DE102006012004A1 - Multi-filament bristles for toothbrushes - Google Patents

Abstract

The invention relates to a bristle (1; 4; 7; 10; 13), in particular for toothbrushes, and a corresponding manufacturing method, the bristle at least two filaments (2, 3; 5, 6; 8, 9; 11 , 12; 14, 15) made of different materials, the cross-sectional area of at least one of the filaments (3; 5; 9; 11) decreasing towards the free end of the bristle.

Description

The The invention relates to bristles, in particular for toothbrushes, their production method and corresponding bristles, the bristles being in the longitudinal direction at least two jointly extruded filaments of different Have materials.

was standing of the technique

bristles for toothbrushes typically polyester or nylon monofilaments, that is, plastic threads, which extruded, stretched and fixed. Nylon bristles are flexible, lightweight deformable and especially water absorbent. You must therefore be designed relatively thick, so given flexibility requirements be achieved. This requires rounding off the ends of the bristles Prevent injuries to the gums.

in the In contrast, polyester bristles, for example, made of polybuthylene terephthalate (PBT) and / or polyethylene terephthalate (PET) are made, a small Absorption degree for Water as well as good durability properties. However, these are enough Bristles usually do not meet the flexural or flexural stiffness requirements. They are typically too stiff and inflexible and thus can to injury of the gums.

To increase the flexibility of polyester bristles is from the EP 1 234 525 B1 a method for producing toothbrushes with highly conical bristles known. Here, polyester monofilament bristles are immersed in corrosive chemicals until the immersed portion of the monofilaments is completely eroded. This eventually leads to a tapered bristle end.

It This is disadvantageous in that the chemically pointed ends of the Bristle attacked and subject by the etching process to some massive damage. By the etching process is Such a high reject produced, which adversely affects the production costs effect. In addition, those made of a monofilament tapered bristles due to the eroded lateral surface a low durability and already too low bending stiffness on. Furthermore, the shape of the tapered bristles in Essentially solely by the etching process determined and can not meet predetermined requirements accordingly be designed.

Furthermore, it is from the prior art, such as from the EP 1 030 937 B1 It is known to make bristles or interdental cleaners from a monofilament of at least two co-extruded polymers. Here, for example, two polymers are coextruded into a monofilament and slit after a subsequent stretching and optionally stabilizing by the action of mechanical forces transverse to the monofilament axis to a locally limited length along the boundary layers between the polymers. As a result, fissurenartige slots can form on the mantle of the monofilament, which can serve to accommodate media, in particular dentifrices or dental or antibacterial preparations.

to Formation of fissurenartiger slots coextruded one of two polymers Monofilament is used to split the monofilament along the boundary layers the at least two polymers always the action of mechanical personnel intended. The mechanical insertion of slits, columns and flags is on the one hand expensive and on the other hand relatively inaccurate, because the formation of such columns depends essentially from the amplitude and the direction of the applied force and the binding forces between the polymers. The slots thus produced have therefore often different and difficult to control lengths, irregular shapes and frayed lateral surfaces on.

task

Of the The present invention is therefore based on the object, tapering tapered Bristles, in particular for toothbrushes, with freely selectable Geometry and improved elasticity properties available put. Furthermore, the object of the invention is to provide a production or processing method for Such bristles from production rational point of view too optimize.

invention and beneficial effects

The The object underlying the invention is by means of a bristle according to claim 1 and a method for producing or processing such Bristles according to claim 11 and with brushware according to claim 17 solved. Further advantageous embodiments The invention are specified in the respective subclaims.

The bristle according to the invention has in the longitudinal direction at least two jointly extruded filaments of different materials and is characterized in that the cross-sectional area of at least one of the two filaments decreases towards the free end of the bristle. Thus, at least one of the at least two coextruded filaments changes its geometry in the region of the bristle end. Crucial here is that the two jointly extruded filaments of different materials, such as Polyes ter and polyamide, which can be subjected to a material-selective machining process to form the bristle of the invention.

By the selection and arrangement of different materials for the common extruded filaments of the bristle can be both the flexurally elastic Properties of the bristle as well as its geometric configuration, especially in the area of the bristle ends, are designed almost arbitrarily.

To a first embodiment takes the cross-sectional area of the at least one filament continuous to the free end of the bristle down. A steady decrease in the cross-sectional area is here with a constantly decreasing surface area and a steadily decreasing Diameter of this bristle filament accompanied. Sharp corners or edges that manifestations discontinuous circumferential surfaces or surfaces are, are thus avoided in an advantageous manner. The risk of injury for sensitive Areas within the oral cavity, such as the gums, can thus be beneficial be lowered.

