Title of Invention	METHOD OF PRODUCING BRISTLES FOR APPLYING MEDIA , BRISTLES PRODUCED THEREBY AND BRUSHES COMPRISING SUCH BRISTLES.
Abstract	Bristles for applying media are produced in that a filament, which can be cut into bristles, is extruded with a core which also determines the mechanical properties of the bristle. Recesses are formed at a separation from the center of the core and open towards the circumference of the filament which can be filled with medium from the outside, wherein the circumferential openings of the recesses are formed such that the medium is discharged only when the bristle is appropriately used. The recesses may also have a larger opening width and be covered by a layer or jacket. A bristle and brushes having such bristles produced in accordance with this method are also described.

Title of Invention

METHOD OF PRODUCING BRISTLES FOR APPLYING MEDIA , BRISTLES PRODUCED THEREBY AND BRUSHES COMPRISING SUCH BRISTLES.

Abstract

Bristles for applying media are produced in that a filament, which can be cut into bristles, is extruded with a core which also determines the mechanical properties of the bristle. Recesses are formed at a separation from the center of the core and open towards the circumference of the filament which can be filled with medium from the outside, wherein the circumferential openings of the recesses are formed such that the medium is discharged only when the bristle is appropriately used. The recesses may also have a larger opening width and be covered by a layer or jacket. A bristle and brushes having such bristles produced in accordance with this method are also described.

