PT2533957E - Treatment of natural cork stoppers and stoppers obtained by said treatment - Google Patents

Description

ΕΡ 2 533 957 / ΡΤ

DESCRIPTION OF THE INVENTION " Treatment of natural cork stoppers and stoppers obtained by said treatment "

FIELD OF THE INVENTION The invention relates to the field of corking of bottles of alcoholic and spirituous wines with the aid of natural cork stoppers or techniques, more specifically to a treatment of natural cork stoppers in order to eliminate their drawbacks.

CONDITION OF THE TECHNIQUE The natural nature of cork, a natural product perfectly adapted to the capping domain, can have drawbacks due to its heterogeneity and the presence of harmful molecules - typically haloanisols and halophenols - which may alter the taste of bottled products. Therefore, no two stoppers are strictly identical.

The natural cork is known and the different treatments to obtain corks. Firstly, in order to obtain the so-called natural stoppers, the stoppers are washed with very hot water to remove small debris and particles of cork or dust, insects etc. In order to obtain the treated stoppers, a second superheated steam treatment is generally applied to natural stoppers to decrease the harmful molecules content and reduce the risk of having unfit bottles if they have a " corks taste ", generally used to designate an unacceptable organoleptic alteration of the bottled liquid due to contamination by the stopper. Such a taste the stopper can be detected from a very low nephrotic molecule concentration threshold of 2 ng / l (nanograms per liter).

In order to limit cork contamination, certain cork stoppers use hydrogen peroxide H2O2, sulphamic acid or metabisulphite which also have an effect of 2 ΕΡ 2 533 957 / bran effect on the surface bleaching of cork. Generally the treatment of stoppers is terminated by the application in the corks of lubricating agents necessary for the automation of the operations of corking and to facilitate the extraction of the stopper in the first opening of a bottle.

There is also known a so-called sealing treatment in which a mixture of waxes and cork powder is applied to the stopper in order to obtain so-called " colmetted stoppers " in order to be able to use a cork rich in cracks. Other heavy treatments have been developed to try to eliminate harmful molecules, and the presence of harmful molecules is one of the major concerns of corking, bottling and consumers.

The so-called critical CO2 process is known which allows cork stoppers with low content of harmful molecules to be obtained. But this critical process of CO2 does not allow treating only microgranulates of cork and not complete stoppers. This makes it necessary to make the reconstitution of the corks with the aid of glues or binders. In this case it is no longer possible to speak of natural cork stoppers, but of technical or synthetic stoppers, since they contain at least both glue material and cork. However, even in the case of a critical CO2 treatment, there is still a non-negligible residual defect rate, about 1% of the bottles having a corks taste.

Also known are treatments with superheated steam or even microwave to reduce the content of harmful molecules in corks. In this case, the rate of defects attached to the stopper is in the order of 3%.

All of these treatments, which drop the defects rate below 5%, meanwhile require very heavy and expensive specific equipment. Globally, around 18 billion bottles of wine or any type of alcoholic beverage produced in 2008, about 10 billion are covered with a natural cork stopper, and it has been established that about 5% of these bottles have a taste defect to cork, 3 ΕΡ 2 533 957 / ΡΤ which represents about 500 million bottles unfit for consumption, about 376 million liters!

Numerous other treatments have been described to reduce taste defects to cork by coating the cork stoppers in order to avoid a direct contact of the cork with the bottled liquid.

Thus the international patent application WO2007 / 115612 discloses a stopper formed from cork granules coated with a polyurethane resin.

Also, the international patent application WO97 / 30098 describes a treatment of cork with a composition comprising a diisocyanate and a diol.

Also, the international patent application WO97 / 11894 describes a process in which the cork stoppers are bathed in a xylene bath and coated with a dispersion of silicone rubber to form a tank which is then cured.

Also, the international patent application WO2007 / 107209 describes a treatment of cork stoppers in which the stoppers are coated by a hydrophilic polymer layer, such as a cellulosic layer, based on starch or polyvinyl alcohol, and a hydrophobic layer , such as a layer based on a silicone derivative.

Also, the international patent application WO96 / 28378 describes a cork stopper encapsulated in a layer preferably of PVC or polyurethane, formed for example by molding and heat treatment.

Also, the international patent application WO9 / 04836 describes a treatment of cork stoppers comprising a step of washing (washing) with the aid of a solution containing sodium hydroxide, sodium silicate and hydrogen peroxide, followed by a drying step and of a third treatment step with a solution containing acetic acid, peracetic acid and hydrogen peroxide. 4 ΕΡ 2 533 957 / ΡΤ

Also, the international patent application WO2004 / 076607 describes a treatment of cork stoppers comprising forming a layer of polyolefin on the stopper.

Also, the international patent application WO003 / 031276 discloses a treatment of cork stoppers comprising depositing a synthetic resin powder on the stopper, and then melting the resin by heating with infrared.

PLACED PROBLEMS

These problems posed by natural cork stoppers, whether treated continuously or untreated, are numerous: (a) To date, with regard to the problem of cork stoppers, known systems for the protection or treatment of cork stoppers have proven to be ineffective in achieving their purpose or difficult or costly to manufacture corks.

