EP0472857B1 - Method and apparatus for fixing bristle tufts to a plastic bristle carrier - Google Patents

Abstract

A method for fixing bristle tufts to a plastic bristle carrier is proposed, by melting the bristles of each tuft at their ends on the attachment side with formation of a thickening, by providing the bristle carrier on the bristle-receiving side with holes receiving the thickenings, by pressing the bristle tufts into the bristle carrier by the thickening, by sealing off the space above the bristle-receiving side and between the bristle tufts, surrounding the bristle area in annular fashion, against the bristle carrier, and by the compound rising during the pressing-in under the application of pressure and filling the sealed-off space being displaced and compressed. In addition to further variants of the method, an apparatus for carrying out the method is also described.

Description

The invention relates to a method for connecting bristle bundles to a plastic bristle carrier, by melting the bristles of each bundle at their fastening-side ends to form a thickening, providing the bristle carrier with holes on the bristle receiving side and / or at least in the thickening receiving areas is melted, the bristle bundle with the thickening is pressed into the holes or in the melted areas of the bristle carrier with thermal deformation, and then the mass rising as it is pressed in is reshaped.

A number of methods are known for connecting bristle bundles to bristle carriers, both of which are made of plastic. In connection with the present invention, only those methods are addressed in which the bristle bundle is provided with a thickening, inserted into prepared holes on the bristle carrier and one of the two joining partners is connected to it by melting or thermoforming and the fixed connection upon solidification of the melt or molecular reorientation of the thermoformed areas.

When welding is also known (e.g. DD-A-221 633), which usually requires the same plastic for bristles and bristle holders, the ends of the bundles are melted and connected to one another by the melt flowing together. Likewise, the bristle carrier is locally limited on the bristle receiving side, namely at the connection points, melted and then the bristle bundle and bristle carrier are brought together. The melts flow together under pressure and form a welded joint. It has been recognized that an irregular surface on the bristle carrier would arise due to the melting processes during solidification. For this reason, it is proposed to smooth the ascending melt by molding, optionally also to provide a recess at the welding point into which the ascending melt can be displaced. As a result, at most a partial smoothing of the surface is achieved. An overall smooth and flat surface cannot be achieved because, in order to achieve a sufficient melting temperature in the outer areas, a higher heat build-up inevitably occurs in the central area of the bristle carrier, so that the melt mass and the viscosity of the melt increase from the inside to the outside. With rectified reworking at the welding point of the individual bundles, it is therefore inevitable that the same work result cannot be achieved over the entire area.

Connecting bristles and bristle carriers made of the same or different plastics in the molten state is a kind of thermal joining process. It is known (EP-A-149 996) to melt the bristle ends into a thickening and to form the bristle bundle into preformed holes on the bristle carrier while the thickening is still plastic. The plastic thickening should be provided with undercuts Fill in holes. The irregularities on the surface caused by the ascending melt should be remedied, among other things, by first forming the holes without undercuts, introducing the thickenings into the holes and then molding the surrounding material onto the thickenings. For this purpose, the bristle carrier has ring-like elevations in the region of the holes, which are then molded on by plasticizing the bristle carrier material. Here, the flatness or unevenness of the bristle carrier surface in turn largely depends on the behavior of the melt in the holes.

Recognizing the disadvantages of the aforementioned method, it has also been proposed (DE-A-36 37 750) only to melt the holes preformed in the bristle carrier in the area of the hole base, the bundle of bristles, the ends of which in this case are not fused together, into the hole and the Introduce melt located in the bottom of the hole. The melt should then rise in the hole and between the bristles in order to ensure their adequate anchoring. The melt volume should be selected with reference to the free volume still present in the hole so that the melt does not rise outside the bristle carrier. Naturally, this is purely wishful thinking, since it is not possible to achieve a sufficiently precise heat transfer from the heating element to the walls in the area of the hole base in order to form a constant melt mass. The bristles are essentially held in a force-locking manner, so that there is no pull-out anchoring in the bristle carrier.

In the method mentioned at the beginning (DE-A-34 03 341), the bristles within the bundle are fused together at their attachment-side end to form a thickened portion, and in a preferably solidified state these are pressed into the bristle carrier, which in turn is melted locally, for example in the form of holes, until the melt of the bristle carrier flows together again behind the thickening due to molecular reorientation. Here, too, it cannot be avoided that the melt rises and forms a bead of melt, which is then leveled by a smoothing or post-forming tool or shaped to a concrete increase. For the reasons already described above (DD-A-221 633), this method too cannot be completely satisfactory.