Full Text	Method of Producing Bristles for Applying Media, Bristles Produced in Accordance with the Method and Brushes Comprising such Bristles The invention concerns a method of producing bristles for applying media through extrusion of a filament which can be cut into bristles and provided with recesses for receiving the medium and from which the medium is discharged during proper use of the bristles, as well as a bristle and brushes comprising such bristles produced in accordance with this method. Brushes comprising bristles for applying liquid, viscous or powdery media are used mainly for body, hair and mouth cara but also in the household and for technical applications. The invention is described below mainly in connection with tooth brushes, one of the main fields of application. Tooth brushes are known which highlight film on the teeth through application of a suitable indicating color to allow the user of the tooth brush to increase brushing of such indicated tooth locations (DE 195 45 644). Towards this end, the brushes are coated with the indicating color or with microcapsules containing the color and the coating is optionally sealed. A hollow brush with inserted indicating medium is also described in this connection. This document does not explain in detail how these hollow brushes are filled. It is further known (CA 549 168) to jacket the brushes of a single-use tooth brush with a tooth care medium. Bristles are also known (US 5,678,275) whose circumference is provided with irregularly shaped grooves. They do not accommodate media but are supposed to accept soilage particles to remove them from the mouth during brushing of the teeth. It is furthermore known (WO 98/24341) to accommodate therapeutically effective or other media having dental medical effects in a hollow brush which are released at the free open end of the brush during use. The hollow brush is optionally reinforced by radial walls such that it comprises three or four chambers with parallel axes. The desired media are introduced in liquid form. Towards this end, filaments having the cross-sectional shape of the finished bristles are extruded and several filaments are combined into multi-veined strands having a diameter up to 5.5 cm and a length up to 1.2 m. One end of the strand is dipped into the liquid medium and suction is applied to the opposite open ends of the filaments. Since a high suction pressure is required due to the capillary cavities and the large strand length and since collapsing of the walls due to the elasticity of a suitable plastic must be prevented, the wall must be quite thick and complete filling of the hollow bristles is not possible. Viscous or dispersed media cannot be introduced into the capillary cavities due to the high pressure drop. During use of the bristle, the medium is only discharged via the open end of the bristles and is therefore fully undefined and incomplete. It is the underlying purpose of the invention to propose a method for economical introduction of media of arbitrary consistency and effect into a bristle and for discharge thereof in a desired dosage during the useful life of the bristle. This object is achieved in accordance with the invention in that the filament is extruded having a core which also determines the mechanical properties of the bristle, wherein recesses are formed at a separation from the center of the core which open towards the circumference of the filament and which can be filled with medium from the outside, wherein the circumferential openings of the recesses are formed such that the medium is discharged only when the bristle is appropriately used. In the inventive method, the media is externally introduced into the recesses which are open to the outside, i.e. they must not be suctioned via a pressure drop over a relatively large distance, which would entail corresponding pressure losses. The recesses may therefore be advantageously filled at constant medium density. The consistency of the medium is not important for introduction. It can be liquid, viscous or disperse. Discharge occurs directly through the circumferential openings during use: they are sufficiently narrow to retain the medium and are discharged only during use, e.g. via the forces applied during brushing or through media present at the location of use which interact with the medium in the brush and rinse or dissolve same, i.e. saliva or a tooth care medium for tooth brushes and, in the simplest case, water or moisture for cleaning brushes. A further advantageous embodiment of the method proposes extrusion of the filament with a core which also determines the mechanical properties of the bristle, with formation of the recesses at a separation from the center of the core, the recesses opening towards the circumference of the filament and being filled with the medium from the outside, wherein the filament is subsequently provided, at least in parts, with a layer which at least partially covers the openings and controls discharge of the medium under normal conditions of brush use. In this method, the shape of the circumferential opening and the opening width are less decisive. The selection of the material of the layer, its thickness and the extent to which the recesses containing the medium are covered can control discharge of the medium over time and in dependence on how long brushes having such bristles are used. If the recesses are preferably closed by a jacket, the medium can be discharged via the open bristle end or through the openings in the recesses exposed during slow wear of the jacket or also by diffusion through the jacket, wherein the jacket may have a thinner wall than the bristle in accordance with WO 98/24341, since it is not subjected to pressure during filling. It is particularly economical when the recesses are formed during extrusion of the filament. Therein, the recesses are preferably formed with substantially parallel axes, optionally at a separation from one another. Another variant consists in that the recesses are formed after extrusion of the filament which would permit a substantially radial formation of recesses having arbitrary contour and arrangement. Both above-mentioned method variants may provide that the recesses are formed as capillary gaps extending from the center of the core towards the outside or that the recesses are formed as channels with openings which narrow into a gap at the circumference. The capillary gaps produce a retaining effect for the medium and same is discharged only under conditions of use, e.g. bristle pressure, added external media, or the like. The shape and/or width of the gaps is preferably adjusted to the consistency of the medium. It is furthermore advantageous to form the gaps such that they are completely closed in the unloaded state and open only under pressure. In a particularly economic fashion, the recesses which open to the outside can be filled in continuous operation on an endless filament, wherein the filament is guided through an optionally pressurized medium bath or through a cross- section, tapering like a nozzle, with the medium being supplied about the circumference. If the opening width of the recesses is large enough and the consistency of the medium sufficiently viscous, filling may also be effected without pressure during continuous operation. In this case, it is advisable to subsequently close the recesses with a jacket disposed on the filament. The jacket preferably consists of a synthetic thermoplastic material which is extruded onto the filament, filled with the medium. It is preferably extruded with excess size and shrunk onto the filament through cooling to thereby particularly protect temperature sensitive media. Liquid components can not evaporate and temperature reactant components do not decompose. If a jacket made from a plastic material permitting diffusion of the medium is applied, it may optionally be covered in parts by a diffusion-tight material to control diffusion locally and/or the diffusion rate. If the jacket is made from transparent plastic, medium consumption can be visually monitored, e.g. through corresponding coloration of the medium. The type of media may thereby also be observed. In addition or instead of displaying the medium and/or its consumption it is possible to provide an effectivity display for the bristle function to guarantee that the bristle is used only as long as it has the properties required for its intended use. The bristle may also be technically designed such that it is used only as long as it is effective, by applying a jacket to the filaments which is made from a thermoplastic material comprising filling agents which determine its wear factor, wherein the plastic and the added filling agents are adjusted to the admissible degree of wear of the bristle during appropriate use. This method can be used to provide any type of bristle, optionally consisting of only a core and a jacket, with an effectivity display. Filling agents which determine the wear factor can, in particular, be solids which reduce the intermolecular bonding in the polymer of the jacket and control the wear factor through their type, size and amount. The solids of an application bristle can be selected such that they simultaneously fulfil a function during application, e.g. calcium carbonate or chloride as mineral agents in tooth brushes. The addition of waxes, in particular ionomer wax, has also proved favorable since they are distributed more uniformly in the polymer matrix and thus provide a uniform wear factor. The sliding behavior of the bristle is also improved. This also permits fine adjustment of an effectivity display. In accordance with a further method variant, for application, different media having different functions may be disposed in layers or with localized separation and can be discharged at separate locations. In the same fashion, it is possible to locally separate components of an agent, having an affinity to one another, which should be effective only at the location of use. An example thereof is the desired formation or regeneration of calcium fluoride layers on teeth which can be effected in ionising media with Ca(+) and F(-) ions which can be produced from locally separated Ca and F compounds in the moist atmosphere of the mouth and throat area. The media or active components can also be separately disposed through layered accommodation in the recesses and combined only when dispensed. The diffusion rate of the media or active components can be controlled through the formation of layers. Furthermore, active components and/or filling agents can be accommodated in the core or in the jacket or in both. Finally, the core may be extruded as a monofilament or multifilament. The core and/or jacket may optionally be foamed during extrusion or afterwards. The invention finally concerns a bristle which is obtained from the filament produced in accordance with the invention through cutting to the desired length and a brush having a bristle support for mounting bristles of the above-mentioned type thereby forming a bristle field or part thereof. In some applications, it is recommended to close the bristles at least at their useful end e.g. using thermal methods such as welding, friction welding, laser welding or the like. The inventive method and bristles produced in accordance with the method are described below by means of some embodiments shown in the drawing. Fig. 1 shows different phases a) to f) of the production of a filament in cross-section; Fig. 2 shows a longitudinal section II-II through a filament; Fig. 3 shows a schematic section of a brush comprising a bristle made from a filament in accordance with Fig. 2; Fig. 4 shows a schematic representation of the medium discharge; Fig. 5 through 10 show cross-sections of different embodiments of a bristle; Fig. 11 shows a cross-section of a further embodiment of a bristle core; Fig. 12 through 14 show further embodiments of a bristle core; Fig. 15 shows a section XV-XV in accordance with Fig. 14; Fig. 16 through 20 show cross-sections of some further embodiments of bristles comprising an extruded jacket; Fig. 21 shows a bristle; Fig. 22 shows a section XXII-XXII in accordance with Fig. 21; Fig. 23 through 25 show further embodiments of the bristle; Fig. 26 shows a cross-section of a bristle with partial coating; Fig. 27 shows a cross-section through a bristle comprising a jacket and partial coating; Fig. 2 8 shows a perspective view of a bristle comprising a