EP1030937B1 - Bristles or interdental consisting of a monofil - Google Patents

Description

The invention relates to bristles or interdental cleaners made of a monofilament with reduced secondary binding forces from at least two in geometrically regular Arrangement of coextruded polymers with interfaces running essentially in the axial direction for the production of bristles or interdental cleaners that by the action of mechanical forces essentially in Axis direction are slit. The invention is also based on a process for the production of bristles or interdental cleaners from such monofilaments and on bristle goods such bristles or aimed at interdental cleaners.

Bristles for bristle products of any kind, e.g. Brushes for Body and dental care, household brushes, technical brushes, Brushes and the like are mostly used today Polymers made by melting the polymer into continuous monofilaments extruded, the monofilaments stretched and, if necessary be stabilized. From such monofilaments the bristles are then cut to the desired length receive. As a rule, the monofilaments, like the Bristles, circular cylindrical cross section. For special ones Bristles with other, e.g. oval or polygonal cross section known. With a the corresponding profile, the monofilament is then extruded.

In many cases it is desirable to have bristles in one fibrous, especially fine-fibrous structure at the end of use use. This applies, for example, to such bristles were used to apply media Surfaces or the like are determined, e.g. Brush. Also then if a fluffy structure is desired, must the bristle should be fine-grained. More recently insights also gained in dental medicine, after which conventional bristles of toothbrushes in their Cleaning effects are inadequate since they are not in the fine fissures penetrate the tooth surface, but glide over them. The same applies to the cleaning effect in the interdental space.

To get highly fibrous structures is already have been proposed, the monofilament from polymer blends to extrude. The following effects are used: during the extrusion and subsequent stretching of the The polymer molecules become monofilament in the longitudinal direction of the Oriented to monofilament. The acting in the longitudinal direction primary binding forces ensure high tensile strength. The longitudinal orientation of the molecules also brings the desired bending elasticity. With monofilament from one the only polymer are the so-called secondary binding forces, namely the forces across the molecular extension big enough to fray or unravel to prevent the monofilament or bristle. at Monofilaments made from two different, mixed polymers however, arise between the molecular chains of the polymers while stretching sliding zones in which the secondary binding forces are reduced. Such one Monofilament or a bristle made from it can be by the action of mechanical forces by means of knife-like Shredding tools. The resulting So-called flags have a very irregular Shape, irregular cross sections and frayed Shell surfaces. In a larger association of such bristles becomes a fluffy and absorbent structure reached, however, the flags show uncontrolled Strength properties. They tear out, break off or lay down. Such are frayed bristles consequently unsatisfactory, even for many applications disabled. The use of toothbrushes is hygienic Reasons questionable.

A known embodiment has the same disadvantages a bristle (WO97 / 14830), which has a core and a Coat owns that by coextrusion of two different ones Polymers are made. On the usage side The end of the bristle is mechanically or chemically ablated to form a recessed pocket which should take up dentifrice or color. Further describes the formation of flags ("flags") which by shredding the material of the jacket, insofar as this tower over the core, be preserved. This fraying too takes place in a conventional manner by means of knives and guides therefore to the same irregular structures.

That is why they are especially useful for toothbrushes Bristles have been proposed from a variety thin fibers similar to textile fibers and one the fibers enveloping jacket exist (DE 94 08 268 U1). Coat and Fibers can also be co-extruded as filaments. After cutting to bristle length, the coat is on end of the bristle on the use side by mechanical processing or cutting away so that the fibers are on a exposed for a short length. Apart from the elaborate manufacture such bristles, they are only of limited use. The sudden change is particularly disadvantageous Change in the bending behavior at the transition from the fibers to the coat. Are such bristles in application equipment used, it can damage the surface due to of the hard transition. The same applies to the Use of such bristles in toothbrushes in terms of Effect on the teeth and gums. In addition, that the fibers are practically limp so that they become stronger Wells, interdental spaces or the like. Not or cannot penetrate sufficiently. The fibers also break with permanent wear on the edge of the coat slightly.