To Another aspect is the cross-sectional area of the free end of the bristle essentially determined by the at least other filament. In preferred embodiment is its cross-sectional area longitudinal the bristles are substantially constant. In particular, it is envisaged that the at least one filament at the free end of the bristle one Cross sectional area of zero, so that the total cross section of the bristle at the free End of the bristle essentially by the remaining at least other filament is determined.

By the effective reduction of the cross-sectional area of the bristle ends may be the Entire bristle the given elasticity or bending stiffness requirements better match. Unlike one produced by chemical etching tapered monofilaments is the bristle of the invention not chemically sharpened at the end of its filament and therefore not attacked or otherwise damaged.

To a particularly advantageous embodiment of the invention the at least other filament of the at least one filament at least partially radially enclosed. In this case, it is provided in particular that the at least other filament a radially inner core portion of Bristle forms while the at least one filament surrounding this inner core filament as a sheath. Tapered towards the bristle end finally this core sheath, until at the free end of the bristle only the the bristle core forming other filament remains and a tapered bristle cross section forms.

Especially it is provided here that the at least other filament, e.g. the core filament, in the axial direction further than the one filament, such as e.g. the sheath filament extends. The free end of the bristle is Accordingly, only formed by that filament whose cross-sectional area is essentially does not change.

It can be further provided that several, in cross-section not changing Filaments regularly over the Cross-section of the bristle arranged distributed and of the at least a filament whose cross-sectional area is a change toward the bristle end has, at least partially enclosed in the radial direction are. By the rejuvenation the cross-sectional area the at least one filament towards the free end of the bristle can ultimately a configuration is formed at the bristle end, which is a variety single, through gaps separate filaments are formed. Such filament arrangements are for example for the inclusion of dentifrices or dental medical or antibacterial preparations advantageous.

To a further embodiment is provided that the at least other filament at its free End rounded or rounded. The the free end of the bristle forming filaments thus have essentially no edges, which cause injuries in the oral cavity could lead.

To a further embodiment According to the invention, the at least two filaments have a different one elasticity and / or a different flexural rigidity. Depending on the proportion the filaments made of different materials on the total material the bristle can the elasticity and / or bending stiffness properties of the bristle targeted to a set default value become.

Furthermore, it is provided that the at least one filament can be removed by means of an etchant, in particular a chemical etchant, such as sodium hydroxide, sulfuric acid or formic acid, wherein the at least other filament is substantially resistant to the respective chemical etchant. By choosing different materials for the at least one and the at least other filaments and a suitable selection of a chemical etchant, the free end of the bristle can be processed material selectively using a chemical etching process. Furthermore, by any arrangement and geometry of individual filaments almost any elasticity properties the bristle ends and correspondingly versatile Bristle end geometries are realized.

To a further embodiment is as material for the filaments polyamide and / or polyester provided. These materials have different elasticity and stiffness properties on. Furthermore, only one of these materials from the for a chemical etching process provided chemicals such as sodium hydroxide, sulfuric acid or formic acid attacked while the other material against the chemical in essence is resistant. The polyamide used here are in particular nylon, PA 6.6, PA 6.10 and PA 6.12, while as a polyester substantially PET and / or PBT are provided.

To another independent Aspect, the invention relates to a process for the preparation or Processing of bristles, in particular toothbrush bristles, in the longitudinal direction at least two jointly extruded filaments of different Have materials. The method is characterized that at least one of the filaments in the region of the free end of Bristles by means of a chemical etching process at least partially is removed. The at least other filament is essentially against in the chemical etching process used chemical resistant and corrodes at most in the chemical etching process in a negligible slight measure.

To a preferred embodiment of the inventive method is by means of the etching process at least one against the etchant essentially resistant filament at least in regions, preferably in the area of the free end, exposed. The parameters of the etching process, such as immersion depth of bristle ends in the chemical as well their residence in the chemical are preferably to the Shape and geometry, in particular to the radial dimensions the filaments, adapted. In this way, the etching process be optimized so that the at least one filaments be completely removed in the area of the free end of the bristle, so that there the at least other filaments are essentially exposed can be.

This is particularly important if the bristle core of a is formed against the chemical resistant filament used, which from those in the etching process corroding filaments is enclosed radially as a sheath. By the etching process is therefore the inner bristle core enclosing coat of mehrfilamentigen Bristle in the chemical etching process removed so that it tapers towards the bristle end. consequently rejuvenated only the bristle coat, while a chemically undamaged Bristle core over the end of the bristle mantle protrudes.