The invention has for its object to improve the method mentioned in such a way that a flawless, flat surface on the bristle carrier is obtained while ensuring a firm integration of the bristle bundle in the bristle carrier.

This object is achieved in that the space above the bristle receiving side and between the bristle bundles is sealed in a ring surrounding the bristle field formed by them against the bristle carrier, and that the mass rising when the bristle bundles are pressed in is displaced and compressed to fill the sealed space using pressure .

In the method according to the invention, the space immediately above the bristle carrier between the bristle bundles on the one hand and the bristle carrier outside the bristle field on the other hand is sealed and the mass that has risen between the bristle bundles used, for example the melt during molten work or the thermoelastically displaced mass during hot forming, is defined therein Space displaced and compacted at the same time. In this way it is possible to achieve a flat surface on the bristle carrier over the entire bristle field and, furthermore, to improve the hold of the bristle bundles in the bristle carrier by the additional compression.

In order to achieve a uniformly good surface quality regardless of the mass displaced in the individual case, the space is preferably elastically sealed at the edge. The measure serves the same purpose in that the pressure which displaces and compresses the rising mass is applied elastically.

Sealing the bristle field and displacing the rising mass with simultaneous compression can take place immediately after the joining process and the plasticity or thermoelasticity still present can be used for the forming process. To equalize the viscosity of the melt over the pressurized surface or for the at least partial, re-melting with a time delay between the joining process and the deformation process, it is provided that heat is supplied to the annularly sealed space at a temperature below the melting temperature of the plastic of the bristles is, so that their stability does not suffer, on the other hand, a perfect displacement and leveling of the rising melt is guaranteed.

In a further embodiment of the invention it is provided that the bristle carrier is provided on the bristle receiving side with a depression which extends over the entire bristle field and into which the ascended mass is displaced when the pressure is applied.

The depression provided on the bristle receiving side and extending over the entire bristle field, which can also be partially interrupted by elevations, for example in the area of the bristle bundle, is also able to absorb a larger melt mass without causing a change in the contour of the bristle carrier surface to lead. The extent of the deepening (area and depth) can depend on the specific application, for example the size or extent of the melting pool or pools, melt volume, etc., displaced by the thickening or the bristle bundles.

In another embodiment of the method according to the invention it is provided that the bristle carrier on the bristle receiving side is provided with elevations surrounding the holes or a part thereof, that the elevations are melted at least to a certain depth and are ring-shaped together with the rising mass in the outside of the elevations sealed space is displaced.

In this variant of the method, cross-sections and height-defined elevations are provided on the bristle receiving side, which are completely or partially leveled during the subsequent compression process.

Another variant of the method is provided in that the bristle carrier is provided with individual small depressions next to the holes receiving the bundle, which serve as deforming displacement spaces when the bristle bundles are pressed in and the rising mass is displaced.

In this embodiment, the additional depressions create free displacement spaces into which the mass displaced during leveling and compaction can escape. The depressions can be designed as holes with a small diameter, which are closed and deformed, in particular reduced, when the holes for the bundles are thermally formed and / or when the ascending melt is leveled.

In order to minimize the melt mass necessary for embedding, it can further be provided that the holes in the bristle carrier which receive the bundles are provided with a profile which is formed, for example, from webs, ribs or the like and which is leveled out when the hole walls are melted.

This embodiment also offers the possibility of not only minimizing the melting mass, but also reproducibly fixing it by melting the profile and the near-surface hole wall. The ribs, webs should be thin-walled, so that they melt and collapse even with little heat input, without the surrounding material of the bristle carrier being melted.

While the aforementioned procedural measures on the one hand contribute to minimizing the melt mass, and on the other hand lead to a leveling of the melt rising during joining, practical studies have shown that not only that, especially for the size of the rising melt mass and for the uniformity of the melting volume increasing in successive joining processes Joining process itself and the thermal conditions during melting are essential, but also the way in which the bundles of bristles are fed to the bristle carrier. The bristle bundles are usually guided in channels which are arranged in alignment in layered guide plates. The bristle bundles are clamped between the guide plates or by means of one of them after being fed in by displacing the channels relative to one another and melted at the ends projecting beyond the guide plates. Practice has shown that, despite the same geometrical relationships, the extent of the ascending melt is different. It has now been found that this undesirable effect can be eliminated, or at least minimized in its effect, if each bundle of bristles is clamped individually by means of fluid pressure or spring force.