jacket and additional binding; Fig. 29 shows a perspective view of a bristle with perforated jacket; Fig. 30 shows a cross-section of a bristle comprising different media in separated recesses; Fig. 31 shows a longitudinal section through a bristle having different recesses at the core; Fig. 32 shows a longitudinal section through a bristle having one closed end; Fig. 33 shows a longitudinal section through a bristle in the initial state; Fig. 34 shows the bristle in accordance with Fig. 33 during or after use; Fig. 35 through 3 8 each show one longitudinal section through a bristle with effectivity display; Fig. 39 shows a longitudinal section through a bristle comprising a wear display; Fig. 1 shows, in illustrations a) through f), different method steps of producing a filament from which bristles are obtained by cutting to a desired length. The filament 1 is extruded in a conventional fashion from a plastic melt in the form of a core 2, which substantially determines the mechanical properties of the bristle. In the embodiment shown, the core 2 consists of a solid center 3 comprising recesses 4 starting at that location and opening towards the outside, which are obtained in this embodiment through a crossed profile of the extruded core (Fig. la). The filament is subsequently drawn in a conventional fashion (Fig. 1b) to obtain a longitudinal molecular orientation. The cross- section is correspondingly reduced through stretching during drawing of the core. Subsequently, the core 2 is preferably thermally stabilized (Fig. 1c). The filament 1 with recesses 4, extruded and pre-treated in this fashion, is subsequently filled with the medium 6. The filament 1 is drawn through a channel (indicated in Fig. 1d with a circular line 5) which optionally narrows like a nozzle from a larger cross-section to the cross-section of the core 2 and into which the medium is constantly supplied such that the medium 6 is accommodated within the recesses 4 of the filament 1. The medium 6 may also be supplied under pressure, as shown in Fig. 1e which indicates a larger density of the medium 6. In the embodiment shown whose depressions have a very open cross-section, it is recommended to dispose a covering layer 7 onto the filament filled with the medium, which is formed like a film and which quickly wears during use of the bristle to discharge the medium 6. This covering layer 7 may also be a thin-walled jacket which consists of a diffusion-permitting polymer to allow either diffusion of the medium 6 at the location of use of the bristle or to achieve a required permeability only in connection with media at the location of use, e.g. saliva, water or the like. The jacket 7 is preferably extruded onto the previously filled filament 1 having a larger size than the core 2 and subsequently shrunk onto the core through cooling. Fig. 2 shows the section of a bristle 8 obtained from cutting a filament produced in accordance with Fig. 1. The bristle 8 thereby consists of a core 2 comprising the medium 6 in the recesses and the jacket 7. Fig. 3 schematically shows a section of a brush 62, e.g. in the region of a tooth brush head, comprising a bristle support 9 to which the bristles 8 are mounted. During use of the tooth brush, pressure and bending forces act on the bristle 8 leading to the schematically shown temporary deformation of the bristle 8. Due to these forces, the medium 6 is discharged at the free end of the bristle as indicated with directional markers. At the same time, if the medium has the corresponding composition, it diffuses through the walls of the jacket, optionally with the cooperation of media present at the location of use, e.g. saliva, water, tooth care means or the like. This is shown in Fig. 4 in an enlarged scale. Fig. 5 through 10 show cross-sections of filaments 1 which do not require separate coating or a jacket, depending on the consistency of the medium. Fig. 5 shows a filament which is extruded in the shape of a substantially circular core 2 having a solid center 3. During extrusion, recesses in the form of capillary gaps 10 are formed, which are disposed regularly and radially in the embodiment shown. The capillary gaps 10 are filled with the medium in a manner described with reference to Fig. 1. Fig. 6 shows a similar embodiment wherein the capillary gaps 10 are additionally provided with a profile 11 in the extrusion direction, thereby achieving an improved retaining capacity for the medium. In the embodiment of Fig. 7, the filament 1 also consists of a solid core 2 and an external core part 12 which may be made from a different plastic material than the core 2. The core 2 is e.g. formed of a polymer providing the subsequent bristle with the required mechanical properties, while the core part 12 may consist of another polymer having properties suitable for use. The filament 1 has channel-like recesses 13 parallel to the axis of the core 2 which extend via gap-like openings 14 at the circumference of the filament 1. Fig. 8 again shows a filament 1 in the shape of an extruded core 2 which only has a few uniformly distributed channels 15 with gap-like openings 16 proximate to the circumference. In the embodiment in accordance with Fig.. 9, the filament 1 is again extruded as core 2 having a solid center 3 from which a plurality of capillary gaps 17 extend to the outside, like shovels. The capillary gaps 17 are almost closed at the circumference 18 of the filament 1. The bridges 20, limiting the capillary gaps 17 in a shovel-like manner, can be elastically deformed to facilitate filling of the capillary gaps 17 in that the filament is turned opposite to the curvature of the shovel to open the gaps. After filling, the. excessive medium is pressed out through turning in the opposite direction or by passing through a corresponding covering cross-section such that the capillary gaps 17 are almost closed at the circumference of the filament 1 or in the subsequent bristle. When brushes equipped with such bristles are used, the pressure forces effect deformation of the bristle such that the medium is discharged about the circumference. Fig. 10 shows a filament 1 having a rectangular cross-section into which axially parallel channels 21 are formed which open at the circumference of the filament 1 via narrow gap-like openings 22. Fig. 11 shows a filament 1 having sector-shaped recesses 23 and a central core 3 which is penetrated by the transverse channels 24. The sector-shaped recesses 2 3 and the transverse channels 24 are filled with the medium. This filament 1 is preferably coated with a film or provided with an extruded jacket, as described with reference to Fig. 1 through 4. Fig. 12 shows a filament 1 in the shape of a coiled core 2, wherein the recesses 63 extend like screws. This embodiment of the filament 1 can also be easily filled with the medium, and a jacket is advantageously subsequently extruded thereon. Fig. 13 shows a filament 1 in the shape of a wavy core 2, wherein the recesses 64 are formed by wave troughs. Fig. 14 shows a filament 1 in the shape of a core 2 comprising annular recesses 65. In both embodiments, a jacket is extruded, preferably after filling of the filament 1. Fig. 16 shows a filament 1 having an extruded core 2 of rectangular cross-section which is drawn e.g. through an annular channel, wherein the medium 6 accumulates at the side surfaces of the rectangular core 2. A jacket 7 is then extruded and optionally fixed through cooling and shrinking. Fig. 17 represents a core 2 with uniformly distributed depressions 26 which are filled with the medium 6 in the same fashion as described above. A jacket 7 is then once more extruded onto the core 2 having the medium 6. The embodiment in accordance with Fig. 18 differs from the one shown in Fig. 17 only by the shape and number of depressions 26. The filament of the embodiment in accordance with Fig. 19 also has the shape of a core 2 having a cross-shaped cross- section thereby forming recesses 27 which are open to the outside and filled with the medium. The core 2 has bead-like enlargements 29 at the free ends of its arms 28. After filling of the recesses 27 of the core 2, a jacket 30 is extruded to surround the bead-like enlargements thereby forming a kind of positive connection. The embodiment in accordance with Fig. 20 differs in that the arms 28 of the core 2 extend straight and that the jacket 31 is extruded and shrunk after filling of the recesses formed between the arms 28. Fig. 21 shows a filament 1 having the shape of a core 2, wherein different embodiments of recesses are indicated. They may be groove-like, straight depressions 32 or groove-like curved depressions 33 or individual punched depressions 34. In the embodiment of Fig. 23, the filament 1 has a core 2 comprising recesses in the shape of equidistantly disposed slots 35 which extend transverse to the filament axis and are formed e.g. after extrusion. Fig. 24 shows a filament 1 whose core 2 consists of a plurality of parallel monofilaments 36 wherein the recesses are formed by the gaps 37 between the monofilaments 36. After filling the gaps and optionally corresponding sizing of the monofilament strand, a jacket 38 is extruded. Fig. 24 shows the jacket 3 8 partially broken away. It is provided with filling agents 65 which determine the wear behavior of the plastic and thereby the wear of the jacket. Fig. 25 shows a filament 1 having the shape of a core 2 which is provided with one or more axially parallel channels 39 (similar to the embodiment of Fig. 7) which extend to the outside via gap-like openings 40. It is possible to additionally provide spaced apart openings 41 having a somewhat larger cross-section. The embodiment of Fig. 26 shows a filament 1 also having the shape of an extruded core 2 with recesses 42 disposed at the circumference which are all covered by a subsequently disposed layer 43 which either releases the medium in the recesses 42 due to wear during use or has a permeability which permits slow diffusion of the media, optionally with cooperation of the media at the location of use. In the embodiment of Fig. 27, the same filament as in Fig. 2 6 comprising a core 2 with recesses, is covered by a jacket 44 of a diffusion-permitting polymer which has e.g. the properties desired for the surface of the bristle. Additional partial coatings 45 in the region of the recesses 42 control the diffusion density and thereby discharge of the media. Fig. 28 shows a filament 1 with a core having a star-shaped cross-section, wherein the recesses 46 are formed between the prongs of the star, and onto which a jacket 47 is also extruded. The jacket 47 is additionally wrapped with a plastic or textile fiber. In the embodiment in accordance with Fig. 29, the filament i consists of a core 2 similar to the embodiment in accordance with Fig. 11, having sector-shaped recesses 23 and an extruded jacket 49 which is provided with a perforation 50 to permit controlled release of the medium and which also provides the surface of the finished bristle with a structure which increases the effect of the bristle. Fig. 30 shows a filament 1 having a cross-shaped core 2 and a jacket 7. Different media 51, 52 and 53 are accommodated in the -recesses 4 between the core 2 and the jacket 7 which are simultaneously released and either have different effects or consist of components which become effective only at the location of use. Alternatively, differing media can also be disposed in a recess 4, in a layered fashion. The filament 1 in accordance with Fig. 31 also consists of a core 2 which has irregularly disposed recesses 54, 55 and 56 and which is surrounded by a jacket 7. These recesses can also accommodate different media, in dependence on their size and shape. Fig. 32 shows a section of a bristle 8 with similar construction to the one according to Fig. 2, i.e. having a core 2 comprising a medium 6 located in its recesses and a jacket 7. The bristle 8 is closed at its useful end 57 e.g. by corresponding thermal formation of the jacket 8. Fig. 33 and 34 show an embodiment of a bristle 8 having an open end 58 in the initial state (Fig. 33) and after a certain period of use (Fig. 34) during which the jacket 8 is worn off and the medium has been released. This makes the mechanical wear and release of the medium visible. Fig. 35 through 3 8 show another variant for indicating the media consumption and/or wear of the bristle. Towards this end, the core 2 optionally comprises several recesses having the shape of continuous grooves or the like which are disposed at a separation from one another and in which an indicating medium 59 is accommodated. During use, the wear of the jacket 7 starts in the region of the end 58 of the bristle 8 and only the core 2 remains. The markings 59 disappear successively such that the user is optically informed of the discharge of the medium or wear of the bristle. Fig. 39 finally shows a bristle 8 whose end 59 forms a more or less regular tip 60 during regular wear. Also in this case, the core 2 has an annular groove 61 which may optionally be filled with an indicating medium such that when same has disappeared, termination of the (optimum) period of use is signalized. WE CLAIM: 1. Method of producing bristles for applying media, through extrusion of a filament, which can be cut into bristles, and providing same with cavities for receiving the medium, from which the medium is discharged during appropriate use of the bristles, characterized by the steps of: - extruding the filament (1) with a core (2) which also determines the mechanical properties of the bristle (8); - forming cavities (10,13,15,17) at a separation from the center (3)) of the core (2) and open towards the circumference of the filament (1) via a gap (14,16,18,22) formed at the circumference, wherein the cavities are filled with medium (6) from the outside; - forming the gaps (14,16,18,22) such that they are closed in an unloaded state of the bristle (8) and first open in response to pressure generated during proper use of the bristle (8) to release the medium (6). 