Farther is the etching process on a variety of different arrangements of different filaments universally applicable. So can for example by means of the etching process also the free ends of several, preferably regularly and spaced apart filaments are exposed. this makes possible ultimately even the most cost-effective and chemical preparation of slits for receiving media can serve. Of Furthermore, the production of bristles with split, several Single filaments existing, use end on chemical and therefore inexpensive Ways possible.

To In another aspect, the bristle ends become after the etching process looped or rounded by grinding.

To a further, particularly advantageous aspect of the invention the bristles before the etching process at one for the bristles provided bristle carrier, in particular on one toothbrush head fixed. Thus, the bristles are already in front of the bristle end processing etching and grinding process at its predetermined position on the brush head and must no longer after the etching process attached to this, resulting in a much higher effort would be connected, since they are tapered at their ends trained bristles with greater care would have to be treated.

The Fixing the bristles on the bristle head before processing the bristle ends allows in particular a simplified production of complicated Taftgeometrien of bristles on the bristle carrier.

To another independent Aspect therefore relates to the invention bristles of any kind, in particular but toothbrushes with a bristle carrier, on which the invention mehrfilamentigen and rejuvenated Bristles are arranged.

embodiments

Further Aims, advantages, features and advantageous features of the present invention Invention will become apparent from the following description of exemplary embodiments based on the drawings. In this case, all described and / or depicted features in meaningful combination the subject the present invention, also independent of the claims or their relationship.

It demonstrate:

1 a cross section through a two-filament bristle in the cross section AA,

2 the two-filament bristle according to 1 in longitudinal section,

3 a multi-filament bristle in cross section,

4 a bristle with segmented filaments,

5 a bristle with external filaments and

6 a bristle end with several exposed filaments.

In the 1 and 2 is a bristle 1 , In particular, the bristle of a toothbrush shown schematically in cross section. The bristle 1 consists of two filaments here 2 . 3 different materials that are extruded, stretched and fixed together. This forms a filament 2 an inner core of the bristle 1 while the other filament 3 the inner filament 2 surrounds as a shell. The inner filament is for example made of polyamide, such as nylon, while the outer filament 3 made of polyester.

By dipping the free end of the bristle 1 For example, in one for the bristle shell 3 corrosive chemical, such as caustic soda or sulfuric acid, becomes the originally cylindrical shell 3 material selectively removed during the chemical resistant bristle core 2 maintains a geometry unchanged from its ground state (not shown). The polyester filament forming the bristle shell 3 is etched away by immersion in the chemical such that the sheath 3 the bristle, before reaching the free end of the bristle, tapers conically with a cross-sectional area which steadily decreases towards the bristle end.

Compared with a previously known etching process with monofilaments, this material-selective etching process has the advantage that the inner core 2 the bristle is in no way damaged by the etching process. This still has a required flexural rigidity and can be easily sharpened or rounded mechanically in subsequent process steps. Furthermore, it is ensured on account of the material-selective etching of the bristle end that a predetermined minimum thickness of the bristle end can not be undershot, so that the risk of breaking or uncontrolled breaking off is reliably counteracted.

Of Furthermore, such a material-selective etching process goes with a reduction associated with the material to be removed, so that a total of a higher yield the etching process can be achieved with corresponding cost advantages.

3 shows a further embodiment of a multi-filament bristle 4 , Here are several filaments 6 made of the same material, regularly and spaced apart, across the cross-section of the bristle 4 arranged distributed. The spaces between the filaments 6 are here with the filament 5 filled in, which is removed by the chemical used in the etching process. By immersing such a bristle end in the corrosive chemical also here, the filament 5 be completely removed at the free bristle end, so that the individual filaments 6 remain with a smaller diameter, which are suitable for receiving material in the Filamentzwischenräumen and for penetration into the smallest interdental spaces.

4 finally shows another embodiment of a bristle 7 , the radially symmetrically arranged segments of different filaments 8th . 9 has in cross section. In contrast to the embodiment according to 3 all filaments run 8th . 9 in each case from the center of the bristle to the edge of the bristle. Again, by a corre sponding etching process individual filaments 8th or 9 be removed at the free bristle end targeted.

5 shows another example of a bristle end, in which individual filaments 12 made of a material adjacent to the bristle perimeter and spaced apart, while the other filament 11 fills the core area of the bristle. In this embodiment, it is provided in particular that the filament 11 Partially removed by the etching process, so that the individual bristle filaments 12 be exposed at least in some areas and so a spread end of the bristle 10 form.