The cause of the irregularities in the formation of the melt should be, among other things, that in the known clamping method, in which all bristle bundles are acted upon by a single clamping plate, different clamping forces on the individual bristle bundles are given with the As a result, individual bundles can dodge or recede more than others during the joining process. The cause is to be presumed in different bundle cross-sections and different bristle packs within the bundle due to the necessarily existing diameter tolerances in the bristle monofilaments. With the individual clamping of each bristle bundle provided by the fluid pressure or spring force according to the invention, it is ensured that an equal clamping force acts on each bristle bundle regardless of cross-section and bristle pack, with the result that none of the bristle bundles or individual bristles within a bundle can move backwards. This ensures that the bristle protrusion above the guide plate when melting the bristle ends is always the same, and it is also ensured during the joining process that all bristle bundles are inserted into the melt on the bristle carrier with the same pressure or the same immersion depth due to the lack of possibility of evasion. This in turn minimizes the melt rising during the joining process, on the other hand it is evened out during successive joining processes.

According to another variant of the method, the aforementioned negative effect can also be largely eliminated by clamping the bristle bundles between the spaced-apart guide plates under the action of a plate-parallel clamping force acting in the intermediate space according to the principle of cable friction.

In contrast to the usual clamping between superimposed plates with different friction ratios between the clamping plate and the bristle bundles and the individual bristles within a bundle, the inventive deflection of the bristle bundle according to the principle of rope friction can exert such a clamping force that the Frictional forces between the bristles of a bundle prevent individual bristles from escaping.

To carry out the method, the invention is based on a known device (for example EP 0 149 996), which has a receptacle for the bristle carrier, at least two guide plates arranged at a distance from one another and parallel to one another with aligned channels with aligned channels for feeding the bristle bundles, at least one Bristle bundle at least during the connection to the bristle carrier in the channels fixing clamping device and at least one of the bristle protruding beyond the channels and the bristle body on the bristle receiving side melting device.

Such a known device is characterized according to the invention in that the guide plate facing the receptacle or a form plate placed in front of it has a sealing zone which surrounds the bristle field in an annular manner and which has a corresponding annular sealing zone on the bristle carrier or on its receptacle when the guide plate or the form plate is moved together and the recording interacts.

In the device designed according to the invention, the sealing zone becomes effective when the bristle holder receptacle and guide plate or mold plate are moved together and forms a closed space above the bristle side, enclosing the bristle field, into which the melt that has risen during the joining process is displaced during further moving together.

There are various options for forming the sealing zone. It can be provided that the annular sealing zone is formed by a groove and a rib engaging in it, one of which is arranged on the guide or form plate, the other on the bristle carrier or on its receptacle.

Instead, the annular sealing zone can be formed by interlocking steps on the guide or molding plate on the one hand and on the bristle carrier or its receptacle on the other hand. The annular sealing zone can also be formed by an elastic ring or such an elastic ring can be assigned to the sealing zone.

The two aforementioned embodiments guarantee, on the one hand, an impeccable seal, on the one hand, as well as a space-filling displacement of the melt, even when the mold plate and bristle holder receptacle have different feed paths.

In another embodiment it is provided that an elastic material layer with channels for the bristle bundles is arranged in the space sealed between the guide or molded plate on the one hand and the bristle carrier on the other hand, which rests on the bristle carrier and deforms elastically when the pressure is applied.

In the aforementioned embodiment, the sealing itself can again take place via a step or the like, while the forming pressure when the melt is displaced always remains the same, even with different melt volumes due to the elasticity of the pressure surface, or the space available automatically adjusts to the volume of the mass to be displaced adjusts.

Finally, the guide plate or the molding plate can be heated in order to ensure a constant viscosity in the area to be formed.

A further embodiment of the device according to the invention is characterized in that at least one of the guide plates has a cavity or a cavity is formed between two adjacent guide plates, and that channels which pass through the cavity are provided for guiding the bundles of bristles, the walls of which are wholly or partly under the Fluid pressure in the cavity against the bristle bundles are deformable.

With this design of the device, a constant clamping force due to the hydrostatic conditions in the cavity is brought into effect for each individual bristle bundle, which can be adjusted so that evasion of the bristle bundle in the guide channel or individual bristles within the bundle is reliably avoided.