2. Method of producing bristles for applying media in that a filament, which can be cut into bristles, is extruded and provided with cavities for receiving the medium, from which the medium is released during appropriate use of the bristles, characterized in that the filament (1) is extruded with a core (2) which also determines the mechanical properties of the bristle (8), the cavities (4) being formed at a separation from the center (3) of the core to open towards the circumference of the filament, and are filled with the medium (6) from the outside, the filament (1) subsequently being provided, at least in parts, with a layer which at least partially covers the cavities...... (4) to control discharge of the medium (6) under normal conditions of use of the bristle (8). 3. Method according to claim 2, characterized in that the layer is disposed in the form of a jacket (7) covering the core (2). 4. Method according to claim 1 or 2, characterized in that the cavities (4) are formed during extrusion of the core (2). 5. Method according to claim 1 or 2, characterized in that the cavities (35) are formed after extrusion of the core (2). 6. Method according to any one of the claims 1 through 5, characterized in that the cavities are formed as capillary gaps (10,17). 7. Method according to any one of the claims 1 through 5, characterized in that the cavities are formed as channels (13,15) having openings which narrow into a gap (14,16) at the circumference of the core (2). 8. Method according to claim 1, 6 or 7, characterized in that the shape and/or width of the gaps (10,14,16,17) is matched to the consistency of the medium (6). 9. Method according to claims 2 and 6 or claims 2 and 7, characterized in that the gaps (17) are formed such that they are closed in the unloaded state of the bristle (8) and open under pressure. 10. Method according to claim 1 or 2, characterized in that the cavities (4) are filled with the pressurized medium (6) via the circumferential openings. 11. Method according to claim 10, characterized in that the filament (1) is guided through a volume in which the medium (6) is kept under pressure. 12. Method according to claim 1 or 2, characterized in that the filament (1) having the cavities (4) is guided through a substantially non- pressurized medium (6), thereby at least partially filling the cavities. 13. Method according to any one of the claims 10 through 12, characterized in that the filament (1) is provided with a jacket (7) forming the covering layer after filling the cavities (4). 14. Method according to claim 13, characterized in that a jacket (7) of thermoplastic material is extruded onto the filament (1) filled with the medium (6). 15. Method according to claim 14; characterized in that the jacket (7) is extruded with a larger size than the filament (1) and is shrunk onto the filament (1) through cooling. 16. Method according to any one of the claims 13 through 15, characterized in that a jacket (7) is applied onto the filament (1), the jacket (7) being made from a plastic material which permits diffusion of the medium (6) and/or media present at the location of the intended use of the bristle (8). 17. Method according to claim 16, characterized in that the jacket (7) of a diffusion-permitting plastic material is covered at least in part by a diffusion-tight layer. 18. Method according to claim 2, characterized in that the jacket (7) of a transparent plastic material forming the covering layer is applied onto the filament (1). 19. Method according to claim 1 or 2, characterized in that different media (51,52,53) are introduced into spaced apart cavities (4) of the filament (1). 20. Method according to claim 19, characterized in that media are introduced into separated cavities (4), those media (51,52,53) each comprising a component which becomes active only through combination of components. 21. Method according to claim 1 or 2, characterized in that different media, and/or media having one component which becomes active only upon combination of the components, are introduced in layers into at least one cavity. 22. Method according to claim 1 or 2, characterized in that active components are directly introduced into the core (2) and/or jacket (7). 23. Method according to claim 1 or 2, characterized in that filling agents are directly introduced into the core (2) and/or the jacket (7). 24. Method according to claim 1 or 2, characterized in that the core (2) is extruded as a multifiiament (36). 25. Method according to claim 1 or 2, characterized in that the core (2) and/or jacket (7) is extruded from a directly or indirectly foamable plastic material. 26. Method of producing a bristle, in particular according to claims 1 through 6, characterized in that a jacket (38) is applied onto the filament (1), the jacket (38) being made from a plastic material having filling agents (65) which determine its wear factor. 27. Method according to claim 26, characterized in that the plastic material and the added filling agents (65) are matched to the admissible wear factor of the bristle (8) during appropriate use, 28. Bristle of plastic material for brushes to apply media which are accommodated in cavities of the bristle and which are released by the bristle during appropriate use of the brush, characterized in that the bristle (8) has a core (2) which contributes to determination of its mechanical properties, wherein the cavities (4) are disposed at a separation from the center of the core (2), extend towards the circumference of the bristle (8), and have at least one opening in the form of a gap (14,16,18,20) at the circumference, the gaps (10,14,17) being closed in an unloaded state of the bristle (8), to first open in response to conditions established during proper use thereof to release the medium (6). 29. Bristle of plastic material for brushes to apply media which are accommodated in cavities of the bristle and which are released by the bristle during appropriate use of the brush, characterized in that the bristle (8) has a core (2) which contributes to determination of its mechanical properties, wherein the cavities (4) are disposed at a separation from the center of the core (2), extend towards the circumference of the bristle (8), and have at least one opening, wherein at least portions of the core (2) are coated with a layer (43) at least partially covering the cavities (42). 30. Bristle according to claim 29, characterized in that the layer (43) completely covers the cavities (42). 31. Bristle according to claim 29, characterized in that the layer is formed as a jacket (7,30,31,38,44) surrounding the core (2). 32. Bristle according to claim 31, characterized in that the jacket (49) is perforated and the perforations (50) are connected with the cavities (23) of the core (2). 33. Bristle according to claim 31, characterized in that the jacket (7) consists of a plastic material which permits diffusion of the medium (6) in the cavities of the core. 34. Bristle according to claim 31 or 32, characterized in that the jacket (7) consists of a plastic material which permits diffusion of a medium present at the location of appropriate use of the brush (62). 35. Bristle according to claim 33 or 34, characterized in that the jacket (7) of the diffusion-permitting plastic material is coated in parts in a diffusion-tight fashion. 36. Bristle according to any one of the claims 31 through 35, characterized in that the jacket (7) consists of a plastic material comprising filling agents (65) which determine the wear factor of the jacket during use of the bristle. 37. Bristle according to any one of the claims 31 through 36, characterized in that the jacket (7) is formed of a transparent plastic material. 38. Bristle according to any one of the claims 31 through 37, characterized in that the jacket (7) consists of a plastic material filled with active components. 39. Bristle according to any one of the claims 28 to 38, characterized in that the cavities are formed as capillary gaps (10,17). 40. Bristle according to any one of the claims 28 to 39, characterized in that the cavities are formed as channels (13,15), parallel to the center (3) of the core (2) and having openings which narrow into a gap (14,16) at the circumference of the core (2). 41. Bristle according to any one of the claims 28 through 40, characterized in that the shape and/or the width of the gap (10,14,16,17) is matched to the consistency of the medium (6). 42. Bristle according to any one of the claims 28 to 41, characterized in that the cavities (22) extend about the circumference of the core (2) in a helical fashion. 43. Bristle according to any one of the claims 28 to 42, characterized in that the cavities (24) are annularly disposed at the circumference of the core (2). 44. Bristle according to any one of the claims 28 to 43, characterized in that the cavities (32,33) are disposed like grooves about the circumference of the core (2). 45. Bristle according to any one of the claims 28 to 44, characterized in that the core (2) is wavy and the cavities (23) are formed by the wave troughs. 46. Bristle according to any one of the claims 28 to 45, characterized in that the cavities are slots (35) extending transverse to the core (2). 47. Bristle according to any one of the claims 28 through 46, characterized in that the core (2) includes cavities which are filled with a medium (59) which indicates the degree of the mechanical wear and/or release of the medium (6). 48. Bristle according to any one of the claims 28 through 47, characterized in that spaced apart cavities (4) of the core (2) contain different media (51,52,53). 49. Bristle according to claim 48, characterized in that the spaced-apart cavities (4) contain media (51,52,53) having different components which form an active component only after being released at the location of use. 50. Brush, consisting of a bristle support (9) and a bristle field mounted thereto, characterized in that at least part of the bristle field is formed of bristles (8) in accordance with any one of the claims 28 through 49. 51. Brush according to claim 50, characterized in that the peripheral region of the bristle field comprises the bristles (8) in accordance with any one of the claims 28 through 49. Bristles for applying media are produced in that a filament, which can be cut into bristles, is extruded with a core which also determines the mechanical properties of the bristle. Recesses are formed at a separation from the center of the core and open towards the circumference of the filament which can be filled with medium from the outside, wherein the circumferential openings of the recesses are formed such that the medium is discharged only when the bristle is appropriately used. The recesses may also have a larger opening width and be covered by a layer or jacket. A bristle and brushes having such bristles produced in accordance with this method are also described.

