EP1073353B1 - 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

The invention relates to a bristle consisting of a Core made of a comparatively hard, flexurally elastic Plastic and at least one profiled layer a rubber-elastic plastic. Furthermore, the Invention a method for producing such bristles and devices equipped with such bristles.

Regardless of the particular use of a brush some basic requirements are placed on bristles. These include in particular the bending elasticity, kink resistance and wear resistance. More and often very different requirements result from the use the brush. For example, brushes for oral and personal care should be soft enough to Avoid injuries while being abrasive technical brushes have hard and rough bristles should. Other technical brushes, such as car wash brushes, on the other hand, in turn, must be smooth and smooth. This also applies to polishing brushes. Brushes or paint brushes used for Applying media to serve must be relatively closely related Have bristles for storing the medium while in other applications, stand-alone bristles or Bristle bundles are desired.

The effect of a bristle on the surface of the to be treated or the object to be processed depends significantly of their own surface quality and of that Bristle material. Usually bristles are made extruded plastic monofilaments. By Selection of the plastic can be essentially only the Bending and wear resistance, but only in very little Scope the surface quality and effectiveness affect the surface once one of simple Longitudinal profiles. It therefore has the status of There is no lack of technology in trials, the surface quality or the effectiveness of the surface of To change bristles by additional measures to the to better meet the respective purpose.

In the bibliography attached to the description describe (1) to (8) bristles with embedded, abrasive particles for different Uses. This is always about Bristle to give a hard, abrasive effect.

Another development shown in (9) to (15) goes there, the one formed from a plastic monofilament Bristle on her coat in different types and Way to profile. It is always about training from more or less sharp edges to frayed Structures.

All of the above solutions with particle-filled or profiled, monofilament bristles have the decisive one Disadvantage that the strength properties, in particular the bending elasticity, the kink resistance and also wear resistance, deteriorate noticeably, so that larger bristle diameters and / or higher quality Plastics must be used. This is but often not for technical reasons possible and also leads to an undesirable increase in price.

Other known suggestions in (16) to (21) are to make the bristle from two plastic components, namely a plastic core and one attached to it Coating either in the form of an envelope enveloping the core Coat or in the form of applied to the core Fibers. In these known solutions, the Strength properties of the bristle essentially controlled. As far as the core is a smooth-walled coat has (16), (17), the effect of the bristle but only slightly modify it. It's just the hard one Profiled core and a rubber elastic following the profile Layer applied (18), the latter to the Elevations of the profile are quickly removed and the hard one Core exposed. As far as flocked fibers on the core (20), the bristle can only be used for certain purposes are used and is their manufacture complex and expensive.

Among the latter proposals is one in (21) Bristle suggested that from an extruded, relative rigid core made of PA (polyamide) or high-density PE (polyethylene) and a soft thermoplastic layer natural or synthetic rubber. This Known bristle is designed for toothbrushes thanks to the soft rubber-elastic coating in the first Line a gentle treatment of the teeth and gums should be ensured while the rigid core for the necessary strength properties of the bristle provides. However, such a bristle does not meet that of Clean requirements because their surface too is smooth. Nor is it suitable for putting media on one To apply object.

Bristles are also known (DE 195 33 815 A1) consist of a core and ribs arranged on it, obtained a spiral profile by twisting becomes. Another known bristle (US 5,137,039 A1) consists of a comparatively hard core and a softer coat that profiles along coat lines, i.e. is provided with longitudinal ribs. This document says nothing about how the bristle and the profiling getting produced. It also slides between the ribs absorbed medium quickly in the longitudinal direction of the bristle out.

The invention is based on this prior art the task of creating a bristle that while maintaining the necessary strength properties with a soft surface nevertheless a good cleaning effect and media receptivity.

Starting from a bristle that consists of a core of a comparatively hard, flexible plastic and at least one profiled layer made of an elastic rubber Plastic is made (US 5,137,039 A1) this object achieved in that the rubber-elastic layer by embossing against the core, is preferably profiled by hot stamping.