6 finally shows a schematic side view of another bristle end 13 which different filaments 14 . 15 which are preferably detached from one another by means of a chemical etching process and thus form a fanned-out bristle end. Here it can be provided, for example, that the filaments consisting of different materials 14 . 15 by means of a further, not explicitly shown filament, such as in the manner of in 5 shown filaments 11 , are first held together, which is finally removed in the etching process, so that ultimately in the 6 shown fan-like structure at the end of the bristle arises.

Claims (17)

Bristle ( 1 ; 4 ; 7 ; 10 ; 13 ), in particular for toothbrushes, which in the longitudinal direction at least two jointly extruded filaments ( 2 . 3 ; 5 . 6 ; 8th . 9 ; 11 . 12 ; 14 . 15 ) of different materials, characterized in that the cross-sectional area of at least one filament ( 3 ; 5 ; 9 ; 11 ) decreases towards the free end of the bristle. Bristle according to claim 1, characterized in that the cross-sectional area of the at least one filament ( 3 ; 5 ; 9 ; 11 ) steadily to the free end of the bristle ( 1 ; 4 ; 7 ; 10 ; 13 ) decreases. Bristle according to claim 1 or 2, characterized in that the cross-sectional area of the at least one other filament ( 2 ; 6 ; 8th ; 12 ) is substantially constant in the longitudinal direction of the bristle. Bristle according to one of the preceding claims, characterized in that the bristle ( 1 ; 3 ; 7 ; 10 ; 13 ) is tapered towards its free end, in particular conical or pointed, is formed. Bristle according to one or more of the preceding claims, characterized in that the at least one other filament ( 2 ; 6 ; 8th ; 12 ) of the at least one filament ( 3 ; 5 ; 9 ; 11 ) is radially enclosed at least partially. Bristle according to one or more of the preceding claims, characterized in that the at least one other filament ( 2 ; 6 ; 8th ; 12 ) in the axial direction further than the at least one filament ( 3 ; 5 ; 9 ; 11 ). Bristle according to one or more of the preceding claims, characterized in that the at least one other filament ( 2 ; 6 ; 8th ; 12 ) is rounded or rounded at its free end. Bristle according to one or more of the preceding claims, characterized in that the at least two filaments ( 2 . 3 ; 5 . 6 ; 8th . 9 ; 11 . 12 ; 14 . 15 ) have different elasticity and / or different bending stiffness. Bristle according to one or more of the preceding claims, characterized in that the at least one filament ( 3 ; 5 ; 9 ; 11 ) is ablatable by means of an etchant against which the at least other filament ( 2 ; 6 ; 8th ; 12 ) is substantially resistant. Bristle according to one or more of the preceding claims, characterized in that as material for the filaments ( 2 . 3 ; 5 . 6 ; 8th . 9 ; 11 . 12 ; 14 . 15 ) Polyamide, in particular nylon, PA6.6, PA6.10, PA6.12 and / or polyester, in particular polyethylene terephthalate (PET) Polybuthylene terephthalate (PBT), is provided. Method for producing or processing bristles ( 1 ; 4 ; 7 ; 10 ; 13 ), in particular toothbrush bristles, which in the longitudinal direction at least two jointly extruded filaments ( 2 . 3 ; 5 . 6 ; 8th . 9 ; 11 . 12 ; 14 . 15 ) of different materials, characterized in that at least one of the filaments ( 3 ; 5 ; 9 ; 11 ) in the region of the free end of the bristles ( 1 ; 4 ; 7 ; 10 ; 13 ) is at least partially removed by means of a chemical etching process. A method according to claim 11, characterized in that by means of the etching process at least one against the etchant substantially resistant filament ( 2 ; 6 ; 8th ; 12 ) is at least partially exposed. Method according to one of the preceding claims 11 or 12, characterized in that by means of the etching process, an inner core of the bristle ( 1 ; 4 ; 7 ; 10 ) enclosing coat of filaments ( 3 ; 5 ; 9 ; 11 ) is at least partially removed. Method according to one or more of the preceding claims 11 to 13, characterized in that by means of the etching process, the free ends of a plurality of regularly arranged filaments ( 6 ; 8th ; 12 ; 14 . 15 ) are exposed. Method according to one or more of the preceding claims 11 to 14, characterized in that the bristle ends after the etching process rounded or rounded by grinding. Method according to one or more of the preceding claims 11 to 15, characterized in that the bristles ( 1 ; 4 ; 7 ; 10 ; 13 ) before the etching process on one of the bristles ( 1 ; 4 ; 7 ; 10 ; 13 ) are fixed bristle carrier provided. Brushware, in particular a toothbrush, with a bristle carrier on which bristles ( 1 ; 4 ; 7 ; 10 ; 13 ) are arranged according to one or more of the preceding claims 1 to 10.