7.
• Differently contoured punching surfaces can also be used to generate differently contoured thickenings 10.
• the punching tool 13 may not have a continuous flat punching surface, but rather a multiplicity of punching surfaces, which may be placed in different planes and/or differently contoured, in order to generate the desired thickening 10 individually for each bristle tuft 7 or for one or more adjacent bristle tufts 7.
• the punching surfaces may be applied to rows and/or special arrangements of bristle tufts 7 in order to generate an identical thickening 10 for several bristle tufts 7.
• Fig. 9 shows a three-dimensional arrangement of cleaning elements 7 which all comprise an equal thickening 10, although they are positioned in different plane.
• the ends of the cleaning elements 7 can be anchored by over- molding in a bristle carrier 5; i.e., they can be cast into the bristle carrier 5 during the production thereof.
• the cleaning elements are cast into the bristle carrier mechanically and the bristle carrier 5 is mounted to the brush head 4.

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• Engineering & Computer Science (AREA)
• Manufacturing & Machinery (AREA)
• Brushes (AREA)
• Polishing Bodies And Polishing Tools (AREA)

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• 2013
  • 2013-06-06 CN CN201380031098.0A patent/CN104363791B/zh active Active
  • 2013-06-06 WO PCT/IB2013/054665 patent/WO2013186674A1/en active Application Filing
  • 2013-06-06 BR BR112014030983-3A patent/BR112014030983B1/pt active IP Right Grant

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