DE10303548B4 - Brush and method for its manufacture - Google Patents

Abstract

Brush, in particular a toothbrush, with a brush head having a bristle bundle, characterized by a bristle composite part (6) connected to the brush head (2) with a film (12) formed by deep-drawing and forming passage openings (16) for the bristle bundles (18). having open nubs (14) and which forms the surface of the brush projecting from the bristle bundles (18), the bristle bundles (18) projecting through the opened nubs (14) and a back-connected to the film (12) and the bristle bundles (18) holding back part (34; 36).

Description

The present invention relates to a brush, in particular a toothbrush, with a brush head having a bristle bundle and a method for producing the brush.

Brushes, especially toothbrushes, have to meet certain requirements regarding the flexibility of the brush bundles. Thus, the bristle bundles, while being as flat as possible with respect to the required cleaning effect on the surface to be brushed, which is not always flat, and act with the required contact force against the surface to be cleaned. On the other hand, however, an excessive contact force must be prevented. In the case of caring brushes for objects, an excessive contact force can lead to scratch marks and brushes for personal care and oral hygiene, an excessive contact force of the usable ends of bristle filaments sometimes injury, especially in toothbrushes to damage the sensitive oral mucosa.

Thus, it is known for toothbrushes to provide a flexible neck area between the grip handle and the brush head of a toothbrush (eg. US 5,054,154 ). Furthermore, for some time individual or grouped bundles of bristles are stored flexibly within the brush head. So it is for example from the WO 97/20484 known to overmold individual bristle bundles at their fastening-side ends with a first hard plastic component to form by shearing of connecting channels required for the injection molding production between the sockets thus produced for the attachment-side ends of the bristle bundles individual islands surrounding the respective bristle bundles and these by encapsulation to connect with a soft component with the handle stem or parts of the brush head and store elastically, which may have further not flexibly mounted bristle bundles.

In another prior art EP 0 930 030 A2 Bristle bundles are attached to a brush head segment, which is rigid in itself, but which is flexible over other brush head segments, which are also flexibly mounted relative to the handle 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 are to be placed on toothbrushes in principle, to meet.

According to a recent solution ( US 6,088,870 ) are fixed to individual bristle bundles of a toothbrush in a network which extends over a central recess of the brush head. This previously known solution for flexible storage of bristle bundles does not meet the hygienic requirements to be imposed. Furthermore, the production of the brush is complicated and there is a risk that the bristle bundles are lost due to insufficient attachment.

It has been shown that the brushes known so far are still in need of improvement with regard to the flexible storage of the bristle bundles, taking into account the hygienic requirements and the pull-out strength of the bundles of bristles as well as production engineering requirements, and so the present invention is based on the problem of providing a brush which has a having increased compliance of the bristle bundles. Furthermore, the present invention is based on the problem of specifying a method for producing such a brush.

To solve the above problem, the present invention proposes a brush having the features of claim 1. This differs from the generic brush by a bristle composite part connected to the brush head, which has a film which forms the surface of the brush projected by the bristle bundles, the bristle bundles and furthermore a back part connected to the film and holding the bristle bundles. The film of the bristle composite part has formed by deep-drawing nubs, which have been opened to form openings for the bristle bundles. To open the nubs can be pierced by a molding tool at the end of the deep drawing. Alternatively, the nubs can also be cut off. The remaining length of the same after opening the nubs serves for the circumferential support of an end-side longitudinal region of the bristle bundles guided through the nubs. The film of the bristle composite part is preferably a plastic film. The film may also be formed of a material other than plastic, for example of metal.

The deep drawing of the film allows easy production of a structural integrity of the brush significantly influencing component. The film and the back form the dense mat-like bristle composite part, which covers the top of the brush head and sealed against ingress of dirt and bacteria.

The film has a thickness of preferably at most 1 mm, more preferably less than 200 microns and the back part may extend over the entire height of the brush body is preferably a very flat component of less than ¼ of the height of the brush body, more preferably from 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. Accordingly, the individual bristle bundles held in the bristle composite part can, in the event of an excessive contact pressure on the use-side ends of the bristle bundles, retreat in the longitudinal direction of the bristle bundles and / or pivot about the fastening-side end. Accordingly, damage to the objects to be cleaned or a violation of the user, in particular a violation of the oral mucosa in the use of the brush can be avoided.