Full Text

Method of Producing Bristles for Applying Media,
Bristles Produced in Accordance with the Method
and Brushes Comprising such Bristles
The invention concerns a method of producing bristles for
applying media through extrusion of a filament which can be
cut into bristles and provided with recesses for receiving
the medium and from which the medium is discharged during
proper use of the bristles, as well as a bristle and brushes
comprising such bristles produced in accordance with this
method.
Brushes comprising bristles for applying liquid, viscous or
powdery media are used mainly for body, hair and mouth cara
but also in the household and for technical applications. The
invention is described below mainly in connection with tooth
brushes, one of the main fields of application.
Tooth brushes are known which highlight film on the teeth
through application of a suitable indicating color to allow
the user of the tooth brush to increase brushing of such
indicated tooth locations (DE 195 45 644). Towards this end,
the brushes are coated with the indicating color or with
microcapsules containing the color and the coating is
optionally sealed. A hollow brush with inserted indicating
medium is also described in this connection. This document
does not explain in detail how these hollow brushes are
filled. It is further known (CA 549 168) to jacket the
brushes of a single-use tooth brush with a tooth care medium.
Bristles are also known (US 5,678,275) whose circumference is
provided with irregularly shaped grooves. They do not
accommodate media but are supposed to accept soilage
particles to remove them from the mouth during brushing of
the teeth.
It is furthermore known (WO 98/24341) to accommodate
therapeutically effective or other media having dental
medical effects in a hollow brush which are released at the
free open end of the brush during use. The hollow brush is
optionally reinforced by radial walls such that it comprises
three or four chambers with parallel axes. The desired media
are introduced in liquid form. Towards this end, filaments
having the cross-sectional shape of the finished bristles are
extruded and several filaments are combined into multi-veined
strands having a diameter up to 5.5 cm and a length up to 1.2
m. One end of the strand is dipped into the liquid medium and
suction is applied to the opposite open ends of the
filaments. Since a high suction pressure is required due to
the capillary cavities and the large strand length and since
collapsing of the walls due to the elasticity of a suitable
plastic must be prevented, the wall must be quite thick and
complete filling of the hollow bristles is not possible.
Viscous or dispersed media cannot be introduced into the
capillary cavities due to the high pressure drop. During use
of the bristle, the medium is only discharged via the open
end of the bristles and is therefore fully undefined and
incomplete.
It is the underlying purpose of the invention to propose a
method for economical introduction of media of arbitrary
consistency and effect into a bristle and for discharge
thereof in a desired dosage during the useful life of the
bristle.
This object is achieved in accordance with the invention in
that the filament is extruded having a core which also
determines the mechanical properties of the bristle, wherein
recesses are formed at a separation from the center of the
core which open towards the circumference of the filament and
which can be filled with medium from the outside, wherein the
circumferential openings of the recesses are formed such that
the medium is discharged only when the bristle is
appropriately used.
In the inventive method, the media is externally introduced
into the recesses which are open to the outside, i.e. they
must not be suctioned via a pressure drop over a relatively
large distance, which would entail corresponding pressure
losses. The recesses may therefore be advantageously filled
at constant medium density. The consistency of the medium is
not important for introduction. It can be liquid, viscous or
disperse. Discharge occurs directly through the
circumferential openings during use: they are sufficiently
narrow to retain the medium and are discharged only during
use, e.g. via the forces applied during brushing or through
media present at the location of use which interact with the
medium in the brush and rinse or dissolve same, i.e. saliva
or a tooth care medium for tooth brushes and, in the simplest
case, water or moisture for cleaning brushes.
A further advantageous embodiment of the method proposes
extrusion of the filament with a core which also determines
the mechanical properties of the bristle, with formation of
the recesses at a separation from the center of the core, the
recesses opening towards the circumference of the filament
and being filled with the medium from the outside, wherein
the filament is subsequently provided, at least in parts,
with a layer which at least partially covers the openings and
controls discharge of the medium under normal conditions of
brush use. In this method, the shape of the circumferential
opening and the opening width are less decisive. The
selection of the material of the layer, its thickness and the
extent to which the recesses containing the medium are
covered can control discharge of the medium over time and in
dependence on how long brushes having such bristles are used.
If the recesses are preferably closed by a jacket, the medium
can be discharged via the open bristle end or through the
openings in the recesses exposed during slow wear of the
jacket or also by diffusion through the jacket, wherein the
jacket may have a thinner wall than the bristle in accordance
with WO 98/24341, since it is not subjected to pressure
during filling.
It is particularly economical when the recesses are formed
during extrusion of the filament. Therein, the recesses are
preferably formed with substantially parallel axes,
optionally at a separation from one another.
Another variant consists in that the recesses are formed
after extrusion of the filament which would permit a
substantially radial formation of recesses having arbitrary
contour and arrangement.
Both above-mentioned method variants may provide that the
recesses are formed as capillary gaps extending from the
center of the core towards the outside or that the recesses
are formed as channels with openings which narrow into a gap
at the circumference. The capillary gaps produce a retaining
effect for the medium and same is discharged only under
conditions of use, e.g. bristle pressure, added external
media, or the like.
The shape and/or width of the gaps is preferably adjusted to
the consistency of the medium. It is furthermore advantageous
to form the gaps such that they are completely closed in the
unloaded state and open only under pressure.
In a particularly economic fashion, the recesses which open
to the outside can be filled in continuous operation on an
endless filament, wherein the filament is guided through an
optionally pressurized medium bath or through a cross-
section, tapering like a nozzle, with the medium being
supplied about the circumference. If the opening width of the
recesses is large enough and the consistency of the medium
sufficiently viscous, filling may also be effected without
pressure during continuous operation. In this case, it is
advisable to subsequently close the recesses with a jacket
disposed on the filament.
The jacket preferably consists of a synthetic thermoplastic
material which is extruded onto the filament, filled with the
medium. It is preferably extruded with excess size and shrunk
onto the filament through cooling to thereby particularly
protect temperature sensitive media. Liquid components can
not evaporate and temperature reactant components do not
decompose. If a jacket made from a plastic material
permitting diffusion of the medium is applied, it may
optionally be covered in parts by a diffusion-tight material
to control diffusion locally and/or the diffusion rate.
If the jacket is made from transparent plastic, medium
consumption can be visually monitored, e.g. through
corresponding coloration of the medium. The type of media may
thereby also be observed.
In addition or instead of displaying the medium and/or its
consumption it is possible to provide an effectivity display
for the bristle function to guarantee that the bristle is
used only as long as it has the properties required for its
intended use. The bristle may also be technically designed
such that it is used only as long as it is effective, by
applying a jacket to the filaments which is made from a
thermoplastic material comprising filling agents which
determine its wear factor, wherein the plastic and the added
filling agents are adjusted to the admissible degree of wear
of the bristle during appropriate use. This method can be
used to provide any type of bristle, optionally consisting of
only a core and a jacket, with an effectivity display.
Filling agents which determine the wear factor can, in
particular, be solids which reduce the intermolecular bonding
in the polymer of the jacket and control the wear factor
through their type, size and amount. The solids of an
application bristle can be selected such that they
simultaneously fulfil a function during application, e.g.
calcium carbonate or chloride as mineral agents in tooth
brushes. The addition of waxes, in particular ionomer wax,
has also proved favorable since they are distributed more
uniformly in the polymer matrix and thus provide a uniform