As for the known systems of protecting the surface of the cork in contact with the liquid, these lead to a random result regarding the migration of the harmful molecules of the cork in relation to the conditioned liquid, since they depend on the tightness of the cork in the garqalo of the bottle and of possible liquid channels between the stopper and the glass on the untreated surfaces. The invention aims to provide stoppers which comprise an effective barrier to the migration of said harmful molecules. The author of the patent application also found in a test carried out from numerous types of commercial cork stoppers that these stoppers, each immersed in a glass of organoleptically neutral water, were capable of transmitting to this water odors and / or tastes to stopper after more than 24 hours of total immersion. This immersion in water allows a migration of the harmful molecules or a change of taste due to corks to be revealed more quickly than in wine or ethyl alcohol. b) It is known that natural cork stoppers have a permeability to oxygen and water vapor varying from one stopper to another. This large variability of the permeability, this impossibility to know the physicochemical characteristics of each stopper is therefore a great disadvantage to obtain a constant quality. The invention aims to produce natural cork stoppers having a permeability to oxygen and to water vapor lying on a narrow margin of predetermined value. c) Cork stoppers are known to have moisture contents varying from stopper to stopper as well as over time, depending on various parameters, such as ambient relative humidity or whether the stopper is in permanent contact or not with or bottled liquid. The moisture content inside the cork is fundamental to maintain these physical characteristics during its life, until the first opening of the bottle. Variations of 3 to> 10% moisture were measured in different commercial stoppers prior to the introduction into the bottleneck of the bottles, while the standard predicts 4 to 8% moisture for cork. Thus, the mechanical characteristics of compression and elastic recovery of corks depend, for the most part, on the moisture contained in the stopper. The more a plug is loaded with moisture, the more it becomes soft and the mechanical properties decrease, which also leads to a loss of tightness, beyond a certain limit of humidity of the order of 10%. The invention thus aims to produce natural cork stoppers having an inner humidity situated at a narrow margin and of predetermined value. (d) in a non-negligible proportion of cases, commercial cork stoppers, problems related to the opening of the stopper and the extraction of the stopper, particularly at the time of cylinder unrolling, result in a significant loss of physical integrity or strength of the cork, which leads in turn to a difficult extraction from the cork - it will take several attempts to extract the whole cork from the bottleneck - and often to a contamination of the conditioned liquid with the debris of this stopper, from where a degradation of quality and quantity drinkable, bottled liquid. The invention aims to obtain natural cork stoppers which retain their physical integrity at the time of their extraction from the bottleneck, often many years after the conditioning of the liquid. (e) The applicant has also noted that the values of the forces of introduction and extraction of natural cork stoppers can vary for the same homogeneous batch in a ratio of 1 to 3, with values exceeding the upper limits of the standard. It is a heterogeneity which is a serious defect.

At the time of extraction of the known stoppers, there are often large variations in the effort for the aperture: if a very weak effort can be considered as a poor conservation index, a very important effort is no longer acceptable on a practical level. It should be thought that consumers are endowed only with a physical force " medium ". The invention thus aims to obtain natural cork stoppers which have an aperturing effort located at a narrow margin and of predetermined value. f) Another major drawback, in particular in the eyes of the bottlers, is that of the cork powders released during the handling of the stoppers at different stages of the manufacturing process until the stopper is placed in the bottle. Indeed, the author of the patent application found that commercial stoppers generate cork powders in the collection, dispensing and placement circuits of the corks on the bottles. It also happens that these powders are inside the bottles, floating on the bottled liquid, despite the use of the suction systems placed on the automatic bottling machines. (g) The author of the patent application also found that a large majority of standard stoppers were not necessarily adapted in terms of barrier level to 7 ΕΡ 2 533 957 / ΡΤ

oxygen or water vapor, for the preservation of wines, each wine requiring a certain level of barrier or a barrier within a given range of values. In fact, the aging of certain wines implies a controlled exchange of oxygen and, therefore, a predetermined barrier level. The oxygen permeability of natural cork stoppers is very random and very variable from one stopper to another. For example, in a statistically representative sample of a homogeneous batch of bottles sealed with natural cork stoppers, it has been found in various cases that the permeability values of the cork stoppers treated by sealing can vary from 0,0001 to 0, 1227 (AWRI P.Godden & AI Enoforum 2005, 21-23 mars, Piacenza, Italy), in a ratio of 1 to 1000, between the extreme values. You can not have a command of wine quality under these conditions. The invention aims to provide stoppers which have an oxygen permeability in a relatively narrow range, as already mentioned and predetermined in order to be adapted to the type of liquid or conditioned wine. h) Although the corking of wine bottles is a constantly evolving field, and most of the wine bottles produced in the world are closed with a natural cork stopper, the natural cork stoppers retain, despite their drawbacks, an excellent brand image linked to an idea of tradition. The invention aims to obtain stoppers which retain the outer appearance of the traditional cork stoppers in natural cork. 1

In addition, by performing bottle-stopping tests containing liquids sensitive to oxidation containing effervescent beverages and conditioned beverage bottles under pressure, the applicant has found that the prior art stoppers do not permit a liquid and gaseous seal in particular with internal container pressures ranging from 10 bar to 15 bar ie from 1 MPa to 1,5 MPa, for a temperature range typically ranging from 0 ° C to 50 ° C and for a period that may several years, sometimes several decades. The stoppers and the treatments according to the invention aim to solve these problems. 8 ΕΡ 2 533 957 / ΡΤ (k) Finally, in the case of high-consumption products such as cork stoppers, the notion of the cost of production - cost of treatment - is essential, as regards investment costs, productivity and production costs. However, account must also be taken of the impact of the process on the environment, as well as the hazardous nature of the process, which may require administrative authorizations or specific investments linked to safety and environmental protection. The invention is directed to a simple, economical and high productivity treatment and requiring no particular means or measures.

Generally, starting from batches of so-called natural or so-called quenched stoppers, the invention aims to transform any batch of natural cork stoppers with their heterogeneity and variability of intrinsic properties, variability from batch to batch and within the batch lot, in a batch of corks with homogeneous characteristics and low variability, from one batch to another and within the same batch.

More particularly, the invention aims to provide stoppers having properties - in particular oxygen permeability - adapted to the liquids to be conditioned.

DESCRIPTION OF THE INVENTION

According to the invention, the treatment of the natural cork stoppers comprises, successively, the following steps a, c and d: a) a batch is supplied with a plurality of natural stoppers (900a) and the batch is impregnated into a composition (903) comprising at least one polymeric material P, under a pressure Pi greater than atmospheric pressure PA, in order to obtain a batch said impregnated, c) thereafter, said impregnated batch is dried, in order to obtain said batch dried, d) finally, said dried batch is subjected to a heat treatment, in order to obtain a batch of treated stoppers 928, each stopper 928 having a film composite " (204, 301, 304) of L cork impregnated with polymeric material P, symbolically represented by " L + P ".

According to the invention a complementary vacuum treatment step b) may be incorporated, the treatment of the natural cork stoppers comprising successively following steps a) to d): a) a batch is supplied with a plurality of said natural stoppers and said batch is impregnated in a liquid CP composition comprising at least one polymeric material P, under a pressure Pi greater than atmospheric pressure PA, in order to obtain a batch said impregnated, b) then said impregnated batch is treated under vacuum P2 < Pa in order to obtain a vacuum treated batch, c) thereafter, said impregnated batch is dried in order to obtain said dried batch, d) finally, said dried batch is subjected to a heat treatment, in order to obtain a batch of treated stoppers is present, each stopper having a " composite film " of cork L impregnated with polymeric material Ρ, represented symbolically by " L + P ".

The stoppers of this batch have on their entire accessible surface, external surface and inner surface of the cavities or recesses of said stoppers, a cork surface area L, comprising a penetration of said polymeric substance P into the cork, so that said stopper a composite film " L + P ".

