EP2347673A1 - Tooth brush and method for the manufacture of a tooth brush - Google Patents

Abstract

The method involves provided a head piece (14) with a small supporting plate that supports the bristles, where the support plate is fixed to the head piece by welding and then a force is exerted on a tooth brush body. A neck piece (32) and the head piece from the original shape are bent relative to each other around a predetermined angle (Alpha) by the force in warm state of a welded zone (51). The force is removed after bending in order to enable the bending back of the tooth brush body into its original shape. An independent claim is also included for a tooth brush with an end section.

Description

The present invention relates to a method for producing a toothbrush according to the preamble of claim 1 and a toothbrush according to the preamble of claim 15. A method and a toothbrush of this kind are disclosed in the document WO 03/086140 A1 known. In an integrally formed on a head part of a toothbrush body receiving geometry is provided with bristles and possibly other cleaning elements provided support plate which is secured by means of ultrasonic welding on the head part. In order to check this fastening, at the end of the bristling process, when the body is already cold from the weld, it is acted upon by a force either directly or indirectly on the head area or on the support plate or the head part of the toothbrush body is slightly bent.

In particular, when using transparent plastics for the toothbrush body, the risk of brittle fractures in the mechanically highly stressed areas, in particular in the neck portion facing end portion of the head portion and in the transition from the head portion in the neck portion, was found. Brittle fractures are dangerous if they occur during the use of the toothbrush, ie the teeth cleaning. The surface of the fracture may have sharp edges and corners that cause injury to the user. It has also been found that fit inaccuracies in the area between receiving recess and support plate, for example in the case of a too large support plate and too small a recess in the head of the toothbrush body, can also have a negative influence on the fracture behavior. This also affects toothbrushes, which are made from today's common hard materials such as polypropylene.

It is an object of the present invention to further develop a generic method for producing a toothbrush in such a way that the risk of brittle fractures is virtually avoided, and to provide a toothbrush produced according to this method.

This object is achieved by a method having the features of claim 1 and with a toothbrush having the features of claim 15.

According to the invention, in the hot state in the welding zone between the toothbrush body and the support plate and the welding zone, the neck part and the head part are bent relative to each other by a predetermined angle from their original shape. To ensure that the welding zone and the zone near the weld are still warm when bent, the bend is made immediately after the welding process.

After bending, the force is released, so that the toothbrush body, due to the elastic properties of its material, can move back to its original shape. By bending the neck portion relative to the head part, the material of the Toothbrush body and in particular the welding zone between the toothbrush body and support plate and partially also near the weld region in the mechanically highly stressed area, ie in the end portion of the support plate against the neck portion stretched, which leads to the alignment of the molecules and thus to improved fracture behavior in this zone.

Preferably, in the bending for maximum effect, the elastic region of the toothbrush body, the support plate and the welding zone is almost completely utilized. As a rule, no plastic deformation of these elements results from the described stretching, it is an elastic bending, that is to say a reversible bending.

The inventive method requires a bonding process between the support plate and the toothbrush body, so that at least a portion of the material of the Trgplättchens and / or toothbrush body is melted, and thus a weld zone by means of material closure.

In addition to the well-known ultrasonic welding, other welding or joining methods come into question here. For example, a weld can be achieved by means of targeted heat or friction. However, it is also possible to produce a weld by means of injection molding by overmolding the support plate with the plastic forming the toothbrush body. Here, we also melted the material of the carrier plate locally by the overmolding material and there is a conclusion of the material.

In the welding methods described here, preferably identical or compatible materials are used in the support plate and toothbrush body at least in the respective sections, so that a material closure can occur during the welding, preferably two hard materials are welded.

By way of example, ultrasound welding is discussed as a consequence, knowing that with the method according to the invention, the fracture behavior can also be improved for other welding or joining methods.

The inventive method can also be used at other locations of a toothbrush. For example, if the welding zone is not provided in the head part, but in the neck part or grip part of the toothbrush, in the relevant welding zone and near-welding zone.

Experiments have confirmed that the known risk of brittle fracture is significantly reduced, if not completely prevented by the inventive method, even when using opaque but also in particular transparent plastics for the production of the toothbrush body.

Preferably, the neck portion is deflected relative to the head portion by an angle of 5 ° to 45 °, in particular by 15 ° to 25 °.

Further, the deflection is preferably maintained for a predetermined period of time before the force is released. This period is preferably about 0.3 seconds to 5 seconds, in particular, it is chosen between 0.5 seconds and 1.2 seconds.

On the basis of experiments, it was found that there is an increased risk of brittle fractures, especially when a support plate which is provided with bristles and / or rubber-elastic massage and cleaning elements was inserted into a receiving geometry of the head part, and the support plate at the head part is ultrasonically Welding has been attached. Due to the ultrasonic welding, the toothbrush body is heated in the welding zone and the weld-near zone due to the vibrations, in particular in the head region and in an end section of the neck region adjoining the head region. Particularly preferably, the force for bending the neck part relative to the head part is applied immediately after the ultrasonic welding, as long as the toothbrush body in the welding zone and the weld region is still warm due to the welding process.

In addition, the risk of breakage can be further reduced by providing a defined gap open to the front between a lateral surface of the receiving geometry in the head part and one of these opposite side surfaces of the support plate. This is preferably 0.03 mm to 0.35 mm, in particular 0.05 mm and 0.18 mm.

This gap can have a different width over its length. The greatest width of the gap is preferably selected in an end section of the receiving geometry facing the neck part.

In a similar manner, the risk of fractures can also be prevented by welding the support plate to the head part in this area, preferably at least in the end part facing the neck part, between the outer surface of the receiving geometry and the side surface of the support plate by means of an adhesion reducer or a Haftunterdrückers the receiving geometry is prevented.

Preferably, the head part is held in a receiving element, while being acted upon by the force on the neck part. Particularly preferably, the head part is supported in the receiving element on its underside facing away from the bristled upper side along a circumferential edge section, wherein the transition region from the head region to the neck region is free.

For holding the head part in the receiving element, for example, a sonotrode, by means of which previously the ultrasonic welding took place, or another element of the welding device can be used. Further, it is also possible to use another auxiliary device for holding the head part in the receiving element.

Accordingly, it is also possible to hold the neck portion in a head portion facing away from the end portion by means of a corresponding receiving element, and act with the force on the head part to deflect it relative to the neck portion bending. If the toothbrush body has a grip part, in the present case the grip part is preferably held by means of the receiving element.

The toothbrush body and the Trgplättchen can be prepared in the one-component injection molding of a hard component. However, they can also be produced in a two-component or multi-component injection molding process from a hard component and one or more soft components or else from two or more hard components and optionally a soft component. The hard component or components form the supporting part of the toothbrush body and the support plate.