Interdental cleaners are also known (WO 96/39117), those made of co-extruded monofilaments in a geometric arrangement consist. Each monofilament consists of at least two polymer components, those in the interface between neighboring ones Monofilaments lead to reduced secondary binding forces. The secondary forces become due to tensile forces in the axial direction degrades and creates a multi-fiber fluffy Structure similar to that of dental floss.

In the case of textile fibers, it is known (US Pat. No. 3,117,362) to have sharp edges To produce structures with a silky sheen that different polymers, each with a suitable cross-sectional shape be co-extruded at their interfaces stick together and by adding a solvent, that dissolves one of the polymers.

The invention has for its object bristles or interdental cleaner from a monofilament propose at least two common extruded polymers. The slotted bristles or Interdental cleaners have reproducible strength properties and form definable according to number, shape and dimensioning Flags or slots. Furthermore, with the invention a method for producing bristles or interdental cleaners from such monofilaments are proposed become.

A bristle solving this task with the characteristics of The preamble of claim 1 is distinguished according to the invention in that the interfaces are boundary layers, in which are subject to the reduced secondary binding forces, and that the monofilament is a matrix from which the physical and chemical properties of the bristle or the interdental cleaner determining polymer, and that second polymer in the form of thinner interfaces Layers are embedded in the matrix.

The geometry of the boundary layers can be used to predict in what way the monofilament for an interdental cleaner, or cut to length from the monofilament bristles produced by the action of mechanical forces is slit or split. The slots or flags arise exactly in the geometry of the extrudate predetermined contour. Because the boundary layers are longitudinal of the monofilament, each owns Flag the same shape and same along its entire length Cross-section. All flags therefore have the same name Strength properties, in particular the same bending behavior and equal tensile strength. It is also possible by appropriate design of the geometry flags with different cross sections. Since that Monofilament or the bristle when subjected to mechanical forces exclusively and exactly slits in the boundary layers or splits, the flags can with appropriate Cross-sectional shape on the facing edges form that support the cleaning effect. Such a way split bristle is consequently on its outer surface also more effective than conventional bristles. by virtue of of congruent forms, the bristle does not spread too much on. In a tightly packed bundle of such bristles each bristle takes on a monofilament shape and that Flags only come about through axial or radial pressure full effect. This makes it easy to record media and give it back when applying by pressing.

In this way, the bristles according to the invention and their flags can be produced have the favorable properties of conventional bristles. On the other hand arise when splitting no fine parts or only to a small extent, so that the bristle also did not undergo extensive cleaning processes must become. Flagged bristles are defined or defines slotted monofilaments for interdental cleaners get where a progressive splitting or Slitting can be avoided.

The polymer of the matrix, as well as the thin layers can be a copolymer or a polymer blend. The The above-mentioned advantages are particularly optimal reached when the thin layers share a portion of the Polymers of the matrix included. In this case it breaks Polymer or the bristle when force is applied to the weakest point, namely in the middle of the thin Layers on, however, the adherence of the remaining layers due to the proportion of polymer corresponding to the matrix sufficient at the emerging neighboring flags large to avoid the formation of fine particles.

The thin layers preferably have a thickness of a few µm. Have practical extrusion attempts shown that such thin layers with the polymer let the matrix co-extrude.

In the thin layers, the two polymers can too about the same parts.

The specific execution of the geometry is determined by the desired Properties of the bristle or interdental cleaner certainly. So the thin layers in the Matrix extend to the extent of the monofilament, so that the Slotted monofilament with relatively little force or can be split.

Instead, it is possible that the thin layers in of the matrix end at a distance from the circumference of the monofilament. In in this case you need a little bit more force, but it is advantageous here that the resulting Flags also in the edge area from the matrix material exist, i.e. the same wear properties as the coat of the bristle or the flags has.

If necessary, the matrix of the monofilament can have a third have embedded polymer in the matrix, which in primarily to influence the strength properties the resulting flags.

