DE10303548A1 - Toothbrush has bristles protruding through holes in naps in a thermoformed film forming the brush head surface and held in place by a rear part to form a composite assembly in the head - Google Patents

Abstract

A bristle composite part (6) connected to the brush head (2) has a thermoformed film with open naps forming openings through which bristle bundles (18) pass. The film forms the brush surface from which the bristles protrude. A rear part holding the bristles in position is attached to the back of the film. Channels formed through the naps have an axial length 0.5-4 times the bristle bundle (18) diameter. The rear part of the bristle composite part(6) is either a film sealed onto the film or an injection molded part molded onto the film. A closed chamber (4) is located in the brush head (2) at the back of the bristle composite part. The chamber is filled with either a gas, a gel or an elastomer, which influences the elasticity of the bristle composite part. A cover (8) over the chamber is flush with the brush head. Bristle bundles are thickened at the fixing end by melting and the bulge formed in each bundle is joined to the rear part of the composite bristle part. An independent claim is included for a process for manufacturing the claimed brush in which: a) a film is thermoformed to form naps; b) the naps are opened to form openings for bristle bundles; c) bristle bundles are inserted into the open naps and the fixing ends of the bristle bundles are placed on the rear side of the film; d) a rear part is applied to the back of the film; e) the bristle composite part(6) is fixed to the brush head.

Description

The present invention relates to a brush, especially a toothbrush, with a bundle of bristles having brush head and a method of manufacturing the brush.

To brush, especially toothbrushes must determine Meet the requirements regarding the flexibility of the brush bundles. So the bristle bundles are supposed to with regard to the required cleaning effect as flat as possible on the brushed Surface, which is not always level, concerns and with the more necessary Apply pressure against the surface to be cleaned. On the other hand, must but an excessive pressing force be prevented. With care brushes for items can an excessive contact pressure lead to scratch marks and with brushes for the personal hygiene and oral hygiene leads to excessive pressure the ends of the bristle filaments on the usage side sometimes cause injuries, especially with toothbrushes to injury the sensitive oral mucosa.

It is known for toothbrushes to provide a flexible neck area between the handle and the brush head of a toothbrush (e.g. US 5,054,154 ). For some time now, individual or grouped bristle bundles have also been flexibly stored within the brush head. For example, it is known from WO 97/20484 to overmold individual bristle bundles at their fastening-side ends with a first hard component made of plastic, by shearing off the connecting channels required for the injection molding production between the frames thus produced for the fastening-side ends of the bristle bundles, the individual ones to form respective bristle bundles surrounding islands and to connect them by extrusion coating with a soft component to the handle or parts of the brush head and to store them elastically, which may have further bristle bundles which are not flexibly mounted.

Another state of the art EP 0 930 030 A2 bristle bundles are attached to a brush head segment which is rigid in itself, but which is flexible compared to other brush head segments which are also flexibly mounted relative to the handle. For this purpose, a film hinge made of a thermoplastic elastomer is usually formed between the brush head segments ( US 5,651,158 ) in order to meet the hygienic requirements that toothbrushes must always meet.

According to a recent solution proposal ( US 6,088,870 ) individual bristle bundles of a toothbrush are fastened in a net which extends over a central recess in the brush head. This known solution for flexible storage of the bristle bundles does not meet the hygienic requirements. Furthermore, the manufacture of the brush is complex and there is a risk that the bristle bundles are lost due to insufficient fastening.

It has been shown that so far known brushes with regard to the flexible storage of the bristle bundles taking into account the hygienic requirements and the pull-out strength of the bristle bundles such as manufacturing requirements are still in need of improvement and so the present invention addresses the problem of a brush to create an increased compliance the bristle bundle having. Furthermore, the present invention is based on the problem to provide a method of making such a brush.

To solve the above problem with the present invention a brush with the features of Claim 1 proposed. This differs from the generic Brush through one with the brush head connected bristle composite part, which is a film that towered over the bristle bundles surface the brush forms the bristle bundle as well as a backwards with back part connected to the film and holding the bristle bundles having. The film of the bristle composite part shows by deep drawing shaped knobs on which to form passage openings for the bristle bundles open have been. To open can the knobs are pierced by a molding tool at the end of deep drawing. Alternatively, you can the knobs can also be cut off. The after opening the Knobs remaining length the same serves the extensive support an end length range of passed through the knobs Bristle bundles. The film of the bristle composite part is preferably a plastic film. The film can also be made of a material other than plastic, be made of metal, for example.

