EP1232092B1 - Method for encapsulating a topical composition - Google Patents

Abstract

A method of encapsulating a topical composition in a breakable capsule, includes the steps of elastically deforming at least a portion of a first deformable film that is impermeable to the composition so as to constitute at least one blister; injecting the topical composition into the blister; applying a second film that is impermeable to the composition onto the first film so as to close the blister; and sealing the second film and the first film together around the periphery of the blister, the portion of the first film being suitable for shrinking after release of the capsule so as to cause the pressure inside the capsule to be greater than atmospheric pressure. While the capsule is being made, at least one weak region is made in the blister, thus making the capsule suitable for being broken by exerting pressure on the capsule.

Description

The present invention relates to an encapsulation process of a topical composition in a fracturable capsule.

A field of application envisaged is notably but not exclusively that of tassels containing cosmetic compositions like creams.

Tufts have been used for a long time in cosmetics for depositing and spreading the rice powder on the face. They are generally housed in the lid of the box containing the powder and the sampling is carried out by pressing the puff against the powder reserve.

We also felt the need to coat the face with liquid or pasty products, in particular skin care creams, requiring tufts of another kind and in particular disposable. it independently requires the cream to be coated in a container, and disposable tassel to deposit and spread said cream on the skin, which in some cases does not raise any difficulty.

For other occasional cases, in particular for tests samples, or for applications made outside the usual place, it has was imagined a tassel in which the product to be coated adjoins the applicator, in a small reservoir capable of being easily opened, including a dose for one application.

Such tassels are difficult to make in the context of a automated production, in particular the development of the capsule forming the small tank.

Patent FR-A-2,644,425 describes a separation device thermo plastic containers filled in a packaging installation packaging, the installation comprising a thermoforming station of containers.

An object of the present invention is to provide a method of production of capsules containing the composition to be coated, easily working.

Another object of the present invention is to propose the application from the process for producing capsules to making tassels, containing the composition to be coated, for single use.

These goals are achieved by a method of encapsulating a topical composition in a fracturable capsule consisting of at least one first deformable film, impermeable to said composition, comprising the following stages: one deforms elastically, during a first step, at least part of said first film so as to constitute at least a pocket ; said composition is injected during the second step topical in said pocket; we apply, during the third step, a second film impermeable to said composition on said first film of so as to close said pocket; we seal, during the fourth step, said second film and said first film around the periphery of said pocket, said part of said first film being capable of shrinking, after release of said capsule, whereby the pressure in the capsule is greater than the pressure atmospheric; and during the realization of said capsule at least one creates a portion of lower mechanical strength at least in said pocket whereby the capsule is capable of being fractured, by means of pressure exerted on said capsule.

The sequence of stages of realization of the capsule allows to produce a capsule, according to an automated process, whose properties mechanical perfectly respond to the problem of opening said capsule, which is carried out by a simple pressure between two fingers, and whose production costs are kept at an acceptable level.

We understand that the process consists, in a first step, in constitute a cavity with an elastically deformable film which by nature is plane, and into which we introduce the topical composition which will be spread on the skin.

The cavity is kept in shape during the filling stages, application of the second film and sealing. So when the capsule is released, the first film substantially retains the shape it was given since the hermetically closed capsule contains said composition. However, given the elasticity of the film, when it is released, that is to say when the capsule is released, it exerts on said press composition. So the pressure on the composition is equal to atmospheric pressure plus induced pressure by the elasticity of the film.

The capsule opening system is provided by a localized weakening of the mechanical strength of the film constituting the poached. Thus the pressure exerted on the capsule creates an internal pressure causing the piercing of said capsule at the weakest point resistance and release of the topical composition. We understand that the pressure to exert on said capsule is all the more effective in releasing the composition it contains that the internal pressure of the capsule, induced by the film, is important.

According to another feature of the process, said part of the first film constituting said pocket undergoes a plastic and elastic deformation of so that said first film portion partially retracts after release of said capsule, whereby the pressure in the capsule is at less equal to atmospheric pressure.

It is not easy to obtain a purely elastic deformation, leading to optimal pressure in the capsule, and most often this deformation is accompanied by a structural modification of the film inducing a part of irreversible deformation called plastic. In this case internal pressure in the capsule is obviously lower.

According to a preferred embodiment of the method, when the two films are assembled around the periphery of said pocket the seal of sealing includes a narrower portion to constitute a portion of lower mechanical strength.

When the capsule is pressed, the opening is made at the level of the portion of the sealing joint of lower mechanical strength, the interface between the two films.

Advantageously, locally transforming a portion of said part of said first film constituting the pocket so as to constitute a portion of lower mechanical strength.

The peculiarity of this mode of implementation lies in the fact that the opening of the capsule is made on one side of said first film and not at the interface with the second film. It is possible in this configuration to eject the topical composition in the center of the capsule and not necessarily on the sealed contours of said capsule.

In order to locally reduce the mechanical strength of the film, we can overwrite the film or distort, but you can also locally melt the film by means of a heating device or ultrasound.

