WIRE-CORE APPLICATOR WITH BEVELLED HOLLOW FIBER BRISTLES

Abstract

A mascara brush comprising a core made of at least two wire sections twisted with one another along a wire-core longitudinal axis and a set of bristles made of bristles formed from plastic filaments, each of said bristles being held in a clamped manner between the two wire sections and being formed on the free ends thereof with or without a wedge-shaped bristle tip, wherein the bristles, at least partially, are formed from internally hollow filaments, a solution is provided with which the mass delivery in relation to the known applicators is improved. Same is achieved in that, in particular at least, the bristles formed on the inside in a hollow manner on the radially outward free ends have an oblique cut in the form of a simple wedge and comprise a wedge-shaped bristle tip comprising at least one cut surface forming a wedge.

Description

FIELD OF THE INVENTION

The invention is directed to a mascara brush with an inner core of at least two wire portions twisted together and with a bristle coveting of bristles formed by internally hollow filaments that are each held clamped between the two wire portions.

BACKGROUND OF THE INVENTION

Applicators of this type are also referred to as wire core applicators,

These applicators are still greatly appreciated today, because not only do they afford advantages with regard to their application, but also have various advantages in production that cannot be achieved with the injected applicators that compete with them. For example, small series can also be manufactured rather effectively because as a rule, very different wire core applicators can be produced on the existing production systems without considerable sums having to be invested in new tools for the one special applicator, unlike for injected applicators.

In general, it also applies to wire core applicators that they are supposed to meet two requirements, in particular:

Their bristle covering is supposed to have as great a mass storage capacity as possible so that the applicator needs to be dipped into the cosmetics supply only once or only a few times in order to envelop the eyelashes with a sufficiently voluminous layer of mascara mass.

On the other hand, their bristle covering is supposed to have as good a separation capacity as possible, i.e. the capacity of separating obliquely overlying eyelashes of the curve of the eyelashes and aligning them in a largely parallel manner. The reason for this is not least that the eyelashes can only be provided with the desired volume by means of the mascara mass if they are each coated all around individually, and not already previously drenched and stuck together in clumps with mascara mass.

In general, it thus applies to wire core applicators that they are supposed to meet high requirements, in particular, for the mass storage capacity with regard to the substance that is, to be applied with them.

In the present case, however, the point is not only to increase the mass storage capacity to such an extent that the applicator does not have to be dipped in anew and recharged all too often during the application of mascara. The primary additional point is to ensure also that an eyelash is wetted as intensively as possible with mascara mass during an application process in order to instantly make the eyelashes appear as voluminous as possible in this manner—without having to coat the eyelashes several times and, in the process, take the risk that the separating action suffers and that adjacent eyelashes still stick together at some point due to the multiple application of mascara.

The approach to achieve this is to provide the mascara applicator with bristles that, each for itself, carries as thick a film of mascara mass as possible after dipping them into the mascara supply.

Various solutions have already been proposed in the prior art to take account for this.

For example, U.S. Pat. No. 4,733,425 proposes the use of bristles that are internally hollow or have a star-shaped, non-circular cross section. These bristles are said to have an excellent mass storage capacity, in particular the internally hollow bristles, because they are capable of storing mascara mass in their interior due to their capillary action, given a corresponding theological setup of the mascara mass.

If such bristles are examined systematically, it is found that the bristles are indeed capable of accommodating mascara mass rather well due to the capillary action of their hollow interior region. In this case, the accommodation of mascara mass is facilitated not least by the fact that, between two application processes, the applicators are frequently immersed for hours in the storage container filled with mascara mass so that the capillary action, which naturally causes a comparatively slow “suction”, is able to come to bear unrestrictedly.

The result appears more critical when it comes to the discharge of the mascara mass during the application, which lasts only a short moment. Even if the bristles are bent back and forth and the supply stored in their interior is thus put under pressure and conveyed towards the outside, it is found in systematic tests that the discharge of mascara, mass constitutes a “bottleneck”, so that in this respect, improvements are called for.

Therefore, it is the object of the invention to specify a mascara brush equipped with hollow bristles in which the mass discharge is improved over the known applicators.

SUMMARY OF THE INVENTION

The mascara brush according to the invention comprises an inner core of at least two wire portions twisted together and a bristle covering of internally hollow filaments that are each held clamped between the two wire portions. In this case, the filaments for bristles, which are internally hollow, though most frequently no longer in the clamping area of the wire core, but otherwise, and thus have the required capillary action for accommodating mascara mass. In this case, the point is not at all that mascara mass is drawn into the bristle over its entire length or a predominant part thereof due to the capillary action; rather, only the processes at the radially outward end of the respective brush are of interest.

In a first aspect, the mascara brush according to the invention is characterized in that the radially outward free ends of the bristles are cut obliquely like a simple wedge, so that a first side of the bristle concerned, viewed from the wire core along the respective bristle, has a maximum longitudinal extent and the second side diametrically opposite to it has a minimum longitudinal extent. This means that the bristle ends are not pointed in the manner a chisel or a roof, i.e. from two sides, Instead, a single end face, which is referred to as a cut face and extends obliquely in a wedge-like manner relative to the longitudinal bristle axis and which, speaking figuratively, is similar to the obliquely cut end of a cut rose, is provided at the end of the bristle concerned.

In this case, the term “cut obliquely” in the sense of the invention is not to be understood to mean that the wedge surface needs to have been produced by a cutting process, i.e. by “obliquely cutting” the filament, rather, it may also have been produced by correspondingly grinding the bristle end; this is actually the preferred manufacturing method.

The crucial point is that the oblique cut, or the wedge surface produced thereby, causes the mouth of the bristle to become significantly larger and thus creates a larger area in which mascara mass can be stored in such a way that it is immediately available for discharge upon application, and that mascara mass that is stored slightly deeper in the bristle interior can also be discharged more easily via the greater area of the mouth.

In addition, the cut face of the bristles produced by the oblique cut forms a large contact area, which the individual eyelash can slide along for a fairly long time before it slips off the end face of the bristle and comes to lie between adjacent bristles. Meanwhile, the eyelash has ample opportunity for being wetted with mascara mass. The invention differs from the prior art also in this respect, because an individual eyelash is capable of remaining only for a much shorter time on a small-surface end face extending substantially perpendicularly to the longitudinal bristle axis of a hollow bristle without an oblique cut face, before it slips into the spaces between the bristles.