Thermoforming of the film allowed a simple manufacture of the structural integrity of the brush is essential influencing component. The film and the back part form the dense mat-like bristle composite part, which the brush head covers the top and prevents the ingress of dirt and bacteria sealed.

The film has a thickness of preferably at most 1 mm, particularly preferably less than 200 μm, and the back part can extend over the entire height of the brush body, is preferably a very flat component of less than 1/4 of the height of the brush body, particularly preferably 1 mm and in particular with a thickness of less than 200 microns, so that the bristle composite part is very flexible due to the low material thickness. The individual bristle bundles held in the bristle composite part can accordingly retreat in the longitudinal direction of the bristle bundles in the event of excessive contact pressure at the ends of the bristle bundles on the use side and / or pivot around the fastening-side end. Correspondingly, damage to the objects to be cleaned or injury to the user, in particular injury to the oral mucosa when using the brush, can be avoided.

With regard to a sufficient Leadership and extensive support the bristle bundle is according to one preferred development of the present invention proposed that the pimple channels train their axial length corresponds to 0.5 to 4 times the bristle bundle diameter. This channels can at its surface end before inserting the bundles of bristles have a slightly smaller diameter than the bristle bundles and so to improve the sealing of the bristle bundles compared to the Contribute slide. The opposite End of channels, where is usually the attachment-side end of the bristle bundle is preferably running conical and accordingly offers a funnel-shaped inlet, who pushes in the bristle bundle of the back the film favored and also a feed area for the fastener end the bristle bundle forms. This catchment area can then in particular lead to an improved fastening the bristle bundle across from the slide, if the bristle bundle have a thickening at their fastening-side end, which is caused by Melting is formed and before the complete cooling and thus curing of the Thickening against the back the film is formed. In this way, for example Thickening to an adapted to the respective catchment area of the channel Graft to be formed.

In terms of different The film is preferably designed as an extrusion film and has different layers of different plastics on. So one layer can ensure the structural integrity of the formed film, whereas the other, preferably on the surface Situation with respect on the hygienic properties and, if necessary, the seal the bristle bundle across from the bristle composite part selected has been. The back Layer is in turn formed from a material, which preferably fastening the back part on the film, if necessary fixing and sealing the bristle bundles against the film favored. It has been found to be advantageous the surface of the Foil covering the surface of the brush forms in the area of the bristle composite part, as well as the other outer surface, that is the back surface each from a polypropylene layer. Between these two outer layers of polypropylene a polyamide layer is preferably provided, through which the mechanical properties of the film is favored.

With a view to a possible high elasticity of the bristle composite part, it is preferable to use the back part to be formed by a back film sealed onto the film. alternative can the back part by injection molding a plastic, for example a thermoplastic or a thermoplastic elastomer against the film and be connected to the film. In both cases this is preferred back at least with the back connected to the slide. With a view to pivoting as freely as possible the bundle of bristles can here on a connection between the back part and the fastening side End of the bristle bundle to be dispensed with. The back part can also be attached to the fastening side Ends of the bristle bundle be liable. In view of this, the backing film can, for example, Po lypropylene be formed. The backing film can be used as well Coextrusion film several layers of different materials, in particular include plastic materials. The surface of the back part preferably has a material which with respect to the desired Adhesion of the back part across from the film and / or the bristle bundles or the brush head selected has been. The back layer the back film can be especially considerate to the desired one elasticity the support and storage of the bristle bundles to be selected.

According to another preferred Design and with respect on the hygienic properties it is suggested on the brush head form a closed cavity, the rear of the bristle composite part is provided. The depth of the cavity in the longitudinal direction of the bristle bundle is preferably chosen such that with every spring back imaginable the bristle bundle in their longitudinal direction the back of the Bristle composite part at no time against the inner surface of a back part of the brush body, which one the recess on the back covers.

According to another preferred The design is the cavity with the elasticity of the film influencing medium filled. This medium can be a gas. Alternatively, the medium can also be a gel or an elastomer. The medium is selected with consideration to the desired one elastic support of the bristle composite part.

