GB2144374A - Process of and apparatus for the production of a cosmetic stick - Google Patents

Abstract

A cosmetic cartridge material in flowable state is filled directly into a sleeve H (which can be made pointed) of a cosmetic stick, and is subsequently solidified. In order to produce cosmetic sticks of cartridge thicknesses less than 6 mm with adequately high pigmenting and using constituents which are volatile at an elevated temperature (e.g. perfume oils) in a more simple way than hitherto, the sleeve is evacuated and the cartridge material sucked into one end of the sleeve under a partial vacuum. The apparatus alternatively includes means, Fig. 3 (not shown), for applying partial vacuum to said one end prior to pouring or means 51,52 for applying partial vacuum to the opposite end of the sleeve during pouring. <IMAGE>

Description

SPECIFICATION Process of and apparatus for the production of a cosmetic stick The invention relates to a process for the production of a cosmetic stick, in which a cosmetic cartridge material in flowable state is filled directly into a sleeve, which can be made pointed, and is subsequently solidified. Furthermore, the invention relates to an apparatus for implementation of the process.

Cosmetic sticks of the type discussed here have grease and wax cartridges and are used as lipsticks, mascara pencils, eyebrow pencils, rouge applicators, i.e. in decorative cosmetics, but also as perfume sticks, deodorant sticks, fresheners and the like. In a known process of the type mentioned above (German Patent Specification 27 18 957), molten cartridge material is poured into a prepared, finished sleeve and the cartridge material is then solidified by cooling. The pouring process has the advantage that the temperature regulation significant for development of the texture and structure of the cartridge can be controlled well during the pouring procedure. A cosmetic stick ready for use is therefore obtained a relatively short time after production, because the application properties of the cartridge no longer change due to the texture and structure achieved in the pouring procedure.However, a significant disadvantage of the pouring process is that cartridge material must be at least substantially liquid during processing and the degree of pigmenting of such materials is relatively limited in density. The consequence is that cartridges produced in this way generally have a transparent smear, i.e. the covering power of such smears is limited, particularly when light pigments are used. Furthermore, this method only allows the trouble-free production, without voids forming, of cosmetic sticks having, at best, a cartridge thickness down to six millimetres, as pigmenting impedes flowability and the cartridge material then tends to begin to solidify before the sleeve is fully filled. In the case of molten cartridge materials, the flowability of the cartridge material can be increased to a certain extent by working at an elevated temperature (up to 800C).However, such elevated temperatures prevent the use of readily volatile constituents in the cartridge material, such as volatile oils and perfumes, and also adversely affect the colouring power of certain dyestuffs, such as crimson, so that this limits the application range of the process. In order to make production of cosmetic sticks of smaller cartridge diameter, in particular in the popular slim size of about 2 mm to 0.5 mm thickness, a feasible proposition and, moreover, to make a stronger pigmenting and therefore covering power possible, it has hitherto been necessary to use the extrusion process for the production of such cartridges.In this process, cartridge material is forced through an extrusion nozzle at a temperature of about minus 20"C and is thus initially produced as a continuous cartridge filament which, in this state, is still of highly plastic consistency. Due to the recrystallisation properties of the greases and waxes used for cosmetic sticks, one of the requirements is the storage of cartridges produced in this way for months until they have acquired the requisite strength and rigidity and therefore have the application properties on the skin typical for a cosmetic cartridge. Variations in quality are frequently unavoidable in this ageing or afterhardening.In addition to this, working such cartridges into the stick sleeves is quite involved, because the cartridges have to be inserted in sleeve halves which are provided with grooves and are subsequently joined together, e.g. by adhesion, and the greatest care must be taken in this operation due to the fragile nature of the cartridges. For, if the cartridges produced in this way experience mechanical pressure during processing, e.g. due to imprecise groove formation of the sleeve halves or during embossing of the cosmetic sticks on the outside of the sleeve, this will cause local changes in the recrystallisation and the structure of the cartridge, which results in crumbling during application on the skin. Finally, a cosmetic stick can only be produced with difficulty by such a process without the cartridge becoming contaminated.

It is therefore an object of the invention to provide a simple process of the above-mentioned type (and the associated apparatus), by means of which cosmetic sticks having cartridge thicknesses of considerably less than 6 mm and having pigmenting and cartridge constituents of a type hitherto only possible when using the extrusion method of production can be obtained.

This object is achieved according to the invention by the sleeve being evacuated either before or during pouring whereby the cartridge material is sucked into the sleeve by a partial vacuum.