• ● Styrolpolymerisate wie Styrolacrylnitril (SAN), Polystyrol (PS), Acrylnitrylbutadienstyrol (ABS), Styrolmethylmethacrylate (SMMA), Styrolbutadien (SB beispielsweise BDS K-Resin von Chevron Phillips Chemical Company);
• ● Polyolefine wie Polypropylen (PP), Polyethylen (PE) beispielsweise auch in den Formen high density Polyethylen (HDPE) oder low density Polyethylen (LDPE);
• ● Polyester wie Polyethylenterephtalat (PET) in Form von säuremodifiziertem Polyethylenterephtalat (PETA) oder glykolmodifiziertem Polyethylenterephtalat (PETG) wie GN005 oder 6763 von Eastman Chemical Company, Polybutylenterephthalat (PBT), säuremodifiziertes Polycyclohexadimethanoltherastalat (PCT-A) wie BR003 von Eastman Chemical Company, glykolmodifiziertes Polycyclohexadimethanoltherastalat (PCT-G) wie DN004 von Eastman Chemical Company ;
• ● Cellulosederivate wie Celluloseacetat (CA), Celluloseacetobutyrat (CAB), Cellulosepropionat (CP), Celluloseacetatphtalat (CAP), Cellulosebutyrat (CB);
• ● Polyamide (PA) wie PA 6.6, PA 6.10, PA 6.12;
• ● Polymethylmethacrylat (PMMA);
• ● Polycarbonat (PC);
• ● Polyoxymethylen (POM);
• ● Polyvinylchlorid (PVC);
• ● Polyurethan (PUR).

Various plastics can be used for the realization of the invention. Exemplary possibilities in the field of thermoplastics are:

• Styrene polymers such as styrene-acrylonitrile (SAN), polystyrene (PS), acrylonitrile-butadiene-styrene (ABS), styrene-methyl-methacrylate (SMMA), styrene-butadiene (SB, for example, BDS K-Resin from Chevron Phillips Chemical Company);
• ● polyolefins such as polypropylene (PP), polyethylene (PE), for example, in the forms of high density polyethylene (HDPE) or low density polyethylene (LDPE);
• ● Polyester such as polyethylene terephthalate (PET) in the form of acid-modified polyethylene terephthalate (PETA) or glycol-modified polyethylene terephthalate (PETG) such as GN005 or 6763 from Eastman Chemical Company, polybutylene terephthalate (PBT), acid-modified polycyclohexadimethanol terephthalate (PCT-A) such as BR003 from Eastman Chemical Company, glycol-modified Polycyclohexadimethanoltherastalate (PCT-G) such as DN004 from Eastman Chemical Company;
• Cellulosic derivatives such as cellulose acetate (CA), cellulose acetobutyrate (CAB), cellulose propionate (CP), cellulose acetate phthalate (CAP), cellulose butyrate (CB);
• ● polyamides (PA) such as PA 6.6, PA 6.10, PA 6.12;
• ● polymethyl methacrylate (PMMA);
• ● polycarbonate (PC);
• ● polyoxymethylene (POM);
• ● polyvinyl chloride (PVC);
• ● Polyurethane (PUR).

• ● Thermoplastische Polyurethan-Elastomere (TPE-U);
• ● Thermoplastische Styrol-Elastomere (TPE-S) wie beispielsweise ein Styrol-Ethylen-Butylen-Styrol-Copolymer (SEBS) oder Styrol-Butadien-Styrol-Copolymer (SBS);
• ● Thermoplastische Polyamid-Elastomere (TPE-A) wie beispielsweise Grilflex von EMS Chemie AG;
• ● Thermoplastische Polyolefin-Elastomere (TPE-0);
• ● Thermoplastische Polyester-Elastomere (TPE-E).

Examples in the field of thermoplastic elastomers (TPE's) are:

• ● Thermoplastic polyurethane elastomers (TPE-U);
• ● Thermoplastic styrene elastomers (TPE-S) such as a styrene-ethylene-butylene-styrene copolymer (SEBS) or styrene-butadiene-styrene copolymer (SBS);
• ● Thermoplastic polyamide elastomers (TPE-A) such as Grilflex from EMS Chemie AG;
• ● Thermoplastic polyolefin elastomers (TPE-0);
• ● Thermoplastic polyester elastomers (TPE-E).

As the hard component, in the case of a non-transparent brush, it is preferable to use PP, most preferably PP having an E modulus of 1000 to 2400 N / mm 2, preferably 1300 to 1800 N / mm 2 is used. For the design of a transparent brush, preference is given to using polyesters such as the listed BR003, CAP, PA, PMMA, SAN or ABS as the hard component.

The soft component used is preferably a TPE-S. The Shore A hardnesses of the soft plastic are preferably below 90 Shore A.

The invention will be explained in more detail with reference to an embodiment shown in the drawing.

• Fig. 1 in Draufsicht einen Bereich einer
  erfindungsgemässen Zahnbürste mit einem Kopfteil
  und einem daran anschliessenden Endbereich eines
  Halsteils eines Zahnbürstenkörpers und einem in
  den Kopfteil eingesetzten, mit Borsten
  versehenen Borstentragelement;
• Fig. 2 in Seitenansicht den in Fig. 1 gezeigte Bereich
  der Zahnbürste;
• Fig. 3 im Längsschnitt sowie in Explosionsdarstellung
  den in den Fig. 1 und 2 gezeigte Bereich der
  Zahnbürste mit Zahnbürstenkörper und beborstetem
  Borstentragelement;
• Fig. 4 im Längsschnitt den Bereich der Zahnbürste
  gemäss den Fig. 1 und 2 mit in den Kopfteil
  eingesetztem beborstetem Borstentragelement;
• Fig. 5 im Längsschnitt und gegenüber Fig. 4
  vergrössert einen in Fig. 4 mit V bezeichneten
  Ausschnitt der Zahnbürste;
• Fig. 6 in gleicher Darstellung wie Fig. 5 einen in Fig.
  4 mit VI bezeichneten weiteren Ausschnitt der
  Zahnbürste;
• Fig. 7 einen Querschnitt entlang der Linie VII - VII
  der Fig. 4 durch die Zahnbürste;
• Fig. 8 gegenüber Fig. 7 vergrössert einen dort mit VIII
  bezeichneten seitlichen Ausschnitt der
  Zahnbürste;
• Fig. 9 in Ansicht und teilweise geschnitten einen Teil
  einer Vorrichtung zum Biegen des Halsteils
  relativ zum Kopfteil;
• Fig. 10 in Draufsicht einen Teil der Vorrichtung gemäss
  Fig. 9 mit einer mit ihrem Kopfteil in ein
  Aufnahmeelement der Vorrichtung eingesetzten
  Zahnbürste;
• Fig. 11 ein prinzipielles Ablaufdiagramm für das
  erfindungsgemässe Verfahren;
• Fig. 12 ein Ablaufdiagramm zur Durchführung des
  erfindungsgemässen Verfahrens an einem Rundtisch
  im AFT-Verfahren;
• Fig. 13 ein Weg-Kraftdiagramm bei einer Belastung einer
  Zahnbürste ohne Recken;
• Fig. 14 in gleicher Darstellung wie Fig. 13 ein Weg-
  Kraftdiagramm bei der Belastung einer Zahnbürste
  deren Zahnbürstenkörper erfindungsgemäss gereckt
  wurde;
• Fig. 15 einen vergrösserter Ausschnitt der in
  verschiedenen vorgängigen Figuren gezeigten
  Schnittstellengeometrie zwischen Tragplättchen
  und Zahnbürstenköper mit der Schweisszone und
  der schweissnahen Zone;
• Fig. 16 ein vergrösserter Ausschnitt der in
  verschiedenen vorgängigen Figuren gezeigten
  Schnittstellengeometrie zwischen Tragplättchen
  
  und Zahnbürstenköper wobei der Materialfluss in
  den Spalt gezeigt ist;