As with bristles, the monofilament can usually be of a circular shape, but also one that deviates from the circular shape Have cross-section. Here are polygonal ones in particular To mention cross sections in their cleaning effect are more effective than round cross-sections.

In this case, the thin layers can go to the corners of the polygonal cross section, so that relative sharp edges with an edge angle of less than 90 ° arise.

Instead, the thin layers can also be added to the Faces of the polygonal cross-section run out, whereby then edges with an edge angle in the range of 90 ° can be realized.

In a preferred embodiment, the matrix consists of polyamide and the thin layers of a polyolefin, especially polypropylene or polyethylene. This pairing of materials shows sufficiently large at the interfaces Secondary binding forces to prevent tearing open or slots during processing and use of the To prevent bristles. With strong and targeted force however, the polymer composite tears open.

The process according to the invention for the production of bristles from the previously described monofilament according to the invention in that the at least two Polymers co-extruded into the monofil, the monofil stretched and, if necessary, stabilized, the monofilament is cut to the desired length of the bristles and the bristle at its use end by action mechanical forces transverse to the bristle axis on a limited Length is split along the boundary layers. Instead, both can be used to make bristles interdental cleaners can also be used in such a way that which coextrudes the at least two polymers to the monofilament and that the monofilament after extruding, stretching and optionally stabilization by action mechanical forces transverse to the monofil axis on local limited length slotted along the boundary layers becomes. The method according to the invention can be used form fissure-like slits on the jacket of the monofilament, that can be used to hold media. For toothbrushes or interdental cleaners come in particular for this Dental care products or dental medicine or antibacterial Preparations in question. Otherwise the monofilament is preserved Interdental cleaner on the jacket through the slit increased roughness.

The interdental cleaners according to the invention can be made from the aforementioned monofilament produce in any length. The same measure can of course also on the bristle cut to length from the monofilament be made. Here, the location of the slit and the expansion of the slots to the length of the bristle be matched to split the bristle end either to avoid or to specifically promote. For example, only the bristle end can be split. The slits still made in the jacket can after the flags have worn down to further split the Bristle serve. Depending on the type and number of stored Layers create a corresponding number of flags at the end of use of the bristle.

In the case of processing the monofilament into an interdental cleaner any length is according to a variant of the Procedures provided that the monofilament during or after the action of mechanical forces in the axial direction is compressed. This will make the slotted Areas or the webs delimiting the slots on Monofilament jacket bulged outwards.

The mechanical forces are preferably on the most of the circumference of the monofilament or bristle applied to ensure that all boundary layers of the polymers are applied.

The slitting of the monofilament or the splitting of the bristles is preferably done by striking forces. Instead can also use crushing or torsional forces to be brought. These forces can be tailored to the Bristle or at the same time on groups of bristles, e.g. on bundles of bristles, before or after their attachment take effect on the bristle holder of the brush.

The bristles are preferably on their usage side Ends rounded. This can be done before and / or after splitting happen. In a further preferred embodiment of the method become the multiple that arise after splitting Ends with a length that visually indicates the usable length Mark it. This signals to the user that after the bristle wears down to the mark, So after the split ends wear out, the Change use properties abruptly, because then the much more rigid cross section of the entire bristle comes into effect. Also the split ends ever shorter and therefore mechanically more aggressive. A such notification is particularly advisable if it are toothbrushes, body care brushes or the like.

Fig. 1 bis Fig. 5

verschiedene Querschnitte eines Monofils;

Fig. 6

eine Ansicht einer Borste mit gespaltenem, nutzungsseitigem Ende,

Fig. 7

eine Ansicht einer Borste bzw. einem Interdentalreiniger mit geschlitztem Mantel;

Fig. 8

eine weitere Variante eines Monofilquerschnitts und

Fig. 9

eine Ansicht eines Interdentalreinigers in einer abgewandelten Ausführung.

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

1 to 5

different cross sections of a monofilament;

Fig. 6

a view of a bristle with a split end on the usage side,

Fig. 7

a view of a bristle or an interdental cleaner with slotted jacket;

Fig. 8

another variant of a monofilament cross section and

Fig. 9

a view of an interdental cleaner in a modified version.