On the basis of this process method, it is possible for the first time in the pouring process, even using highly viscous flowable cartridge material, to realise cartridge thicknesses down to 0.5 mm (at a length of 20 cm), whilst however restricting the working temperature in the processing of molten cartridge materials to about 60"C. Thus, even highly volatile matter and temperature-sensitive substances can be used, meaning that a broad range of cosmetic sticks are producible in this way. It is also possible to carry out considerably stronger pigmenting of the cartridge materials even at low cartridge thicknesses, meaning that the quality and covering power even of thin cosmetic sticks are comparable with those of thick cosmetic sticks.

The shape of the cartridge is freely selectable in accordance with the configuration of the internal cross-section of the sleeve and can be oval, round or polygonal.

The process according to the invention can basically be implemented in two different ways: on the one hand, the sleeve can be strongly evacuated, so that the vacuum produced in it is sufficient that, when connected to a supply of flowable cartridge material, the appropriate quantity is sucked in and fills the sleeve. In this case, it is also possible to process sleeves which are only open at one end. On the other hand, the partial vacuum in the sleeve during the filling procedure can be produced and maintained by continued evacuation, which howev er makes the use of sleeves open at both ends a prerequisite.

The apparatus for implementing the process according to the invention assumes a supply container for the flowable, viscous cartridge material and a mount for the sleeve. According to the invention, the mount has a pour orifice connected to the supply container and a suction connection connected to a suction pump, and a seal assigned to the pour orifice and to the suction connection, respectively, by means of which seal the sleeve end is sealed off from the outside when mounted.

Depending on the type of procedure described above, pour orifice and suction connections are arranged in such a way that either the same sleeve end comes successively into connection first with the suction connection for evacuation and then with the pour orifice for filling, or one sleeve end is connected to the suction connection and the other sleeve end is connected to the pour orifice.

A first embodiment for implementing the firstmentioned process provides for the pour orifice and the suction connection to be made in a terminal plate, which adjoins, in sealed contact, a retainer plate which receives the sleeve end, in sealed manner, in a bore and which is displaceable relative to the terminal plate, such that the bore comes successively into connection with the suction con nection and the pour orifice.

According to a design of the apparatus intended to implement the other process, the apparatus is designed in such a way that the suction connection is assigned to one end of a sleeve open at both ends and the pour orifice is assigned to the other end of the sleeve, and in that at least one of the parts of the apparatus containing the pour orifice and the suction connection is movable in the axial direction ofthe sleeve as far as contact of the seals against the sleeve ends. In this case, the suction orifice and/or the sleeve end assigned to the suction orifice iso are appropriately equipped with a filter which is permeable to air but impermeable to the cartridge material.

The process according to the invention and exemplary embodiments for the apparatus according to the invention are described below in more detail with reference to the accompanying drawings, in which: Figure 1 shows a side view, cut away vertically in part, of an apparatus for the filling of prepared sleeves with cartridge material; Figure 2 shows a plan view of a terminal plate of the apparatus according to Figure 1; Figure 3 shows a diagrammatic section through the apparatus according to Figure 1 along the circular line Ill-Ill in Figure 2, which illustrates the individual processing phases; Figure 4 shows a side view, cut away in part, of another embodiment of the apparatus according to the invention.

The apparatus according to Figures 1 to 3 essentially consists of a stationary mount, which comprises es a base plate 1 and a terminal plate 2 connected to the former via columns 3, as well as a revolving rotary part, which is formed by a retainer plate 4 and a lifting plate 5 as well as a gripper 6, connected to the retainer plate 4, and which can be set in rotation by a central drive shaft 7, rotatably mounted in the plates 1,2.

As shown in Figure 2, the terminal plate 2 has a suction orifice 10forthe production of a prevacuum, a suction orifice 11 for the production of a main vacuum and a pour orifice 12 for the conveyance of flowable cartridge material. The orifices 10, 11 and 12 are each in the form of arc-shaped slots going through the terminal plate 2. The suction orifices 10 and 11 are each in connection with an associated suction connection 13, 14 (for illustrative purposes drawn on the left-hand side in Figure 1); connected to the pour orifice 12 is a supply container 15 for the flowable cartridge material, which is borne by the terminal plate.

The underside of the terminal plate 2 is machined in such a way that the retainer plate 4, which is in contact with and rotatable with respect to the former, seals off the orifices 10, 11 and 12 airtight from the bottom and only permits connection via bores 16 provided in the retainer plate 4. The underside of the bores 16 open into recesses 17, into which seals 18 are fitted. The seals 18 can be of any desired type and be made, for example, of silicon rubber, with plastic-coated ceramic or metal discs and the like. They have seating bores 19, which grip over the sleeve end to be fitted therein to such an extent that a perfect seal of the inside of the sleeve from the outside is ensured.

