EP2688433B1 - Bra cup structure - Google Patents

Description

The present invention relates to a bra cup structure.

We know from the document FR 2 813 167 a bra cup structure consisting of two layers of laminated foam enclosing between them a pouch containing a malleable material, in this case a liquid. The foam layers can be laminated to textile layers. In addition, the document WO 00/47068 also discloses a similar structure, improved by a new choice of malleable material to garnish the pocket.

Although each of these innovations aims to create both a bra with a "push-up" effect, it remains for users to make progress in terms of comfort, invisibility, volumizing effect and upward, and freedom of movement. This is the purpose of the present invention.

To achieve this, the present invention provides a bra cup structure having two soft layers laminated respectively inner and outer enclosing between them, for example in their lower part, a bag containing a malleable material, characterized in that the malleable material is a silicone gel loaded with polymeric microspheres, and in that the inner layer is a viscoelastic foam layer while the outer layer is of flexible material selected from non-viscoelastic foams and textile filler materials.

By textile filling materials are meant here materials based on natural or synthetic fibers arranged to give a certain volume, a certain thickness, with a function of padding, whether by a process of weaving, knitting, needling , felting or otherwise. In particular, an artificial wadding such as the cushioning fibers known under the name Fiberfill®, a bonded double-needle mesh such as the 3D knits known under the name of "spacer" is intended.

If the outer layer is foam, advantageously choose a non-viscoelastic polyurethane foam. Indeed a non-viscoelastic foam has the advantage of being able to be obtained in white then that the viscoelastic foams have a marked tendency to yellowing (on a grayscale used by the Applicant, the rating of the viscoelastic foams is less than 3 while a standard standard foam is greater than 4). However, there is a strong demand for white bra that the realization with viscoelastic foam does not obtain.

The Applicant has found that this particular combination of materials, one of which has no shape memory (the silicone gel) and the other on the contrary has one (the viscoelastic foam of the inner layer) leads to remarkable comfort properties and in particular a behavior very close to that of the flesh when the structure is pressed under the fingers, the outer layer finally intervening only slightly in this artificial texture of the flesh that forms the visco-elastic inner layer and the silicone gel, with a touch close to the texture of the breast. This inner surface, under the action of the heat of the body and the pressure exerted by the breast, is distributed on the periphery of the breast, fills the gaps and creates solid to reshape the breast and give it a naturally round shape. When the outer layer is of standard foam, the Applicant was surprised to discover that the qualities of touch on the inner side in contact with the breast are not noticeably compromised in relation to an embodiment with a visco-outer layer. elastic, even if they are necessarily a little less to the manual touch with the fingers (test to the depression of the fingers). In addition, the use of a standard polyurethane foam on the outside makes it possible to obtain other advantages than the good white color already mentioned: one of the advantages is the lightness of these foams, more often of the order of 30 kg / m ³ while viscoelastic foams are more often than 50 kg / m ³ . By replacing an outer layer of 50 kg / m ³ viscoelastic foam with a standard foam layer of 30 kg / m ³ , a brassiere is approximately 8% lighter. This lightening contributes very significantly comfort to wear: indeed, a lower weight of bra makes that the back tightens the user less and the suspenders pull less. Another advantage of this lightening is that the bra moves less to wear; comparative tests showed a descent of the line neckline after 8 hours to wear only 3 mm with a bra according to the invention against 6 mm on average when the outer shell is visco-elastic polyurethane foam of 50 kg / m ³ . Such a bra thus gives increased satisfaction to the user.

Advantageously, the malleable material is disposed in a pouch consisting of two polymeric films sealed to one another, for example polyurethane. Their thickness is advantageously very low so as not to induce a perceptible effect on the touch. The thickness is preferably less than 40 μm and more preferably of the order of 35 μm.

The malleable material has a density advantageously between 0.60 and 0.75 g / cm ³ .

The bag filled with malleable material is inserted during a molding operation (thermoforming) between the two inner and outer layers, the inner layer being viscoelastic foam, whose density is advantageously between 30 and 65 kg / m ³ and advantageously of the order of 50 kg / m ³ . If an outer layer of polyurethane foam is used for the outer face, its density is preferably of the order of 30 kg / m ³ .

The inner layer of viscoelastic foam is preferably laminated to a textile material, such as a polyester charmeuse, prior to their laminating between them, this textile material being disposed towards the outside of the cup. The outer layer may also be laminated to a textile material, especially in the case of a polyurethane foam. On the other hand, if a padding element such as a "spacer" is used, it already includes a textile face that can serve as the outer surface of the cup.

Advantageously, the weight of silicone gel in the bag is very small, preferably less than 10 grams, advantageously substantially between 7 and 9 grams.