1 has a circular shape Cross section on and is by coextruding at least produced two polymers. It consists of one Matrix 2 from one that determines the properties of the bristle Polymer and in geometric form - in this case in the form of a cross-embedded thin layers 3, made of another polymer or a mixture with the Polymer of matrix 2 exist. In the area of thin Layers 3 or the interfaces to the matrix 2 are the secondary binding forces, i.e. the binding forces greatly reduced across the length of the monofilament. In the embodiment shown, the thin ones run Layers 3 on the outer surface 4 of the monofilament. she but can also end at a short distance from it.

In particular, polyamides come as polymers for the matrix 2 (PA) in question, while the thin layers 3 for example from a polymer mixture PA / PP or PA / PE consist.

2 are the thin ones Layers 3 in the form of a three-armed star Matrix 2 stored, while Fig. 3 with a monofilament 1 polygonal, namely triangular cross section. at this embodiment run the stored thin layers, which can also be seen from the center extend outside, in the corners of the polygon. Instead you can of course also on the areas between end the corners.

4 is with the Matrix 2 of monofilament 1 is yet another of several possible polymers extruded in such a way that it is completely embedded in the matrix. For example it is thread-like structures 5, which according to the manufacture of the bristle and the splitting or slitting the same the bending behavior or the strength of the influence emerging flags.

Fig. 5 shows a flat rectangular monofilament 1, in which the thin layers 3 are laid out like a grid, so that from the monofilament a variety of essentially rectangular ones Flags can be generated. Fig. 8 shows finally a monofilament cross section in which the matrix 2 from four identical outer parts with the cross section of circular sectors and a central core that delimited by correspondingly extending thin layers 3 are.

In Fig. 6, a bristle 6 is shown schematically, which consists of a monofilament, for example according to FIG. 2, by cutting to length manufactured and by the action of mechanical forces its end of use is split up, so that individual Flags 7 arise, the shape of the shape of which Matrix 2 forming areas of the monofilament corresponds. It As many flags are created as the Matrix 2 by thin ones Layers 3 is broken down. The usage length of the Flags can be shown, for example, by the one shown in FIG The dash must be optically marked.

7 are the mechanical forces on the surface of a monofilament at regular intervals or with a cut Bristle at a distance from the end on the usage side to the effect brought. Due to the thickness of the layers and the size of the Force and / or frequency / frequency of their application can be achieved that the jacket of the monofilament or Bristle 6 tears open only to a locally limited length Form slots 8, 9 and 10. These slots are approximately in one flight, namely in those through the thin layers 3 areas formed. Tear in this version the slots at the bristle end forming flags on. Form as the bristle wears out the flags keep on following.

A monofilament according to FIG. 7 can also be of any length Interdental cleaners ("floss") serve the slits Take up dentifrices, antiseptics or antibactericides can. Recommended for an interdental cleaner itself to axially compress the monofilament, as shown in Fig. 9 shows that the webs 10 delimiting the slots bulge outward from the matrix polymer.

The matrix 2 or the polymer forming it can in the individual cross-sectional parts delimited by the thin layers be different colors.

Claims (29)