It shows purely schematically:

• Fig. 1 in plan view an area of a
  toothbrush according to the invention with a head part
  and an adjoining end portion of a
  Collar parts of a toothbrush body and an in
  the headboard inserted, with bristles
  provided bristle carrier element;
• Fig. 2 in side view the in Fig. 1 shown area
  the toothbrush;
• Fig. 3 in longitudinal section and in exploded view
  in the Fig. 1 and 2 shown area of
  Toothbrush with toothbrush body and bristled
  Bristle support member;
• Fig. 4 in longitudinal section the area of the toothbrush
  according to the Fig. 1 and 2 with in the headboard
  inserted bristled bristle support element;
• Fig. 5 in longitudinal section and opposite Fig. 4
  enlarges one in Fig. 4 labeled V
  Cutout of the toothbrush;
• Fig. 6 in the same representation as Fig. 5 one in FIG.
  4 with VI designated further section of
  Toothbrush;
• Fig. 7 a cross section along the line VII - VII
  of the Fig. 4 through the toothbrush;
• Fig. 8 across from Fig. 7 enlarge one there with VIII
  designated lateral section of the
  Toothbrush;
• Fig. 9 in view and partially cut a part
  a device for bending the neck portion
  relative to the headboard;
• Fig. 10 in plan view a part of the device according to
  Fig. 9 with one with her headboard in one
  Receiving element of the device used
  Toothbrush;
• Fig. 11 a basic flowchart for the
  inventive method;
• Fig. 12 a flow chart for performing the
  inventive method on a rotary table
  in the AFT procedure;
• Fig. 13 a path-force diagram at a load of a
  Toothbrush without stretching;
• Fig. 14 in the same representation as Fig. 13 a way
  Force diagram when loading a toothbrush
  whose toothbrush body is stretched according to the invention
  has been;
• Fig. 15 an enlarged section of the in
  shown different previous figures
  Interface geometry between support plates
  and toothbrush body with the welding zone and
  the near-welding zone;
• Fig. 16 an enlarged section of the in
  shown different previous figures
  Interface geometry between support plates
  
  and toothbrush body wherein the material flow in
  the gap is shown;

The Fig. 1 and 2 show a part of a toothbrush 10 according to the invention with a toothbrush body 12 and a bristle carrier element 18 inserted therein in a head part 14 in a receiving geometry 16 and fastened to the head part 14. This comprises a support plate 20, from which the bristles 22 of a known manner Borstenfeldes 24 protrude.

Like this one Fig. 1 can be removed, the receiving geometry 16 has a circumferential lateral surface 26 and the support plate 20 a side surface facing this 28 on. Between the lateral surface 26 and the side surface 28, a circumferential gap 30, preferably an air gap, is present.

The toothbrush body 12 then has, following the head part 14, a neck part 32, which adjoins it in one piece, from which in the Fig. 1 and 2 only a portion facing the head part 14 is shown. In the case of a manual toothbrush, a grip part 34 adjoins the neck part 32, on the side facing away from the head part 14, and which engages in Fig. 9 is shown.

The bristles 22 of the bristle field 24 are on the front side 36 of the toothbrush body 12 of support plate 20 from. The exposed surface of the support plate 20 is aligned with the corresponding surface of the toothbrush body 12.

In the embodiment shown in the figures, the toothbrush body 12 is provided on the rear side 38 facing away from the front side 36 in the head part 14 with a tongue cleaner 40. Embodiments without tongue cleaner 40 are also possible.

In the embodiment shown, the toothbrush body 12 in the neck part 32 and head part 14 consists of a hard component. However, it is also possible that in the two-component or multi-component injection molding process, the tongue cleaner 40 is molded from a soft component to the hard component or also that the soft component for decorative purposes larger surface portions of the surface of the toothbrush body 12, in particular of the head part 14, occupies.

In the Fig. 1 and 2 Furthermore, a fracture region 42 is indicated in which there is the risk of brittle fractures, if not, as in the present invention, the toothbrush body 12 is stretched by bending the head portion 14 relative to the neck portion 32.

Fig. 3 shows in a central longitudinal section on the one hand the same part of the toothbrush body 12 as in Fig. 1 and 2 is shown, and on the other hand, the bristle carrier element 18 with the protruding from these bristles 22 of the bristle field 24 in an exploded view.

The receiving geometry 16 is formed by a stepped recess 44, which is open towards the front side 36, in the head part 14, the bottom 46 of which is closed towards the rear side 38 by a wall of the toothbrush body 12. The oval recess 44 in view of the front side 36 is delimited from the front side 36 of the toothbrush body 12 up to a step 48 by the lateral surface 26 which, in the present example, extends at right angles to the front surface of the toothbrush body 12 in the head part 14. The recess 44 reducing step 48 extends in a plane parallel to the front side 36 of the head part 14 and from it is at the radially inner edge acting as an energy concentrator / Energierichtungsgeber welding bead 50 in the direction against the front 36 before. The cross section of the welding bead 50, which is preferably completely circumferential and self-contained, is preferably triangular.

However, the welding bead 50 can also be designed differently. For example, the width (preferably not the height) may vary over the circumference. Next, the Welding bead 50 have a broken in the direction of rotation, for example, with juxtaposed individual welding points or juxtaposed individual welding edges, the distances and lengths of the elements may vary in both cases. Welding points can be designed, for example, pyramidal or conical. The height of the welding bead 50 is between 0.05 mm and 0.8 mm, preferably between 0.15 mm and 0.4 mm.

Subsequent to the welding bead 50, the recess 44 is bounded by a lower, second lateral surface 52, which preferably also extends at right angles to the front side 36 of the head part 14 or slightly conically tapering to the bottom 46.

Furthermore, in the exemplary embodiment shown, the base 46 has a circumferential groove-like depression 54 in an edge region adjoining the second lateral surface 52.

Next is the Fig. 3 can be removed that the width of the step 48 on the neck portion 32 facing side is greater than on the free end of the head part 14 facing side. The width of the step 48 is between 0.6 mm and 2 mm, preferably 1 mm and 1.2 mm.

The step 48, measured from the bottom 46 to the front 36 of the head part 14 is arranged to a maximum of 70%, preferably at most 66% of the total height, with 50% or less are conceivable. Thus, the welding bead 50 and the later-generated welding zone 51 should be placed as close to the ground 46 as possible.

The depth of the recess 44, that is the dimension from the front side 36 to the bottom 46, is 1.8 mm to 2.6 mm, preferably 2.1 mm to 2.3 mm. The groove-like recess 54 has a depth measured from the front side 36 ago from 2.5 mm to 3.5 mm, preferably from 2.8 mm to 3.2 mm. The height of the step 48, measured from the front side 36 forth forth is between 0.6 mm and 2 mm, preferably between 1 mm and 1.2 mm.