wear factor. The sliding behavior of the bristle is also
improved. This also permits fine adjustment of an effectivity
display.
In accordance with a further method variant, for application,
different media having different functions may be disposed in
layers or with localized separation and can be discharged at
separate locations. In the same fashion, it is possible to
locally separate components of an agent, having an affinity
to one another, which should be effective only at the
location of use. An example thereof is the desired formation
or regeneration of calcium fluoride layers on teeth which can
be effected in ionising media with Ca(+) and F(-) ions which can
be produced from locally separated Ca and F compounds in the
moist atmosphere of the mouth and throat area.
The media or active components can also be separately
disposed through layered accommodation in the recesses and
combined only when dispensed. The diffusion rate of the media
or active components can be controlled through the formation
of layers.
Furthermore, active components and/or filling agents can be
accommodated in the core or in the jacket or in both.
Finally, the core may be extruded as a monofilament or
multifilament. The core and/or jacket may optionally be
foamed during extrusion or afterwards.
The invention finally concerns a bristle which is obtained
from the filament produced in accordance with the invention
through cutting to the desired length and a brush having a
bristle support for mounting bristles of the above-mentioned
type thereby forming a bristle field or part thereof.
In some applications, it is recommended to close the bristles
at least at their useful end e.g. using thermal methods such
as welding, friction welding, laser welding or the like.
The inventive method and bristles produced in accordance with
the method are described below by means of some embodiments
shown in the drawing.
Fig. 1 shows different phases a) to f) of the
production of a filament in cross-section;
Fig. 2 shows a longitudinal section II-II through a
filament;
Fig. 3 shows a schematic section of a brush comprising
a bristle made from a filament in accordance
with Fig. 2;
Fig. 4 shows a schematic representation of the medium
discharge;
Fig. 5
through 10 show cross-sections of different embodiments of
a bristle;
Fig. 11 shows a cross-section of a further embodiment
of a bristle core;
Fig. 12
through 14 show further embodiments of a bristle core;
Fig. 15 shows a section XV-XV in accordance with Fig.
14;
Fig. 16
through 20 show cross-sections of some further embodiments
of bristles comprising an extruded jacket;
Fig. 21 shows a bristle;
Fig. 22 shows a section XXII-XXII in accordance with
Fig. 21;
Fig. 23
through 25 show further embodiments of the bristle;
Fig. 26 shows a cross-section of a bristle with partial
coating;
Fig. 27 shows a cross-section through a bristle
comprising a jacket and partial coating;
Fig. 2 8 shows a perspective view of a bristle
comprising a jacket and additional binding;
Fig. 29 shows a perspective view of a bristle with
perforated jacket;
Fig. 30 shows a cross-section of a bristle comprising
different media in separated recesses;
Fig. 31 shows a longitudinal section through a bristle
having different recesses at the core;
Fig. 32 shows a longitudinal section through a bristle
having one closed end;
Fig. 33 shows a longitudinal section through a bristle
in the initial state;
Fig. 34 shows the bristle in accordance with Fig. 33
during or after use;
Fig. 35
through 3 8 each show one longitudinal section through a
bristle with effectivity display;
Fig. 39 shows a longitudinal section through a bristle
comprising a wear display;
Fig. 1 shows, in illustrations a) through f), different
method steps of producing a filament from which bristles are
obtained by cutting to a desired length. The filament 1 is
extruded in a conventional fashion from a plastic melt in the
form of a core 2, which substantially determines the
mechanical properties of the bristle. In the embodiment
shown, the core 2 consists of a solid center 3 comprising
recesses 4 starting at that location and opening towards the
outside, which are obtained in this embodiment through a
crossed profile of the extruded core (Fig. la). The filament
is subsequently drawn in a conventional fashion (Fig. 1b) to
obtain a longitudinal molecular orientation. The cross-
section is correspondingly reduced through stretching during
drawing of the core. Subsequently, the core 2 is preferably
thermally stabilized (Fig. 1c).
The filament 1 with recesses 4, extruded and pre-treated in
this fashion, is subsequently filled with the medium 6. The
filament 1 is drawn through a channel (indicated in Fig. 1d
with a circular line 5) which optionally narrows like a
nozzle from a larger cross-section to the cross-section of
the core 2 and into which the medium is constantly supplied
such that the medium 6 is accommodated within the recesses 4
of the filament 1. The medium 6 may also be supplied under
pressure, as shown in Fig. 1e which indicates a larger
density of the medium 6. In the embodiment shown whose
depressions have a very open cross-section, it is recommended
to dispose a covering layer 7 onto the filament filled with
the medium, which is formed like a film and which quickly
wears during use of the bristle to discharge the medium 6.
This covering layer 7 may also be a thin-walled jacket which
consists of a diffusion-permitting polymer to allow either
diffusion of the medium 6 at the location of use of the
bristle or to achieve a required permeability only in
connection with media at the location of use, e.g. saliva,
water or the like. The jacket 7 is preferably extruded onto
the previously filled filament 1 having a larger size than
the core 2 and subsequently shrunk onto the core through
cooling.
Fig. 2 shows the section of a bristle 8 obtained from cutting
a filament produced in accordance with Fig. 1. The bristle 8
thereby consists of a core 2 comprising the medium 6 in the
recesses and the jacket 7.
Fig. 3 schematically shows a section of a brush 62, e.g. in
the region of a tooth brush head, comprising a bristle
support 9 to which the bristles 8 are mounted. During use of
the tooth brush, pressure and bending forces act on the
bristle 8 leading to the schematically shown temporary
deformation of the bristle 8. Due to these forces, the medium
6 is discharged at the free end of the bristle as indicated
with directional markers. At the same time, if the medium has
the corresponding composition, it diffuses through the walls
of the jacket, optionally with the cooperation of media
present at the location of use, e.g. saliva, water, tooth
care means or the like. This is shown in Fig. 4 in an
enlarged scale.
Fig. 5 through 10 show cross-sections of filaments 1 which do
not require separate coating or a jacket, depending on the
consistency of the medium. Fig. 5 shows a filament which is
extruded in the shape of a substantially circular core 2
having a solid center 3. During extrusion, recesses in the
form of capillary gaps 10 are formed, which are disposed
regularly and radially in the embodiment shown. The capillary
gaps 10 are filled with the medium in a manner described with
reference to Fig. 1.
Fig. 6 shows a similar embodiment wherein the capillary gaps
10 are additionally provided with a profile 11 in the
extrusion direction, thereby achieving an improved retaining
capacity for the medium.
In the embodiment of Fig. 7, the filament 1 also consists of
a solid core 2 and an external core part 12 which may be made
from a different plastic material than the core 2. The core 2
is e.g. formed of a polymer providing the subsequent bristle
with the required mechanical properties, while the core part
12 may consist of another polymer having properties suitable
for use. The filament 1 has channel-like recesses 13 parallel
to the axis of the core 2 which extend via gap-like openings
14 at the circumference of the filament 1. Fig. 8 again shows
a filament 1 in the shape of an extruded core 2 which only
has a few uniformly distributed channels 15 with gap-like
openings 16 proximate to the circumference.
In the embodiment in accordance with Fig.. 9, the filament 1
is again extruded as core 2 having a solid center 3 from
which a plurality of capillary gaps 17 extend to the outside,
like shovels. The capillary gaps 17 are almost closed at the
circumference 18 of the filament 1. The bridges 20, limiting
the capillary gaps 17 in a shovel-like manner, can be
elastically deformed to facilitate filling of the capillary
gaps 17 in that the filament is turned opposite to the
curvature of the shovel to open the gaps. After filling, the.
excessive medium is pressed out through turning in the
opposite direction or by passing through a corresponding
covering cross-section such that the capillary gaps 17 are
almost closed at the circumference of the filament 1 or in
the subsequent bristle. When brushes equipped with such
bristles are used, the pressure forces effect deformation of
the bristle such that the medium is discharged about the
circumference.
Fig. 10 shows a filament 1 having a rectangular cross-section
into which axially parallel channels 21 are formed which open
at the circumference of the filament 1 via narrow gap-like
openings 22.
Fig. 11 shows a filament 1 having sector-shaped recesses 23
and a central core 3 which is penetrated by the transverse
channels 24. The sector-shaped recesses 2 3 and the transverse
channels 24 are filled with the medium. This filament 1 is
preferably coated with a film or provided with an extruded
