EP0957711B1 - Toothbrush bristle - Google Patents

Abstract

The invention is directed to a bristle (12) for a toothbrush, in particular for an electric toothbrush, which is made of plastic and includes several filaments (13, 14, 15) joined together. The filaments (13, 14, 15) are wound or braided and joined together as a result of the action of chemical agents. This results in a firm bond between the filaments (13, 14, 15), and any cavities between the filaments (13, 14, 15) are reliably avoided. Overall, a toothbrush results which, in addition to having a high cleaning effect, offers bacteria or other germs no possibility of infiltration.

Description

The invention relates to a bristle for a toothbrush, in particular for a electric toothbrush, which is made of plastic and several, together connected filaments.

Such a bristle is known from German utility model 19 97 717. There is described a toothbrush that has a variety of bristles has, with each bristle several filaments approximately parallel to each other arranged and thermally welded together. In this way the cleaning area formed by the free ends of the bristles is increased and thus increases the cleaning effect of the toothbrush. On the other hand arise however, voids between the filaments caused by bacteria or other Germs can be colonized.

DE-PS 906444 describes a method for producing artificial bristles known, which consist of a plurality of individual filaments. These single filaments are glued together after exiting the spinnerets, the gluing is interrupted at intervals. After making the bond the bristle becomes individual bristles in the area of the non-glued areas cut, with the single bristle spliced at the tip. This method is quite complex, since on the one hand the filaments are admitted with an adhesive Need to become. On the other hand, it turns out to be problematic Continuously interrupt gluing at specified intervals.

From DE-AS 1 222 888 a brush with radially outward is on a hub attached bristles known. Each of the bristles points in the middle a stiff soul with at least one fiber made of vibration damping Material is glued and wrapped helically so that only part the surface of the soul is surrounded by the fiber.

JP, A, 03289906 shows a bristle for a toothbrush made of several interconnected filaments that are wound or braided.

The object of the invention is to provide a bristle for a toothbrush mentioned type in such a way that a high cleaning effect is guaranteed cavities should be avoided.

This object is achieved according to the invention in that the filaments are wound or braided and due to the action of chemical agents with each other are chemically welded.

By winding or braiding the filaments or generally by stranding the filaments are caused to make the filaments lie close together. As a result of the action of chemical agents, the surface of the Filaments loosened. In this way it is achieved that the filaments are complete go together and any cavities still present in the center of the wound or braided bristle can be closed. An existing one or tensile stress which can be influenced in a targeted manner and acts on the filaments Support the process. Overall, a void-free is created in this way Bristle, which means that bacteria or other germs have no possibility of storage offers.

By using multiple filaments, however, the for the Tooth cleaning effective surface of the toothbrush increases and thereby the Improved teeth cleaning. Furthermore, by winding or braiding achieves that the surface of the bristles is structured, which is important when cleaning teeth can be used effectively. Both are particularly important beneficial in removing plaque from the tooth surface.

In an advantageous embodiment of the bristle according to the invention is on the bristle a free end is provided. This fanning out can be done by a Breaking the connection points of the individual filaments at the free end the bristle can be reached. In this way, at the free end of the Bristle individual thin tips, the number and diameter of the number and the diameter of the filaments of the bristle. These thin tips can penetrate the interdental spaces of the teeth much easier and deeper and in this way improve the removal of plaque and overall teeth cleaning. Furthermore, due to the expansion the effective cleaning area for tooth cleaning is further enlarged, so that also in that the teeth cleaning is improved.

In a further advantageous embodiment of the bristle according to the invention the filaments of the bristle have different diameters. To this The mechanical properties, for example the stiffness, can be varied or the fatigue or the resilience of the individual bristles and thus the toothbrush as a whole. Furthermore, by choosing the diameter of the filaments also the winding or braiding of each Bristles and thus the structure of the surface of the bristles can be influenced. Both have a direct influence on the cleaning effect and in particular on the comfort of cleaning the toothbrush.