In view of sufficient guidance and extensive support of the bristle bundles, it is proposed according to a preferred development of the present invention that the studs form channels whose axial length corresponds to 0.5 to 4 times the bristle bundle diameter. These channels can have a slightly smaller diameter than the bristle bundles at their surface-side end prior to the introduction of the bristle bundles and thus contribute to an improved sealing of the bristle bundles with respect to the film. The opposite end of the channels, where usually the attachment-side end of the bristle bundles is located, is preferably conical and accordingly provides a funnel-shaped inlet which promotes the insertion of the bristle bundles from the back of the film and further forms a collection area for the attachment-side end of the bristle bundles , This catchment area can in particular lead to an improved attachment of the bristle bundles with respect to the film when the bristle bundles have a thickening at their attachment end which is formed by melting and which is formed against the back of the film before complete cooling and thus curing of the thickening , In this way, for example, the thickening can be reshaped into a graft adapted to the respective catchment area of the channel.

In view of the different requirements, the film is preferably formed as an extrusion film and has different layers of different plastics. Thus, one ply can ensure the structural integrity of the formed film, whereas the other, preferably surface, ply has been selected with respect to the hygienic properties and optionally the sealing of the bundles of bristles to the bristle composite. The back layer is again formed of a material which preferably favors the attachment of the back to the film, optionally the fixing and sealing of the bristle bundles to the film. It has proven to be advantageous to form the surface of the film, which forms the surface of the brush in the region of the bristle composite part, as well as the other outer surface, ie the rear surface in each case of a polypropylene layer. Between these two outer polypropylene layers, a polyamide layer is preferably provided by which the mechanical properties of the film is favored.

With regard to the highest possible elasticity of the bristle composite part, it is preferable to form the back part by a back film which has been sealed onto the film. Alternatively, the back may be formed by molding a plastic, such as a thermoplastic or a thermoplastic elastomer, against the film and bonded to the film. In both cases, the back part is preferably connected at least to the back of the film. With regard to a possible free pivoting of the bristle bundles can be dispensed with a connection between the back part and the fastening-side end of the bristle bundles. As well, the back part can also adhere to the attachment-side ends of the bristle bundles. In view of this, the backsheet may be formed of polypropylene, for example. Just as well, the backsheet may comprise as coextrusion film several layers of different materials, in particular plastic materials. The surface of the back part bearing against the film preferably has a material which has been selected with regard to the desired adhesion of the back part to the film and / or the bristle bundles or the brush head. The backsheet of the backsheet may be selected particularly in consideration of the desired elasticity of the support and storage of the bundles of bristles.

According to a further preferred embodiment and with regard to the hygienic properties, it is proposed to form on the brush head a closed cavity, which is provided at the rear of the bristle composite part. The depth of the cavity in the longitudinal direction of the bristle bundles is preferably chosen such that at any conceivable springback of the bristle bundles in their longitudinal direction, the back of the bristle composite part at no time abuts against the inner surface of a back portion of the brush body, which covers the recess on the back.

According to a further preferred embodiment, the cavity is filled with a medium influencing the elasticity of the film. This medium can be a gas. Alternatively, the medium may also be a gel or an elastomer. The selection of the medium takes place with regard to the desired elastic support of the bristle composite part.

The brush head may be formed as a one-piece component together with the handle stem by means of injection molding. Here, the cavity is created as open to the top of the brush head recess 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 at the front and which is covered on its rear side with a closure lid closing the brush head. In terms of hygienic requirements, the cap is flush with the brush head. The bristle composite part can in this case as an insert into a mold in the injection-molding production of the brush head together with the handle stem of the plastic compound peripherally enclosed and thus be installed in the brush head. In addition, one or more cushions can hereby be arranged on the rear side of the bristle composite part, which are likewise enclosed in the injection molding of the brush head by the plastic melt and thus accommodated in the cavity formed in this case. This pillow can contain a gas or a liquid. Alternatively, the pad may be made of a gel or an elastomer.

In the case of fixing the bristle bundles by forming a fused thickening, this is preferably between the film and the back part and can thus be secured by applying the back part in a simple manner in the axial direction and fixed by connecting to the back part.

To solve the procedural aspect of the problem underlying the invention, a method for producing a brush according to claim 15 is proposed by the present invention. In this method, first a film is deep-drawn to form nubs, and the nubs will then be opened to form openings for the bristle bundles. Thereafter, the bristle bundles are introduced into the film and the attachment-side ends of the bristle bundles are applied to the back of the film. Finally, the back is applied to the back of the film to secure the bundles of bristles with their attachment side end between the film and the back. Thereafter, the bristle composite part thus prepared is attached to a brush head.

With regard to the simplest and most durable and tight seal of the mat-like bristle composite part of this is preferably inserted as an insert in an injection mold and connected by injection molding with the brush head. For the same reason can be arranged on the back of the bristle composite part a cushion and both parts are inserted into the injection mold to receive the composite part together with the cushion by encapsulation in the brush head.