In a mascara brush of the type referred to in more detail in the introduction, which has bristles having at their free ends a wedge-shaped bristle tip and at least one cut face (4) forming a wedge, the surface roughness (Rz) of the respective cut faces (4) can be between 0.2 um and 6.3 μm, in particular between 2.9 μm and 6.3 μm.

The surface roughness Rz, which is also referred to as roughness depth, is to be determined in accordance with DIN EN ISO 4287/4288.

By forming wedge-shaped cut faces, which improve combing, with the indicated roughness Rz between 0.2 μm and 6.3 μm, in particular between 2.9 μm and 6.3 μm, the mascara accommodating capacity of each bristle cut in a wedge-shaped oblique manner is improved. In this case, it is particularly advantageous that, due to the roughness according to the invention, the obliquely extending cut faces have a good mascara accommodating capacity and, thus, also a correspondingly good mascara discharging capacity to the eyelash hairs that first slide along them during the combing process. Thus, the cut faces are of particular importance since, during the make-up process, the eyelashes are fast guided along this surface and slide along it at the beginning of the make-up movement. In particular, the surface roughness (Rz) can be produced by grinding the bristle ends by means of a grinding disk. The roughness and, along with it, the mass accommodating and mass storage capacities for mascara mass ate improved by the grinding. In particular, the desired roughness of the oblique cut Face can be influenced and determined by selecting the roughness of the grinding disk(s) used during grinding accordingly.

That is, the above-mentioned object is achieved with a mascara brush with an inner core of at least two wire portions twisted together and a bristle covering of bristles formed by filaments. The filaments are each held clamped between the two wire portions. The bristles are made from a hollow plastic material and carry at their free ends a wedge-shaped tip instead of an end face extending substantially perpendicularly to the longitudinal bristle axis.

It is therefore useful if the total number of bristles has, for the predominant part, a wedge-shaped tip with at least one cut face, and a part of the bristles has a wedge-shaped tip with a cut face formed by an oblique cut.

As will be explained in greater detail later, the at least one wedge surface with which a bristle can be equipped according to the invention makes it possible to push the bristle between the eyelashes in such, a manner, at the beginning of the application, that the respective eyelash better remains in contact with the bristle, even after the eyelash has slipped from the cut face forming the wedge surface into the area of the bristle shaft. Thus, the respective bristle shaft and the cut faces, which keep a thicker film of mascara mass stored due to their increased roughness, are able to discharge more of this mascara mass to the eyelash. Thus, a better coating of the eyelash takes place. Not least, the eyelash volume to be achieved benefits from this.

Preferably, the wedge-shaped tip of the respective bristle is formed by an oblique cut like a simple wedge, so that a first side of the bristle concerned has a maximum longitudinal extent (L_MAX) and the second side diametrically opposite to it has a minimum longitudinal extent (L_MIN). A particularly long and, relative to the longitudinal bristle axis, gently sloping wedge surface can thus be produced, which benefits the effect to be utilized according to the invention.

For other cases of application, the wedge-shaped tip can be formed by a double oblique cut, which consists of two surfaces that run towards each other and intersect at the free end of the bristle, at least in their imaginary extension. In this manner, the bristle concerned is able to act on both sides and thus influence two eyelashes at the same time, which have come to lie against the bristle from different sides. A part of the bristles can have a wedge-shaped tip formed by a double oblique cut, which has two cut Paces running towards each other which, or the imaginary extensions of which, intersect at or in the area of the free end of a respective bristle. A bristle configured in this manner is able to push eyelashes away to both sides and thus separate them. Unlike a bristle that is simply obliquely cut, such a bristle does not exhibit an irritating preferred direction.

It is particularly beneficial if the cut faces are substantially planar in themselves, ideally, two opposite cut faces at the same bristle end substantially have the same size.

The bristles can be orientated in such a way that the one or the two opposite cut facet(s) at a bristle tip are disposed transversely to the longitudinal wire core axis, wherein, then, particularly those bristles that are equipped only with a unilateral cut face are disposed and orientated in such a way that a part of the respective cut faces is orientated with an orientation towards the brush tip carrying the bristle covering, and a part is orientated towards the opposite brush end. In another embodiment, the invention is therefore characterized in that the cut faces are orientated transversely, in particular perpendicularly, to the longitudinal wire core axis (LD). Further, it is advantageous in this case if the cut faces of the bristles are, in part, orientated with one cut face in the direction towards the brush end and, in part, towards the, brush tip. Accordingly, within the context of this preferred exemplary embodiment, it is provided that the cut face formed by the oblique cut is orientated in such a way that, looking along the longitudinal wire core axis (i.e. looking frontally at the free end of the wire core or frontally at the free end of the wire core provided for attachment to the stem), one looks frontally at the cut face, whereas one does not look at the cut face if one looks in the circumferential direction. Preferably, this applies to all bristles of the covering.

A mascara brush can have several types of bristles configured differently at their bristle tips. For example, a bristle covering can have, in its entirety, bristles with a tip that is not pointed and not formed in a wedge-shape, and bristles with a bristle tip that is formed in a wedge-shape and has two opposite cut faces, and bristles with a bristle tip that is formed in a wedge-shape but has a cut face only on one side, with the cut faces being orientated in different directions, in one case towards the bristle end and in one case towards the bristle tip. Therefore, it is particularly useful if individual types of bristles are systematically arranged in the bristle covering and are respectively associated with areas, zones or sectors of the bristle covering. In one development, the invention is therefore further characterized in that the bristle covering has several areas, sectors or zones, which are orientated to extend, in the circumferential direction of the bristle covering, transversely, in particular perpendicularly, to the longitudinal wire core axis (LD), or, in the circumferential direction of the bristle covering, spiral-shaped to the longitudinal wire core axis (LD), or, in the longitudinal direction of the bristle covering, alongside of, in particular parallel to, the longitudinal wire core axis (LD), and which respectively comprise at least one bristle row consisting of several adjacent bristles that each have an identically configured bristle tip, or are formed by such a bristle row, and which, in the circumferential direction and/or in the longitudinal direction of the bristle covering, are respectively disposed adjacent to one area or sector or zone comprising several bristles, whose bristles have, in comparison therewith, a differently configured bristle tip.