The shape of the pocket is substantially elliptical, with a major axis between 8 and 15 cm and a small axis between 4.5 and 7 cm. Its average thickness is preferably between 2 and 3 mm.

Particularly advantageously, the standardized force of 25% depression in the bonnet of the invention, in the part where the pocket is located, is between about 2 and 3.5 N, and the normalized force at 65% at the same point is between about 15 and 40 N.

Although the pocket is in an advantageous embodiment which will be illustrated later in the lower part of the cap and thus participates in the effect of "push-up" and support of the breasts, it is also possible that the pocket is in the upper part or on the lateral areas, where it brings, in combination with the layers of foam, the comfort of its particular texture.

• en Figure 1, une structure de bonnet conforme à l'invention vue de face ;
• en Figure 2, la section II-II de la structure de bonnet de la figure 1 en coupe verticale ;
• en Figures 3 et 4, deux variantes de forme de poche de matière malléable.

Other features and advantages of the invention will emerge from the following description of an exemplary embodiment. Reference will be made to the accompanying drawings showing:

• in Figure 1 , a cap structure according to the invention seen from the front;
• in Figure 2 , section II-II of the cap structure of the figure 1 in vertical section;
• in Figures 3 and 4 , two variants of pocket shape of malleable material.

A thermoformed cup structure 1 has, after thermoforming, a substantially hemispherical shape, having a depth H of the order of 70 to 75 mm. It is composed of two flexible laminated layers respectively outer 2 (for example in ordinary polyurethane foam of 30 kg / m ³ ) and inner 3 (in visco-elastic foam) which enclose between them, in their lower part, a pocket of material malleable 4, formed by two polyurethane films 5, 6 welded to their edges. As we see on the figure 1 the material pocket 4 has a substantially almond-shaped shape bounded by the dashed curved line which marks the upper edge 7 of the pocket 4; the pocket 4 essentially occupies the lower part of the cup, substantially below half of the cup and preferably on its lower third. In section, as we see on the figure 2 , the bag of material 4 has a generally weakly biconvex shape (substantially flat) but tapered at the edges, the shape of the pocket can change during the wear in contact with the chest and because of the movements. The thickest cup, at the thickest part of the pocket 4, is of the order of 10 to 14 mm (pocket and layers of foam). The layers of ordinary foam 2 and visco-elastic 3 are laminated, before assembly, to a thin textile layer 11 and 12, for example polyester, which facilitates their maintenance and handling, and avoids problems of removal of the material during molding.

The malleable material, in one exemplary embodiment, is based on a two-component silicone gel RTV2 type (crosslinking at room temperature), for example of the Silbione® type marketed by Bluestar Silicones. The silicone gel has a dynamic viscosity before crosslinking which is for example between 6000 and 250,000 mPa.s at 25 ° C. Its density before feed introduction is of the order of 1 to 1.5 g / cm ³ . A charge of polymeric microspheres is mixed with the silicone gel, for example microspheres of the Expancel® brand marketed by Akzo-Nobel. These expanded microspheres of acrylic-based polymer, 20 to 80 μm in diameter, are mixed with the gel so that the density of the material after mixing is between 0.60 and 0.75 g / cm ³ . In one exemplary embodiment, the microspheres form from 1 to 3% by weight of the mixture.

The pouch 4 is manufactured in the following manner. Two thin polyurethane films 5,6 were previously assembled to form an almond-shaped envelope, with edges for example heat-sealed, and having an opening through which the mixture of the two components of the silicone gel is poured into the envelope. The opening is closed, the assembly is optionally placed in a metal mold having the definitive shape of the pocket and the whole is crosslinked by means of a heat treatment. We thus obtain a "pad" or pocket 4 of malleable material. The dimensions of the pocket depend on the size of the bra to which it is applied, but it advantageously measures between 8 and 15 cm along its major axis and between 4.5 and 7 cm along its minor axis, and its thickness, relatively uniform. outside the edges, is between 1.5 and 5 mm, and preferably between 2 and 3 mm. According to the invention, the filling of the envelope is limited, preferably to less than 10 grams, so that the filled envelope is not hard but instead remains flexible, foldable, and allows the depression of a finger . In practice, an envelope 4 in the shape of an almond or ellipse of approximately 10.5 cm x 5.5 cm, with an average thickness of 2.6 mm, filled with 9 g of silicone gel, has been satisfactory . Before thermo-molding, the thickness of the two layers of visco-elastic foam and non-visco-elastic uncompressed is of the order of 8 mm.