In a preferred embodiment of the embodiment mentioned, an approx central filament provided with a preferably higher stiffness, that of Filaments is surrounded with a preferably lower stiffness. The central Filament is preferably used to stabilize the bristle during this central filament surrounding filaments preferably to obtain a high cleaning efficiency and high cleaning comfort are provided.

In an advantageous development of the bristle according to the invention, the Winding or braiding of the bristle periodically formed. This has advantages in With regard to the manufacture of the bristle and has a visually uniform appearance the bristle and thus the toothbrush.

For an electric toothbrush in particular, the following values have been found to be: Particularly useful: 3 or 4 filaments per bristle used, the diameter of the individual filaments has a value between about 0.0762 mm and about 0.127 mm, and the winding or braiding a bristle repeats after about 1.0 mm to about 3.0 mm.

According to a further advantageous embodiment of the invention, the filaments are so chemically welded together that in the area of Fanning a tear strength or a peel force of the filaments of about 0.1N to 0.15N, preferably 0.125N. This ensures that the bristles of the invention according to the conventional, in particular mechanical rounding of an end section, for example after fastening the bristles in a bristle holder, slightly splay at the ends. On the other hand, the tear resistance is still so high that during normal use of the bristles, for example as a bristle Toothbrush, essentially fanning the bristle into individual filaments is prevented.

It has proven to be particularly advantageous that due to the action of chemical agents 10% to 50%, preferably 20% to 35% of the cross-sectional area the filaments are loosened. On the one hand, this creates the formation of Cavities between the filaments safely avoided. On the other hand with such a degree of dissolution, each of the filaments still has a sufficient internal Strength, so that the chemical welding of the filaments into one Bristle can be carried out continuously without problems.

Of particular advantage when using filaments made of crystalline or semi-crystalline material, such as. B. polyamide, an outer jacket of the bristle the chemical welding of the filaments an amorphous structure, while an inner core has an essentially crystalline structure.

Under certain circumstances, an amorphous one can be found in the center of the inner core Structure of the filament or bristle material may be present.

In general, the cross-sectional area with amorphous structure is about 10% up to 50%, in particular 20% to 30% of the total cross-sectional area of the Bristle. The remaining cross-sectional area accordingly has an im essential crystalline structure.

In an advantageous method for producing an inventive The filaments are wound bristle essentially without torsional stress or braided and chemically together by exposure to solvents welded. After the winding or braiding process, a connection is made of filaments due to chemical agents. This way it becomes permanent Connection between the individual filaments achieved, the mechanical Properties of the filaments are essentially retained. It arises a filament composite that forms the bristle. Furthermore, by dissolving closing the filaments in a solvent from those still present Cavities guaranteed safely. The fixation mentioned also represents a simple one and well controllable way, the coiled or braided Process filaments and combine them into bristles.

In an advantageous development of the method according to the invention wetting the filaments with a solvent for between about 5 s and about 50 s, preferably z. B. for coated filaments, between about 20 s and about 30 s. Polyamide filaments have highly concentrated formic acid turned out to be a particularly useful solvent.

There is an advantageous embodiment of the method according to the invention in that at the free end of the bristle by mechanical processing Fanning is generated. The resulting thin tips can be significant penetrate and improve easier and deeper into the interdental spaces of the teeth in this way the removal of plaque there and thus the total Teeth cleaning.

According to another extremely advantageous development of the invention the filaments during chemical welding with tensile stress from about 6MPa to 20MPa, preferably 13MPa. This is ensured that the wound or torsional stress-free braided filament during chemical welding with sufficient radially inward force are against each other, this radially inward force by means of the tensile stress acting on the filaments is produced.

In a particularly advantageous development of the invention, the invention Bristles in the inner field of a preferably electrically driven one Round head toothbrush used.