The in the embodiment shown on the front side 36 flat support plate 20 is shaped such that its peripheral side surface 28, in the assembled state, at least approximately parallel to the jacket wall 26 and the gap 30 forming at a distance to this. This means that the shape of the recess 44 is in each case adapted to the shape of the support plate 20 or of the bristle carrier element 18. The two can therefore assume geometrically other forms, must be coordinated in each case.

Further, on the support plate 20, a step-like planar counter-surface 56 corresponding to the step 48 is formed, which is bounded radially inwardly by a centering wall 58 which projects from the support plate 20 on its rear side. The radially outer surface of the centering wall 58 is formed opposite to the second lateral surface 52 of the receiving geometry 16 and serves to center the bristle carrier element 18 in the toothbrush body 12.

In order that the width of the gap 30 can be maintained in practice in each case, it is necessary, the tools for the preparation of the toothbrush body 12 and the Recess 44 and the support plate 20 to tolerate accordingly. For this purpose, the tolerances of the support plate 20 and the recess 44 of the toothbrush body 12 must be matched to each other in the area of the receiving geometry 16, so that the support plate 20 at maximum dimensions in combination of the recess 44 of the toothbrush head with minimum mass, the gap 30 still in the specified dimension form. This means that on the side of the support plate 20, the tolerances of the centering wall 58, inner edge and outer edge of the counter surface 56, and the tolerance of the side surface 28 on each other and on the recess 44 and the receiving geometry 16 in the toothbrush body 12 must be coordinated. In the toothbrush body 12, the tolerances of the inner and outer edge of the step 48, the lateral surface 26 must be matched to each other and said tolerances of the support plate 20.

With respect to the circumferential centering wall 58 radially inward, the support plate 20 from the front of the support plate 20 to its back continuous bristle receiving passages 60 on.

As is generally known from the AFT method (AFT = Anchor Free Tufting), the bristle carrier element 18 or the carrier plate 20 is produced by injection molding, in the present case preferably from a hard component. In this case, cleaning and massage elements 22 'may be injection-molded from a soft component on the support plate 20. In the support plate 20, the bristles 20 forming the bristle field 24 through the bristle receiving passages 60th passed, and aligned to form the Zahnreinigungsgeometrie. Subsequently, the bristles 20 are melted in their over the back of the support plate 20 projecting end portion, for example by means of a punch, which forms a melted film 62 of molten bristle material on the back of the support plate 20 and within the limited area of the centering wall 58. As a result, the bristles 22 form the bristled bristle carrier element 18.

Subsequently, the bristle bristle carrying member 18 is inserted from the front 36 into the receiving geometry 16 of the toothbrush body 12 until the counter surface 56 of the support plate 20 comes to rest on the welding bead 50 of the receiving geometry 16 of the head part 14. The centering is carried out by the interaction of the centering wall 58 with the second lateral surface 52 and their lying in the direction of the front side 36 final edge. In practice, the melting of the bristles 22 to form the melt film 62 is such that the centering wall 58 tilts radially inwardly due to the action of heat. The result of this change in geometry through the process is that the centering wall 58 forms, as it were, an inlet slope towards its point of attachment, and thus the closing edge in the region of the mating surface 56 is used for the centering.

How this particular out Fig. 4 can be seen, the recess 54 prevents the lining of the rear end surface of the centering wall 58 at the bottom 46th

After inserting the bristled bristle support member 18 in the receiving geometry 16 of the head part 14, the support plate 20 by means of ultrasonic welding in a known manner with the toothbrush body 12 is firmly connected. The welding bead 50 on the toothbrush body 12 serves as an energy concentrator / energy director. It is liquefied during the ultrasonic welding and forms a welded connection with the material of the support plate 20 in the region of its counter surface 56 and forms a welding zone 51. The melt can spread in the region of the step 48 and also melt on the welding bead 50 near regions. preferably, a penetration into the gap 30 is to be prevented. The ultrasonic welding preferably occurs between two compatible hard components which allow a material closure, preferably between two equal hard components.

As this particular from the Fig. 5 to 8 As can be seen, this weld is continuously circulating. Further, these figures can be taken that after completed ultrasonic welding, the counter surface 56 and the step 48 abut each other. Furthermore, these figures can be removed particularly well that the encircling gap 30 remains between the lateral surface 26 of the toothbrush body 12 and the side surface 28 of the support plate 20 and is open towards the front side 36.

To the in the Fig. 5 to 8 Welding zone 51 shown is to be stylized and simplified shown as immersed in the support plate 20 Welding bead 50. That is, the two elements are shown as an overlap. In practice, however, this is different, a practice corresponding representation is in Fig. 15 shown. The welding bead 50 is melted. Its material and also the acting welding energy also heat and melt the welding bead 50 near areas of the support plate 20 and the receiving geometry 16. This melting ultimately brings a material closure between the toothbrush body 12 and the support plate 20. Further, the material in the areas near the welding zone 51st heated by welding, this area is referred to as near-welding zone.

In order to ensure, in particular, in an end region of the recess 44 or the receiving geometry 16 facing the neck portion 32, that the gap 30 remains free of welding melt until the step 48, the step 48 is wider in this area, and the distance between the jacket wall 26 and the welding bead 50 is preferably selected larger than in the other areas; compare in particular FIGS. 5, 6 and 8 which show an end section of the receiving geometry 16 facing the free end region of the head part 14, an end section of the receiving geometry 16 facing the neck part 32 and the receiving geometry 16 in the longitudinal center of the head part 14.

Fig. 9 shows a radially outer edge portion of an indexable about a vertical axis rotatable rotary table 64 ', on which in the circumferential direction, for example, offset by 90 °, each distributed a receiving element 64 for the Head part 14 of a toothbrush body 12 is attached. The receiving element 64 is in Fig. 10 , across from Fig. 9 enlarged and in plan view, also shown. The receiving element 64 has a receiving recess 66 which is open towards the top and which supports the head part 14 on the rear side 38 in a support section 68 extending around the tongue cleaner 40. Radially inside of the support portion 68, the receiving recess 66, for the release of the tongue cleaner 40, formed recessed.

If the toothbrush is designed without a tongue cleaner, the shape of the receiving recess 66 may follow the geometry of the back of the toothbrush head, an exemption is possible but not mandatory. The height of the receiving recess 66 supports the head portion 14 of the toothbrush at a level of 40% to 70% of the total height of the toothbrush body 12 in the head part 14th

As compared with the Fig. 4 can be seen, the support portion 68 extends on the back 38 at least near the region of the step 48 and the welding bead 50, seen in a projection at right angles to the front side 36.

How this continues FIGS. 9 and 10 can be removed, extends from the receiving recess 66 an exemption recess 70 toward the free edge of the receiving element 64, which frees the toothbrush body 12 in the transition region from the head part 14 to the neck portion 32 and the neck portion 32. The cutout recess 70 ends at least approximately at the neck part end of the receiving geometry 16, or the recess 44 for the bristle carrier element 18th

The end of the relief recess 70 is preferably adjusted so that at least at right angles to the front side 36 the step 48 and the welding bead 50 are in line with the support section 68, the relief recess 70 preferably bears directly against the support section 68. This ensures that the receiving geometry 16 or the welding bead 50 is supported in the region perpendicular to the front side 36 during the ultrasonic welding process, so that optimum welding is made possible and yet the bending process is not hindered.