According to another preferred embodiment, a depression between a part of the first deformable film and an imprint of so as to apply said part of film against the internal wall of said imprint to constitute said pocket.

We understand that the fact of placing the film over a cavity constituting an imprint and creating a depression between said film and said cavity tends to press the film against the internal wall of said cavity. Obviously this wall has orifices allowing suction air.

According to yet another preferred embodiment, said seal is sealed. first film and said second film by means of an ultrasonic device.

This embodiment has the advantage of only melting the parts of film in contact, and not to include a thermal source risking degrading the capsule or its container.

Advantageously, the encapsulation method in accordance with the invention is applied to the making of tassels. For this purpose we apply and we secure at least a first foam plate on the wall external of said first film to constitute the tassels.

A layer is applied to the capsule formed according to the invention foam in order to spread the composition over the skin. The foam is secured to the capsule, by the edge of the two films sealed together,

In order to give the tassel a pleasant touch on both sides, preferably a second sheet of foam and / or textile on the outer wall of said second film.

To protect at least the side containing the application foam, advantageously a protective film is applied, constituting a cover, on said first foam plate.

• la Figure 1 est une vue très schématique de dessus d'une installation d'encapsulation et de confection de houppes en continu, et,
• la Figure 2 est une vue schématique en coupe longitudinale de l'installation d'encapsulation et de confection de houppes en continue.

Other features and advantages of the invention will emerge on reading the description given below, by way of indication but not limitation, with reference to the appended drawings in which:

• FIG. 1 is a very schematic view from above of an installation for encapsulating and making tassels continuously, and,
• Figure 2 is a schematic view in longitudinal section of the encapsulation installation and making tassels continuously.

The process for producing a capsule containing a composition topical will be described below with reference to Figures 1 and 2.

A first film 2, wound on a reel 4, is capable of being unwound in the direction of arrow F through an installation for making capsules 6. Film 2 is moved sequentially in the direction of the arrow F, the sequences corresponding to the time for producing the capsule 6.

When the film 2 is stationary, during a first step, we operates a vacuum pump 8 so as to draw the film 2 into the cavity 10 constituting an imprint. The cavity 10 has holes drilled in its wall for the passage of air so that the film 2 is pressed against said wall.

The plastic film is relatively elastic and, under the effect of suction, it tends to deform to conform to the shape of the imprint without folds appearing around the periphery of the pocket 14 formed by the part of film 2 which is sucked up.

Film 2 can be made of polyethylene, or polyether, but it can also be made of polyurethane which has the advantage of being very elastic compared to other types of film.

The suction of film 2 is maintained and therefore the pocket 14 constituted, during a second step, a composition is injected topically in said pocket 14 by means of a filling spout 16.

The spout 16 consists of a bent tube 18 hinged at one end on a swivel connector 20, so that it can be retracted between the filling steps of said pocket 14. Upstream of the spout, provision is made for piston dosing pump immersed in a storage tank of the topical composition. The pump is activated when the end of the nozzle 16 is placed directly above the pocket 14 formed by the film part 2.

Once the bag 14 is filled by injecting a dose of product substantially equal to the volume of the cavity 10, the spout 16 is pivotally actuated at connection 20 so as to be separated from the pocket.

In conjunction with film 2, a second film 22 superimposed on film 2 is able to be moved according to arrow F. The film 22, of width substantially equal to that of film 2, is wound on a reel 24. These two films are sufficiently spaced to plumb with the cavity 10, and so from the pocket formed by the film part, so that the spout filling 16 can be inserted between the two.

The film 22, during a third step, is applied to the part of film 2 so as to cover and close the pocket 14 containing the topical composition.

This third stage is jointly carried out with the fourth sealing step of the two films 2 and 22, by means of a device for ultrasound 26. The latter is actuated vertically according to arrow D and applied to the two films 2 and 22 along the periphery of the cavity 10 on the edges of the imprint. The two films 2 and 22 are compressed, between two substantially circular metallic elements, around the periphery of the pocket, and under the effect of vibrations of the ultrasonic type (greater than 20 kHz) that the two metallic elements print to the two films 2 and 22. These the latter join together by localized merger.

According to a particular embodiment, the capsule 6 has a portion of least mechanical resistance at the sealing joint between the two films 2 and 22, to allow its opening.

In order to achieve this portion, the metal elements are pressed vibrating in contact around the perimeter of the pocket between which the two films 2 and 22 heat up. Said metallic elements present in a part at least a portion of contact less wide than on the whole around the pocket. So, the weld at least in this portion, is it narrower than in the rest of the periphery of the pocket, which constitutes a portion of lower mechanical strength.

During use, the capsule is pressed to break this portion of lower mechanical strength and the topical composition is released.

In another particular embodiment, the capsule has a portion of lower mechanical resistance on a part of said first film, which constitutes the pocket. To do this, we plan to transform locally a portion of film, by deformation or by crushing. These operations are carried out by a device (not shown) located upstream of the capsule forming device.