In this case, however, it is also possible that the bristle covering has several areas, sectors or zones, which are orientated to extend, in the circumferential direction of the bristle covering, transversely, in particular perpendicularly, to the longitudinal wire core axis (LD), or, in the circumferential direction of the bristle covering, spiral-shaped to the longitudinal wire core axis (LD), or, in the longitudinal direction of the bristle covering, alongside of, in particular parallel to, the longitudinal wire core axis (LD), and which respectively comprise at least one bristle row consisting of several adjacent bristles, whose adjacent bristles each have a differently configured bristle tip.

Thus, for example, of the above-described types of bristles or of those described in this application as a whole, all bristle types can be disposed in each case individually alternately adjacent to each other in an area or a zone or a sector and thus form an area or a zone or a sector. However, it is also possible that only one bristle type is respectively disposed in an area or a zone or a sector and that then, for example in the circumferential direction of the bristle covering, an area or a zone or a sector with a respectively different bristle type respectively follows alternately. Preferably, an area or a zone or a sector comprises at least two bristles. Of course, all logically possible combinations of bristle types and areas, zones and sectors are possible. For example, not all of the above-mentioned bristle types or all of the bristle types described herein as a whole have to exist in every zone or every area or every sector or be present, as a matter of principle, in a bristle covering.

The extent of a zone, an area or a sector may vary. In another useful embodiment, the invention therefore provides that the several areas, sectors or zones, in the circumferential direction, transversely or longitudinally to the longitudinal wire core axis (LD), sweep over the circumference or a partial area of the circumference of the bristle covering once.

In principle, an area or a zone or a sector sweeps over an angular distance that constitutes ⅛ to 1/64 of the circumference or of the enveloping circle of the bristle covering, and thus an angular extent between 5.6° and 45°.

With respect to the bristles that are respectively equipped with a beveled cut face, it may be useful to provide, in each case alternately, an area or a sector or a zone in which the cut faces of all bristles are orientated to point in the direction towards the brush tip, and an area or a sector or a zone in which the cut faces of all bristles are orientated to point in the direction towards the brash end. For example, this can be produced by moving, in a first step, a grinding disk over the bristle covering from the brush tip, parallel and alongside the longitudinal wire core axis, to the brush end in order to produce the cut faces, then rotating the bristle covering or the mascara brush by ⅛ of a turn, for example, which corresponds to a rotation by 45°, and then moving the grinding disk in a second step in a direction opposite to the first step from the brush end, parallel and alongside the longitudinal wire core axis, to the brush tip. This sequence of steps is carried out until the grinding disk has moved and swept across the full 360° circumference of the bristle covering once.

Furthermore, it may be advantageous if the bristle covering consists of bristles or filaments with a wedge-shaped pointed portion and consists of further bristles or filaments without a wedge-shaped pointed portion, the bristle covering being preferably configured in such a way that the bristles or filaments with a wedge-shaped pointed portion form one or more sector(s) of the bristle covering and the further bristles or filaments form one or more further sector(s) the sector(s) and the further sector(s) preferably and ideally following each other alternately in the circumferential direction, which an embodiment of the invention also provides.

According to another embodiment of the invention, it is useful if between 1 and 8 sectors and between 1 and 8 further sectors are provided.

In this case, it may further be advantageous that the bristles or filaments with the wedge-shaped pointed portion are disposed in such a way, in the bristle covering that otherwise consists of further bristles or filaments, that they form a track extending in a spiral shape on the circumferential enveloping surface of the bristle covering, which the invention also provides.

Furthermore, it may be useful that the further bristles or filaments are made of the same material as the bristles or filaments with a wedge-shaped pointed portion.

Also in this case, it is advantageous that the chisel faces of the bristles or filaments with a wedge-shaped pointed portion, neglecting their wedge angle, are orientated perpendicularly to the course of the imaginary longitudinal axis of the spiral-shaped track.

It is particularly useful if the angle (a) by which the cut face(s) formed by the oblique cut or the double oblique cut is/are inclined relative to the longitudinal bristle axis complies with the relationship α≦55°, and ideally even α≦35°, This results in each case in a particularly long cut face well-suited for use, because it slopes only gently relative to the longitudinal bristle axis. Compliance with the relationship a 20° has proved to be absolutely ideal. Preferably, this is associated with a so-called double grinding, i.e. one and the same cut thee is ground for a first time and then, in a separate working step, a second time, whereby such a steep angle can be obtained. Therefore, the invention is further characterized in that, for the angle by which the cut face(s) formed by the oblique cut or the double oblique cut is/are inclined relative to the longitudinal bristle axis, the relationship is α≦55°, preferably a α≦35°, in particular α≦20°.

The filaments forming the bristles can have a non-round cross section, and preferably a polygonal or quadrilateral cross section.

Surprisingly, it was found to be particularly beneficial to configure the bristles or filaments, according to the invention, in a tube-shaped, internally hollow manner, preferably over the entire length (prior to twisting). This results in a particularly beneficial synergistic effect, particularly if the oblique cut is produced by grinding the bristles. If the bristle is internally hollow, it is capable of storing mascara mass with its cavity, which is discharged during application to the outside via the mouth of the cavity, which is located right in the center of the cut face. As a result, the eyelashes are already pre-coated as they slide along the cut face, which further improves the application of mascara as a whole. An essential point is in this case that the oblique cut, or the wedge surface produced thereby, causes the mouth of the internally hollow bristle to become significantly larger and thus creates a larger area in which mascara mass can be stored in such a way that it is immediately available for discharge upon application, and that mascara mass that is stored slightly deeper in the bristle interior can also be discharged more easily via the greater area of the mouth. In addition, the cut face of the bristles produced by the oblique cut forms a large contact area, which the individual eyelash can slide along for a fairly long time before it slips off the end face of the bristle and comes to lie between adjacent bristles. Meanwhile, the eyelash has ample opportunity for being wetted with mascara mass. The individual eyelash is capable of remaining only for a much shorter time on a small-surface end face extending substantially perpendicular to the longitudinal bristle axis of a hollow bristle without an oblique cut face, before it slips into the spaces between the bristles. Therefore, the invention is characterized in that the bristles or filaments are configured to be tube-shaped and internally hollow, as well as continuously slit in the direction along their longitudinal axis. It is beneficial to configure the bristles to be continuously slit in the direction along their longitudinal axis. In this manner, the bristles or filaments become slightly more unstable, or their stability can be controlled better, so that during application, the bristles are deformed more strongly in such a way that mascara mass stored in their cavity is discharged via its mouth in the area of the oblique cut.