In addition to the exemption well 70 is in Fig. 10 also the lateral exemption range 70 'shown. This exposes the toothbrush body 12 perpendicular to the release direction of the release recess 70, in this case in a plane parallel to the front side 36 of the support plate 20. The release of the neck portion 32 of the toothbrush body 12 allows the toothbrush body 12 to "move freely" during the bending process. Basically, a free space for displaced material should be created in this way, so that it is not inhibited by a receiving geometry of the device.

The lateral exemption 70 'takes place at the earliest from a range of 75% of the length of the support plate 20, measured from the free end of the bristle field 24. So that the welding happens optimally and also on the front side 36 of the toothbrush body 12 is a possibility of material displacement, can a sonotrode 76 may be designed so that they are in the direction of Toothbrush body 12 lying end is slightly free after the support portion.

The toothbrush 10 is shown with the head part 14, with the back 38 ahead, inserted into the receiving recess 66, while the neck portion 32 and the adjoining this handle portion 34 are exposed. At this point, it should be mentioned that the grip part 34 may have, for example, a thumb rest 72 and a forefinger rest 74 made of a soft component. It should also be mentioned that regions of the neck part 32 and / or of the head part 14 and / or also of the grip part 34 can be equipped with a soft component in a known manner.

Next is in Fig. 9 the sonotrode 76 can be seen, with which in a welding station of the toothbrush manufacturing device the bristle carrier element 18 provided with bristles 22 and the head part 14 or the toothbrush body 12 are welded together.

The sonotrode 76 is, at least in its end portion facing the receiving element 64, annular, that is formed with a cavity in the interior for the bristle field 24. This is in Fig. 1 and 4 in the form of a contact surface 78 of the sonotrode 76 on the carrier plate 20 indicated. This contact surface 78 runs in the head part 14 of the toothbrush around the bristle field 24 respectively in line over the welding bead 50. The over the support plate 20 projecting bristles 22 and optionally the rubber-elastic cleaning elements find in the cavity in the sonotrode 76 place.

In Fig. 9 the bending process is indicated. During the previous welding process or during which the receiving element 64 rotates together with the rotary table 64 ', a support is introduced below the grip part 34, which supports and guides the toothbrush body 12. This support is not shown in the figure and is removed or moved away for the bending process.

Further, the welding station is associated with a stretching device 80, which is intended, the neck portion 32 relative to the head part 14, from the in Fig. 9 shown original shape to bend the angle α, and after a certain waiting time to release again. In the illustrated embodiment, the stretching device 80, a cylinder-piston unit 82, the piston is provided at the free end with a roller 84.

The direction of movement of the roller 84 is orthogonal to a plane defined by the front side 36 of the support plate 20 and the head part 14. Further, the stretching device 80 is arranged such that the roller 84 comes in a remote from the head part 14 and lying at the handle portion 34 end portion 32 ', the neck portion 32, on the front, comes to rest. By the extension movement of the cylinder-piston unit 82, the roller 84 presses on the surface of the toothbrush body 12, rolls on this and deflects the body by the angle α.

Achieved, by rotating the rotary table 64 ', a equipped with a bristle support member 18 toothbrush body 12 equipped receiving element 64, the welding station, the sonotrode 76 is lowered onto the support plate 20 of the bristle support member 18, and by exciting the sonotrode 76, the ultrasonic welding process between the support plate 20 and the head part 14 in a known manner. After the time necessary for the welding process, the sonotrode 76 remains (in an unexercited manner) on the bristle carrier element 18 in abutment in order to hold the head part 14 during the subsequent stretching operation. For stretching by bending, by driving the cylinder-piston assembly 82, the roller 84, in the manner of a ram, brought to the end portion 32 'of the neck portion 32 into abutment and then further lowered by a predetermined stroke to the neck portion 32 relative to the head portion 14th to bend the angle α. After a predetermined period of time, during which the roller 84 is held in the lowered position, the roller 84 is retracted by the cylinder-piston unit 82 back to the starting position, so that the toothbrush body 12, due to its elasticity, move back to its original shape can.

The surface of the roller is concaved to optimally guide the neck portion 32 of the toothbrush body 12 and to pass the deflection in a direction perpendicular to the bristle field 24. This ensures that the toothbrush body 12 does not twist due to the shape of the roller.

It should be noted at this point that it is also conceivable to provide a second plunger in order to support the return of the toothbrush body 12 to its original shape. The design of the second plunger for the return movement is determined by two factors, the speed of the return movement and the effective Position after moving back. If the speed of the backward movement is too small, the cycle of the machine is slowed down, that is, the cycle time becomes larger, resulting in poorer efficiency with less output. The second factor, the position after the return, plays a role in that the support is brought back into the original position after the stretching operation. If the toothbrush is not in the same position at the time as it was originally, it may cause malfunction in the machine and affect process consistency.

Further, it is possible to form the roller other than specified. There are also non-rotatable systems conceivable that preferably rest on the surface of the toothbrush body 12 with low friction. Geometrically are thus also plates with rounded edges as a pressing element analogous to the roller conceivable. However, it is preferably such that these alternative elements are provided with a layer with low frictional resistance.

Bending of the neck portion 32 relative to the head portion 14 occurs immediately after completion of the welding operation, so that the toothbrush body 12 is still warm at least in the head portion 14 and in an adjoining end portion of the neck portion 32, ie in the near-welding zone and especially in the welding zone 51. The exact temperature can not be specified exactly because there is a temperature distribution over the toothbrush body in the region of the weld. In this case, at the time of welding in the area of the weld bead 50 temperatures around the melting point of Materials reached. This heat radiates into the environment and in this way also heats areas of the body that are not directly affected.

The angle α is chosen between 5 ° and 45 °, preferably it is in the range of 15 ° to 25 °. The angle α is defined by the imaginary line from the bending axis to the free end 90 of the handle portion 34 as an angle between the original state and the deflected state. The relief recess 70 and a passage or recess 86 in the rotary table 64 ', see Fig. 10 , allow collision-free bending around this angle.

For the angle consideration, the elasticity of the toothbrush body 12 is disregarded, which means that it is assumed that it behaves rigidly outside the bending zone; no correction factor for the elasticity is introduced. Basically, however, it is the case that the elasticity is lower when the action of the stretching device passes closer to the clamping of the head part 14.

The at least approximately parallel to the front side 36 of the head part 14 and perpendicular to the longitudinal axis of the toothbrush body 12 extending bending axis 88, around which the toothbrush body 12 bends by the force exerted on it by means of the stretching device 80 force is at least approximately at the transition from the head area to the neck area, ie about in Fig. 1 designated area of breakage 42 area in which the risk of brittle fracture is greatest. The bending takes place within a narrow region, viewed in the longitudinal direction of the toothbrush 10, in which the bending axis 88 lies. The length of the region is between 1 mm and 10 mm, preferably between 2 mm and 5 mm, measured from the position of the welding bead 50 on the longitudinal axis of the toothbrush 10 in the direction of the neck portion 32 of the toothbrush body 12.

