CN1105198C - Monofil for prodcing bristles or interdental cleaning elements, and bristle products with bristles of this type and interdental cleaning elements - Google Patents

Abstract

Consisting of at least two coextruded polymers with reduced secondary cohesion, used for the manufacture of bristles or interdental cleaners, which can be slit substantially axially by the action of mechanical force Carry out like this in order to obtain definite cut or flag-shaped part in monofilament, make monofilament have at least one kind of polymer that can determine the physical and chemical properties of mane or interdental cleaner, and at least another kind of filler at least one thin layer of polymer incorporated into said matrix, said at least one thin layer having a reduced secondary binding force compared to the secondary binding force of the polymer matrix.

Description

Monofilaments for and for the manufacture of bristles or interdental cleaners, and bristle articles and interdental cleaners made from such bristles

technical field

The present invention relates to a composition for the manufacture of bristle or interdental cleaners, consisting of at least two polymers co-extruded in a regular geometric arrangement with substantially axially distributed boundary surfaces, with reduced A monofilament of secondary binding force, which can be cut substantially along the axial direction by the action of mechanical force. The invention further relates to a method for the manufacture of bristles or interdental cleaners composed of such monofilaments as well as bristle articles and interdental cleaners comprising such bristles.

Background technique

Bristles for any kind of bristle products, such as body and dental brushes, household brushes, industrial brushes, hairbrushes, etc. are currently mainly made of polymers, as long as the polymer melt is extruded into endless Monofilaments are stretched and if necessary stabilized. Bristles are then obtained from this monofilament by cutting to the desired length. Usually the monofilaments have a round (cylindrical) cross-section like a bristle. Other bristles with, for example oval, polygonal cross-sections are also known for special applications. The monofilaments are then extruded with the corresponding profile.

In many cases it is desirable that the end bristles used have a fibrous, in particular fibrous, structure. This applies, for example, to bristle articles, such as brushes, which are intended to apply media to surfaces or the like. If a fleece-like structure is desired, the bristles must be fine-fiber. It has recently become a popular opinion in dentistry that the bristles of ordinary toothbrushes are deficient in their cleaning action, since they do not enter the fine crevices of the tooth surface, but glide over them. The same is true for the cleaning effect in the interdental spaces.

In order to obtain a strong fiber structure, it has already been proposed to extrude monofilaments from polymer mixtures. The effect here is utilized that the polymer molecules are oriented in the longitudinal direction of the monofilament during extrusion and subsequent drawing of the monofilament. The primary bond in the machine direction provides high tensile strength. Second, the orientation of the molecules in the longitudinal direction brings about the desired bending elasticity. In monofilaments composed of only one polymer, the so-called secondary bonding forces, ie the forces perpendicular to the direction of molecular extension, are also sufficiently high to prevent the monofilaments or bristles from disintegrating into fibers or splitting. In contrast, in monofilaments composed of two different, blended polymers, during stretching, slip zones form between the polymer molecular chains, in which zones the secondary bonding forces are reduced. This monofilament or the bristles made of it can be dispersed into fibers by means of a knife-shaped tool by the action of mechanical force. The resulting so-called flags ("flags") have a very irregular shape, irregular cross-section and wispy outer shell faces. Larger tufts of such bristles achieve a plush and well-absorbent structure, but the flags have unmanageable strength properties. It is prone to tearing, dropping or lodging (umlegen). Such fiber-dispersed bristles are therefore unsatisfactory and even useless for many applications. Use in toothbrushes is conceivable for hygienic reasons.

The known structure of a kind of bristle (WO 97/14830) has the same disadvantage, it has a core and a shell, and they are made by co-extrusion of two different polymers. The core material is mechanically or chemically removed at the used ends of the bristles to form deepened pockets that can hold tooth care agents or paints. Next, the formation of the flag ("flag") is described, which is obtained by dispersing the skin material into fibers - which generally protrude from the core. This dispersion into fibers takes place in the usual way with the aid of a knife, thus resulting in the same irregular structure.