The same effect is achieved in another embodiment in that the wall of each guide channel has a recess into which a spring-loaded clamping body acting against the bristle bundle engages.

Finally, the device can be designed such that two adjacent guide plates are arranged at a distance and between them a clamping plate with bores for the bristle bundles can be displaced parallel to the plates, the distance of the clamping plate from the two guide plates and the displacement path being selected so that that the rope friction angle is reached between the individual bristles of the bundle.

In this embodiment, the bristle bundles are thus displaced into the intermediate space between the guide plates arranged at a distance to form a deflection. The extent of the deflection is chosen so that the bundles or the bristles of a single bundle cannot deflect.

Finally, it is advantageous if the clamping body or the clamping plate is rounded on its surface acting on the bristle bundle without edges.

Fig. 1

eine schematische Ansicht der wesentlichen Teile einer Vorrichtung in verschiedenen Verfahrenstufen a) bis f);

Fig. 2

einen schematischen Schnitt durch eine Bürste in der tatsächlich entstehenden Ausführung;

Fig. 3

einen der Figur 2 entsprechenden Schnitt in idealisierter Ausführung;

Fig. 4

eine Detailansicht der Vorrichtung in verschiedenen Verfahrensstufen a) bis c) mit Abdichtung der Schmelzzone;

Fig. 5

eine gegenüber der Ausführungsform gemäß Figur 4 abgewandelte Ausführungsform;

Fig. 6

eine ähnliche Ansicht einer dritten Ausführungsform;

Fig. 7

eine ähnliche Ansicht einer wiederum abgewandelten Ausführungsform;

Fig. 8

eine schematische Andeutung des Verfahrensablaufs in einer anderen Variante;

Fig. 9

eine schematische Andeutung einer weiteren Verfahrensvariante;

Fig. 10

eine gegenüber der Figur 8 abgewandelte Verfahrensvariante;

Fig. 11

eine schematische Ansicht einer Verfahrensvariante mit zusätzlichen Verdrängungsräumen;

Fig. 12

eine schematische Ansicht einer Verfahrensvariante zur Minimierung der Schmelzmasse;

Fig. 13

eine schematische Ansicht des Verfahrensablaufs in optimierter Kombination zweier Verfahrensvarianten;

Fig. 14

eine schematische Darstellung einer Ausführungsform für die Bündelklemmung;

Fig. 15

eine schematische Ansicht einer anderen Ausführung der Bündelklemmung;

Fig. 16

eine gegenüber Figur 15 abgewandelte Ausführungsform und

Fig. 17

eine wiederum abgewandelte Ausführungsform für die Bündelklemmung.

The invention is described below with reference to some exemplary embodiments shown in the drawing. The drawing shows:

Fig. 1

a schematic view of the essential parts of an apparatus in different process stages a) to f);

Fig. 2

a schematic section through a brush in the actually emerging version;

Fig. 3

a section corresponding to Figure 2 in an idealized embodiment;

Fig. 4

a detailed view of the device in different process steps a) to c) with sealing of the melting zone;

Fig. 5

an embodiment modified from the embodiment of Figure 4;

Fig. 6

a similar view of a third embodiment;

Fig. 7

a similar view of a modified embodiment;

Fig. 8

a schematic indication of the process sequence in another variant;

Fig. 9

a schematic indication of a further method variant;

Fig. 10

a process variant modified compared to FIG. 8;

Fig. 11

a schematic view of a process variant with additional displacement spaces;

Fig. 12

a schematic view of a process variant for minimizing the melt mass;

Fig. 13

a schematic view of the process flow in an optimized combination of two process variants;

Fig. 14

a schematic representation of an embodiment for bundle clamping;

Fig. 15

a schematic view of another embodiment of the bundle clamping;

Fig. 16

an embodiment modified from Figure 15 and

Fig. 17

another modified embodiment for bundle clamping.

The device according to FIG. 1 has a two-part receptacle 1 for a bristle carrier 2, for example produced by injection molding, which is fixed in the receptacle. At a distance from the receptacle, guide plates 3, 4 and 5 are arranged in parallel. A clamping plate 6 is located between the guide plates 3 and 4. The guide plates 3, 4 and 5 have aligned channels 7 for feeding the bristle bundles 8.

