MXPA00010329A - Bristle, method for producing said bristle and a device with a bristle of this type - Google Patents

Abstract

The invention relates to a bristle (1) comprising a core (2) consisting of a relatively hard, flexurally elastic plastic and at least one layer consisting of a rubber elastic plastic. Said layer is shaped by embossment against the core. A film-like layer can also be applied to said layer to even out the profile. A bristle of this type is produced by coextruding the core and the rubber elastic layer and then embossing the latter against the core. The film-like layer is applied after the embossment.

Description

SOW. METHOD TO PRODUCE T / FENCER AND DEVICE WITH A CERE OF THIS TYPE DESCRIPTION OF THE INVENTION The invention relates to a bristle comprising a core of a comparatively rigid, elastic bending plastic, and at least one layer of a rubber-like plastic. The invention also relates to a process for the production of such bristles and to implements equipped with such bristles. Regardless of the proposed use of a brush, certain fundamental demands are made on the bristles. These include, more particularly, bending elasticity, flexural strength and wear resistance. In addition, there are often very different requirements that result from the proposed use of the brush. Thus, for example, brushes for oral and body hygiene should be soft enough to avoid damage, while abrasive industrial brushes should have hard and resistant bristles. Other technical brushes, such as car wash brushes, should once again be soft and pliable. This also applies in the case of polishing brushes. The brushes of the brushes used for the application of means must have vertical bristles juxtaposed relatively closely Ref: 12 265 for storing the medium, whereas in other applications individually held bristles or sets of bristles are desired. The action of a bristle on the surface of the object to be treated to work depends decisively on the surface characteristics of the bristle and the bristle material. Generally, bristles are produced from extruded plastic monofilaments. As a result of the choice of the plastic alone, it is essentially possible to influence the bending and the wear resistance, but only to a very limited extent in terms of the surface characteristics and effectiveness of the surface, in addition to simple longitudinal profiles. Therefore, numerous attempts have been made in the prior art to modify the surface characteristics or effectiveness of the bristle surface by additional measures in order to better meet the requirements of each proposed use. In the literature reference list after the description, documents (1) to (8) describe bristles with particles that act abrasively, incorporated, for different uses. It is in each case a matter of providing the sow with a hard abrasive action. Another development referred to in documents (9) to (15) is the profile of different ways of coating a bristle formed from a plastic monofilament.

In each case it is a matter of forming more or less pronounced edges, and this extends to torn structures.

All the solutions mentioned in the foregoing with particle-filled or profiled bristles of monofilaments suffer from the decisive disadvantage that the strength characteristics, particularly the bending elasticity, the flexural strength and also the wear resistance are significantly reduced, so that the user must once again make diameters of large bristles and / or plastics of superior quality. However, this is often impossible for reasons of use and also leads to undesirably higher costs. Other known proposals according to documents (16) to (1) have the purpose of producing a bristle of two plastic components, specifically a plastic core and a cover applied thereto, either in the form of a coating that surrounds the core or in shape of fibers applied to the core. In these known solutions, the resistance characteristics of the bristle remain substantially controlled. To the extent that the core has a uniform wall covering (16), (17), the action of the bristle can only be modified insignificantly. If only the hard core is profiled and a rubber elastic coating is applied following the profile (18), the latter wears quickly as the profile arches and the hard core is exposed. To the extent that the core is coated with fibers (20), the bristle can only be used for specific purposes and is also complicated and expensive to manufacture. Among the proposals mentioned at the end, document (21) proposes a bristle comprising a relatively rigid extruded core of high density PA (polyamide) or PE (polyethylene) and a soft thermoplastic coating of natural or artificial rubber. This known bristle is designed for toothbrushes, where the elastic soft rubber coating is designed primarily to ensure careful treatment of the teeth and gums, while the rigid core ensures the necessary strength characteristics for the bristle. However, such a bristle does not satisfy the demands made during cleaning, because its surface is too smooth. Nor is it suitable for a means of application to an object. Based on this prior art, the problem of the invention is to provide a bristle which, while maintaining the necessary strength characteristics in the case of a smooth surface, must also provide a good cleansing action and absorptivity for a medium. At the base of a bristle comprising a core of a comparatively rigid, elastic bending plastic and at least one layer of rubber-like plastic, the invention solves this problem to the extent that the rubber-like layer is profiled by stamping against the core, preferably by hot stamping. The invention is based on the surprising finding that a rubber-like plastic, for example a thermoplastic elastomer, even with a very limited thickness, which necessarily arises in the case of bristles and with toothbrushes is only a few tenths of a millimeter , can be profiled by stamping or engraving, without there being any recovery of shape of rubber-like plastic. A decisive part is made by the relatively rigid core against which the stamping or engraving forces are going to be applied. It is possible to implement thin to thick structures with any random shape. Particularly small depths are chosen in the case of bristles for oral and body hygiene, while depths of greater profile are used for cleaning or coating brushes, in the first case to receive dirt and in the second case for application of media. The rubber-like layer may surround the core in a coating-like manner or also only in zones, and the resulting profiling for embossing may be provided over the entire length of the bristle or only over partial lengths thereof.