In an alternative embodiment, the bristle composite part is used after the separate production of the brush head together with an integrally molded handle on a recessed on the brush head recess and connected to the brush head. On the side opposite the bristle composite part, this recess is closed by a closure lid, which prevents the ingress of dirt and impurities in the area of the brush head on the rear side of the bristle composite part.

Further details, advantages and features of the present invention will become apparent from the following description of an embodiment in conjunction with the drawings. 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 embodiment of a method for producing a bristle composite part for the toothbrush according to the invention;

3a C shows the essential method 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 another embodiment of the brush according to the invention.

In 1 is a longitudinal sectional view of the front portion of an embodiment of the brush according to the invention in the form of a toothbrush shown with a brush head 2 which is a recess 4 which is at the front of the brush head 2 from a bristle composite part 6 and on the opposite of this front back of a cap 8th is covered. The brush head 2 has a brush head body made by injection molding 10 on top of the recess 4 circumferentially surrounds and on the two longitudinal sides of the brush head 2 and is formed on the front end side only as a thin frame part. The cap 8th is at the back of the brush head body 10 flush with this connected z. B. bonded or welded, whereas the bristle composite part 6 in the injection molding production of the brush head body 10 is connected by molding with this. 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 for producing the bristle composite part 6 is described below with reference to the 2a to 2f explained in more detail. In this process, first a coextruded film 12 , which has two outer polypropylene layers of approximately equal thickness and a middle low-strength polyamide layer interposed therebetween, deep-drawn. The shape of the film 12 By deep-drawing takes place such that on the film a plurality of nubs 14 are formed, which are pierced in the embodiment shown at the end of the forming step of the thermoforming tool. Accordingly, the nubs point 14 in the 2a and 2 B shown embodiment already on the front side 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 foil 12 to the front 14b the knob 14 tapered. The at the back of the film 12a trained entrance opening 20 the foil 12 is a little larger, the diameter of the opening 16 on the front side 14b the knob 14 is a little smaller than the diameter of the associated bristle bundle 18 ,

The in the 2a and 2 B shown and by deep drawing the film 12 for the formation of pimples 14 and opening the pimples 14 produced contoured film is in a subsequent step (see. 2c ) on a tool part 22 an injection mold placed, which is the number of bristle bundles 18 corresponding retaining channels 24 as well as a contact area 26 for the deep-drawn film 12 having. The contact surface 26 has one of the top of the thermoformed film 12 corresponding contouring on, so that the thermoformed film 12 flat on the tool part 22 is supported. To every open knob 14 is one of the holding channels 24 intended. The contour of the contact surface, in this 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 foil 12 are then through the inlet openings 20 the foil 12 each bristle bundle 18 pushed through and through the channels 19 in the holding channels 24 introduced (cf. 2d ). After that, the back of the film 12 protruding ends of the bristle bundles 18 melted, for example, by applying hot air (arrows in 2e ) or preferably by melting with a hot mold, which against the ends of the bristle bundles 18 is pressed. The heating forms a thickening at the attachment-side ends of the bristle bundles 28 made in the case of a hot mold by the mold so that it forms the inlet openings 20 the pimples 14 each seals, optionally - with suitable material pairs - even with the back 12a the foil 12 is welded. The thickenings 28 then have a diameter which is greater than the diameter of the bristle bundles and project radially beyond the inlet opening 20 the foil 12 , This will make the bristle bundles 18 with the necessary pull-out safety against the foil 12 secured. The introduction of the bristle bundles is made easier 18 through the opposite to the diameter of the bristle bundles 18 enlarged inlet opening 20 , The passage opening 16 when inserting the bristle bundles 18 radially widened and the film 12 lies circumferentially on each of the bristle bundles 18 at.

Thereafter, another mold part 30 for forming a mold cavity against against the tool part 22 created (cf. 2f ) and the mold cavity becomes with a flowable material, for example an elastomer for forming a back part 34 filled ( 2f .). This back part 34 combines fluidly with the back 12a the film or with the exposed to the mold cavity part of the thickening 28 , In injection molding, they seal against the film 12 deformed thickening 18 in the foil 12 trained channels 19 prevent and prevent plastic injected into the mold cavity through the channels 19 passes.

The bristle composite part thus produced 6 will after opening the injection mold 22 . 30 from the tool part 22 demolded and to another injection mold for encapsulation with the material of the brush head body 10 to hand over.