Therefore, especially for toothbrushes, a bristle has been proposed, which consists of many fine fibers similar to textile fibers and a sheath layer surrounding the fibers (DE 9408268 U1). Also the sheath and fibers can be co-extruded as filaments. After cutting to bristle length the sheath at the use end of the bristle is removed by machining or cutting, leaving a short length of fiber exposed. In addition to the high cost of manufacturing such bristles, its applications are limited. A big disadvantage is the abrupt change in the bending properties especially at the interface from the fiber to the outer shell. If this bristle is used for a brushing tool, it can cause surface damage due to the hard transition. The bristle works equally well on the teeth and gums for toothbrush applications. In addition, the fiber is practically bent and loose, so that it cannot or cannot penetrate deep depressions, interdental spaces, etc. sufficiently. The fibers at the edge of the shell layer are also easy to break off under the condition of long-term stress.

Secondly a kind of interdental cleaner (WO 96/391117) is known, and it is made up of the monofilament that compound extrudes by certain geometric arrangement. Each monofilament is composed of at least two polymer components which lead to reduced secondary bonding forces in the boundary surfaces between adjacent monofilaments. The secondary bonding forces are eliminated by pulling in the axial direction and a multi-fiber long-pile structure similar to dental floss is formed.

It is known (US-A-3 117 362) on textile fibers that a sharp-edged structure with silk luster is produced by co-extruding different polymers with suitable cross-sectional shapes, which are attached to each other on the boundary surface and are separated by the addition of a solvent that dissolves one of the polymers.

Contents of the invention

The object of the present invention is to propose a monofilament consisting of at least two coextruded polymers which is suitable for the manufacture of flags with reproducible strength properties and which can be defined in terms of number, shape and size Or incisional bristles or interdental cleaners. Secondly, the invention should propose a method for producing bristles or interdental cleaners composed of such monofilaments.

In order to achieve the above objects, the present invention provides a polymer with substantially axially distributed boundary surfaces for the manufacture of bristles or interdental cleaners, at least two co-extruded in a regular geometric arrangement Consisting monofilaments with reduced secondary cohesion, which can be cut substantially axially by the action of mechanical forces, characterized in that said monofilaments have at least one material capable of determining bristles or The physical and chemical properties of the interdental cleaner in the form of a matrix, and at least one other polymer in the form of at least one thin layer filled in said matrix, compared with the secondary bonding of the polymer matrix, The at least one thin layer has reduced secondary bonding.

The geometry of the boundary layer can be predetermined, for example in what way the monofilaments for the interdental cleaner or the bristles produced from the monofilaments by cutting are notched or split by the action of mechanical forces. Just form a cut or flag with a profile determined by the geometry of the extrudate. Because the boundary layer extends longitudinally of the monofilaments, each flag has the same shape and the same cross-section throughout its length. All flags therefore also have the same strength properties, in particular the same bending properties and tensile strength. However, it is also possible to produce flags with different cross-sections by correspondingly designing the geometry. Since the monofilaments or bristles under the action of mechanical forces cut or split only and exactly at the boundary layer, the flag forms, with a corresponding cross-sectional shape, edges on the surfaces facing each other which facilitate the cleaning effect. Thus split bristles are also more effective than normal bristles on their outer surface. Due to the perfectly equal shape the bristles do not split excessively. In a bundle of such bristles, each bristle again assumes the monofilament-like shape, and the flags can only fully function through axial or radial pressure. As a result, the medium can be well contained and released again by pressing during application.

In this way it is possible to produce bristles whose flags have the advantageous properties of conventional bristles. On the other hand, no fine particles are formed during splitting, or only a small amount is formed, so that the bristles do not have to be subjected to extensive cleaning procedures. The result is a bristle that is definitely divided into flags or a monofilament for an interdental cleaner that is definitely notched, wherein further splitting or notching can be avoided.

The matrix, and also the sheet polymer, can be a copolymer or a polymer mixture. The above-mentioned advantages are best achieved if the thin layer contains a constituent of the matrix polymer. In this case the polymer or the bristles are torn apart under the action of the force at the weakest point, approximately in the center of the thin layer, but due to the formation of adjacent flags corresponding to the polymer of the matrix The adhesion of the remaining layer of ingredients is sufficiently great to avoid the formation of fine particles.