A guide column 8, which is secured to the retainer plate 4 and along which a sleeve gripper 9 is vertically adjustable, is assigned to each bore 16 and associated seal 18.

The lifting plate 5 is mounted on the central drive shaft 7 to be rigid in a rotational sense and bears lifting discs 21 corresponding in number to and arranged directly beneath the bores 16, which discs are actuated by a cam-controlled swing arm 22. The lifting discs 21 are displaceable in associated bores of the lifting plate 5 and are supported on the swing arm 22 via a lower extension 23 and a roller mounted thereto. At its free end, the swing arm 22 bears a roller 24, which rolls along a cam ring 25 during rotation of the drive shaft 7.The cam ring 25 is fixed to the base plate 1 by means of the columns 3 and, as will become clear from the following description, has a hollow in the region of t he receiving station and of the delivery station for sleeves to be filled, into which hollow the roller 24 drops when it passes over and thereby enables the lifting disc 21 to be lowered. The upper side of the lifting disc 21 is provided with a gasket, which is not shown in more detail.

The process and mode of action of the apparatus according to the invention are now illustrated with reference to Figures 2 and 3: the drive shaft 7 and thus the retainer plate 4 and the lifting plate 5 rotate continuously at a predetermined rotational speed (e.g. of 8.5 revolutions per minute). In a feed station I, a feed device (not shown) passes empty sleeves H, which are open at both ends and machined flat on at least the lower face and cut off perpendicular to the sleeve's longitudinal axis, to the sleeve gripper 9 which holds them between the sleeve ends. At this point, the shaped ring 25 has a hollow, so that the swing arm 22 is in the downward swung position and the lifting disc 21 is consequently lowered into the lifting plate 5. This makes space available for inserting the sleeve H in the manner shown in Figure 3.As the drive shaft 7 continues to rotate, the sleeve gripper 9 holding the sleeve H reaches a lifting station II, in which the roller 24 of the swing arm 22 leaves the hollow of the cam ring 25 and runs on the elevated level of the ring, which causes the lifting disc 21 to be moved via the swing arm 22 against the lower face of the sleeve H which it pushes together with the sleeve gripper 9 along the guiding column 8 up into the bore 19 of the seal 18. In this state, the sleeve H is closed off completely vacuum-tightfrom the outside, at the lower end by the lifting disc 21 and at the upper end by the seal 18 and by the tight contact between the retainer plate 4 and the terminal plate 2. As the drive shaft 7 rotates further, the sleeve H reaches the pre-vacuum station Ill, which is determined by the arc length of the associated suction orifice 10.As the sleeve H passes through this station, the sleeve is pre-evacuated via a suction pump (not shown). As the drive shaft 7 rotates further, the sleeve comes into the area of a main vacuum station IV, the length of which is in turn determined by the arc length of the associated suction orifice 11. During the time in which the sleeve is connected to the suction orifice 11 via the bore 16, it is evacuated by a pump (likewise not shown) until a pressure of, for example, 10-3 bar is adjusted in it. This vacuum is maintained as the drive shaft 7 continues to rotate, until the sleeve reaches the filling station V, the length of which is, in turn, determined by the arc length of the pour orifice 12.

The vacuum prevailing in the sleeve H now causes flowable cartridge material to be sucked in through the pour orifice 12 in a very short time (e.g. over a period of just half a second), completely filling the space inside the sleeve. In a subsequent removal station VI, which is not shown in Figure 3, the roller 24 of the swing arm 22 drops again into a hollow provided there of the cam ring 25, so that the lifting disc 21 and consequently the sleeve gripper 9 can drop under the force of gravity. This brings the sleeve H back into a position analogous with the feed station I, so that it can be removed from the sleeve gripper 9 by a removal device (not shown).No special precautionary measures need be taken when processing highly viscous cartridge material to ensure that it remains in the sleeve H after release, because it has in any case already solidified adequately by the time it is removed. In certain circumstances, with more highly liquid cartridge materials, a deliberate measure taken between the filling station V and the removal station VI can ensure that the onset of cartridge material solidification is at an early enough time. When processing molten cartridge materials, a measure of this type means cooling; when processing cartridge materials the composition of which is made up of several components and materials which cure by chemical reaction, such a measure may be a controlled supply of heat, for example by means of microwaves.

As previously mentioned, the respective period for pre-evacuation and main evacuation and for filling is determined by the rotational speed of the drive shaft 7 and the length of the orifices 10, 11 and 12. In the case of the speed specified, as an example, of 8.5 revolutions per minute, these procedures can be performed in times of 1/3,2/3 and half a second, respectively. In order to ensure the necessary sealing between the invididual stations, at this rotational speed, distances between the stations corresponding to an idle running time of 1/3 second in each case are necessary.