The distance between the last bristles 22 on the longitudinal central axis of the bristle field 24 and the point at which the stretching device 80 acts on the toothbrush body 12 is 20 mm to 60 mm, preferably 30 mm to 50 mm. The point of action of the stretching device 80 on the toothbrush body 12 is preferably in front of the thumb rest 72.

The speed at which the stretching device 80 acts on the toothbrush body 12 to bend it by the angle α is controlled via a throttle on the cylinder-piston unit 82 or in the supply and is selected according to the ratios. The start of the stretching operation is preferably controlled by the position of the sonotrode 76. Between 0.1 seconds and 0.8 seconds, preferably 0.2 seconds, after the sonotrode 76 has reached its final position in the welding process, but the welding is still in progress, the stretching process begins with the drive away from the support and the subsequent extension of the ram.

In the deflected position (stretching position), the toothbrush body 12 is held for 0.3 seconds to 2 seconds, preferably between 0.5 seconds and 1.2 seconds. The whole additional process, that is to say from the moment in which the vibration of the sonotrode 76 is stopped until the time when the sonotrode is raised, is called the hold time. This takes between 0.8 seconds and 2 seconds, preferably 1 second, with an integrated stretching process. This ensures that with the stretching process no loss of efficiency must be taken into account and the machine must therefore take no extension of the cycle time in purchasing. Nevertheless, the hold time used in the invention is greater than the hold time in the "normal" process, in this case it is in the range of 0.1 seconds to 0.8 seconds, preferably 0.2 seconds to 0.5 seconds.

In general, the cycle time for welding and stretching should be lower than the cycle time for the bristling of a carrier plate 20 (machine cycle time) in the case of in-line production.

The width of the gap 30 between the head part 14 and the support plate 20, that is between side surface 28 of the support plate 20 and lateral surface 26 of the receiving geometry 16, is selected between 0.03 mm and 0.35 mm, preferably between 0.08 mm and 0.18 mm. Preferably, the gap 30 in its neck portion 32 facing the end portion is wider than in the lateral portions and in the free end of the head portion 14 facing end portion. The width of the gap 30 is preferably 0.1 mm to 0.2 mm in the end portion facing the neck portion 32, 0.09 mm to 0.19 mm in the end portion facing the free end, and 0.03 mm to 0.35 mm in the lateral portions , preferably 0.05mm to 0.18mm. The change of the gap width is preferably continuous. But it is also conceivable to make a gap 30, the circumferentially constant Width in the range between 0.03 mm and 0.35 mm preferably between 0.08 mm and 0.18 mm.

According to the general flowchart of FIG. 11 , which shows the integration of the invention into the AFT process, the toothbrush body 12 produced in a generally known manner by the injection molding process (one-component, two-component or multi-component injection molding process) and in a generally known manner in the injection molding process. Method (one-component or two-component injection molding method) prepared and bristled in the AFT process bristle carrier elements 18 (bristled AFT platelet) supplied, and then the welding of bristled with the head part 14 of the toothbrush body 12 bristle carrying member 18, preferably by means of ultrasonic Welding. Immediately thereafter, in the still warm state from the welding, the stretching of the toothbrush body 12 heated by the welding takes place by bending the head part 14 relative to the neck part 32, for example as described above in connection with FIG FIGS. 9 and 10 is described in more detail. After stretching, the toothbrush, which is in its original form again, is fed to 10 further process steps, for example for packaging, labeling or the like.

At this point it should be mentioned that the stretching process is due to the still warm near-welding zone and welding zone 51 Although provided immediately after the welding process, but this can still take place spatially displaced. In other words, the one described above Embodiment by stretching process on the welding station to understand by way of example.

In the flowchart of Fig. 12 For example, one possible embodiment of contacting the toothbrush body 12 with the bristled bristle carrier member 18, ultrasonic welding, and subsequent bending for stretching purposes is shown in more detail. This procedure shows, inter alia, the application of the invention to an existing machine which performs the bristling of the toothbrush by means of the AFT method.

The toothbrush body 12 is fed to the rotary table 64 'and inserted into the receiving recess 66 of a receiving element 64 on the rotary table 64', cf. Fig. 10 , By means of a clamping mechanism of the toothbrush body 12 is clamped in the region of the neck portion 32 or the handle portion 34 on the receiving element 64 and on a support, not shown, in the handle portion 34. Subsequently, the rotary table 64 '(see in particular also Fig. 9 ) rotated by 90 °, for example. In the insertion station achieved thereby, a supplied bristled bristle carrying element 18 is inserted into the receiving geometry 16 or recess 44 of the head part 14; compare to 3 and 4 ,

By means of a so-called. Primary holding mechanism, the bristle carrier element 18 inserted into the toothbrush body 12 can be held in the receiving geometry 16. Under this holding another rotation of the rotary table 64 'takes place, for example, again by 90 °. In this case, the clamping mechanism, which clamps the tooth bust body 12 on the supports, mechanically solved something and in parallel stabilized so that it exerts only a slight, no further increasing pressure on the toothbrush body 10. This ensures that the clamping mechanism takes no further influence on the process in this position of the rotary table 64 '.

Then, re-clamping may take place by moving a so-called secondary holding mechanism for holding the bristle carrying member 18 thereto, and then moving the primary holding mechanism away therefrom. The secondary holding mechanism also has the task, in addition to holding the bristle carrier element 18, of pressing the bristles 22 on the bristle field 24 in the direction of the center of the bristle carrier element 18. This creates space that the sonotrode 76 - see Fig. 8 -, Preferably by lowering, can be fed to the support plate 20 and that the bristles 22 are introduced during lowering of the sonotrode 76 in said cavity of the sonotrode 76. Then the secondary holding mechanism is released so that the sonotrode 76 can be moved up to the support plate 20 or head part 14 zoom. At this point it should be mentioned that a change from the primary holding mechanism to the secondary holding mechanism is not absolutely necessary. There are also embodiments of the method and the associated facilities conceivable that make do with only one holding mechanism, which combines the above-mentioned functions of the two holding mechanisms.

Subsequently, by the known corresponding excitation of the sonotrode 76, the welding process during a predetermined time, for example of 0.03 seconds to 0.8 seconds, preferably from 0.05 seconds to 0.2 seconds, in particular 0.08 seconds. In a preferred manner, the gripping part 34 has been supported up to this time by means of a support, not shown in the figures. If this was the case, at the present time this edition is moved away, so that the grip part 34 is released. Since the clamping mechanism has been released, the toothbrush body 12 is not loaded for a moment after driving away the support.

In the step "stretching of the toothbrush body" is bent by appropriate driving the cylinder-piston unit 82, as described above, the neck portion 32 relative to the head portion 14 by the angle α, held in this deflected position said period and then released again. This allows the toothbrush body 12 to move back to its original shape, due to its elasticity, automatically back. However, this retraction can be assisted by delivery of the aforementioned support to the handle portion 34 or by other means. For the stretching operation, the sonotrode 76 can be raised from the welding position by 0.1 mm to 0.5 mm, preferably 0.2 mm to 0.3 mm. This space can be created so that the toothbrush body 12 can expand during the stretching process at the appropriate places. Preferably, however, the position is not changed, the sonotrode 76 remains in the position in which the welding is completed. A change of position can at best by forces take place, which act on the sonotrode 76 by the stretching process through the toothbrush body 12.