The brush head can be designed as a one-piece component together with the handle by means of injection molding. Here, the cavity is created as a recess open to the top of the brush head and later completely closed by attaching the bristle composite part. In an alternative embodiment, the brush head is formed with an edge surrounding a central recess, which holds the bristle composite part on the front side and which is covered on the rear side with a closure cover which closes the brush head. With regard to the hygienic requirements, the cover is embedded flush in the brush head. The bristle composite part can be enclosed as an insert in a mold in the injection molding of the brush head together with the handle of the plastic compound on the edge and thus be installed in the brush head. In addition, one or more cushions can be arranged on the back of the bristle composite part, which are also enclosed by the plastic melt during the injection molding of the brush head and are thus accommodated in the cavity formed in the process. This pillow can contain a gas or a liquid. Alternatively, the pillow can be made of a gel or an elastomer.

In the case of attachment of the bristle bundles through Forming a melted thickening is preferably located between the film and the back part and can thus be easily created by putting on the back part secured in the axial direction and by connecting to the back part be fixed.

To solve the procedural aspect The problem underlying the invention is solved with the present Invention proposed a method for manufacturing a brush according to claim 15. This procedure will start with thermoformed a film to form pimples, and the pimples will then be opened to form openings for the bristle bundles. Then the bristle bundles introduced into the film and the attachment-side ends of the bristle bundles to the back the slide. Finally becomes the back part to the back the film applied to the bristle bundle with its fastening side Secure the end between the film and the back part. After that the bristle composite part thus produced is attached to a brush head attached.

With a view to a possible simple and permanent as well as tight sealing of the mat-like Bristle composite part is preferably used as an insert in an injection mold inserted and connected to the brush head by injection molding. Same thing Reason can be found on the back of the Bristle composite part arranged a pillow and both parts in the injection mold be inserted around the composite part together with the pillow by overmolding in the brush head take.

In an alternative embodiment becomes the bristle composite part after the separate production of the brush head together with a molded handle on a recessed on the brush head Recess inserted and connected to the brush head. On the opposite the bristle composite part Side, this recess is closed by a cover, which prevents the ingress of dirt and impurities in the area of the brush head at the back of the bristle composite part prevented.

More details, advantages and Features of the present invention result from the following Description of an embodiment in connection with the drawing. In this show:

1 : a longitudinal sectional view of the embodiment of a brush according to the invention;

2a-f , the essential method steps of a first exemplary embodiment of a method for producing a bristle composite part for the toothbrush according to the invention;

3a-c the essential process steps of a second exemplary embodiment of a method for producing a bristle composite part for the toothbrush according to the invention; and

4 : A longitudinal sectional view of a further embodiment of the brush according to the invention.

In 1 is a longitudinal sectional view of the front region of an embodiment of the brush according to the invention in the form of a toothbrush shown with a brush head 2 which has a recess 4 has at the front of the brush head 2 from a bristle composite part 6 and on the back opposite this front side of a cover 8th is covered. The brush head 2 has a brush head body made by injection molding 10 on the the recess 4 circumferentially surrounds and on the two long sides of the brush head 2 and is only formed as a thin frame part on the front end. The sealing cover 8th is on the back of the brush head body 10 Connected flush with this, for example glued or welded, whereas the bristle composite part 6 in the injection molding of the brush head body 10 is connected to it by injection molding. The edge area of the bristle composite part 6 is accordingly on all sides of the plastic material of the brush head body 10 surround.

A method of manufacturing the bristle composite part 6 is described below with reference to the 2a to 2f explained in more detail. In this process, a coextruded film is first used 12 , which has two outer polypropylene layers of approximately the same thickness and an intermediate middle polyamide layer of low thickness, deep-drawn. The shape of the film 12 by means of deep drawing such that a large number of knobs on the film 14 are formed, which are pierced by the deep-drawing tool in the exemplary embodiment shown at the end of the forming step. Accordingly, the knobs 14 the in the 2a and 2 B shown embodiment already on the front of each knob 14 recessed openings 16 for bristle bundles 18 on.