Thanks to this treatment according to the invention, the applicant of the patent application was able to impregnate a layer of cork from the surface or film by said liquid composition CP. Said film corresponds to all accessible surfaces of the stopper and comprising suberous fabric, said surfaces being accessible: the said external surface of the stopper comprising the cylindrical surface of the stopper as well as the two circular faces at the ends of the stopper. the inner surface comprising all the surfaces of the cavities, the cracks and all kinds of open recesses, i.e. opening on said outer surface.

Thus, the author of the patent application found that the cork, or at least its main constituent, the alveolar suberous tissue, was able to absorb said liquid CP composition, as has been shown in particular with the aid of contrast agent micrographs.

However, since a natural cork stopper is a heterogeneous material which comprises, in addition to the suberous tissue with alveolar cells which gives elasticity to the cork, parts, typically formed by other constituents rich in lignin and tannins, which may be harder and more impermeable, and comprising said liquid composition under pressure, a stopper may thus present locally, in particular in terms of heterogeneities of the cork or in the recesses of the stopper, portions of the surface having a film " L + P " of low thickness, or may possibly be covered by a layer of polymeric material " P ".

As will be apparent from the following description and in the examples, the succession of at least steps a), c) and d) of the treatment is necessary to obtain stoppers that solve the set of problems placed, at least when the batch of corks is a lot of so-called natural corks. In particular, it should be noted that, with the naked eye, the stoppers obtained by the treatment according to the invention retain the general appearance of natural cork stoppers, which would not be the case if the stopper were coated with a polymeric or film-forming composition . Accordingly, the treatment according to the present invention provides the stopper with a composite film " L + P " based on cork L and polymeric material P, largely intended to be brought into contact with the neck of the container and in part in contact with the conditioned liquid, this film forming a deformable plastic material which continues after rolling, under the effect of radial compression, after the elastic recovery of the cork, to the relief of the inner surface of said neck.

As will be seen in more detail in the following, the invention, thanks to this succession of at least steps a), c) and d), solves the problems posed. Indeed, such a treatment of natural cork stoppers enables: to considerably reduce the migration of harmful molecules from the stopper to the conditioned liquid, so as to eliminate " taste the stopper ", the stoppers according to the invention brought into contact with a hydroalcoholic medium, do not alter taste or odor. obtain stoppers which have an oxygen permeability and water vapor within a restricted range and of predetermined value. to obtain stoppers having a moisture content within the corks substantially constant from one stopper to another and maintained within the range of 4 to 8% moisture of the cork provided for by the standard so that all corks have the same mechanical characteristics of compression and elastic recovery and a poor loss of these mechanical characteristics over time. - to obtain corks which retain their physical integrity, in particular at the time of their extraction from the bottleneck, often several years after the conditioning of the liquid. - obtaining stoppers which have a force for the aperture within a restricted range of predetermined value. obtain natural cork stoppers free of cork dust. to obtain permeability stoppers adapted to their particular use adapted to the type of liquid or conditioned wine. 12 ΕΡ 2 533 957 / ΡΤ - to obtain the corks which visually preserve the appearance of natural cork stoppers, whether at the time of the corking or at the time of the cylinder unrolling, in order to convey an image of " tradition ". - obtaining stoppers which have a liquid and gaseous tightness and even in the case of liquid contents under pressure. - to obtain these stoppers with a particularly economical process, either in investment cost, using current equipment or in running costs, with high productivity and which, on the other hand, presents neither risks to the environment nor health risks nor any danger in the its implementation.

DESCRIPTION OF THE FIGURES Figure 1a is a view of a bottle neck 101 filled by a stopper 100 and covered with a cover cap 102, this view forming, in the right half-part of the figure, a half- viewed from the side and in the left half-part of the figure an axial half-cut according to the axial direction 104 of the stopper and the neck.

Figures 1b and 1c are transverse cut portions of the stopper, perpendicular to its axial direction, which illustrate said composite film 204 forming an outer composite film 301. Figure 1b is a photograph -macrography-of this cut portion, a black dye being incorporated in the liquid composition. Figure 1c is the schematic representation of Figure 1b.

Figures 2a to 2d are sections of stoppers (100) obtained in accordance with the invention. In order to observe the impregnation of the cork in its recesses or cracks, by visual or microscopic observation, a black dye was added to the liquid composition CP. It is thus very clearly realized that recesses such as lenticels, pores, slits, gaps are impregnated with the liquid composition colored with black so as to obtain a visual contrast. Figure 2a is a photograph representing a left half-cut (300b) of a stopper. Figure 2b is a schematic representation of a right half-cut 300a of the stopper of Figure 2a. Figure 2c is an enlarged photograph of the portion A framed in Figure 2a. Figure 2d is a schematic representation of Figure 2c. Figure 3 is a diagram relating to the corking and coring forces, with the extraction done 26 days after the stopper and storage at an ambient temperature of 15 ° C.

In the abscissa, the tests E0 to E7 appear and in the ordinates the forces in daN, the measurements being carried out on a sample of 10 stoppers. The test E0 corresponds to commercial cork stoppers which are uncapped and treated with silicones. The tests EI to E7 correspond to stoppers obtained with the treatment according to the invention.

Curve A Curve B Curve C Curve D Curve and Curve F maximum extraction value average extraction value minimum extraction value maximum value of corking average value of corking minimum value of corking Figure 4 is a diagram of the moisture content of corks after 9 months in the neck of an empty bottle and stored at 15 ° C.

In the abscissa, the tests E0 to E7 appear and in the ordinates the humidity in%, being the measurements made in a sample of 10 stoppers.

Figure 5 schematically represents, in axial section, the device used to measure the oxygen permeability of a portion of the bottle (600) with a diameter of at least one portion of the bottle (600). a stopper (100) to be tested. This portion of bottle 600 is subjected to a metal plate 611 in a watertight manner thanks to a cord 612, the plate being provided with gas inlet tubes 613 and gas outlet 614, (610) overlying said portion of the bottle (600). Figure 6 schematically shows a first embodiment of the device for carrying out steps a) to d) of the treatment object of the invention.

Figures 7a to 9c illustrate another embodiment of the device for carrying out steps a) to d) of the treatment object of the invention. In this embodiment, all steps of the treatment are performed, without transferring the stoppers, into a dryer reactor (800).