The invention is based on the surprising finding that a rubber-elastic plastic, e.g. a thermoplastic Elastomer, even with a very thin thickness with bristles and toothbrushes is in the range of a few tenths of a millimeter Embossing can be profiled without a provision of the rubber-elastic plastic is to be determined, whereby the relatively hard core plays a significant role, against which the embossing forces are applied. Leave it fine to rough structures in any Realize design. You choose shallow tread depths especially for bristles for mouth and body care, larger profile depths, however, with cleaning brushes or Order brushes to get dirt in the first case, in the second Case record order media.

The rubber-elastic layer can be core-shaped or only partially surrounded and can by Embossed profile along the entire length the bristle or only provided on part of the same his.

In the bristle designed according to the invention there is The core of the bristle is resistant to bending and kinking determining plastic and the rubber-elastic layer with their profiling from a surface effect the bristle on the object and determining the wear resistance Plastic. By choosing the two plastics and the type of profiling can be any bristle Adjust requirements easily.

In a preferred embodiment, the core consists of a Plastic with a Shore hardness D> 45 and the rubber elastic Layer of a plastic with a Shore hardness D <35th In a particularly preferred embodiment, the Shore hardness of the plastic for the core at D> 65 and the the rubber-elastic layer at 20 <D <35. Materials that meet the aforementioned requirements are, for example for the core PE (polyethylene), PP (polypropylene) or PA (polyamide) and for the rubber elastic Layer of thermoplastic elastomers.

The profiling of the rubber-elastic layer can distributed, locally delimited depressions be educated. Instead, the profiling also in the direction of extension of the bristle, for example run along surface lines or helically. Finally, the profiling can also be predominantly transverse be oriented to the direction of extension of the bristle.

According to a further feature of the invention, the profiled rubber-elastic layer itself Profile conforming, film-like layer of a soft Plastic applied. This can affect the profile a certain smoothing effect can be achieved without taking away the surface effect from the profiling.

The core can be formed from one or more monofilaments his. The first version is recommended for Tooth and body brushes, the latter version at technical brushes, especially for car wash brushes. In this application, the bristles have to be limp be on the one hand the contour of the to be cleaned Optimally lay out area, on the other hand the surface easy to clean. These bristles wear out a lot quickly from the free end. This means according to the invention trained bristle that the rubber elastic Layer is removed first at the bristle ends. at the inventive training with several core monofilaments these are exposed in the form of fibers, which then compared to a single core monofilament of larger diameter still ensure gentle treatment.

Bristles usually have a circular cross section. In the training according to the invention, however any other bristle cross-section can be realized, by the core being different from the circular shape Cross-section, e.g. a narrow rectangular or cross-shaped or star-shaped cross-section. The rubber elastic Layer can then nonetheless be circular Have cross-section so that they are different Has thickness and in the thicker areas for example can be shaped more deeply. Instead, it can also a cross section following the cross section of the core have so that regardless of the location of the embossing equal depth profiles can be generated, whereby also here the core again acts as an abutment.

Finally, the entire bristle can be made of core and more elastic Layer transverse to the direction of extension of the Bristle be wavy.

Good adhesion of the rubber-elastic layer on the The core is formed by a surface structure that acts as an adhesion promoter preserved at the core.

To make the bristle described above the invention proposes a method in which the core and the rubber-elastic layer coextruded as a strand and the rubber-elastic layer while running Is profiled by embossing against the core.

With this process, an endless bristle material becomes obtained from which the bristles immediately after embossing can be cut to length on request. Instead, can the bristle material can also be spooled and only on the occasion the brush manufacture the bristle from the unwound The strand can be cut to length as required.

Another variant of the method is that the core and the rubber-elastic layer as endless The strand can be coextruded, the strand wound and the rubber-elastic layer when unwinding the strand Embossing is profiled against the core. With this procedure can emboss at the manufacturer of the bristle material or only at the brush manufacturer. This Procedure can also be recommended if the rubber elastic Layer of a slowly cross-linking elastomer exists and the embossing process only after the completion of Crosslinking reaction should be carried out.

In this process, the rubber-elastic layer preferably by means of one another and against the core effective stamping tools profiled, the stamping tools can create different profiles. It can only one-sided profiling can be provided, then the embossing tool with an unprofiled Counter tool works together.

In a further embodiment of the method according to the invention can on the profiled strand on the occasion of the Production of the bristle material or before cutting to length the bristles a soft plastic film-like by extrusion, Dip, spray or shrink-wrap a film be applied, for example, to the profile smooth.