Preferably, the outer diameter of bristles 1 with a circular configuration is ≧115 μm, and even better ≧215 μm, in the predominant number of cases, the outer diameter of the bristles 1 with a circular configuration used in the invention is ≦320 μm. in an embodiment, the invention is therefore also characterized in that the outer diameter of bristles with a circular configuration is ≧115 μm, preferably ≧215 μm, and ≦320 μm.

Where the bristles are non-circular, it applies that the outer enveloping circle of bristles configured to have a non-circular cross section has an enveloping circle diameter which is ≧100 μm, and better still ≧200 μm. In the predominant number of cases, the outer enveloping circle of the bristles with a non-circular configuration used in the invention is ≦340 μm, and better still, ≦320 μm. Finally, the invention is characterized in that the outer enveloping circle of bristles configured to be non-circular has an enveloping circle diameter which is ≧100 μm, preferably ≧200 μm, and ≦340 μm, in particular ≦320 μm. The enveloping circle is to be understood to be the circle into which the respective cross section of the bristle can be plotted with the best fit.

Both the outer diameter of the bristles and the enveloping circle diameter are configured to be ≦340 μm, in particular ≦320 μm, because the bristles would otherwise become so coarse that their capacity for separating the eyelashes is limited too much.

Where the bristles are hollow, the wall thickness of the bristles used, which is measured perpendicularly to the outer surface, can be between 15 μm and 100 μm. The wall thickness of the bristles, or of their bristle jacket which delimits the cavity inside the bristle, is in each case selected such that the hollow bristle, under the influence of the forces typically occurring during application, undergoes sufficiently strong deformation to press the mass stored in its interior towards the outside.

It has proved to be particularly beneficial if the corners of the radially outward bristle tips are rounded.

In addition, particles can also be admixed to the plastic material, or a supplementary effect improving the mass accommodating capacity can also be obtained by so-called indentations, i.e. point-shaped depressions, instead of by particles protruding locally from the surface, i.e. by a plurality of local depressions in the bristle surface which, seen microscopically or greatly enlarged, provide the bristle surface with a profile like a crispbread and thus make it more absorbent. Advantageously, the number of indentations or point-shaped depressions or impressions distributed over a respective bristle is greater than 200.

A further need for optimization may exist if the wire core applicator has a particularly dense bristle covering. In that case, it is basically clear that the separation capacity of the bristles can be increased further by producing the bristles from as hard a material as possible, which provides the bristle with a higher rigidity or buckling strength with the same diameter, and thus causes two positive effects. A rigid bristle is inherently better capable of penetrating between overlying eyelashes of the curve of the eyelashes. In addition, a rigid bristle has a much smaller tendency to evade the grinding disk, and therefore offers the possibility of a more pronounced grinding of the tips than a softer bristle. However, the attempt to use hard materials and, in particular, hard plastic materials reveals the problem that the quality of the outer edge of the ground surface can decline during grinding. The problem may occur that the edge no longer forms a clean continuous line but possibly exhibits a ragged contour, which may impede the sliding of the eyelashes along the edge. In order to avoid this, it may be provided that the bristles are made from two different plastics; that they have a bristle jacket of a first, softer material and a bristle core, which is connected to the bristle jacket, of a second, harder material. Since bristles that are as hard as possible and, at the same time, slender are advantageous for separating the eyelashes as efficiently as possible, it would as such have been obvious to produce the jacket of the filament or the jacket of the bristles from the harder material, and not the core. This reason for this is that the radially outward areas of a cylinder are known to contribute much more to the bending rigidity than the central or core area of a cylinder located close to the neutral fiber. However, it was found that the core also provides the filament or the bristles formed by the filament with a greater bending rigidity, even when the bristle ends are ground to a generous extent and in the process lose the predominant part of their original jacket in the ground area. The hard core, which is preserved to a good extent even during grinding, simplifies making the free bristle ends pointed in as flat a manner as possible by grinding them, for it prevents the bristles from being able to evade the grinding disk all too easily, thus coming into contact with the grinding disk with insufficient intensity, so that they are efficiently ground and, above all, ground over a considerable length. Thus, the above-described embodiment of the bristles makes it much easier to provide the respective bristle end with as flat a wedge angle as possible and at least with as long a wedge surface as possible.

On the other hand, the behavior of the soft jacket supported by the hard core is exceptionally non-problematic during grinding, and it surprisingly forms a well-defined outer edge, free from fraying and/or chipping, i.e. irregularities that the individual eyelashes could hook into when the pointed bristle end penetrates the eyelash cover, which could affect the separation result adversely.

It can be advantageous if the predominant part of the filaments or bristles of the bristle covering is made from such a material mix and structure. For example, a certain number of filaments, e.g. thinner filaments, which frequently forms a minority and which consists of only a single material in each case, may be among the filaments that, for example, form the bristle covering or the brush covering These are preferably filaments that are consistently made from the softer material also used for the ground filaments.

It can be provided that at least 75% of all filaments, and ideally even all of the filaments used for a mascara applicator, are made from the claimed material mix.

The first and preferably also the second material can be a plastic, ideally a thermoplastic plastic.

The two plastics can be firmly bonded to each other by co-extrusion, and the filaments can be sections of a continuously co-extruded thread or several continuously co-extruded threads. In this case, co-extrusion is not simply an arbitrary, exchangeable method, but embosses the continuous thread, and thus also the filaments cut from it, and in turn the bristles formed therefrom, with its particular microstructure. On the one hand, this microstructure is characterized in that the two different plastic, materials are glued or welded or fused with each other particularly intimately and, on the other hand, that their plastic molecule chains have a significant orientation in the direction of the longitudinal axis, which later forms the longitudinal bristle axis. A cavity can be formed, for example after co-extrusion of such a filament, by slitting and partial removal of the core.

As the second material, such a material is to be preferred which has a modulus of elasticity (E modulus) of at least ≧1300 N/mm². It is significantly better if the second material has an E modulus of at least ≧1700 N/mm². For most cases of application, it is advisable if the modulus of the second material does not exceed 2700 N/mm².

It may be beneficial to incorporate polyamide 6.12 into the bristle core as the first material. In this case, the first material may have a Shore D hardness of ≦80. The method for measuring the Shore hardness D is standardized; the relevant standards are the standards DIN EN ISO 868 and DIN ISO 7619-1.