Figures 7a to 8b are cross-sections along the plane C-C of Figure 9c. Figure 7a shows step a) of impregnation under pressure. Figure 7b shows step b) of desorption treatment under vacuum. Figure 8a shows the rinsing step c). Figure 8b shows the drying step d).

Figures 9a to 9c are longitudinal cuts according to the invention;

axis or central shaft (803, 803 ') and according to the plane A-A of figure 7a, illustrating different variants of driers (800). Figure 9a shows a ball reactor (800, 800a) of spherical shape. Figure 9b shows a dryer reactor (800, 800a) of cylindrical shape. Figure 9c shows a dryer reactor (800, 800a) of bi-truncated-conical shape.

DETAILED DESCRIPTION OF THE INVENTION

In the treatment according to the invention, in step (a) of said treatment, said batch of stoppers (900a) may be immersed in a first pressure-resisting container (902) containing said liquid composition (903) and the said pressure vessel (902) having an air pressure Pi of between 2 and 6 bar, and preferably of 3 to 5 bar, said air pressure Pi being applied inside said first vessel (902) of a duration comprised from 1 to 15 minutes and preferably from 3 to 10 minutes.

With regard to step a) of impregnation and having tested various methods of coating application, such as brushing, spray painting, immersion, ultrasonic immersion, it appeared to the applicant in the patent application that these methods do not allow solving the problems posed. These problems were not resolved if not with the treatment comprising a pressure impregnation of said liquid polymeric CP composition allowing said liquid composition CP to penetrate homogeneously into the cork structure, cracks, craters, crevices and galleries created insects or other open recesses that appear on the surface of the cork. However, as can be seen in Figures 2a and 2b, it appears that, at the time of pressure impregnation step a), almost all of the recesses are impregnated with said liquid composition CP, even in the case of recesses or cracks which do not appear directly to the surface. It thus appears that the pressure used in step a) of the treatment allows introducing said liquid composition CP into any network of recesses or cracks in the stopper. The applicant was thus observed at ambient temperature with the aid of the film-forming or polymeric coating added with a dye and applying, for example, a pressure of 5 bar for 3 Ρ Ρ 2 533 957 / ΡΤ minutes or 3 bar for 5 minutes, the penetration goal was fully achieved.

The same tests were performed under different pressures at stepped temperatures between 20 ° C and 38 ° C, without observing notable variations in the results. However, the viscosity of the polymer coating which decreases as a function of the temperature rise, has shown that the duration of the pressure impregnation could be decreased in relation to the lowering of the viscosity rate. Thus, preferably and also to be freed from external temperature variations, it will be preferred to work to impregnate under pressure at a relatively constant temperature of 38øC + 2øC.

On the other hand, the author of the patent application also found in the course of his experiments that the brutal placement out of pressure favored the desorption of the surplus of the CP liquid composition.

Thus, as can be seen in figure 6, a batch of raw cork stoppers from the wash (900) previously conditioned in an adapted net bag (901), wherein the mesh does not exceed the smaller size of the stoppers to be treated, is introduced into a pressure resisting reactor or reservoir (902) within which the liquid composition CP (903) typically comprising an aqueous phase emulsion of acrylic polymers or an aqueous composition based on EVOH, ethylene copolymer and of vinyl alcohol. The batch of stoppers must be completely immersed in the liquid composition 903, and then the cap 904 of said reservoir will be hermetically sealed. An overpressure of filtered and controlled air (905) is then applied into the reservoir (902). The reservoir 902 is regulated in temperature so as to maintain constant the viscosity of the liquid composition 903. The pressure is then brutally relaxed within the reservoir 902 and then the lid 904 is withdrawn. The net bag (901) is raised above the level of the liquid composition (903) and allowed to dry for a few moments. 17 ΕΡ 2 533 957 / ΡΤ

At the end of this first impregnation step and before proceeding to the next step, it was found that a stoppage step of the stoppers allowed to save a non negligible amount of the liquid composition (903). Thus, a pour time of the order of one to two minutes, accompanied by a shaking, allows to save about 5 to 20% of the amount of the liquid composition (903). Thus, any loss of liquid composition is, if not avoided, at least very limited. The inventor of the patent application found that the amount of the liquid composition CP consumed could vary depending on different parameters, such as the surface tension of the stoppers, the viscosity of the liquid composition CP and thus its temperature, but also the quality of the stoppers. Thus it can be seen that the quality stoppers " 0 " (superior quality called " Super ") without cracks or craters or galleries, consumed much less quantity of polymer material than quality stoppers, for example of quality 3 or beyond, being filled with holes, craters, slits and galleries which allow to accumulate a much larger amount of liquid composition CP (903) and of polymeric material P. As will be indicated below, the treatment according to the invention may also be used with so-called quenched stoppers, typically formed from stoppers of quality 3 or beyond. In this case, the recesses and cracks of the stoppers being already filled, the consumption of the liquid composition will be further reduced.

In optional step b) of the treatment, said impregnated batch may be vacuum treated within a vessel capable of withstanding vacuum (902 ') λ with a pressure P2 ranging from 0.1 to 4 mbar and preferably 0 , 5 to 1.5 millibar. Said vacuum may be made inside said vessel for at least one minute and preferably in cycles with the recovery of atmospheric pressure between each cycle, the number of cycles being from 1 to 10 and preferably ranging from 3 to 7, each comprising one set-up step under vacuum for about one minute. 18 ΕΡ 2 533 957 / ΡΤ

In the case of a batch of so-called natural cork stoppers, the author of the patent application found that this desorption step under vacuum was necessary. In fact, in the absence of desorption under vacuum, the author of the patent application found the formation of bubbles or micro-bubbles on the surface of the stopper at the time of drying and curing step d of the polymeric material P, which greatly the technical quality of the stopper and its appearance and aesthetics. The inventor of the patent application has assumed that the vacuum treatment enables a surplus of the liquid composition CP to be expelled from the small recesses or cracks which drying in step c) of the treatment does not allow to be eliminated. The desorption operation of step b) is carried out by depressurizing the reservoir containing the batch of corks to be desorbed. Typically, the tests showed that a P2 pressure of 4 mbar per one-minute cycle could be used. The inventor of the patent application can verify that several alternating cycles of vacuum placement and relaxation, significantly increased the level of desorption. Thus, series of 3 to 5 alternating cycles of vacuum placement for 1 minute and relaxations gave excellent results. The conditions of this desorption are such that this desorption occurs only with the liquid composition CP " free " which is in the recesses and not with the liquid composition that has penetrated the cork to form said composite film " L + P ".