In another execution of the method, the Core and the rubber-elastic layer coextruded as a strand, then cut the bristle from the strand and then the rubber-elastic layer by embossing profiled against the core. With this procedure the film-like layer before or after cutting to length Dip, spray or shrink-applied a film become.

The bristle designed according to the invention is for devices of various types can be used. In the simplest case Such bristle can be used directly as an interdental cleaner can be used, either in the form of a Sticks or similar to a floss.

In contrast, a brush with a plurality of Bristles designed according to the invention, wherein the bristles can be provided in separate arrangements can. In particular, such a brush can have bristles differently profiled, rubber-elastic layers exhibit.

Below is the invention based on some in the Drawing of schematically represented exemplary embodiments described, each a bristle in perspective Show cross-sectional view.

1 has a core 2 made of a flexible and kink-resistant plastic, e.g. PA, PP or PE, and a shell 2 surrounding the core rubber-elastic layer 3, for example from a thermoplastic elastomer. In the rubber elastic Layer 3 is a profile 4 in the form of locally delimited, indentations 5 distributed on the circumference. The embossing takes place against the hard core 2.

2 is the bristle 1 only over part of its length with that shown in Fig. 1 Profile coined while remaining along the length 6, for example the attachment-side end of the Includes bristle, is not profiled. Otherwise there is they in turn consist of a core 2 made of a hard plastic, the rubber-elastic layer 3 with the embossed Wells and one covering the profiling film-like layer 7, which conforms to the profiling, but with a certain smoothing effect brings. 3 there is Bristle, in turn, consists of a core 2 and a region only applied rubber elastic layer 3. This namely runs on the core 2 in the form of longitudinal ribs, which are profiled by cross-stamping, so that depressions 8 and wart-like elevations 9 arise.

4 is the rubber elastic Layer 3 longitudinally profiled on the core 2, the profile being produced by coining after coextrusion becomes. In addition, the rubber-elastic layer 3 depressions obtained by embossing similar to those in FIG. 1 and 2 or transverse embossings as in FIG. 3 exhibit.

While in the exemplary embodiments according to FIGS. 1 to 4 at least the core has a circular cross section Fig. 5 is a bristle, the core 2 a cross-shaped Cross section 10, while the rubber elastic Layer 3 has a circular cross-section. So it is in the area of the ends of the bars of the cross section 10 thinnest. This makes sharp abutments formed against which the profile - as with the arrows 11 indicated - can be shaped particularly well.

6, the bristle has 1 in turn a core 2 with a circular cross-section. The him enveloping rubber-elastic layer 3 is with a wave profile 12 coined.

FIG. 7 shows an embodiment modified compared to FIG. 1, by the core 2 consisting of four monofilaments 13, that can be in parallel or twisted. The rubber-elastic layer 3 in turn surrounds the core 2 a circular cross section and points to it Coat the embossed profile.

8, the core 2 an elongated cross section. The rubber elastic Layer 3 is provided with a constant thickness, so that it follows the cross section of the core 2 and a band-shaped bristle is obtained, for example, only similar on its narrow sides with an embossed profile 4 which is provided in Fig. 3.

9 in turn has a core 2 and a rubber-elastic layer 3 with one by embossing obtained profiling 4. As a variation on The bristle 14 is in accordance with the previously described bristles Fig. 9 corrugated transversely to the longitudinal extent.

State of the art publications

1) DE 322 089 A

2) US 2,642,705

3) DE 1 014 964 B

4) DD 32 963 A.

5) GB 1 327 329 A.

6) FR 2 546 097 A

7) EP 0 354 352 A.

8) WO 93/18891 A

9) US 2,110,371 A.

10) US 2,317,485 A

11) US 3,325,845 A.

12) US 4,373,541 A.

13) DE 3 116 189 A

14) US 5,678,275 A

15) DE 1 140 901 B

16) DE 1 037 434 B

17) DE 83 00 846 U

18) US 3,090,061 A.

19) US 4,627,950 A.