We will now describe the manufacture of the cup from the foam layers 2,3 laminated to their textile layer 11, 12. The foam layers 2, 3 in the non-thermoformed state have a thickness of about 6 mm.

For the manufacture of the cup structure 1, the outer foam layer 2, 11 is first thermoformed in a mold adapted to the shape of the cup, for example between 1 and 2 minutes at a temperature in the range of 160 to 190 ° C, for example 180 ° C, by adjusting the spacing of the two parts of the mold to allow compression / uniform molding of this layer 2, 11.

In a second step that can be performed in the same mold or in a similar mold, the inner visco-elastic foam layer 3, 12 that has just been thermoformed is laminated to the non-viscoelastic outer layer 2, 11 together. which has not been yet, for example by coating the two layers of foam facing glue, preferably a water-based adhesive. There is placed between the two faces to be laminated a temporary mask preventing gluing at the area that will later be occupied by the pocket and an adjacent area communicating with the edge of the layers. This mask may comprise a foam pad substantially occupying the surface that will occupy the pocket. The spacing between the male and female parts of the mold is adjusted to allow the compression of the two layers, and the thermoforming is performed for example 40s at the same temperature as before. Following this step, the two layers 2 and 3 are glued to their interface 8, except in the zone where the pocket 4 must be inserted and in a passage allowing access to this zone. The mask and the foam cushion are removed. The combined thickness of the two layers 2, 3 thermoformed is between 2 and 3 mm.

In a third step, the pocket 4 and / or the zone between the foam layers 2 and 3 are inserted into the pocket and the pocket 4 is placed in this zone. The passage left open is also sealed. Fixing is ensured by the heat and the pressure in the mold, for example during 40s at 180 ° C.

The set can be cut to the exact shape that must be the cup, as shown in Figures 1 and 2 .

The thermoforming mold may for example be of the type described in the document GB 1,577,099 or the document FR 2,906,111 in the name of the Claimant.

During the thermoforming of the structure 1, a compressed edge 9 has been formed on the lower half of the hemispherical cap which will allow the possible insertion of an armature and the connection of the cap with the substantially flat brass bra (by sewing, welding or gluing) and at the upper part of the cap an upper lug 10 which will be used for the connection with the bra strap. The border 9 may be formed either as shown in the plane of the base of the cup and facing outwards, or on the contrary in the extension of the cup, according to the preparation technique envisaged.

Once the cup structure 1 thermoformed, we can use it in a conventional bra, where it is assembled by conventional clothing. The structure is then advantageously covered on the outside by a decorative textile material, possibly a lace, while the inner surface 12 made of polyester can be used directly as the inner textile surface of the finished bra.

One could also according to a principle that does not go beyond the invention manufacture directly by thermoforming the entire bra, according to known techniques for multilayer bra. In this case, the pocket 4 is disposed in locations between layers of foam laminated to textile layers and already having substantially the shape of the final bra (cups, separator, basque and back).

Various experiments were carried out to determine the essential parameters which led to a result judged particularly satisfactory by the users. The penetration force for 25% and 65% compression was measured on different samples according to a procedure standardized by ASTM D3574-95 but adapted to the subject of the invention, so as to enable the realization of tests on finished products (ie the bra cup). We therefore essentially adapted the size of the plates of the dynamometer test machine, brand Zwick 22.5 with a 1000 N force sensor, namely a 150 mm x 150 mm perforated square bottom plate and a 45 mm diameter circular top plate.

The samples are prepared by marking the area to be measured, in the middle of the pocket area 4. The sample is first compressed twice to 75% of its thickness, at a speed of 4 mm / s and then left rest for 6 minutes. The indentation force deflection (IFD) compressive strength measurements at 25% and 65% are made by compressing the sample at a speed of 0.85 mm / s over 25% and then 65% of its thickness. the force being measured after a rest of 60s.

The results of 24 measurements are reported in the attached table, where the tests performed on cups prepared by juxtaposing an inner layer of viscoelastic foam and a silicone gel bag according to the invention were made bold. various variations as to the nature of the silicone gel, its weight, and the thickness of the polyurethane film or the outer layer. The foam is unchanged in these samples with a density of 50 kg / m ³ . Although the bra of the present invention has an outer layer or non-viscoelastic foam shell, it has been found that the wearing quality of the wear is not substantially modified by the viscoelastic shell layer replacement by non-viscoelastic layer, indicating that most of the qualities of touch to wear comes from the combination of the two inner layers of the bra (visco-elastic foam and silicone gel), constituting the artificial flesh. The other tests were made on commercial hats at different structures supposed to bring comfort and support to the chest.