In step c) of the treatment, after being replaced in the open air, the batch of vacuum-treated stoppers can be, once introduced into a dryer 910, by cycle drying, each cycle comprising a drying step for 0.5 5 minutes, preferably between 1 and 3 minutes, with a number of cycles comprised between 1 and 5 and preferably comprised between 2 and 3, a cork stopper phase being intercalated between each drying step, lasting between 3 seconds and 1 minute, and preferably 5 seconds and 30 seconds, during 19 Ε 2 533 957 / ΡΤ which the stoppers change position and place inside the drain drum (910).

Typically, the batch of stoppers may be subjected to a centrifugal force of between 20 and 80 Newtons, for example between 30 and 60 Newtons. The applicant of the patent application found that this draining step c) prior to curing the coating was necessary to complete or supplement the desorption step b) in order to avoid excess polymer emulsion in the recesses of the stoppers, causing bubbles remaining after healing. In addition to the unsightly appearance of these bubbles, they are removed during the handling, distribution and storage of the corks, thereby releasing into the air particles of cork susceptible of being redeposited in the different materials and optionally in the bottled liquid.

Likewise, drying prevents the presence of agglomerates of liquid CP composition on the surface of the stopper. All stoppers of a batch which have undergone the steps of placing under pressure and then placing under vacuum, followed by drying, respecting the cycles experienced by the applicant of the patent, presenting an outer surface absolutely clean and free from any visible surface defect to the naked eye of any pile of liquid CP composition or polymeric material P. The drying may be practiced in a machine with a vertical or horizontal axis drum. Machines with horizontal axis will be preferred, in view of the possible return steps during two drying sessions. These flaps allow the stoppers to move to provide different coating product extraction angles and thus homogenize this operation. The author of the patent application has shown that the choice of a machine with a drum with a diameter of 450 to 500 nm for a range of rotational speeds of 1200 to 1500 revolutions per minute, allowed to solve the problem placed, low rotation cycles: about 60 revolutions / minute. Preferably, 20 Å 533 957 / ΡΤ is alternated with the reversal of the rotation and drying cycle.

When a web bag is used to contain a batch of stoppers, the patent applicant has made it clear that the stoppers could be introduced into the dryer housing, preconditioned in the mesh bag already used during wetting-impregnation operations and desorption means, said net bag, typically with mesh in the order of 10 x 10 mm having a slightly larger overall volume than the dryer drum, in order not to counteract the effects of the centrifugal force during the bleeding cycles.

In step d) of the treatment, after having extracted the batch of stoppers 921 from the dryer 910 in step c) of the treatment, said batch of stoppers 921 may be treated in an enclosure 920 by a flow of hot air having a velocity of between 3.0 and 20.0 meters per second and preferably between 5.0 and 10.0 meters per second in order to form said heat treatment, said heat treatment being to eliminate a solvent of said liquid composition CP, when said liquid composition CP comprises a solvent.

At the end of step d) of the treatment, the batch of stoppers can be cooled by a cold air flow and, optionally, the speed of said cold air flow can be increased upwards of 15 m / s, in order to expel the said batch of stoppers out of said enclosure and thus to collect the batch of stoppers directly into a bag or container adapted for this purpose. Said hot air stream may be applied at a temperature in the range of 80 to 120 ° C and preferably in the range of 90 to 100 ° C in the range of 3 to 15 minutes, and preferably in the range of 5 to 10 minutes.

However, in the first instance, said reflux of hot air may be applied at a temperature of from 40 to 80øC, and preferably from 50 to 70øC at 21 ÅΡ 2 533 957 / ø for a duration of from 1 to 10 minutes, and preferably between 2 and 5 minutes.

Preferably, after said air flow has been applied, heating of said hot air stream may be stopped, said air reflux then passing at ambient temperature so as to cool said batch of stoppers at ambient temperature for a time substantially equivalent to that of said heat treatment.

After testing different processes, such as the traditional ventilated oven, the microwaves, it seems to the patent applicant that during the evaporation operation of the solvent phase and polymerization of the coating, the stoppers should preferably not be in contact with a wall, in order to obtain corks that present an excellent traditional cork appearance and avoid the presence of visible marks on corks. The inventor of the patent application developed a drying-cure system as shown in Figure 6. After different tests and a set-up phase, the solution of levitation of corks under pulsed hot air flow was considered excellent for obtaining corks without defects of surface. The aqueous phase polymer emulsion forming said liquid composition requires a solvent evaporation step. When the solvent in question is water, which is the preferred case, the water must be evaporated, prior to coagulation and polymerization of the coating, if no bubble formation is observed. The following Time / Temperature cycle will be preferred: 1-40 at 60 ° C for 2 to 3 minutes 2-70 at 120 ° C for 3 to 15 minutes and preferably 80 to 90 ° C for 5 minutes, and then cooling to room temperature with an equivalent duration.

At the end of step d) of the treatment, the batch of stoppers can be cooled with a flow of cold air whereby the speed of said cold air flow can then be increased beyond 15 m / s in order to expel said batch of stoppers out of said enclosure and thus to collect the batch of stoppers directly into a bag or container adapted for this purpose.

According to another embodiment of the treatment according to the invention, step a) of the treatment can supply a batch of said stoppers and the step b) can be suppressed under vacuum. Indeed, the invention applies to any type of stoppers. For obvious economic reasons, this will be preferable to use with types of stoppers of relatively inexpensive cost, which is the case of the stoppers called natural. But the so-called corked stoppers are also of a substantially close cost since the over-cost of said sealing treatment is appreciably balanced by the cost of the cork starting, the latter of inferior quality, comprising the disadvantage of recesses or cracks, number or depth.

As the cracks have been previously filled, the desorption stage b) of the stoppers can thus be suppressed, there being no further reason to exist.

Advantageously, the fluids used in the different steps of said treatment, whether in the case of compressed air in step a) of the treatment, or of hot air in step d) of the treatment, should be neutral and free from germs, bacteria, yeasts and of all contaminant sources of pollution for liquids filled by the stoppers so treated.

In the treatment according to the invention, said liquid composition CP (903) may comprise, in addition to said polymeric material P, at least one additive A intended to favor the sliding of the stopper in contact with the glass, so that said treated stopper has a " skin " of composition represented by " L + P + A ".

In the treatment according to the invention, said liquid CP composition (903) may form an emulsion or an aqueous phase dispersion of at least one polymeric material P selected from the polymer materials: a ) acceptable for contact with food, b) capable of forming a barrier to said harmful molecules, said polymeric material P being preferably an aqueous acrylic polymer emulsion or an aqueous composition based on EVOH, a copolymer of ethylene and vinyl alcohol.