Fig. 1a bis 1c

zeigen eine schematische Darstellung eines ersten Ausführungsbeispiels einer erfindungsgemäßen Borste für eine Zahnbürste in einer Ansicht und zwei Querschnitten,

Fig. 2a und 2b

zeigen eine schematische Darstellung eines zweiten Ausführungsbeispiels einer erfindungsgemäßen Borste für eine Zahnbürste in einer Ansicht und einem Querschnitt,

Fig. 3a und 3b

zeigen eine schematische Darstellung eines dritten Ausführungsbeispiels einer erfindungsgemäßen Borste für eine Zahnbürste in einer Ansicht und einem Querschnitt,

Fig. 4

zeigt eine schematische Darstellung des freien Endes der Borste der Figur 3 mit einer Aufspleißung in einer Ansicht,

Fig. 5

zeigt einen vergrößerten Querschnitt einer Borste gemäß Fig. 3b im Detail.

Further features, advantages and possible applications of the invention result from the following description of exemplary embodiments, which are shown in more detail in the drawing. All of the described and / or illustrated features, alone or in any combination, form the subject matter of the invention, regardless of how they are summarized in the claims and their relationship.

1a to 1c

1 shows a schematic illustration of a first exemplary embodiment of a bristle according to the invention for a toothbrush in one view and two cross sections,

2a and 2b

1 shows a schematic illustration of a second exemplary embodiment of a bristle according to the invention for a toothbrush in a view and a cross section,

3a and 3b

1 shows a schematic illustration of a third exemplary embodiment of a bristle according to the invention for a toothbrush in a view and a cross section,

Fig. 4

3 shows a schematic illustration of the free end of the bristle of FIG. 3 with a fanning out in a view,

Fig. 5

shows an enlarged cross section of a bristle according to FIG. 3b in detail.

A bristle 1 is shown in FIGS. 1a to 1c, which consists of three filaments 2, 3, 4 is composed. The filaments 2, 3, 4 consist of the same plastic and all have the same diameter. The filaments 2, 3, 4 are braided, which among other things from the cross sections of Figures 1b and 1c can be seen. The braiding is carried out evenly, so that the braiding and thus the structure of the surface of the bristle 1 is repeated periodically. This is identified in FIG. 1 a by the reference number 5.

FIGS. 2a and 2b show a bristle 6 which consists of four filaments 7, 8, 9, 10 is composed. The filament 7 is arranged centrally and is from the other filaments 8, 9, 10 surround. The filament 7 has a larger one Diameter on than the filaments 8, 9, 10.All filaments 7, 8, 9, 10 consist of plastic, the filaments 8, 9, 10 of the same plastic are made, while the central filament 7 from another Plastic can exist. The central filament 7 preferably has a high rigidity, while the surrounding filaments 8, 9, 10 have a lower Possess rigidity. The different stiffnesses can vary different diameters and / or different plastics the filaments result, for example, from softer or harder plastics. The central filament 7 is wrapped by the other filaments 8, 9, 10. The Winding is carried out evenly, so that the winding and thus the Structure of the surface of the bristle 6 is repeated periodically. This is in the figure 2a marked with the reference number 11.

In Figures 3a and 3b, a bristle 12 is shown, which consists of three filaments 13, 14, 15 is composed. The filaments 13, 14, 15 consist of the same Plastic and all have the same diameter. The filaments 13, 14, 15 are wound. The winding is even, so that the Winding and thus the structure of the surface of the bristle 12 is repeated periodically. This is identified in FIG. 3a with the reference number 16.

The filaments mentioned in FIGS. 1a to 1c, 2a and 2b and 3a and 3b 2, 3, 4, 7, 8, 9, 10, 13, 14, 15 of the bristles 1, 6, 12 can be made of polyamide, Polyester or polypropylene. The diameter of the above Filaments can be between about 0.0762 mm (3 mil) and about 0.127 mm (5 mil) be. The period 5, 11, 16 of the braiding or winding of the above Filaments can be between about 1.0 mm and about 3.0 mm. How else the individual filaments 2, 3, 4, 7, 8, 9, 10, 13, 14, 15 of the bristles 1, 6, 12 firmly connected.