The device also has a cutting device 9 (FIG. 1 a) and e)) and a heating element 10 (FIG. 1 b) and c)) which can be inserted between the bristle holder receptacle 1 and the guide plates 3, 4 and 5. The operation of the device is as follows:
The bristle bundles 8 are unwound from a spool, for example as an endless strand. The bristle carrier 2 is fixed in the receptacle 1, for example by clamping. The bristle bundles 8 are introduced as so-called short cuts or as an endless strand of coils in the channels 7 of the guide plates 3, 4 and 5, which initially lie directly on top of one another. The guide plate 5 is then moved to just before the free ends of the bristle bundles 8. In this position it serves as a cutting surface for the cutting device 9, which cuts the protruding ends of the bristle bundles 8 to the same final dimension.

Then the guide plate 5 moves back so that the bristle bundles 8 are released at their ends. The heating element 10 is then inserted between the bristle ends and the bristle carrier 2. The heating element 10 has the shown Exemplary embodiment on the side facing the bristle receiving side of the bristle holder 2 heated pins 11 and on the opposite side a heating mirror 11a. Appropriate moving together of the guide plates 3 to 5 and the receptacle 1, on the one hand, the heated pins 11 penetrate into the bristle receiving side of the bristle carrier 2 and form depressions there, while at the same time the free ends of the bristle bundles 8 are melted, so that thickenings 12 form there. The guide plates 3 to 5 and the receptacle 1 are then moved apart again, as can be seen in FIG. 1 d), and the heating element is extended. The entire unit is then moved together again, as shown in FIG. 1e). The bristle bundles 8 penetrate with their thickening 12 into the melted depressions 13 on the bristle carrier 2. In the process stages mentioned in FIGS. 1 b) to 1 e), the clamping plate 6 has been displaced relative to the guide plates 3, 4 in accordance with the direction arrow, so that the bundles are clamped in the channels 7.

After the joining process shown in FIG. 1 e), the melt of the bristle carrier 2 flows behind the thickenings on the bristle bundles 8. If sufficient tear-out strength has been achieved after the melt has solidified, the package of guide plates 3 to 5 is raised again, as in FIG. 1 f) shown. The lower guide plate 5 runs into a predetermined position and the bundles of bristles are then cut to length by means of the cutting device 9 at their ends on the use side.

A brush manufactured according to the aforementioned method is indicated schematically in FIG. 2. As a rule, more or less significant irregularities arise in the area of the melted parts of the bristle carrier 2. For example, burrs 14 can rise above ascending melt form the surface of the bristle carrier and in the region of the bristle bundle 8. Instead of this, craters 15 and, in addition, cavities (right bundle in FIG. 2) can form in the area of the attachment point of the bristle bundle and finally there is a risk that the bristle carrier 2 will generally be deformed on the bristle receiving side, as indicated at 16 . These irregularities are not only undesirable for optical reasons, but also for technical and hygienic reasons. FIG. 3 shows an ideal configuration in comparison with this, which is the aim of the invention to achieve.

FIGS. 4 to 7 show a first procedural measure to correct the irregularities described in connection with FIG. 2. In the exemplary embodiment according to FIG. 4, a form plate 17 is placed in front of the guide plate 5 or instead of this, below which a space 18 is formed with a sealing zone 19 which surrounds the bristle field in a ring. During the joining process, in which the thickenings 12 of the bristle bundles 8 penetrate into the recess 13 of the bristle carrier 2, the mold plate 17 moves downward, so that the space 18 above the bristle receiving side of the bristle carrier 2 is completely closed by the sealing zone 19 with the bristle carrier 2 interacts. In the exemplary embodiment shown, the sealing zone is formed by a groove 20 in the mold plate 17 and a web-like elevation 21 on the bristle receiving side of the bristle carrier 2. In the retracted state, which is shown in FIG. 4 b), the space located above the bristle receiving side is sealed to the outside in the annular sealing zone 19. As a result, the melt displaced by the molding plate is evenly distributed in the space and at the same time compressed. Figure 1 c) then shows the final process product, in which due to the forming process on the bristle receiving side of the bristle carrier 2 a flat depression 22 is formed with a flat surface.