Thereafter, the sonotrode 76, for example, by lifting, moved away from their investment in the bristle carrier element 18 and the rotary table 64 ', for example rotated by a further 90 °. Parallel to the start of rotation or immediately before the clamping mechanism is released again so that he holds the toothbrush body 12 on the receiving element 64 and the support again under full pressure, including during rotation of the rotary table 64 '. At a removal station, the clamping mechanism is first released and the toothbrush released. The finished bristled and stretched toothbrush 10 is then removed from the receiving element 64 and the support and, for example by means of a robot or manipulator, supplied to the further process steps. For example, if the bristles 22 were not previously rounded, another process step may be to round the ends of the bristles 22 in a known manner. Another process step may be that the toothbrush body 12 is labeled or printed or embossed. Another process step may be that the toothbrush 10 is packaged.

The Fig. 13 illustrates in a Weg-force diagram as an example of the behavior of a toothbrush 10 whose toothbrush body 12 has not been stretched by bending the head part 14 relative to the neck portion 32. For the measurement of the handle portion 34 of the toothbrush is held up to the thumb rest 72 and index finger rest 73 and the head part 14, for example centrally, acted upon by a force which is the same direction throughout the test and in the unloaded state at right angles to the front side 36 is directed towards the support plate 20. The force increases approximately proportionally to the deflection (= way) until it breaks, usually at the transition from the neck portion 32 to the head portion 14 - see break area 42 in Fig. 1 - comes. This can be recognized by the abrupt change in the path-force diagram.

Fig. 14 shows the path-force diagram for a toothbrush 10 prepared according to the present invention, the toothbrush body 12, as described above, was stretched. By applying force to the head part 14 with the grip part 34 held in place, the region of the approximately linear relationship between displacement (path) and force is approximately twice as large as when the toothbrush body 12 is not stretched (cf. Fig. 13 ) and then there is not a break, but a plastic deformation. This can be seen in the diagram due to the rounded shape of the curve and a desired result of the invention.

For force-displacement measurement, it should also be noted that the force required for the deflection, that is to say the force required for stretching, does not matter or is ignored. The only important thing is the angle α achieved.

In FIGS. 15 and 16 is shown in sectional view, as the interface geometry between the support plate 20 and the toothbrush body 12 may look after welding by welding. The illustrations are based on Analyzes of the welding of sliced and polarized bodies.

In Fig. 15 a possible form of the result of the welding is shown. It can be seen that a third zone has formed between the toothbrush body 12 and the support plate 20 as a result of the welding. This welding zone 51 is shown simplified as a separate zone, but in the result it is a connection between the two adjacent elements and preferably forms together with them a continuous body. It can also be seen that the molten material does not spread into the gap 30 and thus does not contact the lateral surface 26 and the side surface 28 or are not connected by material. This figure also shows that, for example, a part of the support plate 20 can be melted and the welding zone 51 can also spread in the region of the centering wall 58. However, this is only to be seen as a possibility, preferably the welding zone 51 does not spread so far that no fusion in the form of the welding zone 51 propagates between the centering wall 58 and the support plate 20. The Fig. 15 of course shows only one case from practice. The image in this area of the toothbrush 10 may vary from toothbrush to toothbrush. Many factors play a role in the shape and propagation of the weld zone 51. These include on the one hand the tolerances in the field of injection-molded parts, such as support plate 20 and toothbrush body 12, as well as any influences that bring the melting and fixing of the bristles on the support plate 20 with it. Finally, the welding process plays a big The role, for example, the welding parameters as well as the tolerances in the structure of the welding arrangement in the process a role.

The representation in Fig. 16 shows a situation how to avoid it. The difference compared to Fig. 15 is that the welding zone 51 and with it the molten material in the region of the gap 30 between the lateral surface 26 and the side surface 28 flows or flows into him. It can also be seen that the melt and the welding process also melt welding-near geometries. This is when comparing the FIGS. 15 and 16 It can be seen that the gap walls, that is, the jacket surface 26 and the side surface 28, in Fig. 16 no longer run as they were made in injection molding. This also shows how the connection of support plates 20 and toothbrush body 12 in the region of the interface of the welding zone 51 proceeds. By melting additional material, the welding is supported.

It is also possible to attach the bristles in the IMT process (In Mold Tufting) on the support plate 20 and then to mount this in the receiving geometry 16 of the head part 14 and to weld with this, in particular by means of ultrasound. It is also possible to produce toothbrushes 10 completely in the IMT process and to improve them by stretching in the still warm state from injection molding. The warm state stirs in In this case mostly from injection molding and not from a welding process.

Another boron process that can be used in the context of the present invention is the IAP (Integrated Anchorless Production) process. Again, the brush is stretched while still warm.

The embodiment shown, in which the receiving element 64 together with the other devices required around a rotary table 64 'is arranged, is to be regarded as an example. It is also possible to arrange the receiving element 64 in a circulating chain, an endless conveyor or another appropriately adapted transport means and thus implement the invention in the production process.

It is also possible to attach a part of the bristle field 24 on the head part 14 itself, and the other part on the bristle carrier element 18. This may also apply in the case of rubber-elastic cleaning elements.

The inventive manufacturing method is not only suitable for manual toothbrushes, but also for the production of sonic toothbrushes and electric toothbrushes with rotating and / or pivoting head parts 14th

Furthermore, it is also possible to prepare other types of cosmetics, body care or oral hygiene products, for example tongue cleaners or interdental cleaners, by the process according to the invention.

The reference numeral 22 'in Fig. 1 relates to rubber-elastic cleaning and massage elements, which may be provided here instead of bristles 22 or together with bristles 22 on the support plate 20. Further 20 further additional elements can be integrated into the support plate, such as movable or fixed-shaped elements with snap or snap connections.

The method according to the invention is particularly suitable when the toothbrush body 12 has become warm by means of the action of ultrasound in the region of the head part 14 and / or of the neck part 32.

In order to avoid the connection of the lateral surface 26 and the side surface 28, alternative variants are possible in addition to the executed variant of the gap 30. Thus, for example, adhesion reducers or adhesion suppressants may be printed, painted or sprayed onto the lateral surface 26 and / or the side surface 28. Further, a soft component could be designed laterally on the support plate 20, which acts like a seal, can not be welded (due to the material properties), the gap 30 fills and thus avoids the lateral welding.

Further, to avoid the lateral connection of lateral surface 26 and side surface 28, the counter surface 48 on the support plate 20 and / or the step 48 are geometrically adjusted. By designing a reservoir / bunker / buffer in this area, this element can capture a portion of the melt created during ultrasonic welding so that the melt does not penetrates into the gap 30 and thus brings a deterioration of the fracture behavior with it.