According to another embodiment of the invention, said treatment may comprise: a) a said first succession of at least steps a), c) and d) from said first liquid polymer composition CPi, typically formed by said liquid composition CP comprising said polymeric material P, in order to form said first impregnation, b) and a complementary treatment comprising, for example, said second succession of at least steps a), c) and d) from a the second polymeric liquid composition CP2, at least said second polymeric liquid composition CP2 comprising said additive A adapted to favor the sliding of said stoppers, so as to form said second impregnation, so that said treated stopper has a " skin " composition composite symbolically represented by " L + P / A ".

Said first and second polymer compositions may be different and, for example, only the second impregnation may comprise said additive A. There has not yet been a possibility to establish precisely whether the second impregnation overlaps and / or if it is mixed with the first impregnation. Said liquid composition CP (903), CPi or CP2 may comprise an elastomeric material E selected from: butyl rubber, nitrile rubber, thermoplastic elastomers such as SIS (styrene-isoprene-styrene ), SBS (styrene-butadiene-styrene), SEBS (styrene-ethylene-butylene-styrene), Polymer MS (Modified Silicon Polymer) or PDMS (polydimethylsiloxane). Said additive A for promoting the sliding of the stopper in contact with the glass may be an anionic emulsion wax, typically based on paraffin wax or carnauba wax or a silicone resin when said first liquid polymer composition CPi comprises said EVOH-based aqueous composition so as to cover said EVOH-based polymeric material P with a layer forming at the same time a barrier to water and a glidant, said additive A being an additive A2 constituting said layer second polymeric liquid composition CP2, said second liquid polymeric composition being then free of EVOH. Said liquid composition CP 903 may comprise a micronised mineral filler B which forms a barrier, in particular to diffusion of the gases, said mineral filler being chosen from: silica S102, or a SiO2 silicon oxide (with x <2) , titanium oxide TiO2, micronized clay, kaolin, barium sulfate.

In step (a) of the treatment according to the invention, said liquid CP composition (903) may have a dynamic viscosity at 20Â ° C of between 5 and 1000 cps, and preferably between 10 and 40 cps.

Advantageously, at least during steps a) and b) of the treatment according to the invention and depending on the technical embodiments of the treatment according to the invention and in the case of the process as illustrated in figure 6, said batch of stoppers may be contained in a mesh bag of a chemical and knitted nature (e.g. 10 mm x 10 mm) adapted to pass said liquid composition CP (903) and being inert with respect to said liquid composition and with a mesh of a smaller size than the smaller size of the stoppers to be treated, so as to have to be handled only a web bag in which said batch of stoppers is located during steps a) to c) of the stopper. treatment.

A further object of the invention is a cork stopper, typically a batch of stoppers, obtained by the treatment according to the invention and characterized in that it has on its entire accessible surface the outer surface and the inner surface of the cavities or recesses of said stoppers , a cork surface area L, comprising a penetration of said polymeric material P into its mass an incorporation of said polymeric substance P into the cork, so that said stopper has a composite film (204, 301, 304) of represented composition symbolically by &quot; L + P &quot;, said composite film (204, 301, 304) having a thickness E of at least 10 Âμm and up to 1 mm depending on the local hardness or porosity of the natural cork or their constituents.

Typically, said polymeric material P may be an acrylic resin having a density of from 0.95 to 1.2 and preferably from 0.98 to 1.00, or an aqueous composition based on EVOH, an ethylene copolymer and poly vinyl alcohol).

As already indicated, the presence of a composite film &quot; L + P &quot; is not exclusive to the possibility of having, at least locally, a part of said polymeric material P deposited on the surface of the cork, in particular inside the recesses of the cork.

According to the invention, said cork surface area L forming said composite film (204, 301, 304) may comprise, in addition to the incorporation of said polymeric substance P into the cork, the incorporation of said additive A intended to favor the sliding of the stopper in contact with the glass, so that said treated stopper presents a composite film of composition symbolically represented by &quot; L + P + &quot; or by &quot; L + P / A &quot; wherein said additive A is incorporated in said polymeric material P or recovers said polymeric material P. 26 ΕΡ 2 533 957 / ΡΤ Said cork surface area L may comprise, in addition to the incorporation of the polymeric material P in the cork and the incorporating said additive, incorporating at least one auxiliary selected from: a micronized mineral filler B forming a barrier, in particular to gas diffusion, an E-elastomeric resin.

A further object of the invention is the use of cork stoppers according to the invention or obtained by the treatment according to the invention for obturating containers, typically in glass, containing alcohols, wines or spirits.

DESCRIPTION OF THE EXAMPLES (A) Selected starting materials for the tests: (A) Cork Stoppers: A batch of untreated corks was procured from natural cork suppliers and processors: these natural stoppers, which do not were subjected to no treatment other than washing in hot water, they are said to be natural. These natural cork stoppers are of standard dimensions of 45 mm x 24 mm (height x diameter).

On the other hand, lots of corked stoppers were also supplied. A2) Liquid compositions comprising a film-forming or polymeric material:

A polymer composition P selected from among food grade materials is selected and provisioned as follows: A20 = Michem Coat ™ MC40EAF-E from Michelman Inc. A21 = VaporCoat ™ 2200E from Michelman Inc. dispersions of acrylic resins in aqueous emulsion.

These two materials were selected after testing with a large number of materials suitable for food contact. 27 ΕΡ 2 533 957 / ΡΤ

However, comparative test batteries have made it possible to better attest the Vaporcoat ™ 2200e to the problem. The physico-chemical characteristics of the MC40EAF-E do not allow it to be applied at room temperature with a simple process. It is necessary to apply strong pressures, greater than or equal to 5 bar to at least 38 ° C and with longer durations, longer than 5 minutes, to obtain the correct results. The inventor of the patent application thus selected Vaporcoat ™ 2200E as the polymeric liquid CP composition for preparing and testing the stoppers according to the invention.