Figure 4 diagrammatically shows an apparatus in which the vacuum used for filling the sleeve H is produced and maintained constantly during the actual filling procedure. This apparatus consists of a base plate 41 and a terminal plate 42, which are connected to one another by means of a column 43.

Guided along the column 43, to be vertically displaceable, is a lifting plate 44 in which a lifting disc 45 is displaceably arranged via a shank 46. Screwed on to the shank 46 is a nut 47, through which the pretension of a compression spring 48 can be adjusted. The lifting disc 45 has a recess 49, into which a seal 50 is fitted. The shank 46 has a central bore 51, which is connected to a suction pump (not shown) and is controllable by means of a valve 52.

The terminal plate 42 bears a supply container 55 for the flowable cartridge material, which contains a spring-loaded outflow valve 56. A bore 57 in the terminal plate 42 forms a pour orifice, which is enclosed by a seal 58.

By pressing down the lifting disc 45 against the force of the compression spring 48, space is created for inserting the sleeve H between the seals 50 and 58 and clamping them in such a way that the sleeve H is closed off vacuum-tight from its surroundings. A filter (frit) 59, which is permeable to air but not to the cartridge material to be filled, is inserted in the lower end of the sleeve H. Opening the valve 52 causes the interior of the sleeve H to be evacuated through the filter 59 to the desired partial vacuum. During this time, the outflow valve 56 in the supply container 55 is closed. After a predetermined time, for example after 0.5 second, the outflow valve 56 (programcontrolled in a practical configuration) is opened, so that cartridge material from the supply container 55 flows into the sleeve H due to the vacuum existing in it. Due to the continuing connection of the interior of the sleeve to the vacuum pump via the bore 51, the vacuum is constantly maintained during entry of the cartridge material into the sleeve, meaning that the filling procedure does not slow down in the lower section of the sleeve. Filter 59 prevents cartridge material entering the bore 51. After filling the sleeve, valves 52 and 56 are closed again and the finished finished cosmetic stick can be removed from the apparatus.

Claims (11)

1. A process for the production of a cosmetic stick, in which a cosmetic cartridge material in flowable state is filled directly into a sleeve with the assistance of the application of a partial vacuum to the interior of the sleeve to suck the cartridge material into the sleeve, the cartridge material then being subsequently solidified.

2. A process according to claim 1, wherein the partial vacuum in the sleeve is maintained by continued evacuation during the filling process.

3. A process according to claim 1, wherein the partial vacuum is applied to the sleeve prior to the filling process.

4. Apparatus for the production of a cosmetic stick using the process of claim 1, said apparatus comprising a supply container for the flowable cartridge material, a mount for a sleeve to be filled, said mount having a pour orifice connected to the supply container and a suction connection connected to a suction pump, and sealing means for sealing the interior of the sleeve off from the outside when, in use of the apparatus, a sleeve carried by the mount is aligned with the pour orifice and/or the suction connection.

5. Apparatus according to claim 4, wherein the pour orifice and the suction connection are provided in a fixed terminal plate, the mount comprises a retainer plate in sealed contact with the terminal plate, the retainer plate comprising a bore for sealingly receiving an open end of a sleeve to be filled and being displaceable relative to the terminal plate in such a way that the bore comes successively into connection with the suction connection and the pour orifice.

6. Apparatus according to claim 5, wherein the mount comprises a sleeve gripper and an adjusting mechanism for the sleeve gripper whereby a sleeve held by the gripper in use of the apparatus can be pressed up to said bore.

7. Apparatus according to claim 5 or 6, wherein the suction connection has a first suction orifice for carrying out a pre-evacuation step and, arranged at a distance therefrom, a second suction orifice for carrying out a main evacuation, said base being successively alignable with said suction orifices prior to alignment with the pour orifice upon displacement of the retainer plate.

8. Apparatus according to claim 4, wherein the suction connection is adapted to engage one end of a sleeve open at both ends and the pour orifice is arranged to cooperate with the other end of the sleeve in use of the apparatus, at least one of the parts of the apparatus respectively containing the pour orifice and the suction connection being movable in the axial direction of the sleeve to cause contact of seals comprising the sealing means against the opposite ends of the sleeve.

9. Apparatus according to claim 7, wherein the suction orifice contains a filter which is permeable to air but impermeable to the cartridge material.

10. A process for the production of a cosmetic stick substantially as herein described with reference to and as illustrated in the accompanying drawings.

11. Apparatus for the production of a cosmetic stick constructed and arranged to operate substantially as herein described with reference to and as illustrated in Figures 1 to 3 or Figure 4 of the accompanying drawings.