jacket, as described with reference to Fig. 1 through 4.
Fig. 12 shows a filament 1 in the shape of a coiled core 2,
wherein the recesses 63 extend like screws. This embodiment
of the filament 1 can also be easily filled with the medium,
and a jacket is advantageously subsequently extruded thereon.
Fig. 13 shows a filament 1 in the shape of a wavy core 2,
wherein the recesses 64 are formed by wave troughs. Fig. 14
shows a filament 1 in the shape of a core 2 comprising
annular recesses 65. In both embodiments, a jacket is
extruded, preferably after filling of the filament 1.
Fig. 16 shows a filament 1 having an extruded core 2 of
rectangular cross-section which is drawn e.g. through an
annular channel, wherein the medium 6 accumulates at the side
surfaces of the rectangular core 2. A jacket 7 is then
extruded and optionally fixed through cooling and shrinking.
Fig. 17 represents a core 2 with uniformly distributed
depressions 26 which are filled with the medium 6 in the same
fashion as described above. A jacket 7 is then once more
extruded onto the core 2 having the medium 6. The embodiment
in accordance with Fig. 18 differs from the one shown in Fig.
17 only by the shape and number of depressions 26.
The filament of the embodiment in accordance with Fig. 19
also has the shape of a core 2 having a cross-shaped cross-
section thereby forming recesses 27 which are open to the
outside and filled with the medium. The core 2 has bead-like
enlargements 29 at the free ends of its arms 28. After
filling of the recesses 27 of the core 2, a jacket 30 is
extruded to surround the bead-like enlargements thereby
forming a kind of positive connection. The embodiment in
accordance with Fig. 20 differs in that the arms 28 of the
core 2 extend straight and that the jacket 31 is extruded and
shrunk after filling of the recesses formed between the arms
28.
Fig. 21 shows a filament 1 having the shape of a core 2,
wherein different embodiments of recesses are indicated. They
may be groove-like, straight depressions 32 or groove-like
curved depressions 33 or individual punched depressions 34.
In the embodiment of Fig. 23, the filament 1 has a core 2
comprising recesses in the shape of equidistantly disposed
slots 35 which extend transverse to the filament axis and are
formed e.g. after extrusion.
Fig. 24 shows a filament 1 whose core 2 consists of a
plurality of parallel monofilaments 36 wherein the recesses
are formed by the gaps 37 between the monofilaments 36. After
filling the gaps and optionally corresponding sizing of the
monofilament strand, a jacket 38 is extruded.
Fig. 24 shows the jacket 3 8 partially broken away. It is
provided with filling agents 65 which determine the wear
behavior of the plastic and thereby the wear of the jacket.
Fig. 25 shows a filament 1 having the shape of a core 2 which
is provided with one or more axially parallel channels 39
(similar to the embodiment of Fig. 7) which extend to the
outside via gap-like openings 40. It is possible to
additionally provide spaced apart openings 41 having a
somewhat larger cross-section.
The embodiment of Fig. 26 shows a filament 1 also having the
shape of an extruded core 2 with recesses 42 disposed at the
circumference which are all covered by a subsequently
disposed layer 43 which either releases the medium in the
recesses 42 due to wear during use or has a permeability
which permits slow diffusion of the media, optionally with
cooperation of the media at the location of use.
In the embodiment of Fig. 27, the same filament as in Fig. 2 6
comprising a core 2 with recesses, is covered by a jacket 44
of a diffusion-permitting polymer which has e.g. the
properties desired for the surface of the bristle. Additional
partial coatings 45 in the region of the recesses 42 control
the diffusion density and thereby discharge of the media.
Fig. 28 shows a filament 1 with a core having a star-shaped
cross-section, wherein the recesses 46 are formed between the
prongs of the star, and onto which a jacket 47 is also
extruded. The jacket 47 is additionally wrapped with a
plastic or textile fiber.
In the embodiment in accordance with Fig. 29, the filament i
consists of a core 2 similar to the embodiment in accordance
with Fig. 11, having sector-shaped recesses 23 and an
extruded jacket 49 which is provided with a perforation 50 to
permit controlled release of the medium and which also
provides the surface of the finished bristle with a structure
which increases the effect of the bristle.
Fig. 30 shows a filament 1 having a cross-shaped core 2 and a
jacket 7. Different media 51, 52 and 53 are accommodated in
the -recesses 4 between the core 2 and the jacket 7 which are
simultaneously released and either have different effects or
consist of components which become effective only at the
location of use. Alternatively, differing media can also be
disposed in a recess 4, in a layered fashion.
The filament 1 in accordance with Fig. 31 also consists of a
core 2 which has irregularly disposed recesses 54, 55 and 56
and which is surrounded by a jacket 7. These recesses can
also accommodate different media, in dependence on their size
and shape.
Fig. 32 shows a section of a bristle 8 with similar
construction to the one according to Fig. 2, i.e. having a
core 2 comprising a medium 6 located in its recesses and a
jacket 7. The bristle 8 is closed at its useful end 57 e.g.
by corresponding thermal formation of the jacket 8.
Fig. 33 and 34 show an embodiment of a bristle 8 having an
open end 58 in the initial state (Fig. 33) and after a
certain period of use (Fig. 34) during which the jacket 8 is
worn off and the medium has been released. This makes the
mechanical wear and release of the medium visible.
Fig. 35 through 3 8 show another variant for indicating the
media consumption and/or wear of the bristle. Towards this
end, the core 2 optionally comprises several recesses having
the shape of continuous grooves or the like which are
disposed at a separation from one another and in which an
indicating medium 59 is accommodated. During use, the wear of
the jacket 7 starts in the region of the end 58 of the
bristle 8 and only the core 2 remains. The markings 59
disappear successively such that the user is optically
informed of the discharge of the medium or wear of the
bristle.
Fig. 39 finally shows a bristle 8 whose end 59 forms a more
or less regular tip 60 during regular wear. Also in this
case, the core 2 has an annular groove 61 which may
optionally be filled with an indicating medium such that when
same has disappeared, termination of the (optimum) period of
use is signalized.
WE CLAIM:
1. Method of producing bristles for applying media, through extrusion of a
filament, which can be cut into bristles, and providing same with cavities for
receiving the medium, from which the medium is discharged during
appropriate use of the bristles, characterized by the steps of:
- extruding the filament (1) with a core (2) which also determines the
mechanical properties of the bristle (8);
- forming cavities (10,13,15,17) at a separation from the center (3)) of the
core (2) and open towards the circumference of the filament (1) via a gap
(14,16,18,22) formed at the circumference, wherein the cavities are filled
with medium (6) from the outside;
- forming the gaps (14,16,18,22) such that they are closed in an unloaded
state of the bristle (8) and first open in response to pressure generated
during proper use of the bristle (8) to release the medium (6).
2. Method of producing bristles for applying media in that a filament, which can
be cut into bristles, is extruded and provided with cavities for receiving the
medium, from which the medium is released during appropriate use of the
bristles, characterized in that the filament (1) is extruded with a core (2)
which also determines the mechanical properties of the bristle (8), the
cavities (4) being formed at a separation from the center (3) of the core to
open towards the circumference of the filament, and are filled with the
medium (6) from the outside, the filament (1) subsequently being provided,
at least in parts, with a layer which at least partially covers the cavities......
(4) to control discharge of the medium (6) under normal conditions
of use of the bristle (8).
3. Method according to claim 2, characterized in that the layer is
disposed in the form of a jacket (7) covering the core (2).
4. Method according to claim 1 or 2, characterized in that the cavities
(4) are formed during extrusion of the core (2).
5. Method according to claim 1 or 2, characterized in that the cavities
(35) are formed after extrusion of the core (2).
6. Method according to any one of the claims 1 through 5,
characterized in that the cavities are formed as capillary gaps
(10,17).
7. Method according to any one of the claims 1 through 5,
characterized in that the cavities are formed as channels (13,15)
having openings which narrow into a gap (14,16) at the
circumference of the core (2).
8. Method according to claim 1, 6 or 7, characterized in that the shape
and/or width of the gaps (10,14,16,17) is matched to the
consistency of the medium (6).
9. Method according to claims 2 and 6 or claims 2 and 7, characterized
in that the gaps (17) are formed such that they are closed in the
unloaded state of the bristle (8) and open under pressure.
10. Method according to claim 1 or 2, characterized in that the cavities
(4) are filled with the pressurized medium (6) via the circumferential
openings.
11. Method according to claim 10, characterized in that the filament (1)