Within the context of a preferred exemplary embodiment, it is provided that the filaments, in the non-clamped state, i.e. prior to their being clamped between the wire legs twisted together, have a non-round cross section, and preferably a quadrilateral cross section, over the entire length. The bristles that are formed from these filaments after twisting have a corresponding cross section.

Within the context of a preferred exemplary embodiment, it is provided that the angle α by which the cut face formed by the oblique cut is inclined relative to the longitudinal bristle axis IL complies with the relationship α≦55°, and ideally even α≦35°. In particular, the compliance with the preferred value results in a long oblique cut via which a significant part of the mascara mass stored by the bristle concerned can also be discharged again. Within the context of a particularly preferred exemplary embodiment, which is produced by a second grinding in the predominant number of cases, an angle of α≦20° is provided, which results in particularly slender bristles.

It has proved to be particularly beneficial if the cut face of the oblique cut is orientated in such a way that, looking along the longitudinal applicator axis (i.e. looking frontally at the free end of the wire core or frontally at the five end of the wire core provided for attachment to the stem), one looks at the cut face, and not when looking along the circumferential direction. Given such an orientation of the cut face, the surface in the direction of movement of eyelashes moving into the bristle covering in the radially inward direction has the maximum size, so that the chance of individual eyelashes directly impacting the cut face is particularly large.

It has proved to be particularly beneficial if the corners of the radially outward bristle tips are rounded.

Preferably, it applies for the outer diameter of the bristles according to the invention, which are configured to be circular, that the outer diameter is greater than or equal to 115 μm, and better still greater than or equal to 215 μm. In this case, the outer diameter in many cases of applications should preferably not exceed 320 μm, because the bristles would otherwise become so coarse that their capacity for separating the eyelashes is limited too much.

Similar dimensions should be complied with if bristles with a non-round cross section are used.

In this case, it preferably applies that the outer enveloping circle of the bristles according to the invention configured to be non-circular has an enveloping circle diameter which is greater than or equal to 100 μm, and better still greater than or equal to 200 μm. The enveloping circle is to be understood to be the circle into which the respective cross section of the bristle can be plotted with the best fit. Preferably, there is also an upper limit for the enveloping circle diameter in this case which should be complied with in order to avoid too-coarse bristles with an insufficient separation capacity. Also in this case, the enveloping circle diameter for many cases of application should not exceed 350 μm, and better yet 320 μm.

The wall thickness of the bristles, or of their bristle jacket which delimits the cavity inside the bristle, must in each case be selected such that the hollow bristle, under the influence of the forces typically occurring during application, undergoes sufficiently strong deformation to press the mass stored in its interior towards die outside. Preferably, the wall thickness of the bristles according to the invention, which is measured perpendicularly to the outer surface, is therefore between 15 μm and 100 μm. in each case including the limit values.

Further mechanisms of action, advantages and optional embodiments and modifications of the invention become apparent from the following description of some exemplary embodiments with reference to the Figures.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 shows an exemplary embodiment of the bristle according to the invention from the front, in a top view onto the cut face forming the desired wedge surface.

FIG. 2 shows a bristle of the invention according to FIG. 1 in a side view of its wedge surface.

FIG. 3 shows a section of FIG. 2 along the longitudinal bristle axis and loaded with mascara mass.

FIG. 4 shows a second exemplary embodiment of a bristle according to the invention from the front, i.e. in a top view onto the wedge surface.

FIG. 4a shows a section through the bristle shaft of the bristle according to FIG. 4, which is carried out underneath the wedge surface along a plane perpendicular to the longitudinal bristle axis.

FIG. 5 shows a third exemplary embodiment of a bristle according to the invention from the front, i.e. in a top view onto the wedge surface.

FIG. 6 shows a section through the bristle according to FIG. 5, which is carried out along a plane perpendicular to the longitudinal bristle axis.

FIG. 7 shows another modified exemplary embodiment that is closely based on the exemplary embodiment described FIGS. 1 to 3.

FIG. 8 is a complete overview of a wire core applicator equipped with the bristles according to the invention.

FIG. 9 shows the orientation of the cut face of the oblique cut, which is orientated in such a way that, looking along the longitudinal applicator axis, one looks at the cut face.

FIG. 10 once again shows the orientation of the cut face of the oblique cut, which is orientated in such a way that, looking along the longitudinal applicator axis, one looks at the cut face.

FIG. 11 shows a variant of the invention with alternately pointed and non-pointed bristles.

FIG. 12 shows an enlarged detail from FIG. 6.

FIG. 13 shows a section of the variant shown by FIG. 6, in a frontal view from the front.

FIG. 14 shows a section of an alternative embodiment of the bristle variant shown in FIGS. 11 and 12.

DETAILED DESCRIPTION OF THE INVENTION

Generally, such an applicator or such a mascara brush 18 as it is shown by FIG. 8 is produced by placing a plurality of, at first, mostly straight filaments between at least one wire clamp 11 with two straight wire portions 12, 13. Preferably, a portion of a continuously extruded fiber is referred to as a filament in the sense of the invention. Generally, the filaments are placed between the wire sections 12, 13 of the wire clamp 11 in such a way that they protrude to a substantially equal extent (preferably maximally +/−10%) on both sides of the wire clamp 11 or of its wire portions 12, 13.

The wire portions 12, 13 are then twisted together, whereby the filaments are distributed and then firmly clamped between the wire portions. Generally, each filament forms two bristles 1. After twisting, While the brush is rotating, the brush contour is cut by means of a milling cutter and a counter blade in such a way that the plurality of the radially protruding bristles corresponds to a predetermined brush body, exactly according to the drawing. In a next step, the bristles are then beveled according to the invention, most frequently by grinding.

Thus, it is only “different sides of the same coin” that are addressed within the context of this description when the term “filament” is used at one time and the term “bristle” at another time.

FIGS. 1 and 2 show the details of an exemplary embodiment of a bristle 1 according to the invention.

In this exemplary embodiment, the bristle has a circular cross section, and the bristle is internally hollow, preferably over its entire length up to its anchoring point at its base between the twisted wires, see FIG. 1. Thus, the bristle forms a tube whose interior is able to accommodate and store mascara mass, at least in the area close to its mouth towards the outside.