In addition, a composition of Kuraray's EVOH, reference AQ-4104, was selected and provided under reference A22 as the liquid composition comprising said polymeric material P selected from food-grade materials. A3) Additives A intended to promote the sliding of the cork in contact with glass: A30 = ML160PFHS.E from Michelman Inc. (Carnauba Wax Emulsion) A31 = ML723HSA-E from Michelman Inc. (Paraffin Emulsion)

Selection of these additives: sliding tests on glass, as well as full-scale tests on corks with statistically representative series, have made it possible to show that Vaporcoat 2200E poses a problem of adhesion in the glass, reaching the point where the forces of introduction and of extractions found certain values far beyond the upper ranges of the standards in force. Numerous additives were then tested and two of these (A30 and A31) were retained for comparative testing in relation to reference products, which are natural cork stoppers. 28 ΕΡ 2 533 957 / ΡΤ Α (4) Mineral loads Β intended to form a gas barrier:

The following products of the trade were procured; silica SiC &gt; 2, talc, ... A5) Other raw materials:

Silicone based and synthetic rubber based elastomeric dispersions, in particular a silicone based dispersion of Bluestar, reference CAF 72582, are referred to as reference A50. B) Equipment for the accomplishment of the treatment according to the invention

The different tests carried out carried out the treatment of the invention, as represented schematically in figure 6.

For this purpose, the different equipments needed are provided and manufactured, namely: BI - A first container (902) able to withstand a pressure of 5 bar, with a capacity of 20 1, provided with a removable cover (904 ) equipped with a pressure gauge (905) and a compressed air inlet. A second container (902 '), substantially the same capacity as the first container (902), capable of withstanding vacuum, namely a residual pressure of 0.1 milibar, said second container (902') being provided with a removable cap (904 ') provided with a vacuum gauge (905') and a vacuum nozzle connected to a vacuum pump. B3 - A dryer (910) provided with a variable speed drum and a pump for extracting the recovered filmogenic liquid composition. A drying device comprising: a vertical drying column forming a cylindrical tube (920), capable of being fed with air (hot or cold) by its lower part, and comprising: (924) forming a support for the batch of corks to be dried, * at its upper end, a removable perforated upper grid (925), so as to allow air to cool or cool, but to retain in the upper part - just below said upper end - an upper lateral tubular conduit (927) coming out in the vertical enclosure by an opening, capable of being firmly closed or opened by means of a movable flap (920) (926), which allows for the transfer of the stoppers to a conditioning medium, such as a net bag (929). an air propulsion turbine (922) in a lower side duct, an air heating means such as electrical resistors (923). B5 - Centralized control means of this equipment, with registration of parameters. These means were not shown in Figure 6. B6 - A stopper retention net bag capable of containing 100 corks per test. All equipment has been supplied commercially, with the exception of the B4 drying device which has been designed and constructed in the field of the invention.

Assays were also performed with a single vessel device, as shown in Figures 7a to 9c, which allows performing the four steps a) to d) of the treatment in the same reactor. C) Generic implementation of steps a), b), c) and d) of the treatment 30 ΕΡ 2 533 957 / ΡΤ

Cl- Step a) of impregnation under pressure

In an autoclave vessel or reactor, a batch (900) of 100 natural cork stoppers, namely crude brine, is introduced into an adapted net bag (901), the mesh of which does not exceed the smaller size of the corks. a liquid composition CP (903) forming a bath, as shown in step 1 of Figure 6, so that the stoppers are fully immersed in the liquid composition CP in the aqueous phase. After closure of cap 904, an overpressure of filtered and controlled air 905 of 3 bar (1 bar or 105 Pa) was applied to the interior of the vessel for 5 minutes. At the end of this time the compressed air was cut off and the inside of the vessel was allowed to reach atmospheric pressure. After removing the cap 904, the net bag 901 is lifted above the bath formed by the liquid composition 903, so that the net bag and the batch of stoppers 900 run for about of two minutes, in order to recover excess of said liquid composition CP.

It is noted that the autoclave vessel was self-regulated at a temperature around 38 ° C so as to maintain constant the viscosity of the liquid composition CP. Vacuum desorption treatment step b) The batch of stoppers 900 from impregnation step a, always conditioned in the net bags 901, was introduced into a second depression resistant reservoir or reactor 902 ' , and then the lid (904 ') of said reservoir was hermetically sealed. The interior of the reservoir was placed under vacuum under pressure controlled by a 1 milibar vacuum gauge (905 ') for 1 minute. The vacuum is then cut and this second reservoir (902 ') is subjected to atmospheric pressure. Repeat this cycle 5 times. Thereafter the cap 904 'was taken out and said batch of stoppers 900' was drawn from said second reservoir 902 '. The desorbed liquid composition CP (906) was recovered at the bottom of the reservoir (902 '). This small amount (906) of said liquid CP composition was extracted either by gravity or with the aid of a pump, and then filtered and recycled in the first step a) of impregnation under pressure. The batch of stoppers impregnated with the polymer emulsion, always within the mesh bag (901), was introduced into a dryer (910) through the borehole (910). access (911). The batch of corks (900 ') was then subjected to alternating run-off and return cycles, the net bag volume being slightly higher than that of the dryer drum. Into the inner tub of the dryer, the polymer exudates which were ejected by the pump (912) into a recovery tank were recovered, to be filtered and recycled to the impregnation circuit. C4 - Heat treatment step (drying - cure) The batch of corks was extracted from the dryer directly with the aid of the net bag (901). The corks were poured from the mesh bag directly into a heavily vented vertical oven (920). The stoppers were retained by a grille with a calibrated mesh (924) above the low temperature heating system (923). The heating was increased to its chosen point and a vertical hot air flow ("A" circuit) was circulated from below with a very high flow rate or flow to keep the stoppers (921) in levitation or suspension up in the air. A second calibrated grid (925) in the upper part of the duct retained any stoppers lighter than the batch average and which under the upward pressure would have risked escaping the duct 920. The heating (923) was not brought to its nominal level if not after a first evaporation step of the solvents. The stoppers were kept in a levitation or flotation state, in order to avoid the effects of bonding therebetween, but also to avoid any strongly supported contact with the wall of the upright conduit (920). Advantageously, the walls of the vertical duct 920 have been surface treated with the PTFE tank or with any other matter which favors sliding and limiting the risks of accumulation of the coating material object of the invention. When the heating cycle was completed, according to the expected durations and temperatures, the air heating was stopped, so that fresh air circulated instead of the hot air, which allowed the batch of stoppers (921) to cool to a temperature close to ambient temperature.

The air velocity, for example, has been lowered to about 3 m / s, in order to force all of the stoppers back down to the bottom flap (924) and thus enable the flap (926) to move until it closes the vertical duct 920 without being impaired by any levitating stoppers and thus opens the horizontal duct 927.