In the exemplary embodiment according to FIG. 5, the sealing zone 19 (see FIG. 5 b)) is formed by a step 23 on the mold plate 17 and the outer contour of the bristle carrier 2, which also acts as a step 24. In this embodiment, the bristle receiving side is slightly increased compared to the edge contour of the bristle carrier 2. The shaped plate 17 is formed in two parts by consisting of an outer frame part 25 and a plate 26 which can be moved separately. From the starting position shown in Figure 5 a), the mold plate 17 is moved down until the frame part 25 with its step 23 seals against the step 24 of the bristle carrier. The plate 26, which may be under an elastic force, remains when moving together and takes over the balancing and compression of the melt, which is distributed up to the sealing step. In the finished product according to FIG. 5 c), a low and barely perceptible, but in particular not disadvantageous step 27 arises on the bristle receiving side of the bristle carrier.

In the exemplary embodiment according to FIG. 6, the bristle carrier 2 is configured similarly to the exemplary embodiment according to FIG. 5. In a modification of that, the molding plate 17 is provided with an elastic sealing ring 28 which interacts with the receptacle 1 of the bristle carrier 2. The sealing zone 19 is in turn formed by a gap seal, as in FIG. 5. When the receptacle 1 and the mold plate 17 move together, the elastic seal 28 ensures a balancing pressure distribution when displacing the melt on the bristle receiving side of the bristle carrier 2. The product produced in this way can be seen in FIG. 6 c). It has an absolutely smooth surface on the bristle receiving side of the bristle carrier 2.

In the exemplary embodiment according to FIG. 7, the molding surface of the molding plate 17 is essentially formed by an elastic material layer 29, which can be compressed when the receptacle 1 and molding plate 17 move together, as shown in FIG. 7b). Here, too, the sealing zone 19 is again formed by steps or by a gap seal. The elastic material layer 29 in turn ensures a uniform pressure distribution on the bristle receiving side of the bristle carrier 2.

FIGS. 8 to 10 show further process variants for producing a brush in the form idealized in FIG. 3. In the exemplary embodiment according to FIG. 8, the bristle carrier 2 is provided with a depression 30 which extends over the entire bristle field and into which the holes 13 are formed by means of the heated pins 11 of the heating element 10. The melt that rises to the top reduces the depth of the depression 30 in some areas. In the subsequent leveling in one of the process variants according to FIGS. 4 to 7, the melt escaping upwards and to the side is displaced into the remaining depressions 31 of the depression 30, so that in turn a smooth surface on the bristle receiving side is obtained. This is shown in Figure 8 c).

FIG. 9 shows an exemplary embodiment in which the bristle carrier 2 has prefabricated holes 13 '(FIG. 9a), which are only melted onto the hole wall and thereby formed into the holes 13 (FIG. 9b). This minimizes the melt mass and equalizes it in the manner already described (FIG. 9c).

In the exemplary embodiment according to FIG. 10, a depression 30, which extends over the entire bristle field, is again provided on the bristle receiving side of the bristle carrier 2. In contrast to the embodiment of the bristle carrier according to FIG. 8, however, this has preformed holes 32 with a the bottom of the recess 30 projecting collar 33. After the holes 32 according to FIG. 9 a) have melted and the bristle ends have melted into the thickening 12, deeper holes 13 are formed on the bristle carrier 2, the geometrically regular bundles 33 being deformed irregularly. In this exemplary embodiment, the molding plate 17 has a depression 35 in the region of each channel 34 of a bristle bundle 8. When the bristle receptacle and the mold plate 17 move together, the melt is in turn displaced and compressed in the remaining depressions 31 of the depression 30, the end product according to FIG.

In the embodiment according to FIG. 11, each bristle bundle 8 or the hole 13 assigned to it (FIG. 11b) is assigned, in addition to the depression 30 which extends over the entire bristle field, smaller depressions 30 'which extend deeper in the bristle carrier 2 than the bundles when fastened. These small depressions 30 'are closed and, at the same time, reduced in size when the holes 13 (FIG. 11b) are formed. When the bundles of bristles are then inserted and the ascending melt is compressed, further plastically deformable mass can be displaced into the depressions (FIG. 11 c).

In the exemplary embodiment according to FIG. 12, the melt mass is minimized in that the bristle carrier 2 has prefabricated holes 13 'with inwardly projecting ribs 13''- 4 pieces in a diametrical arrangement in the exemplary embodiment shown. Only these ribs and the near-surface hole wall are melted, so that, as FIG. 12 b shows, only a little melt mass is displaced upwards when the bundles 8 are melted and inserted. The subsequent compression can optionally be carried out in such a way that each bristle bundle 8 is surrounded by a narrow collar on the surface of the bristle carrier.