The thin layer preferably has a thickness of a few μm. Practical extrusion tests have shown that such thin layers can be co-extruded with the matrix polymer.

Both polymers may be present in approximately equal amounts within the layer.

The specific geometry is determined by the desired properties of the bristles or interdental cleaner. For example, the thin layer can extend within the matrix up to the periphery of the monofilaments, so that the monofilaments can be cut or split with little effort.

Instead of this, it is also possible for the thin layer to terminate within the matrix at a distance from the periphery of the monofilament. In this case a slightly greater force is required, but there is the advantage that even the flag formed in the edge region consists of a base material, that is to say has a sheath with the bristles or the flag The same wear resistance as the surface.

The matrix of the monofilaments can optionally have a third, matrix-filled polymer, which serves primarily to influence the strength properties of the formed flag.

As usual with bristles, the monofilaments can be circular, but can also have a cross-section other than circular. Special mention should be made here of polygonal cross sections, which are more effective in their cleaning action than circular cross sections.

In this case, the thin layer can terminate at the corners of the polygonal cross section, so that relatively sharp edges are formed with corner angles of less than 90°.

In addition, the thin layer can also terminate the plane of the polygonal cross-section, in which case edges with corner angles in the range of 90° can be realized.

In a preferred construction, the substrate consists of polyamide and the thin layer consists of polyolefin, in particular polypropylene or polyethylene. This pairing of materials has a secondary bond of sufficient magnitude on the boundary faces to prevent early tearing or separation during bristle processing and use. But the polymer bond is torn apart under the action of strong and predetermined force.

According to the method according to the present invention for the manufacture of manes consisting of the above-mentioned monofilaments, it is characterized in that at least two polymers are co-extruded into monofilaments, the monofilaments are stretched and stabilized if necessary, and the monofilaments The filaments are cut to the desired bristle length, and the bristle is split at its use end to a finite length along the thin layer by mechanical force perpendicular to the bristle axis. Another method of making either bristles or interdental cleaners can be carried out by co-extruding at least two polymers into monofilaments, after extrusion the monofilaments are stretched, stabilized if necessary, and By the action of mechanical force, the thin layer is partially opened to a limited length perpendicular to the axis of the monofilament. By means of the method according to the invention, slit-shaped cuts can be formed on the surface of the monofilament sheath, which can be used to accommodate the medium. In the case of toothbrushes or interdental cleaners it is contemplated to contain, inter alia, tooth care or dental medicines or antibacterial preparations. In addition, the monofilament interdental cleaner has an increased roughness on the outer shell surface through the cutouts.

Interdental cleaners of any length can be produced from the monofilaments described above. Of course, the same measures can also be carried out on the mane cut off from the monofilament. The position of the incision and the extension of the incision can here be adapted to the length of the bristles in order to either avoid splitting at the ends of the bristles or to promote splitting as required. For example only the ends of the bristles can be split. Secondly, the otch that is done on the shell face can be used for the continuation of splitting of the mane after the flag is used up. Depending on the type and number of layers to be filled, a corresponding number of flags are formed on the bristle use ends.

When processing the monofilaments to form interdental cleaners of any length, according to one variant of the method, it is envisaged that the monofilaments are axially upset during or after the action of the mechanical force. As a result, the region of the longitudinal incision or the small ribs on the outer surface of the monofilament bounded by the incision bulge outwards.

The mechanical force is preferably applied over most of the circumference of the monofilament or bristle so as to ensure that the entire boundary layer of the polymer is stressed.

Monofilament cutting or bristle splitting is best done by impact. However, kneading or twisting forces can also act. These forces can act on the cut bristles before or after the bristles are attached to the bristle carrier of the brush, or can also act simultaneously on a group of bristles, for example a tuft of bristles.

The bristles are preferably rounded at their used ends. This can be done before and/or after cleaving. In a further preferred variant of the method, the ends formed after cleavage are provided with markings which optically indicate their usable length. The user is thus informed that after the bristles have been used up to the mark, the performance changes abruptly, since thereafter the effect of a much higher bending strength of the entire bristle cross-section occurs. Split ends become shorter and more susceptible to mechanical damage from this. Such marking should especially be provided if toothbrushes, body care brushes etc. are involved.