From the in 2 B shown enlarged sectional view through a knob 14 it can be seen that the diameter of one through the knob 14 formed channel 19 from the back 12a the slide 12 to the front 14b the pimple 14 tapered. The one on the back of the film 12a trained entrance opening 20 the slide 12 is a little bigger, the diameter of the passage opening 16 on the front side 14b the pimple 14 is a little smaller than the diameter of the associated bristle bundle 18 ,

The in the 2a and 2 B shown and by thermoforming the film 12 for the formation of pimples 14 and opening the knobs 14 The contoured film produced is processed in a subsequent step (cf. 2c ) on a tool part 22 an injection mold, which corresponds to the number of bristle bundles 18 corresponding holding channels 24 as well as an investment area 26 for the thermoformed film 12 having. The investment area 26 has one of the top of the thermoformed film 12 appropriate contouring so that the thermoformed film 12 flat on the tool part 22 is supported. For every open knob 14 is one of the holding channels 24 intended. The contour of the contact surface, in the present case a concave contour, corresponds to the desired contouring of the bristle composite part to be produced in the unloaded state.

From the back 12a the slide 12 are then through the entry openings 20 the slide 12 each bundle of bristles 18 pushed through and through the channels 19 into the holding channels 24 introduced (cf. 2d ). After that, the back of the slide 12 protruding ends of the bristle bundle 18 melted, for example by exposure to hot air (arrows in 2e ) or preferably by melting with a hot mold, which against the ends of the bristle bundle 18 is pressed. As a result of the heating, a thickening forms at the ends of the bristle bundles on the fastening side 28 which, in the case of a hot molding tool, is deformed by the molding tool in such a way that it has the inlet openings 20 the pimple 14 each seals, if necessary - with suitable material pairs - even with the back 12a the slide 12 is welded. The thickening 28 then have a diameter that is larger than the diameter of the bristle bundles and protrude radially beyond the inlet opening 20 the slide 12 , This will make the bristle bundles 18 with the necessary pull-out security compared to the film 12 secured. The insertion of the bristle bundles is facilitated 18 due to the compared to the diameter of the bristle bundle 18 enlarged entrance opening 20 , The passage opening 16 when inserting the bristle bundle 18 radially widened and the slide 12 lies extensively on each of the bristle bundles 18 on.

Then another mold part 30 to form a mold nest 32 against the tool part 22 created (cf. 2f ) and the mold nest 32 is with a flowable material, such as an elastomer to form a back part 34 filled ( 2f .). This back part 34 connects fluidly to the back 12a the film or with the opposite of the mold cavity 32 exposed part of the thickenings 28 , During injection molding, they seal against the film 12 deformed thickenings 18 the one in the slide 12 trained channels 19 and prevent it from entering the mold cavity 32 injected plastic through the channels 19 passes.

The bristle composite part produced in this way 6 after opening the injection mold 22 . 30 from the tool part 22 removed from the mold and onto another injection mold for extrusion coating with the material of the brush head body 10 to hand over.

In the in the 3a-3c Stations of an exemplary embodiment of a method for producing the bristle composite part shown are first those with regard to FIG 2a-2b explained process steps performed. In the embodiment of the 3a-3c However, reshaping of the thickenings and sealing of the channels 19 can be dispensed with. Because in the embodiment of 3a-3c is the back part by a back film sealed on the back of the film 36 formed, so the problem of plastic melt passing through the channels 19 does not exist.

The back film 36 is when sealing onto the film 12 at least with the film 12 connected. With regard to a relatively free mobility of the bristle bundles 18 at their fastening-side ends, the thickenings can be fastened 28 against the back film 36 to be dispensed with. Like that in 3c shown enlarged detail of the in 3b shows the sectional view shown after applying the backing film, the backing film 36 with the slide 12 between the knobs 14 , ie between the thickenings 28 connected. This type of connection between the back sheet 36 and the slide 12 allows a certain mobility of the attachment-side ends of the bristle bundles 18 , so that they can pivot more freely at right angles to their longitudinal axis in order to avoid excessive contact pressure at their ends on the use side.

This in 4 Embodiment shown differs from that in 1 shown embodiment in that the recess 4 tub-shaped from the brush head body 10 is surrounded. The cover of the recess 4 takes place exclusively via the bristle composite part 6 , This is a prefabricated component on the brush head body 10 placed and connected to it, for example by gluing or welding. To the in 4 shown brush head body 10 can as well as in the embodiment of the 1 a cushion can be inserted which contains a gaseous fluid, for example air, or a liquid fluid.