In the in the 3a - 3c shown stations of an embodiment of a method for producing the bristle composite part are first with respect to the 2a - 2 B explained method steps performed. In the embodiment of the 3a - 3c However, it may be necessary to reshape the thickenings and seal the channels 19 be made. Because in the embodiment of 3a - 3c is the back part by a back-sealed on the film backsheet 36 formed, so that the problem of passing plastic melt through the channels 19 does not exist.

The backsheet 36 is when sealing on the slide 12 anyway with the foil 12 connected. With regard to a relatively free mobility of the bristle bundles 18 At their attachment-side ends may be on a mounting of the thickenings 28 against the backsheet 36 be waived. Like the one in 3c shown enlarged detail of in 3b shown sectional view after applying the back sheet illustrates the back sheet 36 with the foil 12 between the pimples 14 ie between the thickenings 28 connected. This type of connection between the backsheet 36 and the foil 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 an excessive contact force at their use-side ends.

This in 4 embodiment shown differs from that in 1 shown embodiment in that the recess 4 trough-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 as a prefabricated component on the brush head body 10 placed on and connected to this, for example by gluing or welding. To the in 4 shown brush head body 10 can as well as in the embodiment of 1 a cushion is inserted, which contains a gaseous fluid, for example air, or a liquid fluid.

LIST OF REFERENCE NUMBERS

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

34

back

36

back film

38

grip style

Claims (19)

Brush, in particular toothbrush, with a bristle bundle having brush head, characterized by a with the brush head ( 2 ) connected bristle composite part ( 6 ) with a foil ( 12 ) formed by deep drawing and for the formation of passages ( 16 ) for the bundles of bristles ( 18 ) opened pimples ( 14 ) and which of the bristle bundles ( 18 ) protruding surface of the brush formed by the open pimples ( 14 ) projecting bristle bundles ( 18 ) and one at the back with the film ( 12 ) and the bristle bundles ( 18 ) holding back part ( 34 ; 36 ). Brush according to one of the preceding claims, characterized in that through the nubs ( 14 ) Channels ( 19 ) whose axial length is 0.5 to 4 times the diameter of the tube in the respective channel ( 19 ) received bristle bundles ( 18 ) corresponds. Brush according to claim 1 or 2, characterized in that the film ( 12 ) is a different layers of different plastics having coextrusion film. Brush according to one of the preceding claims, characterized in that the back part ( 34 ) by one on the film ( 12 ) sealed back sheet ( 36 ) is formed. Brush according to one of claims 1-3, characterized in that the back part ( 34 ) by injection molding against the film ( 12 ) is connected to this. Brush according to one of the preceding claims, characterized in that the back part ( 34 ) is formed of a flexible plastic, in particular a thermoplastic elastomer (TPE). Brush according to one of the preceding claims, characterized by a back of the bristle composite part ( 6 ) arranged closed cavity ( 4 ) located in the brush head ( 2 ) is omitted. Brush according to claim 7, characterized in that the cavity ( 4 ) with a 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 ) at the back of the brush head ( 2 ) with one flush with the brush head ( 2 ) final closure lid ( 8th ) is covered. Brush according to one of the preceding claims, characterized in that the bristle bundles ( 18 ) at their fastening-side ends a melted thickening ( 28 ) between the film ( 12 ) and the back ( 34 ; 36 ) is arranged. Brush according to claim 13, characterized in that the thickening ( 28 ) on her the film ( 12 ) facing away from the back ( 34 ) connected is. A method of making a brush according to any one of claims 1-14, comprising the steps of: thermoforming a film ( 12 ) for the formation of pimples ( 14 ); Opening the pimples ( 14 ) for the formation of passages ( 16 ) for bristle bundles ( 18 ); Introduction of the bristle bundles ( 18 ) in the open pimples ( 14 ) and applying 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 fixing the thus produced bristle composite 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 introduction of the bristle bundles ( 18 ) and the thickenings ( 28 ) of the bristle bundles ( 18 ) after melting, but widened by plastic deformation before complete cooling and against the back of the film ( 12 ). A method according to claim 15 or 16, characterized in that the bristle composite part ( 6 ) as an insert in an injection mold ( 22 . 30 ) and by injection molding with the brush head ( 2 ) is connected. Method according to claims 17, characterized in that the bristle composite part ( 6 ) is encapsulated together with a cushion arranged on the back of the same. A method according to claim 15 or 16, characterized in that the bristle connection part ( 6 ) over one in the brush head ( 2 ) recessed recess ( 4 ) with the brush head ( 2 ) connected to the bristle composite part ( 6 ) opposite side by a closure cover ( 8th ) is closed.

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