20) DE 3 717 475 C

21) US 4,263,691 A

Claims (28)

1. Bristle, comprising a core of a comparatively hard, bending-elastic plastic and at least one layer of a rubber-elastic plastic, characterized in that the rubber-elastic layer (3) is profiled by stamping against the core (2).
2. Bristle according to claim 1, characterized in that the rubber-elastic layer (3) is profiled by hot stamping against the core (2).
3. Bristle according to claim 1 or 2, characterized in that the rubber-elastic layer (3) surrounds the core (2) in jacket-like manner.
4. Bristle according to claim 1 or 2, characterized in that the rubber-elastic layer (3) zonally surrounds the core (2).
5. Bristle according to one of the claims 1 to 4, characterized in that the core (2) comprises a plastics material defining the bending and flexural strength of the bristle (1) and the rubber-elastic layer (3) with its profiling (4) a plastics material defining the surface action of the bristle (1) on object and the resistance to wear.
6. Bristle according to one of the claims 1 to 5, characterized in that the core (2) comprises a plastics material with a Shore hardness D>45 and the ruber-elastic layer (3) a plastics material with a Shore D<35.
7. Bristle according to one of the claims 1 to 6, characterized in that the core (2) comprises a plastics material with a Shore hardness D>65 and the rubber-elastic layer (3) a plastics material with a Shore hardness 20<D<35.
8. Bristle according to one of the claims 1 to 7, characterized in that the core (2) is of PE (polyethylene), PP (polypropylene) or PA (polyamide) and the rubber-elastic layer (3) of a thermoplastic elastomer.
9. Bristle according to one of the claims 1 to 8, characterized in that the rubber-elastic layer (3) has circumferentially distributed, locally defined depressions (5).
10. Bristle according to one of the claims 1 to 8, characterized in that the rubber-elastic layer (3) has a profile (8, 9) in the extension direction of the bristle (1).
11. Bristle according to one of the claims 1 to 8, characterized in that the rubber-elastic layer has a profile extending transversely to the extension direction (8, 9).
12. Bristle according to one of the claims 1 to 11, characterized in that to the profiled, rubber-elastic layer (3) is applied a film-like coating (7) of a soft plastics material which clings to the profile (4).
13. Bristle according to one of the claims 1 to 12, characterized in that the core (2) is formed from a monofilament.
14. Bristle according to one of the claims 1 to 12, characterized in that the core (2) is formed from several monofilaments (13).
15. Bristle according to one of the claims 1 to 13, characterized in that the core (2) has a non-circular cross-section (10).
16. Bristle according to one of the claims 1 to 15, characterized in that the rubber-elastic layer (3) has a circular cross-section differing from the cross-section of the core (2).
17. Bristle according to claim 15, characterized in that the rubber-elastic layer (3) has a cross-section following that of the core (2).
18. Bristle according to one of the claims 1 to 17, characterized in that the core (2) with the rubber-elastic layer (3) is corrugated transversely to the extension direction of the bristle (1).
19. Bristle according to one of the claims 1 to 18, characterized in that the core (2) has a surface structure or a corresponding coating acting as a primer for the rubber-elastic layer (3).
20. Process for the production of bristle material for bristles according to one of the claims 1 to 19, characterized in that the core and the rubber-elastic layer are co-extruded as a continuous strand and, with the strand moving, the rubber-elastic layer is profiled against the core by stamping.
21. Process for the production of bristle material for bristles according to one of the claims 1 to 19, characterized in that the core and the rubber-elastic layer are co-extruded as a continuous strand, the strand is wound and the rubber-elastic layer is profiled on unwinding the strand by stamping against the core.
22. Process for the production of bristles according to one of the claims 1 to 19, characterized in that the core and the rubber-elastic layer are co-extruded as a strand, the bristle is cut to length form the strand and subsequently the rubber-elastic layer of the bristle is profiled by stamping against the core.
23. Process according to one of the claims 20 or 22, characterized in that the rubber-elastic layer is profiled by means of stamping tools acting against one another.
24. Process according to claim 12 and 20 or 21, characterized in that to the profiled strand is applied in film-like manner a soft plastics material by extrusion, dipping, spraying or the shrinking on of a film.
25. Process according to claim 12 and 22, characterized in that to the profiled bristle is applied in film-like manner a soft plastics material by dipping, spraying or shrinking on a film.
26. Interdental cleaner having at least one bristle according to one of the claims 1 to 19.
27. Brush having a plurality of bristles according to one of the claims 1 to 19.
28. Brush according to claim 27, characterized in that the plurality of bristles have differently profiled, rubber-elastic layers.

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