1. Bristles (6) or interdental cleaner made from a monofilament (1) with reduced secondary binding forces from at least two polymers commonly extruded in regular geometric configuration having bordering surfaces extending substantially in the axial direction, wherein the of bristles (6) or interdental cleaners can be substantially axially split by the action of mechanical forces, characterized in that the monofilament has a matrix (2) of a first polymer determining physical and chemical characteristics of the bristle (6) or of the interdental cleaner and a second polymer which is embedded into the matrix in the form of thin bordering layers (3), wherein the reduced secondary forces are present in the bordering layers (3) and the bristles (6) or interdental cleaner can be slit in the bordering layers.
2. Bristles or interdental cleaner according to claim 1, characterized in that the matrix comprises a copolymer or a polymer blend.
3. Bristles or interdental cleaner according to claim 1 or 2, characterized in that the thin layers in the matrix comprise a copolymer or a polymer blend.
4. Bristles or interdental cleaner according to claim 1 or 2, characterized in that the polymer of the thin layers comprise a portion of the polymer in the matrix.
5. Bristles or interdental cleaner according to claim 4, characterized in that the two polymers are present in roughly equal parts in the thin layer.
6. Bristles or interdental cleaner according to claim 1 to 5, characterized in that the thin layers have a thickness of a few µm.
7. Bristles or interdental cleaner according to claim 1 to 6, characterized in that the thin layers in the matrix extend up to the ci rcumference of the monofilament.
8. Bristles or interdental cleaner according to claim 1 to 6, characterized in that the thin layers in the matrix terminate at a distance from the monofilament circumference.
9. Bristles or interdental cleaner according to claim 1 to 8, characterized in that the monofilament matrix has a third polymer incorporated into said matrix.
10. Bristles or interdental cleaner according to claim 1 to 9, characterized in that the polymer of the matrix and that of the thin layers have different colors.
11. Bristles or interdental cleaner according to claim 1 to 10, characterized in that the monofilament has a cross-section diverging from the circular shape.
12. Bristles or interdental cleaner according to claim 11, characterized in that the monofilament has a polygonal cross-section.
13. Bristles or interdental cleaner according to claim 12, characterized in that the thin layers run out to the corners of the polygonal cross-section.
14. Bristles or interdental cleaner according to claim 12, characterized in that the thin layers run out to the surfaces of the polygonal cross-section.
15. Bristles or interdental cleaner according to claim 1 to 14, characterized in that the matrix comprises a polyamide and the thin layers a polyolefine.
16. Method for producing bristles from monofilaments according to one of the claims 1 to 15, characterized in that the at least two polymers are coextruded into the monofilament, the monofilament is stretched, optionally stabilized and is cut to bristles of a desired length, the bristles are split at their use ends transverse to the axis of the bristle along the boundary layers through a limited length by the action of mechanical forces.
17. Method for producing bristles or interdental cleaners from monofilaments according to one of the claims 1 to 15, characterized in that the at least two polymers are coextruded to a monofilament, said monofilament is stretched and optionally stabilized and is slit transverse to the axis of the monofilament along the boundary layers through a locally limited length for forming short slits, under the action of mechanical forces.
18. Method according to claim 17, characterized in that the monofilament is compressed in its axial direction during or after the action of the mechanical forces.
19. Method according to claim 16 to 18, characterized in that the mechanical forces act on a greater part of the circumference of the monofilament or bristle.
20. Method according to claim 16 to 19, characterized in that the monofilament or bristle is split or slit by impact forces.
21. Method according to claim 16 to 19, characterized in that the monofilament or bristle is split or slit by squeezing forces.
22. Method according to one of the claims 16 to 19, characterized in that the monofilament or bristle is split or slit by torsional forces.
23. Method according to claim 16 to 22, characterized in that, prior to splitting, the use-side end of the bristle is rounded.
24. Method according to one of the claims 16 to 23, characterized in that, after splitting, the use-side end of the bristle is rounded.
25. Method according to one of the claims 16 to 24, characterized in that the several flags of the bristle resulting from splitting are provided at a distance from their ends with a marking optically indicating the usable length.
26. Brushware, comprising a bristle carrier and bristles fixed thereto, wherein at least a part of the bristles are produced from a monofilament according to one of the claims 1 to 15 by a method according to one of the claims 16 to 25.
27. Brushware according to claim 26, characterized in that the several ends of the split bristles have a marking indicating their usable length.
28. Brushware in the form of a interdental cleaner, produced from a monofilament according to one of the claims 1 to 17 by a method according to claim 19 or 20, characterized in that the interdental cleaner is slit at equal distances about its circumference.
29. Brushware according to claim 28, characterized in that the interdental cleaner is bulged in the area of the slits.

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