In the case of the bristle constructed in accordance with the invention, the core is made of a plastic material that defines the resistance to bending and bending of the bristle and the rubber-like layer with its profiling from plastic materials defining the Surface action of the bristle on the object and wear resistance. By choosing the two plastics and the nature of the profiling, the bristle can be easily adapted to random requirements. In a preferred embodiment, the core is fabricated from a plastic material having a Shore D hardness of > 5 and the rubber-like layer of a plastic material with a Shore D hardness < 35. In a particularly preferred embodiment, the Shore hardness of the core plastic is D > 65 and that of the rubber-like layer is 20 < D < 35. Materials that meet the requirements mentioned above are, for example, in the case of PE core (polyethylene), PP (polypropylene) or PA (polyamide) and for the rubber-like layer, thermoplastic elastomers. Profiling of the rubber-like layer can be performed by locally defined depressions distributed over the circumference. Instead, the profiling can also be carried out in the extension direction of the bristle, for example along the generatrices or in a helical manner. Finally, the profiling can also be predominantly orienting transverse to the direction of extension of the sow. According to a further feature of the invention, the profiled rubber-like layer is applied as a film-like coating of a soft plastic adhesion to its profile. As a result, a certain uniform effect on the profiling can be obtained without removing the surface action thereof. The core can be formed from one or more monofilaments. The first mentioned form is recommended for toothbrushes and body brushes, while the second is better for industrial brushes and in particular for brushes for washing cars. In this particular application, the bristles must be bent gently, so that they are applied optimally to the contour of the surface to be cleaned and also to carefully clean the surface. These bristles are subjected to a very fast wear from the free end. This means, in the case of the sow according to the invention, that the rubber capacity wears first as the sow ends. In a variant according to the invention with several core monofilaments which are arranged in the form of fibers, which will then ensure a careful action in comparison with a single larger diameter core monofilament.

Normally the bristles have a circular cross section. However, in the case of the construction according to the invention, it is possible to implement any other bristle cross section, insofar as the core has a cross section that is different from the circular shape, for example a narrow cross section , rectangular or cruciform or star-shaped. The rubber-like layer can have a circular cross section, so that it has a different thickness and can be stamped, for example, deeper into the thicker areas. Instead of this, one can also have a cross section that follows a core cross section, so that, independently of the position of the equal depth of the stamp, profiles can be made and here again the core serves as a stop. Finally, the whole of the bristle constituted by the core and rubber-like layer can be corrugated transversely in the extension direction of the bristle. Good adhesion of the rubber-like layer to the core is obtained through a surface structure in the core that acts as a primer. For the manufacture of the sow described in the above, the invention proposes a process in which the core and the rubber-like layer are co-extruded as a filament and a rubber-like layer, with the filament in motion, is profiled by stamping against the core. This process leads to a continuous bristle material, from which the bristles can be cut, if desired, to the length immediately after stamping. Instead of the bristle material being rolled up and then the bristle cut to the length, as desired, of the filament developed at the time of making the brush. In another variant of the process, the core and the rubber-like layer are co-extruded as a continuous filament, the filament is rolled and the rubber-like layer is profiled against the core when the filament is unwound. In this process the stamping can be carried out at the manufacturer of the bristle material or only at the brush manufacturer. This process can also be advantageous if the rubber-like layer is constituted by a slow crosslinking elastomer and the stamping process only takes place at the end of the crosslinking reaction. In this process, the rubber-like layer is preferably shaped by stamping tools that act against each other and against the core, and the tools can produce different profiles. In the case of profiling on only one side, the stamping tool cooperates with a non-profiled counter-tool.