To design the interface geometry between the support plate 20 and the toothbrush body 12, which, among other things, the receiving geometry 16, it should be added that other arrangements of the welding bead 50 are possible. The welding bead 50 may, for example, also be arranged at the free end of the centering wall 58. The correspondingly adapted elements bottom 46 and groove-like recess 54 contribute to the fact that the welding takes place between the support plate 20 and the toothbrush body 12 in the region of the bottom. Furthermore, the position of the welding bead 50 can also be varied in relation to the distance from the bottom 46 or to the front side 36 of the toothbrush body 12. In this case, the position is, as already described above, formed rather deeper than shown. Other possibilities not listed arrangement and geometric adjustment of the elements are not excluded from the invention.

The ultrasonic welding process is defined by means of various parameters. Thus, the welding path, ie the distance which the sonotrode 76 travels during the welding, is preferably between 0.15 mm and 0.05 mm to 0.4 mm. up to 0.2 mm. The sonotrode 76 is excited with ultrasound at a frequency of 25,000 Hz to 45,000 Hz, preferably from 35,000 Hz to 40,000 Hz, with an amplitude of 0.02 mm to 0.12 mm, preferably 0.05 mm to 0.09 mm. In this case, an energy of 5 Ws to 35 Ws spent, preferably 15 Ws to 25 Ws. With of this parameter constellation and the previously described geometry, the welding process lasts 0.03 seconds to 0.8 seconds, preferably from 0.05 seconds to 0.2 seconds, especially 0.08 seconds. Of course, the design variants shown in this document are exemplary and the individual forms and elements of these design variants can with others Embodiment variants can be combined without departing from the scope of this invention.

For the sake of completeness it should be mentioned that, for example by means of polarization microscopy on the toothbrush 10 itself can be determined whether the toothbrush body 12 has been stretched or not. This is especially true when using transparent or opaque material for the toothbrush body 12.

Claims (24)

Method for producing a toothbrush, in which a toothbrush body (12) having at least one head part (14) and a neck part (32) adjoining the head part (14) is produced, the head part (14) having a bristle (22) provided carrying support plate (20) and by means of welding the support plate (20) on the head part (14) is fastened and then on the toothbrush body (12) a force is exercised, characterized in that still in the warm state of the welding zone (51) by means of the force the neck portion (32) and the head portion (14) are bent relative to each other from the original shape by a predetermined angle (α), and after bending, the force is released to return the toothbrush body (12) to its original shape enable. A method according to claim 1, characterized in that the bending of the toothbrush body (12) takes place reversible in the elastic region. A method according to claim 1 or 2, characterized in that the angle (α) is 5 ° to 45 °, preferably 15 ° to 25 °. Method according to one of claims 1 to 3, characterized in that the bend during a held for a predetermined period of time and then the power is released. Method according to Claim 4, characterized in that the period of time is 0.3 s to 5 s, preferably 0.5 s to 1.2 s. Method according to one of claims 1 to 5, characterized in that the cycle time for the bristles of the support plate (20) is greater than the time required for the welding and bending. Method according to one of claims 1 to 6, characterized in that on the head part (14), during manufacture of the toothbrush body (12), a receiving geometry (16) for a support plate (20) is formed, then in the receiving geometry (16) with Bristles (22) is provided, the support plate (20) on the head part (14), preferably by means of ultrasonic welding, is attached and then the neck part (32) relative to the head part (32) is bent by the force. A method according to claim 7, characterized in that the bending in the heated by the ultrasonic welding welding zone (51) and a weld near zone takes place. A method according to claim 7 or 8, characterized in that in the generation of the receiving geometry (16) a lateral surface (26) is formed such that - when inserting the support plate (20) - between it and a Side surface (28) of the support plate (20) a gap (30), preferably from 0.03 mm to 0.35 mm, remains free to avoid welding there. A method according to claim 7 or 8, characterized in that the tolerances of the head part (14) with the receiving geometry (16) and the support plate (20) are set such that at maximum size of the support plate (20) and minimum size of the receiving geometry (16 ) between a lateral surface (26) of the receiving geometry (16) and a side surface (28) of the support plate (20) a gap (30) with a width of 0.03 mm to 0.35 mm is maintained, such that no material from the welding zone (51) penetrates into the gap (30), and preferably the tolerances of a support plate (20) projecting centering wall (58) and cooperating with this second lateral surface (52) of the receiving geometry (16) and between the lateral surface (26) and the second lateral surface (52) extending step (48) and a cooperating with this mating surface (56) on the support plate (20) are set accordingly. A method according to claim 7 or 8, characterized in that in the generation of the receiving geometry (16) a lateral surface (26) is formed, and between the lateral surface (26) and a side surface (28) of the support plate (20) a Haftverminderer is arranged, to reduce or prevent welding there. Method according to one of claims 1 to 11, characterized in that the head part (14) is held in a receiving element (64) and with the force, preferably in the manner of a plunger (82), on an end portion facing away from the head part (14) (32 ') of the neck portion (32) is acted upon. Method according to one of claims 1 to 11, characterized in that the neck part (32) in an end portion (32 ') facing away from the head part (32) by means of a receiving element (64) and held with the force, preferably in the manner of a ram ( 82), on the head part (14), preferably - measured in the longitudinal direction - approximately in the middle, is acted upon. Method according to one of claims 1 to 11, characterized in that the toothbrush body (12) in a on the head part (14) facing away from the neck portion (32) subsequent grip part (34) held by a receiving element (64) and with the Force, preferably by means of a plunger (82), on the head part (14), preferably - measured in the longitudinal direction - approximately in the middle, is acted upon. Toothbrush, produced by the method according to one of Claims 1 to 14, having a receiving geometry (16) integrally formed on the head part (14) for a support plate (20) and a support plate (14) provided with bristles (22) ( 20), which on the head part (14) by means of welding, in particular ultrasound Welding is fixed, wherein between a lateral surface (26) of the receiving geometry (16) and a side surface (28) of the support plate (20) either a gap (30), preferably from 0.03 mm to 0.35 mm, or substantially prevents welding is. Toothbrush according to claim 15, characterized in that the molecules are aligned by means of stretching at least in a partial region in the welding zone (51). Toothbrush according to claim 16, characterized in that this portion is located at an end portion of the carrier plate (20) facing the neck portion (32). Toothbrush according to one of claims 15 to 17, characterized in that the width of the gap (30) is different. Toothbrush according to claim 18, characterized in that the width of the gap (30) in a neck portion (32) facing the end portion is greatest. Toothbrush according to one of claims 15 to 19, characterized in that the gap (30) in the upper third, measured from the front side (36) ago, is free of welding material. Toothbrush according to claim 20, characterized in that the lateral surface (26) and the Side surface (28) in the neck portion (32) facing the end portion of the gap (30) are free of sweat. Toothbrush according to one of claims 15 to 21, characterized in that the gap (30) has a width between 0.08 mm and 0.18 mm. Toothbrush according to one of claims 15 to 21, characterized in that the width of the gap (30) in the neck portion (32) facing end portion preferably 0.1 mm to 0.2 mm, in a free end of the head part (14) facing the end portion 0.09mm to 0.19mm and in between, in lateral sections, 0.03mm to 0.35mm, preferably 0.05mm to 0.18mm. Toothbrush according to one of claims 15 to 23, characterized in that the lateral surface (26) and the side surface (28) in the gap (30), measured from the front, to a depth of at least 1 mm, preferably 2 mm, relative to each other are connection-free.

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