A further variant for the sealing zone 19 is shown in FIG. After the melting on the bristle side 3 and the formation of the holes 13, the bristle carrier 2 again has an irregular surface due to the melt of the bristle carrier rising. In this exemplary embodiment, the mold plate 17 is provided with a web 37 which surrounds the bristle field in an annular manner and which penetrates into the bristle carrier 2 when the receptacle 1 and mold plate 17 move together and thus forms the sealing zone 19, as can be seen from FIG. 13 b). The product produced in this way and shown in FIG. 13 c) has on the bristle receiving side of the bristle carrier 2 a groove 38 which surrounds the bristle field in a shallow manner and which does not impair the product in terms of use or hygiene.

FIGS. 14 to 17 show process variants for the defined clamping of the bristle bundles 8. In the exemplary embodiment according to FIG. 14, the guide plates 3, 4 with the channels 7 for guiding the bundles 8 are arranged at a greater distance from one another, at least in the clamping positions. Between the guide plates 3, 4 - again at a distance from both - the clamping plate 6 is displaceable, the bores 39 of which are very rounded. By moving the clamping plate 6 crosswise, the bristle bundles 8 between the guide plates 3, 4 are deflected strongly to the side, so that the bundles 8 are fixed uniformly and reproducibly in the clamped position. The frictional relationships between the individual bristles of a bundle are also such that even individual bristles cannot escape during the joining process.

Figure 15 shows a modified version. Here, a guide plate 40 is provided which has a cavity 41 which is penetrated by sleeves 42, which in turn form the channels for the bristle bundles 8. The sleeves 42 have at least a recess 43 and are surrounded by an elastic tube 44. The cavity 41 can be pressurized hydraulically or pneumatically, so that the tube is deformed into the recess 43 of the sleeves 42, as shown in FIG. 15 b). Due to the fluid pressure and the hose section 45 penetrating into the recess of the sleeve 42, the bristle bundle 8 is jammed within the sleeve 42. Here - regardless of fluctuations in the outer diameter of the bundle 8 or the packing of the bristles - a constant clamping force is guaranteed within the bundle for each bristle bundle.

The embodiment according to FIG. 15 can also be embodied according to FIG. 16 in a purely mechanical embodiment, in that the sleeve 42 again has a recess 43, but inside the guide plate there are clamping bodies 46 which, for example, by means of spring force from the one in FIG Figure 16 b) shown clamping position are movable. Instead of this, these clamping bodies 46 can of course also be acted upon by means of a fluid with appropriate guidance and sealing.

In the exemplary embodiment according to FIG. 17, the guide plate 40 in turn has a cavity 41, as in the embodiment according to FIG. 15. However, instead of the sleeves 43, a multi-chamber membrane 47 is inserted into the cavity 41, which according to the previously described embodiments has passages 48 in the guide plates 3, 4 and 5 through which the bristle bundles 8 are fed. The membrane 47 is again pressurized by means of a fluid, so that its wall bulges in the area of the passages 48, as shown in FIG. 17 b). Due to the hydrostatic pressure conditions within the membrane 47, the same clamping force acts on each bundle of bristles 8.

Claims (21)