FIG. 4 shows a free end 17 of the bristle 12 of FIGS. 3a and 3b. The free end 17 has a splice 18. This means that the free ends 19, 20, 21 of the filaments 13, 14, 15 are not firmly together are connected, but as individual tips from the free end 17 of the bristle 12 stick out. The length of the splice 18 is chosen such that the protruding ones Tips are suitable in a user's interdental spaces penetrate.

The described fanning out of the free end of the bristle can be done in a corresponding manner Way also with the bristles of Figures 1a to 1c and / or Figures 2a and 2b be present.

To produce the bristles 1, 6, 12, the filaments 2, 3, 4, 7, 8, 9, 10, 13, 14, 15 braided or wound or in general stranded. It is possible to wind or braid with already stretched filaments 2, 3, 4, 7, 8, 9, 10, 13, 14, 15 perform that already have the desired mechanical properties.

Then the braided or wound filaments 2, 3, 4, 7, 8, 9, 10, 13, 14, 15 dipped in a solvent and fixed there by dissolving. The Residence time in the solvent is from about 5 seconds to about 50 s. As a solvent, e.g. for filaments made of polyamide, can Phenol, M-cresol or formic acid can be used. When using Highly concentrated formic acid has one in coated filaments Time period between about 20 s and about 30 s was found to be advantageous. By wetting the filaments 2, 3, 4, 7, 8, 9, 10, 13, 14, 15 with the Solvents become the connection points of the filaments 2, 3, 4, 7, 8, 9, 10, 13, 14, 15 firmly connected.

Then the solvent is mixed with water or other suitable media neutralized or the excess solvent removed. Then they will Filaments 2, 3, 4, 7, 8, 9, 10, 13, 14, 15 dried. Then the resulting one Bristles 1, 6, 12 can be further processed in a known manner.

To generate the splice 18 at the free end 17 of the bristle 12 in a subsequent process the free end 17 mechanically processed. This Mechanical processing can for example be a grinding process or the like or be another blow treatment of the free end 17. In In any case, the mechanical processing is the chemical Fixation caused firm connection of the filaments 13, 14, 15 of the bristle 12 broken open again in the region of the free end 17 of the bristle 12. It this creates the free ends 19, 20, 21 of the filaments 13, 14, 15, wherein the length of the free ends 19, 20, 21 and thus the length of the splice 18th depends on the degree of mechanical processing of the free end 17 the bristle 12. The chemical fixation of the filaments 13, 14, 15 is thereby carried out in such a way that on the one hand a breaking of the solid connection on free end 17 of the bristle 12 is possible, but that on the other hand by the normal Using the bristle does not break the tight connection of the filaments 13, 14, 15 is possible.

From Fig. 5 it can be seen that the bristle 12 due to the chemical bonding the filaments 13, 14, 15 made of partially crystalline material has a special structure in cross-section. An outer jacket 22 of the bristle 12 has a substantially amorphous structure that is indicative of the dissolution of the Outer jacket of the individual filaments 13, 14, 15 due to the solvent is. The inner core 23 of the bristle 12 essentially has one crystalline structure, this inner core 23 essentially by the undissolved cores of the filaments 13, 14, 15 is formed. At the center 24 of the Inner core can be a small area with an amorphous cross section Structure. So chemically welded together Filaments 13, 14, 15 have about 10% to 50%, in particular 20% to 30% of the total cross-sectional area an amorphous structure. Accordingly about 90% to 50%, in particular 80% to 70% of the cross-sectional area in the essentially crystalline.