At its radially outward free end, the bristle 1 has an oblique cut 3 like a simple wedge. This means that a first side of the bristle concerned, seen in the direction along the longitudinal bristle axis L, has a maximum longitudinal extent L_MAX and the second side diametrically opposite to it has a minimum longitudinal extent L_MIN. Thus, one side of the bristle is longer than the side diametrically opposite to it, see FIG. 2.

In this case, the bristle is, in any case, not only “slightly” obliquely cut, but exhibits a clearly recognizable oblique cut 3. Preferably, the angle by which the cut face 4 formed by the oblique cut 3 is inclined relative to the longitudinal bristle axis L complies with the relationship α≦55°, and ideally even α≦35°. An additional grinding, with which an angle α≦20° can be obtained, has a particularly advantageous effect on the degree of slenderness of the wedge.

It is ensured in this manner that the cut face is sufficiently large to obtain the effect intended by the invention, once again see FIG. 2.

Not only because of this, the result is a very pronounced cut face 4, which preferably has such a length that it extends over at least 1/10, better yet over at least ⅙ of the total length of a bristle, hi other words, it can be said that it is particularly beneficial for many cases of application if the following relationship is complied with: L_MAX≦L_MIN+½×filament diameter to L_MIN+2×filament diameter. With said additional grinding, this can be increased to up to L_MAX≦L_MIN+4×filament diameter—as can be seen in FIG. 2, which in this respect is not drawn to scale, referring to the cut face length AFL dimensioned there.

It must be noted that FIGS. 1 and 2 show an optional exemplary embodiment whose cut face 4 is substantially planar, i.e. level in itself. Another embodiment preferred even more for certain cases of application is illustrated in FIG. 7.

This embodiment corresponds fully to the embodiment shown by FIGS. 1 and 2, and differs from it only by the cut face 4 being curved convexly outward, at least in some areas, mostly predominantly. Ideally, the cut face (for example like a pocket watch glass) is convexly curved in two mutually perpendicular directions. Surprisingly, tests have shown that such a convex curvature significantly improves the discharge of the stored mascara mass and the wetting of the eyelashes sliding past even more.

The effect obtained with the invention can best be explained with reference to FIG. 3. The mascara mass, which in this case is depicted in black, enters into the hollow bristle core 5 completely or at least to some extent, and is stored there. If the bristles are moved or bent, e.g. when passing the wiper and/or during the actual application, a certain overpressure is produced in the hollow bristle core, which, in any case, presses the mascara mass stored in the area close to the mouth slightly outwards, so that the mascara mass is available for transfer to the eyelashes.

Due to the oblique cut 3 according to the invention, with its cut face 4, the surface on which mascara mass is available for transfer to the eyelashes is now significantly increased, which FIG. 3 makes clearly recognizable.

In addition, the cut face 4 is able to better (generally, longer and more intensively) come into contact with the eyelashes than a small end face extending approximately perpendicularly to the longitudinal bristle axis L. Because such a small end face is more difficult to hit by the eyelashes, and when an eyelash has placed itself on this small end face, then the further movement of the eyelash in the direction towards the inside of the covering is impeded, so that soon, a tension builds up that causes the eyelash to jump off the small end face, often even before a large part of the mascara mass available at the bristle mouth can be transferred onto it. This is different in the bristles with the configuration according to the invention. Here, the movement of the eyelashes W in the direction towards the inside of the covering is not impeded substantially. Instead, the eyelash W is able to gradually slide along the large cut face 4 in the direction towards the inside of the covering and intensively accommodate mascara mass. Thus, the loading of the eyelashes with mascara mass is improved, and at the same time, the capacity of the bristles to penetrate between the eyelashes is improved.

Turning again to FIG. 1, the outer bristle diameter 9 can be found to be drawn into it, which in the case of circular bristles should preferably be at least 115 μm, and better yet at least 215 μm.

Furthermore, the wall thickness 7 of the bristles according to the invention can be found to be drawn into FIG. 1, which should preferably be between 15 μm and 100 μm, in each case inclusive.

Looking at FIG. 2, it is to be noted that the cut face 4 preferably does not transition into the outer circumferential surface of the bristle in a sharp-edged manner, but forming a rounded portion, which of course need not be circular.

Preferably, the oblique cut is not produced by a corresponding oblique cutting during the separation of the continuous thread into individual filaments, but by grinding the radially outward ends of the bristles that are held between the wire portions already twisted together.

In this manner, given a corresponding movement and positioning of the grinding disk relative to the bristle to be ground, the preferred embodiment can be realized in which the cut faces 4 of the oblique cuts 3 are orientated in such a way that, looking along the longitudinal axis LD of the wire core or of the brush, one looks at them as a whole. This considerably improves the contact between the eyelashes and the bristles, because the cut faces 4 in that case present the maximum surface viewed in the direction in which the eyelashes move relative to the bristles.

At which angle the grinding disk has to be held and moved relative to the brush for this purpose cannot be generally defined in numbers, due to the strong dependency on the rigidity and length of the specifically used bristles; however, the person skilled, in the art is able to find out by tests common in the field of the bristles specifically used by him, once he has been instructed on what he is to achieve systematically.

FIG. 4 shows a second exemplary embodiment, which is a modification of the first exemplary embodiment. This sole difference is that the bristle according to the invention is slit in the direction of the longitudinal bristle axis in this exemplary embodiment.

Preferably, the slit is configured as illustrated by FIG. 4a. In that case, the slit is configured so as to “gape”, i.e. that the edges of the slit, do not come to rest against each other if the bristle is not under strain, that the free cross section of the slit becomes practically zero. Furthermore, the slit is preferably configured in such a way that it takes up between 7% and 21% of the total surface area of the wall cross section that an identical but unslit bristle has. These definitions for the slit also apply to bristles with a non-round cross section.

For bristles with a round cross section, it, preferably applies that the cut-out angle β describing the slit complies with the following relationship 15°≦β≦50° β.

The above-described slit is the result of filaments continuously slit alone their length. Of course, the filaments are “squeezed together” in the region of their clamping area between the twisted wire portions, so that they form bristles that are slit from their radially outward end up to the clamping area between the twisted wire portions.

The slit offers the advantage that the bristles tend to become more easily deformable, so that also the small forces already occurring during the actual application can be sufficient to deform the bristles in such a way that the mascara mass first stored in their hollow bristle core 5 escapes towards the outside through the mouth at the cut face 4 and/or the slit 8 and is then available at this location to be taken up by the eyelashes.

