Patent Application
20210022481
For a long time there has been a widespread need for applicators for applying mascara mass, cosmetic mass to the eyebrows or cosmetic mass to the main hair, which have the largest possible mass storage capacity, i.e which are loaded with the cosmetic to be applied as far as possible already after being immersed in and pulled out of the supply once so that the entire application process can be carried out without immersing the applicator again.
In order to remedy this, it has been proposed in a wide variety of variants to incorporate more or less narrow grooves into the finished bristle facing of a wire core applicator, i.e. areas in which there are lower-lying short bristles that are surrounded by higher bristles. The basic idea here is that cosmetic can be retained in the grooves formed in this way, which is not being completely stripped off by the wiper when the applicator is pulled out. This actually improves the storage capacity significantly.
However, due to the relatively large-scale and noticeable grooves, the haptic behavior of the applicator is impaired for the perception of many female users.
Then, some very different variants of applicators with sprayed bristles have already been proposed, which are designed so that they have an improved mass storage capacity. Sprayed bristles however still offer only a weaker performance in terms of bend recovery capabilities and are therefore as well not the single solution.
The invention is based on the objective to create an applicator which is characterized by a particularly good mass storage capacity on the one hand, and which also enables an exceptionally smooth application experience on the other.
To solve this problem, it is proposed to build an applicator which consists of bristle-forming filaments clamped between at least two wires that are twisted together. A filament usually forms two bristles. The part of a filament that extends from the clamping point between the twisted wires to the radially outer free end is named bristle. According to the invention, a TPE is used for the bristle-forming filaments. The elastomers from the TPE group are characterized by their particular flexibility. It is to be ensured that even within the TPE a particularly soft material is used, namely a material that has a hardness of less than 60 Shore D and ideally 55 Shore D, ideally with max. 1% tolerance. The smallest possible Shore hardness within the scope of the invention is 40 Shore D and in exceptional cases 35 Shore D.
In principle, such a material would only be suitable for the production of bristle-forming filaments to a very limited extent, since it is actually too soft to produce bristle-forming filaments which subsequently lead to bristles with sufficient bending resistance. In order to compensate for this, not only is the outer diameter of the filaments increased, but also additional ribs are provided which protrude radially outward on all sides from the solid core cross-section of the bristle-forming filament. Grooves, which are characterized by a particularly high mass storage capacity, are formed between the ribs.
The ribs in conjunction with the enlarged diameter and the, on the other hand, quite soft material result in a bristle that is not only very supple, but also does not buckle prematurely.
Surprisingly, compliance with these specifications also results in an unexpectedly useful storage effect. This is because the grooves between the ribs can not only absorb material particularly well, but also collapse easily locally when the later bristles come into contact with the treated surface or come into contact with the hair to be treated and bend in the process due to the extremely soft plastic that is used for the bristle-forming filaments. As a result of this collapse, the stored material is released very well. As a result, this type of filament leads to bristles that show an exceptionally good capacity for mass storage and re-release with a special, haptic experience on skin contact that has never been seen before.
The bristles according to the invention must, as far as the specific dimensioning is concerned, be matched very precisely to the individual case, since the choice of material according to the invention and the geometric configuration goes into a range that is not variable at will anymore concerning the closely related length and thickness parameters.
Where these bristles are used to build an eyebrow applicator, the outside diameter of the filaments should be at least 0.25 mm in an undisturbed area. Smaller diameters lead to a disruption of the desired storage function of the grooves. The length of the bristles formed by these filaments should be a maximum of 3 mm for an eyebrow appliator, measured from the pinching wire core to the radially outward free end. Ideally, the bristles are at least 1.5 mm long.
Where these bristles are used to build a mascara applicator, the outside diameter of the filaments should be at least 0.35 mm in an undisturbed area. Smaller diameters lead to a disruption of the storage function of the grooves which is desired for the application of the typically very highly viscous mascara mass. The length of the bristles formed by these filaments should be a maximum of 6 mm in the case of an eyebrow applicator, measured from the pinching wire core to the radially outward free end. Ideally, the bristles are at least 2 mm long.
Where these bristles are used to build a main hair applicator, the outside diameter of the filaments should be at least 0.7 mm at an undisturbed point. In many cases it is not favorable if the outer diameter of the filaments is more than 0.9 mm. Smaller diameters are unsuitable for treating the main hair, which usually offers some resistance, since they make the bristles too sensitive to kinking. The length of the bristles formed by these filaments should be a maximum of 12 mm in the case of an eyebrow applicator, measured from the pinching wire core up to the radially outward free end.
Ideally, the bristles are at least 5 mm long.
A particularly advantageous further development option is to produce the filaments according to the invention from a thermoplastic elastomer (TPE). Despite its according to the invention low Shore hardness D, this material allows fine structures to be extruded, such as the filaments required here. Surprisingly, even with the very high degree of softness chosen here, a TPE is clearly superior in terms of the bend recovery capacity, while at the same time ensuring the required relative movement behavior of the ribs relative to the solid core, when the later bristle is having contact with the surface or hair to be treated and is bent in the process.