2

brush head

4

recess

6

Bristle composite part

8th

cap

10

Brush head body

12

foil

12a

back

14

burl

14b

front

16

Through opening

18

bristle bundles

19

channel

20

inlet opening

22

tool part

24

retaining channel

26

contact surface

28

thickening

30

tool part

32

cavity

34

back

36

back film

38

grip style

Claims (19)

Brush, in particular toothbrush, with a bristle bundle of brush heads, characterized by a brush head ( 2 ) connected bristle composite part ( 6 ) with a foil ( 12 ), which are formed by deep drawing and to form passage openings ( 16 ) for the bristle bundles ( 18 ) open knobs ( 14 ) and which of the bristle bundles ( 18 ) forms the surface of the brush, which is opened by the knobs ( 14 ) outstanding bundles of bristles ( 18 ) and one on the back with the foil ( 12 ) connected and the bristle bundles ( 18 ) holding back part ( 34 ; 36 ). Brush according to one of the preceding claims, characterized in that the knobs ( 14 ) Channels ( 19 ) are formed, the axial length of which is 0.5-4 times the diameter of the in the respective channel ( 19 ) picked up bristle bundle ( 18 ) corresponds. Brush according to claim 1 or 2, characterized in that the film ( 12 ) is a coextrusion film having different layers of different plastics. Brush according to one of the preceding claims, characterized in that the back part ( 34 ) by a on the slide ( 12 ) sealed back film ( 36 ) is formed. Brush according to one of claims 1-3, characterized in that the back part ( 34 ) by spraying against the film ( 12 ) is connected to it. Brush according to one of the preceding claims, characterized in that the back part ( 34 ) is made of a flexible plastic, in particular a thermoplastic elastomer (TPE). Brush according to one of the preceding claims, characterized by a rear of the bristle composite part ( 6 ) arranged closed cavity ( 4 ) in the brush head ( 2 ) is left out. Brush according to one of the preceding claims, characterized in that the cavity ( 4 ) with the elasticity of the bristle composite part ( 6 ) influencing medium is filled. Brush according to claim 8, characterized in that the cavity ( 4 ) contains a fluid, in particular a gas. Brush according to claim 8, characterized in that the cavity ( 4 ) is filled with a gel. Brush according to claim 8, characterized in that the cavity ( 4 ) is filled with an elastomer. Brush according to one of claims 7-11, characterized in that the cavity ( 4 ) on the back of the brush head ( 2 ) with a flush with the brush head ( 2 ) closing cap ( 8th ) is covered. Brush according to one of the preceding claims, characterized in that the bristle bundles ( 18 ) a melted thickening on its fastening-side ends ( 28 ) between the film ( 12 ) and the back part ( 34 ; 36 ) is arranged. Brush according to claim 13, characterized in that the thickening ( 28 ) on their the foil ( 12 ) opposite side with the back part ( 34 ) connected is. Method for producing a brush according to one of Claims 1-14, comprising the following steps: deep-drawing a film ( 12 ) for the formation of pimples ( 14 ); Opening the knobs ( 14 ) for the formation of passage openings ( 16 ) for bundles of bristles ( 18 ); Bristle bundle insertion ( 18 ) in the open knobs ( 14 ) and the attachment-side ends of the bristle bundles ( 18 ) to the back of the film ( 12 ); Applying the back part ( 34 ) on the back of the film ( 12 ) and attaching the bristle composite thus produced part ( 6 ) to the brush head ( 2 ). A method according to claim 15, characterized in that the fastening-side ends of the bristle bundles ( 18 ) to form a thickening ( 28 ) after inserting the bristle bundle ( 18 ) are melted and the thickenings ( 18 ) after melting, the bristle bundle is widened by plastic deformation before it cools completely and against the back of the film ( 12 ) are pressed. Method according to one of the preceding claims, characterized in that the bristle composite part ( 6 ) as an insert in an injection mold ( 22 . 30 ) and by overmolding with the brush head ( 2 ) is connected. A method according to claim 17, characterized in that the bristle composite part ( 6 ) is injection molded together with a cushion arranged on the back of the same. A method according to claim 15 or 16, characterized in that the bristle connecting part ( 6 ) over one in the brush head ( 2 ) recessed recess ( 4 ) with the brush head ( 2 ) connected on the bristle composite part ( 6 ) opposite side through a cover ( 8th ) is closed.