FIG. 5 shows a third exemplary embodiment winch is a modification of the above-described exemplary embodiments in the shape of bristles with a circular cross section. The only difference is that, in this exemplary embodiment, the bristle according to the invention does not have a round cross section, but a non-round one, or preferably a polygonal or quadrilateral one, preferably a square one.

Thus, the statements made previously with respect to the other exemplary embodiments also apply to this exemplary embodiment, unless otherwise defined because of its non-round cross section.

The crucial point is that bristles with a non-round cross section are in many cases even more suitable for realizing the invention than bristles with a round cross section. Because in the case of bristles with a non-round cross section, the bristles can be given a so-called preferred direction, i.e. a direction in which the bristles have an increased bending rigidity. The preferred direction can be combined in such a way with the cut 3 that the forces that are generated at the wedge surface and tend to bend the bristles to the side are absorbed particularly well, so that the bristle does not draw aside prematurely, but remains in contact long and intensively with the eyelash resting against the cut face 4.

The statement above applies to a greater extent if the bristle is slit in the direction of the longitudinal axis, because in that case, the non-slit surfaces that are laterally adjacent to the slit surface can be dimensioned in such a way that the weakening effect of the slit can be compensated to the exact extent this appears necessary in the individual case in order to obtain an optimum application result.

Furthermore, it applies that it is particularly advantageous for a series of cases of applications—particularly in those in which slit filaments are used—if the bristle cross section is selected not only to be non-round, but polygonal, or so as to have bends. In particular, it is configured to be rectangular.

As is easy to understand by referring to FIG. 5, such a cross section, in which the wall of the bristles has bends, results in a stabilization of the bristle, similar to that obtained by beads or edges in a metal sheet. An excessive weakening of the bristle by the slit can also be avoided in this manner. This means that, on the one hand, the bristle is able to “work” or be deformed in such a way, not least under the influence of the forces occurring during application, that the mascara mass stored in the core of the bristle is discharged towards the outside, but that, on the other hand, it is reliably avoided that the bristle is regularly overloaded in such a way during application that it collapses or buckles due to the slit, and is then no longer capable of contributing meaningfully to the make-up result, but instead starts to “smear” until it has straightened up again after the overload has ended.

FIG. 6 shows some characteristic parameters of this exemplary embodiment according to FIG. 5. For example, the enveloping circle can be seen here, which is depicted with a dash-dotted line and envelops the outer circumference of the bristle profile. Preferably, the diameter of the bristle profile is selected in such a way that the following applies to the enveloping circle diameter 9*:9*≧100 μm, and better 9*≧200 μm.

For the wall thickness 7, however, the same applies as or the bristles with the circular cross section.

Finally, it is stated that the bristle covering of the applicators according to the invention preferably completely consists of hollow filaments for most cases of application. For other, most frequently more special cases of application, a mix of the hollow filaments according to the invention and massive, preferably equally ground filaments is preferred, wherein the hollow filaments most frequently form the majority.

FIGS. 11, 12 and 13 illustrate a variant of the mascara brush according to the invention, with an exceptionally advantageous application and separation action.

As can be seen, the bristle covering in this case consists of bristles la with an oblique cut formed from filaments, as described above, and of further bristles lb without an oblique cut that are also formed from filaments.

In this case, the bristle covering is configured in such a way that the bristles la with an oblique cut form several sectors 100 of the bristle covering and the further bristles 1b form another sector 101. In the example illustrated by the Figures, the sectors and the further sectors follow each other alternately, repeated in a pattern that ends flush in the circumferential direction.

The number of the sectors depends on the individual case of use and the theological properties of the cosmetic used. Preferably, between 1 and 8 sectors and between 1 and 8 further sectors are provided.

Alternatively, there is the option of the filaments or bristles with the oblique cut being disposed in such a way, in the bristle covering that otherwise consists of further filaments, that they form a track extending in a spiral shape on the circumferential enveloping surface of the bristle covering, which is not shown here in the Figures.

Ideally, the further filaments are made of the same material as the filaments with an oblique cut.

In another variant of the mascara applicator previously explained with reference to the Figures which is also inventive and therefore claimed, the covering is configured in such a way that the oblique surfaces of the filaments with an oblique cut, neglecting their wedge or beveling angle, are orientated perpendicularly to the course of the imaginary longitudinal axis of the spiral-shaped track.

FIG. 14 illustrates a variant of the mascara brush according to the invention, with an exceptionally advantageous application and separation action.

As can be seen, the bristle covering 26 in this case consists of bristles 1a, 1c with a wedge-shaped pointed portion that are formed by filaments, and of further bristles 1b without a wedge-shaped pointed portion that are also formed from filaments, with the bristles 1a, 1c only differing with regard to the orientation of their cut face 4. The cut face 4 of each of the bristles 1a points towards the brush end 16, and the cut face 4 of each of the bristles 1c points towards the brush tip 15.

In this case, the bristle covering 26 is configured in such a way that the bristles 1a with the wedge-shaped pointed portion, of which several are disposed adjacent to each other in a bristle row 17, form a sector 100 of the bristle covering 26, the bristles 1c with the wedge-shaped pointed portion, of which several are disposed adjacent to each other in a bristle row 17′, form a sector 102 of the bristle covering 26, and the further bristles 1b, disposed in a bristle row 17″, form a further sector 101 of the bristle covering 26. In the example illustrated in FIG. 14, the sectors 100 and 102 and the further sector 101 follow each other alternately in the circumferential direction. The sector 102 is followed again by a sector 101. The sequence of sectors is continued until an arc of a circle of 360° is completed over the circumference of the bristle covering 26.

The number of the sectors depends on the individual case of use and the rheological properties of the cosmetic used. Preferably, between 1 and 8 sectors 100, 102 and between 1 and 8 further sectors 101 are provided.

Alternatively, there is the option of the filaments or bristles 1a, 1c with the wedge-shaped pointed portion being disposed in such a way, in the bristle covering 26 that otherwise consists of further filaments or bristles 1, 1b, that they form a track extending in a spiral shape on the circumferential enveloping surface of the bristle covering 26, which is not shown here in the Figures.

Ideally, the further filaments or bristles 1b are made of the same material as the filaments or bristles 1a, 1c with a wedge-shaped pointed portion.