Further advantageous design options emerge from the subclaims.
The following description of various preferred embodiments based on the figures also gives rise to further design options, modes of operation and advantages.
A first overview of an applicator according to the invention 1 in the form of a mascara applicator is shown in
Said specially designed bristle-forming filaments have a filament longitudinal axis FL. They are shown as such—in various variants—in the context of
The cross section according to the invention of a bristle-forming filament 5 to be used according to the invention is shown in
It can be seen immediately that this bristle-forming filament used according to the invention has a solid core in the cross section running perpendicular to its longitudinal axis, which is denoted by the reference number 7 and which is marked in
At least eight and in the present case ten ribs 8 protrude outward in the radial direction from this bristle-forming core. The ribs protrude outward on all sides relative to the filament longitudinal axis FL, which usually forms the center. This means at each point of the outer jacket of the core, there is preferably a rib 8 present, which protrudes outward in the radial direction, as shown in
As can best be seen from
It is noteworthy that the maximum diameter DKmax of the solid core 7 is preferably more than twice the radial extension Re of a rib. This can be seen clearly from
To put it even more succinctly, one can say that the following relationships should ideally be observed for the maximum outer diameter DAmax and the maximum core diameter of the solid core
The bristle-forming filament according to the invention preferably consists of a thermoplastic elastomer, that is to say of an elastomer from the TPE family. Thermoplastic elastomers are characterized by the fact that they are particularly soft and pliable. This gives the bristles 6, which are formed by the bristle-forming filaments 5 clamped between the wires 3, 4, a particularly good conformability. Nevertheless, in order not to let the bristles become too soft and pliable, the invention provides that a comparatively large bristle outer diameter is realized, as already stated numerically above for a mascara applicator and also defined later for eyebrow applicators and brushes for main hair.
In the light of this consideration, the function of the radially outwardly protruding ribs 8 is revealed. They increase the effective outer diameter DAmax of the bristle-forming filament and thus the flexural strength of the later bristle 6, even if extremely soft material is used.
However, associated with this, there is also another very positive aspect. This goes back to the fact that a relatively deep groove 9 is formed between two ribs 8 that are directly adjacent in the circumferential direction. Ideally with all applicators—at least with mascara and/or main hair applicators—the radial depth RT of such a groove 9 between two ribs 8 adjacent in the circumferential direction is greater than 0.08 mm. For eyebrow applicators, this value is optionally reduced from the aforementioned value to 0.05 mm.
As a result, a not inconsiderable amount of the cosmetic product to be applied can be placed in these grooves 9, which is not stripped off by the scraper when the applicator is pulled out of the supply comprising the substance to be applied (according to this embodiment example mascara mass).
Instead, the substance stored in these grooves 9 is only released—usually gradually—when the bristle formed by the filament in question bends back and forth several times in contact with the surface to be treated or the hair to be treated and thereby the substance in the area of the grooves 9 is pushed out. This ideally gradual release of the substance to be applied allows the applicator to work very long-term without having to “reload” in between.
The storage effect according to the invention is further enhanced by the fact that the ribs 8, considering the circumferential direction, have a width that changes in the radial direction.
As can best be seen from
It is noteworthy that the tip section 11 of the ribs 8 according to the invention—as soon as one moves in the radial direction outward from the transition base section/tip section in the circumferential direction—by far predominantly (more than 50%, better than 75%) has a greater extent EU1, as the transition between the base section and the tip section of the relevant rib, the extent of which in the circumferential direction is only EU2, cf.
As a result, two ribs 8 directly adjacent to each other in the circumferential direction form a groove 9 between them, the width of which gradually decreases again in the radial direction from the inside to the outside. This reinforces the holding effect that the relevant groove 9 gives the substance to be applied.
It has proven to be particularly favorable for the holding effect if the transition between the base section 10 and the tip section 11 of a rib 8 forms a kink, meaning a geometry in which max. an imaginary measuring circle 12 can nestle with a maximum diameter of 0.015 mm, cf.
At this point it should be said that it has also proven to be very beneficial for the all-round wetting of a hair that has penetrated the groove between two ribs if the groove base narrows in a V-shape—ideally into a narrowest area, the one at the base kink forms, i.e. shows a geometry in which at most an imaginary measuring circle 12 with a maximum diameter of 0.015 mm can nestle, cf.
It has proven to be particularly favorable to make the tip section of a rib predominantly circular in cross section (or alternatively, to approximate it in a multipolygonal manner). This preferably means that the cross-sectional profile, seen perpendicular to the filament longitudinal axis FL, has a circular profile over an angle beta of more than 220°, cf.
It can be clearly seen from
In exceptional cases, however, it can nevertheless be useful to leave the dogma of the straight rib 8 and to make the ribs 8 spiral, i.e. in such a way that they wind around the filament longitudinal axis FL like a helical line.
As a result, however, there is usually a somewhat lower release of material from the bristle 6 formed by the filament 5 in question when it comes into contact with the surface to be treated or the hair to be treated.