is guided through a volume in which the medium (6) is kept under
pressure.
12. Method according to claim 1 or 2, characterized in that the filament
(1) having the cavities (4) is guided through a substantially non-
pressurized medium (6), thereby at least partially filling the cavities.
13. Method according to any one of the claims 10 through 12,
characterized in that the filament (1) is provided with a jacket (7)
forming the covering layer after filling the cavities (4).
14. Method according to claim 13, characterized in that a jacket (7) of
thermoplastic material is extruded onto the filament (1) filled with
the medium (6).
15. Method according to claim 14; characterized in that the jacket (7) is
extruded with a larger size than the filament (1) and is shrunk onto
the filament (1) through cooling.
16. Method according to any one of the claims 13 through 15,
characterized in that a jacket (7) is applied onto the filament (1),
the jacket (7) being made from a plastic material which permits
diffusion of the medium (6) and/or media present at the location of
the intended use of the bristle (8).
17. Method according to claim 16, characterized in that the jacket (7) of
a diffusion-permitting plastic material is covered at least in part by a
diffusion-tight layer.
18. Method according to claim 2, characterized in that the jacket (7) of a
transparent plastic material forming the covering layer is applied
onto the filament (1).
19. Method according to claim 1 or 2, characterized in that different
media (51,52,53) are introduced into spaced apart cavities (4) of the
filament (1).
20. Method according to claim 19, characterized in that media are
introduced into separated cavities (4), those media (51,52,53) each
comprising a component which becomes active only through
combination of components.
21. Method according to claim 1 or 2, characterized in that different
media, and/or media having one component which becomes active
only upon combination of the components, are introduced in layers
into at least one cavity.
22. Method according to claim 1 or 2, characterized in that active
components are directly introduced into the core (2) and/or jacket
(7).
23. Method according to claim 1 or 2, characterized in that filling agents
are directly introduced into the core (2) and/or the jacket (7).
24. Method according to claim 1 or 2, characterized in that the core (2)
is extruded as a multifiiament (36).
25. Method according to claim 1 or 2, characterized in that the core (2)
and/or jacket (7) is extruded from a directly or indirectly foamable
plastic material.
26. Method of producing a bristle, in particular according to claims 1
through 6, characterized in that a jacket (38) is applied onto the
filament (1), the jacket (38) being made from a plastic material
having filling agents (65) which determine its wear factor.
27. Method according to claim 26, characterized in that the plastic
material and the added filling agents (65) are matched to the
admissible wear factor of the bristle (8) during appropriate use,
28. Bristle of plastic material for brushes to apply media which are
accommodated in cavities of the bristle and which are released by
the bristle during appropriate use of the brush, characterized in that
the bristle (8) has a core (2) which contributes to determination of
its mechanical properties, wherein the cavities (4) are disposed at a
separation from the center of the core (2), extend towards the
circumference of the bristle (8), and have at least one opening in the
form of a gap (14,16,18,20) at the circumference, the gaps
(10,14,17) being closed in an unloaded state of the bristle (8), to
first open in response to conditions established during proper use
thereof to release the medium (6).
29. Bristle of plastic material for brushes to apply media which are
accommodated in cavities of the bristle and which are released by
the bristle during appropriate use of the brush, characterized in that
the bristle (8) has a core (2) which contributes to determination of
its mechanical properties, wherein the cavities (4) are disposed at a
separation from the center of the core (2), extend towards the
circumference of the bristle (8), and have at least one opening,
wherein at least portions of the core (2) are coated with a layer (43)
at least partially covering the cavities (42).
30. Bristle according to claim 29, characterized in that the layer (43)
completely covers the cavities (42).
31. Bristle according to claim 29, characterized in that the layer is
formed as a jacket (7,30,31,38,44) surrounding the core (2).
32. Bristle according to claim 31, characterized in that the jacket (49) is
perforated and the perforations (50) are connected with the cavities
(23) of the core (2).
33. Bristle according to claim 31, characterized in that the jacket (7)
consists of a plastic material which permits diffusion of the medium
(6) in the cavities of the core.
34. Bristle according to claim 31 or 32, characterized in that the jacket
(7) consists of a plastic material which permits diffusion of a medium
present at the location of appropriate use of the brush (62).
35. Bristle according to claim 33 or 34, characterized in that the jacket
(7) of the diffusion-permitting plastic material is coated in parts in a
diffusion-tight fashion.
36. Bristle according to any one of the claims 31 through 35,
characterized in that the jacket (7) consists of a plastic material
comprising filling agents (65) which determine the wear factor of the
jacket during use of the bristle.
37. Bristle according to any one of the claims 31 through 36,
characterized in that the jacket (7) is formed of a transparent plastic
material.
38. Bristle according to any one of the claims 31 through 37,
characterized in that the jacket (7) consists of a plastic material
filled with active components.
39. Bristle according to any one of the claims 28 to 38, characterized in
that the cavities are formed as capillary gaps (10,17).
40. Bristle according to any one of the claims 28 to 39, characterized in
that the cavities are formed as channels (13,15), parallel to the
center (3) of the core (2) and having openings which narrow into a
gap (14,16) at the circumference of the core (2).
41. Bristle according to any one of the claims 28 through 40,
characterized in that the shape and/or the width of the gap
(10,14,16,17) is matched to the consistency of the medium (6).
42. Bristle according to any one of the claims 28 to 41, characterized in
that the cavities (22) extend about the circumference of the core (2)
in a helical fashion.
43. Bristle according to any one of the claims 28 to 42, characterized in
that the cavities (24) are annularly disposed at the circumference of
the core (2).
44. Bristle according to any one of the claims 28 to 43, characterized in
that the cavities (32,33) are disposed like grooves about the
circumference of the core (2).
45. Bristle according to any one of the claims 28 to 44, characterized in
that the core (2) is wavy and the cavities (23) are formed by the
wave troughs.
46. Bristle according to any one of the claims 28 to 45, characterized in
that the cavities are slots (35) extending transverse to the core (2).
47. Bristle according to any one of the claims 28 through 46,
characterized in that the core (2) includes cavities which are filled
with a medium (59) which indicates the degree of the mechanical
wear and/or release of the medium (6).
48. Bristle according to any one of the claims 28 through 47,
characterized in that spaced apart cavities (4) of the core (2) contain
different media (51,52,53).
49. Bristle according to claim 48, characterized in that the spaced-apart
cavities (4) contain media (51,52,53) having different components
which form an active component only after being released at the
location of use.
50. Brush, consisting of a bristle support (9) and a bristle field mounted
thereto, characterized in that at least part of the bristle field is
formed of bristles (8) in accordance with any one of the claims 28
through 49.
51. Brush according to claim 50, characterized in that the peripheral
region of the bristle field comprises the bristles (8) in accordance
with any one of the claims 28 through 49.
Bristles for applying media are produced in that a filament,
which can be cut into bristles, is extruded with a core which
also determines the mechanical properties of the bristle.
Recesses are formed at a separation from the center of the
core and open towards the circumference of the filament which
can be filled with medium from the outside, wherein the
circumferential openings of the recesses are formed such that
the medium is discharged only when the bristle is
appropriately used. The recesses may also have a larger
opening width and be covered by a layer or jacket. A bristle
and brushes having such bristles produced in accordance with
this method are also described.

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Patent Number

225261

Indian Patent Application Number

IN/PCT/2002/01236/KOL

PG Journal Number

45/2008

Publication Date

07-Nov-2008

Grant Date

05-Nov-2008

Date of Filing

30-Sep-2002

Name of Patentee

PEDEX & CO. GMBH ,

Applicant Address

HAUPTSTRASSE 67, 69483 WALD-MICHELBACH

Inventors:

#	Inventor's Name	Inventor's Address
1	WEIHRAUCH, GEORG	AM ROSSERT 1, 69483 WALD-MICHELBACH

PCT International Classification Number

A46D 1/00

PCT International Application Number

PCT/EP2001/03466

PCT International Filing date

2001-03-27

PCT Conventions:

#	PCT Application Number	Date of Convention	Priority Country
1	100 17 306.3	2000-04-09	Germany