In a further variant of the process according to the invention, the filament profiled at the time of manufacture of the bristle material or before cutting it from the length of the bristles, a soft plastic can be applied in a film-like manner by extrusion, dipping, sprinkling or shrinking on a film, for example in order to standardize the profile. In another variant of the process, the core and the rubber-like layer are coextruded as a filament, the bristle is then cut to length from the filament and then the rubber-like layer is profiled against the core. In this process, the film-like coating can be applied before or after cutting the length by dipping, spraying or shrinking onto a film. The bristle constructed in accordance with the invention is usable for implements of the most varied types. In the simplest case such a bristle can be used directly as an interdental cleaner, either in the form of a bar or in a similar manner as dental floss. In contrast to this, a brush may be provided with a plurality of bristles constructed in accordance with the invention and the bristles may be provided in separate arrangements. In particular, such a brush may have bristles with rubber-like layers profiled differently.

The invention is described in detail in the following in relation to the modalities represented diagrammatically in the accompanying drawings and which, in each case, a cross section of a bristle is respectively shown. The bristle 1, according to FIG. 1, has a core 2 of a plastic resistant to bending, elastic to bending, for example PA, PP or PE and a rubber-like layer 3 similarly surrounding the skin to the core 2. , for example, of a thermoplastic elastomer. In the rubber-like layer 3, a profile is printed in the form of circumferentially distributed depressions 5, defined in their entirety. The stamping is carried out against the rigid core 2. In the embodiment according to figure 2, the bristle 1 is only stamped with the profile shown in figure 1 on a part of its length, while it is without profiling on the remaining length 6, which includes, for example, the end of the clamping side of the bristle. Otherwise, it again comprises a core 2 of a rigid plastic, the rubber-like layer 3 with the embossing and a film-like covering 7, which covers the profiling and joins the latter, but leaves a certain effect uniforming In the embodiment of figure 3, the bristle once comprises a core 2 and a rubber-like layer 3, which is only applied in a zonal manner and runs on the core 2 in the form of longitudinal protrusions, which are profiled by transverse stamping, so that depressions 8 and arcuate 9 similar to protrusions are obtained. In the embodiment according to céi? * FIG. 4, the rubber-like layer 3 is profiled longitudinally on the core 2 and the profile can be produced during the coextrusion or stamping operation. In addition, the rubber-like layer 3 has depressions produced by embossing as in Figures 1 and 2 or transverse patterns, as in Figure 3. While in the embodiments according to Figures 1 to 4 at least the core has a circular cross-section, figure 5 shows a bristle with a core 2 having a cruciform cross-section 10, while the rubber-like layer 3 has a circular cross-section. Therefore, it is thinner in the region of the ends of the stem of the cruciform cross-section. This leads to sharply defined joints against which the profile can be particularly well stamped, as indicated by the arrows 11. In the embodiment according to Figure 6, the bristle 1 once again has a core 2 with a cross section circular. The rubber-like layer 3 envelops this pattern with a wavy profile 12. Figure 7 shows a modified embodiment compared to Figure 1, wherein the core 2 comprises four monofilaments 13, which can be placed parallel or crooked. The rubber-like layer 3 once again surrounds the core with a circular cross-section and has the outline in profiled. In the embodiment according to Figure 8, the core 2 has an elongated cross section. The rubber-like layer 3 has a constant thickness, so that it follows the cross-section of the core 2 and a strip-like bristle is obtained, which, for example, can only be provided on its narrow sides with a patterned profile 4 , in a manner very similar to that of figure 3. The bristle according to figure 9, once again has a core 2 and a rubber-like layer 3 with profiling 4 resulting from the stamping. As a var compared with the bristles previously described, the bristle 14 according to Figure 9 is corrugated transversely in the longitudinal extension. It is noted that in relation to this date, the best method known to the applicant to carry out the aforementioned invention, is that which is clear from the present description of the invention.