One can only guess from
This results in a very special application behavior because, viewed overall, there are fewer bristles available on the finished applicator that can store the mass to be applied. However, this is overcompensated by the extremely increased storage capacity of the individual bristles, which they receive from their surface structured according to the invention.
It should also be noted that the filaments according to the invention which are used here for forming bristles are preferably continuously extruded filaments. This is very advantageous in so far as the filaments are strongly stretched in the direction of their longitudinal filament axis as they pass through the extruder nozzle. This means that extrusion is not just a manufacturing process, but also a physically reflected “product-by-process” feature, because extrusion means that the molecular chains of the filament-forming plastics are aligned to a high degree in the same direction and increasingly parallel to the filament longitudinal axis, i.e. drawn out. As a result, such filaments or the bristles formed from them have an excellent ability to straighten up, which is also referred to as bend recovery ability. In this respect, they are physically different (namely with regard to their sub-macroscopic structure) and therefore clearly superior to sprayed bristles.
It is particularly favorable if the filaments used according to the invention for forming the bristles consist of pure TPE. Particularly preferred TPE used are the subgroups TPE-A and TPE-S, which on the one hand can be extruded particularly well with the required dimensional accuracy and on the other hand have a superior bend recovery capacity, which is an essential property for a material, used for the production of bristle-forming filaments.
Especially for applications where however long-term stability is not required because the applicator is more of a disposable applicator, it can also be useful to add filler materials to the TPE that forms the said filaments. A filler material which has just proven to be very suitable for use in accordance with the invention is calcium carbonate. Added in small amounts, calcium carbonate hardly changes the application properties of the TPE. Used in slightly larger quantities, the elasticity is reduced. This is process-wise easily controllable, i.e. the desired bristle properties can be set very quickly and efficiently using the teaching according to the invention.
Charcoal has proven to be just as suitable.
Regardless of whether with or without filler material, the material of the bristle-forming filaments is always chosen according to the invention n such a manner that it has a hardness that is below 60 Shore D and ideally 55 Shore D, plus any tolerance values, as already mentioned above.
Investigations carried out in connection with the invention have shown that the bristles according to the invention, which are provided with a very large diameter, have difficulties in developing the desired separation effect due to their design according to the invention.
In order to remedy this problem it has been found beneficial to sharpen the bristles. Sharpening is typically only carried out after the filaments have been installed and the wires holding them twisted, i.e. at a stage in which each filament has already formed two bristles.
For this purpose, the bristles are usually fed to a grinding wheel. In the simplest case, all or a predominant part of the bristles are given a simple, one-dimensional bevel, which gives them a pent-roof-like bevel 13 at their free end, which
An even better separation effect can be achieved if the bristles or at least the majority of the bristles are ground from two sides so that they have a chisel-shaped tip or a bevel 14 in the shape of a gable roof. This constellation is visualized in
An even more favorable constellation is shown in
The second embodiment is an eyebrow applicator. All of the above applies identically to it. The figures also apply. The only difference is that the parameters of the filament as well as bristle outer diameter and the bristle length that are required for eyebrow application that were already specified at the beginning must be observed.
The third embodiment is a main hair applicator. All of the above applies identically to him, and the figures also apply. The only difference is that the parameters of the filament required for the main hair application as well as the outer bristle diameter and the bristle length that were already specified at the beginning must be observed.
The tip section 11 of each or the predominant number of the ribs 8 is preferably designed to be circular in cross-section, as can also be seen from the figures explained below.
It is particularly favorable—depending on the particular application of the applicator—to maintain certain depths for the grooves 9.
If the applicator which is equipped with the fiber according to the invention is an eyebrow applicator, i.e. an applicator that is intended for the application of a cosmetic to the eyebrows or is even specialized in this, then the depth of the groove 9 should be dimensioned so that the maximum depth of groove 9 is chosen in such a way that the circle with diameter DKmax, which forms the sheath of the solid core 2 and the circles inscribed in the tip sections 11 with the radius r are still tangent, cf.
If the applicator which is equipped with the fiber according to the invention is a mascara applicator, i.e. an applicator that is intended for the application of a cosmetic on the eyelashes or is even specialized in this, then the depth of the groove 9 should be such that the groove 9 is at least deep enough that the circle that forms the sheath of the massive core 2 and the circles inscribed in the tip sections 11 are still tangent or the depth of the groove should be made larger so that the said circles no longer tangle (and certainly do not intersect), cf.
If the applicator to which the fiber according to the invention is to be applied is an applicator for the main hair, i.e. an applicator which is intended for the application of a cosmetic on the main hair or is even specialized in this, then the depth of the groove 9 should be such that the groove 9 is always made so deep that the circle that forms the sheath of the solid core 2 and the circles inscribed in the tip sections 11 no longer tangle (and certainly do not intersect), cf. again
| Number | Date | Country | Kind |
|---|---|---|---|
| 20 2018 101 427.7 | Mar 2018 | DE | national |
| Filing Document | Filing Date | Country | Kind |
|---|---|---|---|
| PCT/EP2019/056027 | 3/11/2019 | WO | 00 |