In another variant of the mascara applicator previously explained with reference to the Figures, which is also inventive and therefore claimed, the covering is configured in such a way that the chisel faces of the filaments or bristles with a wedge-shaped pointed portion, neglecting their wedge angle, are orientated perpendicularly to the course of the imaginary longitudinal axis of the spiral-shaped track.

While all the bristles 1a, 1b, 1c of a respective bristle row 17, 17′, 17″ are identically configured with regard to the configuration of the bristle tip in the exemplary embodiment according to FIG. 14, a bristle row ma of course also be formed of bristles that each have differently configured bristle tips. For example, it is possible that bristles 1a, 1b, 1c are formed next to one another and adjacently in a bristle row, which are disposed in a repeating pattern relative to each other, with the pattern forming a sector, an area or a zone. All logically possible combinations can be realized. Also, sectors, areas or zones may extend in a spiral shape over the circumference of the bristle covering 26 or be disposed, configured and orientated so as to extend in the longitudinal direction of the longitudinal wire core axis LD.

Claims

1. A mascara brush, comprising:

an inner core of at least two wire portions twisted together; and

a bristle covering of bristles formed by internally hollow filaments that are each held clamped between the two wire portions, wherein radially outward free ends of the bristles have an oblique cut like a simple wedge, so that a first side of each bristle has a maximum longitudinal extent (LMAX) and a second side diametrically opposite to the first side has a minimum longitudinal extent (LMIN).

2. A mascara brush comprising:

an inner core of at least two wire portions twisted together along a longitudinal wire core axis (LD); and

a bristle covering of bristles of plastic formed b filaments that are each held clamped between the two wire portions and that are configured at their free ends with a wedge-shaped or without a wedge-shaped bristle tip, wherein at least some the bristles are formed from internally hollow filaments, and the bristles formed to be internally hollow have at their radially outward free ends an oblique cut like a simple wedge, and comprise a wedge-shaped bristle tip with at least one cut face forming a wedge.

3. The mascara brush according to claim 2, wherein the cut faces of the bristles are, in part, orientated in a direction towards a brush tip and, in part towards a brush end opposite the brush tip.

4. The mascara brush according to claim 2, wherein the bristle covering has a plurality of areas, sectors or zones, which are orientated to extend, in a circumferential direction of the bristle covering, transversely to the longitudinal wire core axis (LD), or, in the circumferential direction of the bristle covering, spiral-shaped to the longitudinal wire core axis (LD), or, in a longitudinal direction of the bristle covering, alongside of the longitudinal wire core axis (LD), and which respectively comprise at least one bristle row consisting of a plurality of adjacent bristles that each have an identically configured bristle tip, or are formed by such a bristle row, and which, in the circumferential direction and/or in the longitudinal direction of the bristle covering, are respectively disposed adjacent to one area or sector or zone comprising a plurality of bristles each having a differently configured bristle tip.

5. The mascara brush according to claim 1, wherein the bristle covering has a plurality of areas, sectors or zones, which are orientated to extend, in a circumferential direction of the bristle covering, transversely to a longitudinal wire core axis (LD), or, in the circumferential direction of the bristle covering, spiral-shaped to the longitudinal wire core axis (LD), or, in a longitudinal direction of the bristle covering, alongside of the longitudinal wire core axis (LD), and which respectively comprise at least one bristle row consisting of a plurality of adjacent bristles, whose adjacent bristles each have a differently configured bristle tip.

6. The mascara brush according to claim 4, wherein the a plurality of areas, sectors or zones, in the circumferential direction, transversely or longitudinally to the longitudinal wire core axis (LD), sweep over the circumference or a partial area of the circumference of the bristle covering once.

7. The mascara brush according to claim 2, wherein the bristle covering consists of bristles or filaments with a wedge-shaped pointed portion and of further bristles or filaments without a wedge-shaped pointed portion, wherein the bristles or filaments with a wedge-shaped pointed portion form one or more sector(s) of the bristle covering and the further bristles or filaments form one or more further sector(s) the sector(s) and the further sector(s) following each other alternately in a circumferential direction.

8. The mascara brush according to claim 7, wherein between 1 and 8 sectors and between 1 and 8 further sectors are provided.

9. The mascara brush according to claim 7, wherein the bristles or filament with the wedge-shaped pointed portion are disposed in such a way, in the bristle covering that otherwise consists of further bristles or filaments that the bristles or filaments with the wedge-shaped pointed portion form a track extending in a spiral shape on a circumferential enveloping surface of the bristle covering.

10. The mascara brush according to claim 7, wherein the further bristles or filaments are made of the same material as the bristles or filaments with a wedge-shaped pointed portion.

11. The mascara brush according to claim 9, wherein chisel faces of the bristles or filaments with a wedge-shaped pointed, portion, neglecting their wedge angel, are orientated perpendicularly to a course of an imaginary longitudinal axis of the spiral-shaped track.

12. The mascara brush according to claim 4, wherein an area or a zone or a sector sweeps over an angular distance that constitutes ⅛ to 1/64 of a 360° circumference or of a 360° enveloping circle of the bristle covering.

13. The mascara brush according to claim 4, wherein an area or a sector or a zone in Which the cut faces of all bristles are orientated to point in a direction towards a brush tip, and an area or a sector or a zone in which the cut faces of all bristles are orientated to point in a direction towards a brush end opposite the brush tip, are configured respectively alternately.

14. The mascara brush according to claim 1, wherein the cut faces formed by the oblique cut each have a surface roughness (Rz) of between 0.2 μm and 6.3 μm.

15. The mascara brush according to claim 2, wherein the filaments are slit along their length or the bristles or filaments are tube-shaped and internally hollow, as well as continuously slit in a direction along their longitudinal axis.

16. The mascara brush according to claim 1, wherein an angle (α) by which a cut face formed by the oblique cut is inclined relative to a longitudinal bristle axis (L) complies with the relationship α≦55°.

17. The mascara brush according to claim 1, wherein the filaments have a non-round cross section.

18. The mascara brush according to claim 1, wherein the oblique cuts forming the simple wedge are orientated relative to a longitudinal axis (LD) of the wire core in such a way that, looking along the longitudinal axis, one looks at the oblique cuts.

19. The mascara brush according to claim 1, wherein an outer diameter of bristles with a circular configuration is ≧115 μm.

20. The mascara brush according to claim 1, wherein an outer enveloping circle of bristles configured to be non-circular has an enveloping circle diameter (9*) which is ≧100 μm, and ≦340 μm.