The sealing of the two films can also be carried out by means of so-called high frequency techniques which have the advantage, all like ultrasound, not to heat the environment in which they are uses. Indeed the films used to encapsulate the topical compositions are relatively fragile, and a soldering iron device would tendency to overheat a larger area of film, and would also risk degrading the topical composition contained in the capsule.

The material of the films used 2, 22 is obviously thermoplastic, otherwise welding would be impossible.

When the required welding time is reached, the device 26 is vertically raised according to arrow R so as to release the two films 2, 22 thus welded. The capsule containing the topical composition is thus hermetically sealed.

The operation of the vacuum pump can be interrupted by so as to release the capsule from the cavity 10 in which it is located. In releasing the capsule, the film 2 which has elastic properties is retracts and exerts some pressure on the topical composition, which during opening of the capsule tends to release more easily.

Depending on the nature of the film, the deformation is more or less elastic. The more elastic it is, the greater the internal pressure of the capsule and the more complete and rapid the release of the topical composition.

In order to release the capsule from the cavity in which it is located, the film strip 22 is expected to make a certain angle α with the horizontal, and therefore with the film strip 2, so that when the tension of the film 22 is greater than the tension of the film 2 and the cylinders 28 and 30 are partially raised, the capsule is released from the cavity 10.

The joint scrolling of the two films 2, 22 can occur in the direction of arrow F, so as to separate the capsule 6 previously produced and proceed with the production of a new capsule. The capsules are thus linked together by the two superimposed film strips 2 and 22.

The advance of the films is therefore sequential, and the capsules are formed so that the distance between them is sufficient to carry out the subsequent tassel making operations.

In accordance with the embodiments shown in Figures 1 and 2, the installation includes peripheral equipment for make the tassel.

A cookie cutter device 32 is located directly above the strip capsules 34 at a distance from the cavity in which the pockets multiple of the distance between two capsules. This provision allows you to make the tassel for the time necessary for the capsule formation.

On the outer wall of the pocket 14 which constitutes the capsule 6, we simultaneously applies a padding foam 36, a foam application 38 and a protective cover 40. Just like films 2 and 22, the foams 36, 38 and the cover are applied in strips during the continuous process of encapsulation and making of the tassel.

When the capsule is housed in the lower part 42 of cookie cutter, padding, application foams and film constituting the cover are applied to the external wall of the pocket constituting the capsule. Then the upper part of the cookie cutter 32 is applied and forced on the lower part 42 to cut to shape desired all the elements constituting the tassel.

The cookie cutter 32 includes a device for welding, simultaneously with cutting, all the edges of the different layers so that the tassel does not have an edge that could injure the user.

Claims (9)

1. A method of encapsulating a topical composition in a breakable capsule constituted by at least a first deformable film (2) that is impermeable to said composition,
      the method being characterised in that it comprises the following steps:

   a first step in which at least a portion of said first film (2) is deformed elastically so as to constitute at least one blister (14);

   a second step in which said topical composition is injected into said blister (14);

   a third step in which a second film (22) that is impermeable to said composition is applied onto said first film (2) so as to close said blister (14); and

   a fourth step in which said second film (22) and said first film (2) are sealed together around the periphery of said blister (14), said portion of said first film (2) being suitable for shrinking after release of said capsule (6) so as to cause the pressure inside the capsule to be greater than atmospheric pressure;

      and in that, while said capsule (6) is being made, at least one region of weaker mechanical strength is made at least in said blister (14), thus making the capsule (6) suitable for being broken by exerting pressure on said capsule (6).
2. An encapsulating method according to claim 1, characterised in that said portion of the first film (2) constituting said blister (14) is subjected to deformation that is both plastic and elastic such that said portion of the first film (2) shrinks in part after said capsule (6) has been released, whereby the pressure inside the capsule (6) is not less than atmospheric pressure.
3. An encapsulating method according to claim 1 or claim 2, characterised in that the seal includes a fraction of reduced width to constitute a region of weaker mechanical strength.
4. An encapsulating method according to any one of claims 1 to 3, characterised in that a fraction of said portion of said first film (2) constituting the blister (14) is transformed locally so as to constitute a region of weaker mechanical strength.
5. An encapsulating method according to claim 1 or claim 4, characterised in that suction is established between a portion of the deformable first film (2) and a recess so as to apply said film portion against the inside wall of said recess to as to constitute said blister (14),
6. An encapsulating method according to any one of claims 1 to 5, characterised in that said first film (2) and said second film (22) are sealed together by means of an ultrasound device (26).
7. The use of the encapsulating method according to any one of claims 1 to 6 for making pads, characterised in that at least a first sheet of foam (36, 38) is pressed against and secured to the outside wall of said first film (2) to constitute the pads.
8. The use for making pads according to claim 7, characterised in that a second foam and/or textile sheet is applied onto the outside wall of said second film (22).
9. The use for making pads according to claim 7 or claim 8, characterised in that a protective film (40) is also applied to constitute a membrane on said first sheet of foam (36, 38).

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