It proves particularly advantageous that the filaments after winding, braiding or stranding in almost or essentially torsion stress-free Condition. This is ensured by the fact that each of the filaments 2, 3, 4; 7, 8, 9, 10; 13, 14, 15 during braiding, wrapping or stranding in the opposite sense to that required for roping, braiding or winding Rotation is rotated around its own axis, so that torsional stresses in the are substantially avoided. There is therefore a knot of the filament composite chemical welding and after stranding, braiding or winding, locked out. This essentially torsion-free stress state leaves prove themselves after welding using microtome sections if these are analyzed under polarized light. For optimal chemical Welding of filaments 2, 3, 4; 7, 8, 9, 10; 13, 14, 15 to ensure fixation takes place under tensile stresses of approximately 6MPa to 201MPa, preferably at around 13MPa. The fixation followed by exposure to chemical agents, which, however, has practically no residues or reaction products after washing left in the filament composite. The fixing time is like this chosen that 10% to 50%, preferably 20% to 35% of the cross-sectional area of the Individual filaments are loosened. The fixing times are for filaments 2, 3, 4; 7, 8, 9, 10; 13, 14, 15 without surface coating between 5 sec and 20 sec, or at about 10 sec. If filaments with a silicone coating are used, fix times between 20 sec and 40 sec, preferably 25 sec to 30 sec into consideration. Such a silicone coating improves the sliding behavior of the filaments are conveyed during production. The connection strength can about the measurement of the peeling forces and the wear behavior of the bristle 1, 6, 12 can be determined. To unravel the multifilament ends during of the mechanical rounding process, for example, must be ensured adjust the process parameters so that the peeling forces are in the range of 0.1 N to about 0.15N.

The fixing times given above naturally vary depending on the Process parameters and apply in particular to the special case that concentrated Formic acid used as a solvent at a temperature of about 20 ° C. the filaments are made of polyamide (PA6.12) and have a diameter from about 0.076 mm to 0.126 mm.

By winding, braiding or stranding the filaments, the individual filaments become brought into close contact. By acting on the filament composite Tensile force creates a resulting force towards the center 24 of the Bristle 1, 6, 12. Due to the action of chemical agents or solvents the surface of the filaments 2, 3, 4; 7, 8, 9, 10; 13, 14, 15 dissolved, so that a doughy state is achieved. Here, the substance cohesion secondary valency forces caused by the solvent are reduced, whereby the covalent bonds are practically not attacked or destroyed become. This state enables the diffusion of molecular segments over the interfaces into the neighboring component. The depth of penetration of the molecular chains depends on the degree of resolution and the amount of Tensile stress and influences the bond strength of the overall system. The Connection in turn is based on the secondary valence forces of the neighboring atoms Molecular chains after the subsequent washing out of the solvent come back to full development.

In the context of this application, a connection is made under chemical welding of the filaments together by loosening the surface of the filaments understood by means of a chemical solvent. In contrast to this in the case of thermal welding, the surface of the filaments by action softened by heat. When filaments are glued on the filament surface permanently applied an additional fabric that the Connecting filaments.

The bristles 1, 6, 12 described in FIGS. 1a to 1c, 2a and 2b and 3a and 3b are intended for use in toothbrushes, in particular for Use in electric toothbrushes. The bristles 1, 6, 12 described are particularly advantageous for use in the inner field of a round-head toothbrush.

Claims (20)