Description of drawings

The invention is explained below with the aid of an exemplary embodiment represented in the drawing. The figure shows:

Different cross-sections of monofilaments in Figures 1 to 5;

Figure 6 is a view of the bristles with split use ends;

Figure 7 is a view of a bristle or interdental cleaner with a notched shell surface;

Figure 8 Alternative scheme for monofilament cross-section; and

Figure 9 is a view of an interdental cleaner of a slightly modified construction.

Examples

The monofilament 1 according to FIG. 1 has a circular cross section and is produced from at least two polymers by coextrusion. It consists of a matrix 2 of a polymer that determines the properties of the bristles and a mixture of another polymer or polymers containing the matrix 2 filled in a certain geometric shape (in this case a cross) Composition of thin layers 3 composition. In the region of the boundary surface of the thin layer 3 or of the base body 2 , the secondary bonding forces, that is to say the bonding forces perpendicular to the longitudinal direction of the filaments, are greatly reduced. In the exemplary embodiment shown, the thin layer 3 terminates at the sheath surface 4 of the monofilament. However, it can also end at a small distance from the housing surface.

In particular, polyamide (PA) is considered as the polymer of the substrate 2 , while the thin layer 3 consists, for example, of a PA/PP or PA/PE polymer mixture.

In the embodiment according to FIG. 2 , the thin layer 3 fills the main body 2 in the form of a three-armed star, while FIG. 3 shows a monofilament 1 with a polygonal, ie triangular, cross-section. In this embodiment the infill, here also the thin layers extending from the center outward terminate at the corners of the polygon. Of course it can also end not at the corners but in the plane between the corners.

In the embodiment according to FIG. 4 it is also possible to extrude another polymer out of many possible polymers together with the matrix 2 of the monofilaments 1 in such a way that it is completely embedded in the matrix. For example, it can be a filament-shaped structure 5 which influences the bending properties and the strength of the flag formed after the production of the bristles and the splitting or cutting of the bristles.

FIG. 5 shows a flat rectangular monofilament 1 in which the thin layers 3 are laid in a grid, so that a plurality of substantially rectangular flags can be produced from the monofilament. Finally, FIG. 8 shows a monofilament cross-section in which the base body 2 consists of four identical peripheral parts with a fan-shaped cross-section and a central core, which are separated by correspondingly distributed thin layers 3 .

Fig. 6 shows schematically a bristle 6, which is made, for example, by cutting the monofilament according to Fig. The monofilaments form the shape of the regions of the base body 2 . As many flags are formed as there are partitions formed by dividing the substrate 2 by the thin layer 3 . The length of use of the flag can be visually marked, for example, by the horizontal lines shown in FIG. 6 .

In the exemplary embodiment according to FIG. 7 the mechanical force acts at regular intervals on the outer surface of the monofilaments, or in the case of cut bristles at a distance from the end of use. Through the thickness of the layer and the magnitude of the force and/or the frequency of its use, it can be achieved that the outer surface of the monofilament or bristle 6 is only split over a locally limited length and openings 8 , 9 and 10 are formed. These cutouts are approximately flush, that is to say in the region formed by the thin layer 3 . In this construction, the incision is torn at the end of the bristle while forming the flag. The flag is continuously reformed as the bristles progressively wear away.

The monofilament according to FIG. 7 can be used in any length as an interdental cleaner (dental floss "floss"), wherein the incisions can accommodate tooth care agents, antibacterial agents or bactericides. A second suggestion for interdental cleaners is to axially upset the monofilament, as shown in Figure 9, so that small ribs bounded by the incision arch outward from the base polymer.

The base body 2 or the polymers that form it can be of different colors in the individual cross-sectional sections bounded by the thin layer.

Claims (29)

1. one kind is used for making mane or interdental cleaner, at least form by the polymer that has the boundary face that distributes vertically basically of the common extrusion molding of geometrical arrangements of rule by two kinds, monofilament with the secondary adhesion that reduces, this monofilament can be cut open along axis direction basically by the effect of mechanical force, it is characterized in that: described monofilament has the polymer of the substrate forms of at least a physics that can determine mane or interdental cleaner and chemical property, at least the another kind of polymer of inserting the thin layer form of one deck at least in the described matrix, compare with the secondary adhesion of polymeric matrix, the described thin layer of one deck at least has the secondary adhesion that has reduced.