These results were confirmed by touch and wear tests, which revealed that structures with the inner layer of the viscoelastic foam and the silicone gel pocket were perceived significantly more favorably than the others. exception of sample 22 considered too hard, probably due to an excessive combination of weight and pocket thickness of silicone and polyurethane film thickness, and to a lesser extent, sample 19 also with a thickness of 40 microns of polyurethane film. In particular, the sample 24 whose outer layer is made of non-viscoelastic polyurethane foam was considered satisfactory. Finally, it has been found that the satisfactory samples of the invention have the remarkable property of having a 25% IFD measurement substantially between 2 and 3.5 N and a 65% IFD measurement substantially between 15 and 40 N for cups of average size. This combination gives a soft felt remarkable to the touch and wear, and provides a cap with high adaptability, adjusting perfectly to the shape and the particular size of the breast to provide a round chest and reassembled. This comfort lasts throughout a day wearing and allows great freedom of movement: the silicone pocket can deform and adapt to the chest in motion, filling hollow spaces permanently.

The measurements reported above were carried out on cups of average size (90B France / 75B Europe). For cups of different sizes, the shape of the bag, its dimensions and its weight in particular, may differ, which may influence the values of the measurements. The figure 3 represents a pocket 4 adapted to a small cup (70A Europe), more compact in shape with a truncated end relative to the basic shape, about 90 mm by 47 mm. The figure 4 represents a pocket 4 adapted to a larger cup (80D Europe), more elongated form relative to the basic shape, about 120 mm by 30 mm. Comparative table Sample IFD25% (N) IFD65% (N) comments 1 1.71 7.34 Foam hull 2 1.72 7.61 Silicone gel pad 3 2.26 10.52 Foam hull 4 3.25 12.72 Foam hull 5 1.25 13,31 Foam hull 6 2.06 15.49 Inv gel-1 / 9g / 35μm film 7 2.28 15 , 62 Inv gel-0 / 20g / film <35μm 8 3.37 17.17 Foam and air pad 9 4.27 17.62 Foam hull 10 2.25 18.17 Inv gel-1 / 9g / 35μm film 11 2.32 19,01 Inv gel-2 / 5g / 40μm film 12 4.09 20.48 Fiber hull 13 2.41 20.6 Inv gel-1 / 9g / 35μm film 14 2.2 21.75 Inv gel-1 / 7g / 35μm film 15 2.26 23.45 Inv gel-2 / 5g / 35μm film 16 2.48 26 Inv gel-2 / 5g / 40μm film 17 2.3 30.85 Inv gel-2 / 7g / 35μm film 18 6.11 31.74 Foam hull 19 2.79 39,12 Inv gel - 2 / 5g / 40μm film 20 5.11 45.32 Foam and air pad 21 7.53 72.38 Foam hull 22 4.71 89.47 Inv gel-2 / 10g / 40μm film 23 3.64 102.29 Foam and air pad 24 3.29 35.98 Inv gel-1 / 9g / 35μm film + non-viscoelastic polyurethane foam

Claims (9)

1. Bra cup structure including two flexible, interior and exterior, layers (2, 3) stuck together, enclosing between them a pouch (4) containing a malleable material, characterized in that the malleable material is a silicone gel charged with polymer microspheres and in that the interior layer is a visco-elastic foam layer while the exterior layer is made of flexible material chosen from non-visco-elastic foams and textile filling materials.
2. Structure according to Claim 1, characterized in that the malleable material is disposed in a pouch (4) constituted by two polymer, for example polyurethane, films (5, 6) sealed to each other.
3. Structure according to Claim 2, characterized in that the thickness of the films (5, 6) is less than 40 µm.
4. Structure according to any one of Claims 1 to 3, characterized in that the malleable material of the pouch (4) has a mass per unit volume between 0.60 and 0.75 g/cm³.
5. Structure according to any one of Claims 1 to 4, characterized in that at least the interior layer (3) of visco-elastic foam is stuck to a textile material (12).
6. Structure according to any one of Claims 1 to 5, characterized in that the weight of silicone gel in the pouch (4) is substantially between 7 and 9 grams.
7. Structure according to any one of Claims 1 to 6, characterized in that the shape of the pouch (4) is substantially elliptical, with a major axis between 8 and 15 cm and a minor axis between 4.5 and 7 cm.
8. Structure according to any one of Claims 1 to 7, characterized in that the mean thickness of the pouch (4) is between 2 and 3 mm.
9. Structure according to any one of Claims 1 to 8, characterized in that in the cup of the invention, in the part in which the pouch (4) is situated, the normalized 25% depression force is between approximately 2 and 3.5 N and the normalized 65% depression force at the same location is between approximately 15 and 40 N.

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