1. A bristle (1, 6, 12) for a toothbrush, in particular for an electric toothbrush, which is made of plastic and includes several filaments (2, 3, 4; 7, 8, 9, 10; 13, 14, 15) joined together, said filaments (2, 3, 4; 7, 8, 9, 10; 13, 14, 15) being wound or braided, characterized in that said filaments are chemically welded together as a result of the action of chemical agents.
2. The bristle (1, 6, 12) as claimed in patent claim 1, characterized in that the free end (17) of the bristle (12) has a fanned arrangement (18).
3. The bristle (1, 6, 12) as claimed in any one of the patent claims 1 or 2, characterized in that between two and eight filaments are provided per bristle, in particular three or four filaments per bristle.
4. The bristle (6) as claimed in any one of the patent claims 1 to 3, characterized in that the filaments (7 or 8, 9, 10) of the bristle (6) have different diameters.
5. The bristle (1, 6, 12) as claimed in any one of the preceding patent claims, characterized in that the diameter of the filaments (2, 3, 4; 7, 8, 9, 10; 13, 14, 15) lies between 0.0508 mm (2 mils) and 0.254 mm (10 mils), approximately, in particular between 0.0762 mm (3 mils) and 0.127 mm (5 mils), approximately.
6. The bristle (6) as claimed in any one of the patent claims 1 to 5, characterized in that one approximately central filament (7) is provided with greater rigidity and is surrounded by filaments (8, 9, 10) of less rigidity.
7. The bristle (1, 6, 12) as claimed in any one of the patent claims 1 to 6, characterized in that the winding or braiding of the bristle (1, 6, 12) follows a periodic pattern (5, 11, 16).
8. The bristle (1, 6, 12) as claimed in patent claim 7, characterized in that the repeat value (5, 11, 16) is between 0.5 mm and 5.0 mm, approximately, in particular between 1.0 mm and 3.0 mm, approximately.
9. The bristle (1, 6, 12) as claimed in any one of the patent claims 1 to 8, characterized in that the filaments (2, 3, 4; 7, 8, 9, 10; 13, 14, 15) are made of polyamide, polyester and/or polypropylene.
10. The bristle as claimed in any one of the preceding claims, characterized by a tear-growth resistance of the fanning (18) or a peeling force of the filaments (13, 14, 15) of between 0.1 N and up to 0.15 N, preferably of 0.125 N.
11. The bristle as claimed in any one of the preceding claims, characterized in that amounts of 10% up to 50%, preferably 20% to 35%, of the cross-sectional area of the filaments (2, 3, 4; 7, 8, 9, 10; 13, 14, 15) are partially dissolved as a result of the action of the chemical agents.
12. The bristle as claimed in any one of the preceding claims, characterized in that in cases in which filaments of a crystalline or part-crystalline material are employed, an outer envelope (22) of the bristle (1, 6, 12) has an essentially amorphous structure, and an inner core (23) has an essentially crystalline structure.
13. The bristle as claimed in claim 12, characterized in that a center (24) of the inner core (23) has an amorphous structure.
14. The bristle as claimed in any one of the claims 12 to 13, characterized in that amounts of about 10% up to 50%, in particular 20% up to 30% of the area of cross-section of the bristle (1, 6, 12) possess an amorphous structure.
15. A method of manufacturing a bristle for a toothbrush as claimed in any one of the patent claims 1 to 14, characterized by the processes of winding or braiding the filaments (2, 3, 4; 7, 8, 9, 10; 13, 14, 15) essentially without torsional stress and chemically welding them together by the action of a solvent.
16. The method as claimed in patent claim 15, characterized by the process of wetting the filaments (2, 3, 4; 7, 8, 9, 10; 13, 14, 15) with a solvent for a period of between 5 s and 50 s, approximately, preferably for a period of between 5 s and 15 s or 20 s and 30 s, approximately, depending on the surface coating of the filaments.
17. The method as claimed in any one of the patent claims 15 or 16, characterized by the use of phenol, M-cresol and/or formic acid as solvents.
18. The method as claimed in any one of the patent claims 15 to 17, characterized by a mechanical operation producing a fanned arrangement (18) of the free end (17) of the bristle (12).
19. The method as claimed in any one of the patent claims 15 to 18, characterized by exposing the wound and/or braided filaments (1, 6, 12) during the chemical welding process to a tensile stress of between 6 MPa and up to 20 MPa, approximately, preferably 13 MPa.
20. The use of the bristle (1, 6, 12) as claimed in any one of the preceding patent claims in the inner field of a preferably electrically powered round-head toothbrush.

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