Claims (29)

CLAIMS Having described the invention as above, the content of the following claims is claimed as property:

1. A bristle, characterized in that it comprises a core of a comparatively rigid elastic bending plastic, and at least one layer of a rubber-like plastic, characterized in that the rubber-like layer is profiled against the core.

2 . The bristle according to claim 1, characterized in that the rubber-like layer is hot stamped against the core.

3. The bristle according to claim 1 or 2, characterized in that the rubber-like layer surrounds the core in a coating-like manner.

4. The bristle according to claim 1 or 2, characterized in that the rubber-like layer surrounds the core zonally.

5. The bristle according to one of claims 1 to 4, characterized in that the core comprises a plastic material that defines the resistance to bending and bending of the bristle, and a rubber-like layer with its profiling of a plastic material defining the surface of action of the bristle on the object as well as the resistance to wear.

6. The sow according to one of claims 1 to 5, characterized in that the core comprises a plastic material with a Shore D hardness> 45 and the rubber-like layer of a plastic material with a Shore D hardness < 35

7. The sow according to one of claims 1 to 6, characterized in that the core comprises a plastic material with a Shore D hardness> 65 and the rubber-like layer, a plastic material with a Shore 20 hardness < D < 35

8. The bristle according to one of claims 1 to 7, characterized in that the core is PE polyethylene, PP polypropylene or PA polyamide, and the rubber-like layer is made of a thermoplastic elastomer.

9. The bristle according to one of claims 1 to 8, characterized in that the rubber-like layer has circumferentially distributed and locally defined depressions.

10. The bristle according to one of claims 1 to 8, characterized in that the rubber-like layer has a profile in the extension direction of the bristle.

11. The bristle according to one of claims 1 to 8, characterized in that the rubber-like layer has a profile that extends transversely in the direction of extension.

12. The bristle according to one of claims 1 to 11, characterized in that a film-like coating of a soft plastic material which is attached to the profile is applied to the profiled rubber-like layer.

13. The sow according to one of claims 1 to 12, characterized in that the core is formed of a monofilament.

14. The sow according to one of claims 1 to 12, characterized in that the core is formed of several monofilaments.

15. The bristle according to one of claims 1 to 13, characterized in that the core has a non-circular cross-section.

16. The bristle according to one of claims 1 to 15, characterized in that the rubber-like layer has a cross section that differs from that of the core and in particular a circular cross-section.

17. The bristle according to claim 15, characterized in that the rubber-like layer has a cross section that follows that of the core.

18. The bristle according to one of claims 1 to 17, characterized in that the core with the rubber-like layer is corrugated transversely in the direction of extension of the bristle.

19. The sow according to one of claims 1 to 18, characterized in that the core has a corresponding surface structure or coating that acts as a primer for the rubber-like layer.

20. The process for producing a sow bristle material according to one of claims 1 to 19, characterized in that the core and the rubber-like layer are co-extruded as a continuous chain and, with the chain in motion, the similar layer rubber is profiled against the core by stamping.

21. The process for the production of a sow bristle material according to one of claims 1 to 19, characterized in that the core and the rubber-like layer are coextruded as a continuous filament, the filament is wound and the rubber-like layer it is profiled by unwinding the filament by stamping against the core.

22. The process for the production of bristles, according to one of claims 1 to 19, characterized in that the core and the rubber-like layer are coextruded as a filament, the bristle is cut to the length from the filament and subsequently the similar layer The rubber of the bristle is profiled by stamping against the core.

23. The process according to one of claims 20 to 22, characterized in that the rubber-like layer is profiled by means of stamping tools acting on one another.

24. The process according to claim 12 and 20 or 21, characterized in that the plastic filament is applied in a film-like manner to a soft plastic material by extrusion, dipping, spraying or shrinking onto a film.

25. The process according to claim 12 and 22, characterized in that a soft plastic material is applied to the profiled bristle by immersion, sprinkling or shrinking in a film in a film-like manner.

26. The bristle material, characterized in that it is produced by the process according to one of claims 20 to 25.

27. An interdental cleaner, characterized in that it has at least one sow according to one of claims 1 to 19.

28. A brush, characterized in that it has a plurality of bristles according to one of claims 1 to 19.

29. The brush in accordance with the claim 28, characterized in that the plurality of bristles have rubber-like layers profiled differently.