1. Method for fixing bristle bundles to a plastic bristle carrier, in that the bristles of each bundle are melted on at their fastening-side ends accompanied by the formation of a thickening, the bristle carrier is provided at the bristle reception side with thickening-receiving holes and/or is melted on at least in the areas receiving the thickenings, the bristle bundles with the thickening being pressed into the holes or into the melted on areas of the bristle carrier accompanied by thermal shaping and then the mass rising during pressing in is reshaped, characterized in that the space above the bristle reception side and between the bristle bundles is sealed against the bristle carrier annularly surrounding the bristle field formed by it, and that the mass rising on pressing in the bristle bundles is displaced and compressed filling the sealed space and accompanied by the application of pressure.
2. Method according to claim 1, characterized in that the space is marginally elastically sealed.
3. Method according to claim 1 or 2, characterized in that the pressure displacing and compressing the rising mass is elastically applied.
4. Method according to one of the claims 1 to 3, characterized in that the annularly sealed space is supplied with heat at a temperature above the melting point of the bristles.
5. Method according to one of the claims 1 to 4, characterized in that the bristle carrier is provided on the bristle reception side with a depression extending over the entire bristle field and into which the rising mass is displaced on applying pressure.
6. Method according to one of the claims 1 to 5, characterized in that the bristle carrier is provided on the bristle reception side with elevations surrounding the holes or a part thereof, that the elevations are melted on at least to a certain depth and together with the rising mass displaced into the annularly sealed space outside the elevations.
7. Method according to one of the claims 1 to 6, characterized in that the bristle carrier is provided with individual, small depressions alongside the holes receiving the bundles and which during the pressing in of the bundles and the displacement of the rising mass serve as shaping displacement spaces.
8. Method according to one of the claims 1 to 7, characterized in that the holes in the bristle carrier receiving the bundles are provided with a profile, which is levelled out during the surface-near melting on of the hole walls.
9. Method according to one of the claims 1 to 8, characterized in that the holes are provided with profile-forming webs, ribs, etc.
10. Method according to one of the claims 1 to 9, characterized in that each bristle bundle is individually clamped by means of fluid pressure or spring tension.
11. Method according to one of the claims 1 to 9, characterized in that the bristle bundles are clamped between the spaced guide plates under the action of a plate-parallel clamping force acting in the intermediate space according to the rope friction principle.
12. Apparatus for performing the method according to claim 1, with a receptacle (1) for the bristle carrier (2), at least two guide plates (3, 4, 5) spaced from the receptacle and parallel to one another and which are provided with aligned channels (7) for supplying the bristle bundles (8), at least one of the bristle bundles at least during the fixing to the bristle carrier in the channel-fixing clamping device and at least one of the bristle ends projecting over the channels and optionally a heating device (10) zonally melting the bristle carrier at the bristle reception side, characterized in that the guide plate (5) facing the receptacle (1) or a platen (17) positioned upstream thereof has a sealing zone (19) annularly surrounding the bristle field and which cooperates with a corresponding annular sealing zone on the bristle carrier (2) or on its receptacle on bringing together the guide plate or platen and the receptacle.
13. Apparatus according to claim 12, characterized in that the annular sealing zone (19) is formed by a groove (20) and a rib (21) engaging therein, whereof one is located on the guide plate (5) or platen (17) and the other on the bristle carrier (2) or on its receptacle (1).
14. Apparatus according to claim 12, characterized in that the annular sealing zone (19) is formed by interengaging steps (23, 24) on the guide plate (5) or platen (17) on the one hand and on the bristle carrier (2) or its receptacle (1) on the other.
15. Apparatus according to claim 12 for performing the method according to claim 2, characterized in that the annular sealing zone (19) is formed by an elastic ring (28).
16. Apparatus according to one of the claims 12 to 15 for performing the method of claim 3, characterized in that in the space (18) sealed between the guide plate (5) or platen (17) on the one hand and the bristle carrier (2) on the other is positioned an elastic material layer (29) with channels for the bristle bundles (8), which bears on the bristle carrier (2) and elastically deforms when pressure is applied.
17. Apparatus according to one of the claims 12 to 16 for performing the method according to claim 4, characterized in that the guide plate (5) or platen (17) is heated.
18. Apparatus according to one of the claims 12 to 17 for performing the method of claim 10, characterized in that at least one of the guide plates (3 to 5) has a cavity (41) or a cavity is formed between two adjacent guide plates (3, 4) and that cavity-traversing channels (42, 44, 48) are provided for guiding the bristle bundles (8) and whose walls (44) are wholly or partly deformable under the action of a fluid pressure in the cavity (41) against the bristle bundles (8).
19. Apparatus according to one of the claims 12 to 17 for performing the method according to claim 10, characterized in that the wall of each guide channel (42) has a recess (43) in which engages a spring-loaded clamping body (46) acting against the bristle bundle (8).
20. Apparatus according to one of the claims 12 to 17 for performing the method of claim 11, characterized in that two adjacent guide plates (3, 4) are spaced and between them in spaced manner therefrom is displaceable in plate-parallel manner a clamping plate (6) with bores (39) for the bristle bundles (8), the spacing of the clamping plate (6) from the two guide plates and the displacement path being selected in such a way that between the individual bristles of the bundle (8) the rope friction angle is obtained.
21. Apparatus according to claim 19 or 20, characterized in that the clamping body (46) or clamping plate (6) is rounded in edge-free manner on its face acting on the bristle bundle (8).

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