2. by the monofilament of claim 1, it is characterized in that: matrix polymer is a kind of copolymer or polymeric blends.

3. by the monofilament of claim 1 or 2, it is characterized in that: the polymer of thin layer is a kind of copolymer or polymeric blends.

4. by the monofilament of claim 1 or 2, it is characterized in that: thin layer contains the composition of matrix polymer.

5. by the monofilament of claim 4, it is characterized in that: two kinds of polymer exist by roughly the same deal in thin layer.

6. by the monofilament of claim 1 or 2, it is characterized in that: thin layer has the thickness of several μ m.

7. by the monofilament of claim 1 or 2, it is characterized in that: thin layer is stretched over the edge of monofilament always in matrix.

8. by the monofilament of claim 1 or 2, it is characterized in that: thin layer ends in matrix from a distance, monofilament edge.

9. by the monofilament of claim 1 or 2, it is characterized in that: the matrix of monofilament has the third and inserts the interior polymer of matrix.

10. by the monofilament of claim 1 or 2, it is characterized in that: the polymer of matrix and thin layer is not homochromy.

11. the monofilament by claim 1 or 2 is characterized in that: monofilament has the cross section that is different from circle.

12. by the monofilament of claim 11, it is characterized in that: monofilament has the polygon cross section.

13. by the monofilament of claim 12, it is characterized in that: thin layer ends at the angle of polygon cross section.

14. by the monofilament of claim 12, it is characterized in that: thin layer ends at the face of polygon cross section.

15. by the monofilament of claim 1 or 2, it is characterized in that: matrix is made up of polyamide, thin layer contains polyolefin.

16. method that is used for making by the mane of forming by each monofilament of claim 1 to 15, it is characterized in that: at least two kinds of compound monofilament that are extruded into of polymer, with filament stretch, carry out stabilized treatment under the necessary situation, then cut into desirable mane length, mane is rived to limited length perpendicular to the mane axis by the effect of mechanical force along thin layer at its use side.

17. be used for making by the mane of forming by each monofilament of claim 1 to 15 or the method for interdental cleaner, it is characterized in that: at least two kinds of compound monofilament that are extruded into of polymer, with filament stretch, carry out stabilized treatment under the necessary situation, and the effect by mechanical force along thin layer perpendicular to the monofilament axis direction in partial cut-out to limited length.

18. by the method for claim 17, it is characterized in that: monofilament is during being subjected to mechanical force or later on along the axis direction jumping-up.

19. by each method of claim 16 to 18, it is characterized in that: mechanical force acts on most of circumference of monofilament or mane at least.

20. each the method by claim 16 to 18 is characterized in that: monofilament or mane are by the impulsive force otch or rive.

21. each the method by claim 16 to 18 is characterized in that: monofilament or mane are by rubbing power otch or rive.

22. each the method by claim 16 to 18 is characterized in that: monofilament or mane are by the twisting resistance otch or rive.

23. each the method by claim 16 to 18 is characterized in that: mane before riving at its use side place rounding.

24. each the method by claim 16 to 18 is characterized in that: mane after riving at its use side place rounding.

25. by each method of claim 16 to 18, it is characterized in that: mane is provided with the mark of the length used of visual demonstration mane resulting many flag shape parts after riving.

26., it is characterized in that: make according to each method of claim 16 to 25 by each monofilament to the small part mane by claim 1 to 15 by mane carrier and be fixed on the bristle goods that the mane above it is formed.

27. the bristle goods by claim 26 is characterized in that: many ends of the mane of riving have demonstration, and it can use the mark of length.

28. the bristle goods by the interdental cleaner form of making according to the method for claim 17 or 18 by each monofilament of claim 1 to 15 is characterized in that: interdental cleaner on its circumference by uniform spacing otch.

29. by the bristle goods of claim 28, it is characterized in that: interdental cleaner bulges by jumping-up in incision tract.

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