A drying cycle comprises steps A to F as follows: A - Stabilized system installation at temperature and air velocity at about 3 m / s. B - Introduction of a batch of corks in the vertical chimney previously opened. C - Clogging of the stopper introduction hole with the aid of a calibrated section retaining grid, in order not to introduce any load losses. D - Adjusting the air speed between 5 and 10 m / s, depending on the size and the mass of the corks, so that they remain in levitation or fluctuation in the volume of the chimney, and to avoid contact with the walls and shutters ducts. E - Heat stroke and introduction of fresh air of the same duration. F - reduction of air velocity to about 3 m / s.

But the mode of operation used in the tests was as follows: a first solvent evaporation cycle with an air temperature of 50 ° C + 10 ° C (in certain embodiments, this temperature can be up to 70 ° C + 10 ° C), but which does not include steps E &amp; F, a second cycle comprising raising the heating temperature, with an air temperature of 80 ° C + 10 ° C (in certain embodiments, this temperature can be up to 90 ° C + 10 ° C). 33 ΕΡ 2 533 957 / ΡΤ C5 - Removal of corks and conditioning

When the temperature of the treated and polymerized stoppers has reached the ambient temperature substantially, the batch of said stoppers is expelled out of the vertical kiln by means of a movable hatch (926) which seals the main vertical duct, to orient them towards the outlet through the horizontal conduit thus released, with a discharge velocity, for example of 10 m / s. The stoppers 928 are collected in an intermediate conditioning bag network (929) or in its final package. The patent applicant can verify that draconian hygiene rules have to be respected in order to avoid any accidental pollution of any origin during the treatment cycle. The materials, materials, utensils and fluids used must be under permanent physical and chemical control, in particular the presence of bacteria, germs must be ensured in order to avoid any risk of contamination and to provoke organoleptic or chemical modifications of the bottled product.

Moreover, the final conditioning is advantageously performed free of dust so as not to introduce external dust to the conditioned stoppers in view of their end use. D) Different tests performed

Numerous exploratory tests have been carried out by the author of the patent application, both as regards the chemical nature of the starting liquid composition CP (903) and the process parameters for applying these compositions (903). By way of information, the applicant has carried out the following tests which show, in the case of a supply of natural cork stoppers, the necessity, as the case may be, of the three steps of the treatment according to the invention (a, ced of the process designated PR1), with, in the table below, &quot; 1 &quot; if the corresponding step was accomplished and &quot; 0 &quot; otherwise: 34 ΕΡ 2 533 957 / ΡΤ

Step a Step b Step c Step d Notes 1 1 1 1 PR1 Stoppers according to the invention 1 1 1 0 Stoppers not usable 1 1 0 0 Stoppers not usable 1 0 0 0 Stoppers not usable 1 o ** 1 1 PR2 Stoppers according to the invention ** 1 0 0 1 Corks with very irregular surface coating 1 1 0 1 Corks with very irregular coating on the surface 0 * 0 1 1 Corks with very irregular coating on the surface * The stoppers were impregnated under pressure. On the contrary, as already mentioned, in particular in the case where a batch of said stoppers is filled, vacuum desorption step b) is no longer necessary to obtain the stoppers according to the invention.

Dl Liquid composition tests with the same treatment

Different liquid CP compositions (903) were prepared by mixing a polymer composition or material P in the form of an aqueous dispersion and a slip agent A, optionally in the form of an aqueous dispersion.

For each test, the nature and percentage of constituents P and A were given. Test No. (process) Nature and percentage of P Nature and percentage of EI (PRl) A21 - 100% 0% E2 (PRl) A21 - 95% A30 - 20% E5 (PRl) A21 - 95% A31 - 5% E6 (PRl) A21 - 90% A31-10% E7 (PRl) A21-80% A31-20%

Numerous other complementary assays were performed. 35 ΕΡ 2 533 957 / ΡΤ

Thus, the ε7 assay was also performed from a batch of said stoppers, according to process PR2.

In the same way the EI test was also carried out by completing it with a later application of a slip agent, possibly corresponding to the products A30, A31 or possibly A50.

Also, stoppers with two impregnations were manufactured, one with a liquid CPI composition comprising 80% by weight of A21 and 20% of a barrier mineral filler, and a second with a liquid composition CP2 comprising 80% by weight of A21 and 20% of A31.

Corks with two impregnations, a first with a liquid composition CPi comprising 80% by weight of A21 and 20% of a barrier mineral filler and a second with a liquid composition CP2 comprising 60% by weight of A21 , 20% by weight of A31 and 20% of a dispersion of an elastomer.

In the treatments comprising two impregnations, each of these impregnations may be carried out according to process PR1 and / or PR2, with all possible combinations: PR1-PR1, PR2-PR2, PR1-PR2, PR2-PR1; 'PR2-PR1' meaning that the first impregnation is carried out according to process PR2 which does not encompass vacuum treatment step b), while the second impregnation is carried out according to process PR1 which comprises one.

Corks having an impregnation with a liquid CP composition comprising the composition A22 EVOH from Kuraray, reference AQ-4104, using each of PR1 or PR2 processes, said impregnation being followed by an application of at least one layer, and preferably two-layer, Bluestar silicone based A50 fluid dispersion, reference CAF 72582, said application being followed by a pulsed air flow drying, the inventor having been verified that it was it is thus possible to advantageously obtain a silicone resin-based outer layer while forming a moisture barrier to protect the underlying moisture sensitive EVOH layer and a slip agent for the stopper. E) Results obtained:

It should be noted that the results of the complementary assays which led to results comparable to the best results of the EI to E7 tests were not mentioned hereinafter. 1 - Visual aspect

On the one hand, all corks from the same lot had a high homogeneity and a visual examination of a single cork confirms that the composite film formed on the surface of the cork is perfectly regular, taking into account the proper texture of the natural cork used as a carrier and gives the cork a natural cork appearance.

On the other hand, cuts of these stoppers, as illustrated in Figures 2a to 2d, demonstrated, on the one hand, by the use of a colored contrast agent, on the one hand, an excellent penetration of the filmogenic liquid composition in the recesses of the cork and, on the other hand, the formation of a composite film 'L + P' to the surface of the suberous fabric of the cork stopper, as shown in Figures 1b and 1c. 2 - Introduction and extraction force

The bottles were capped with the stoppers of the preceding tests in the usual manner: with the aid of a commercial apparatus for measuring vertical force, the stopper is radially compressed and then introduced by vertical mechanical thrust into the neck of a bottle.

After storage for 26 days at 15 ° C, the stoppers were extracted with an apparatus to measure the extraction force.

The results of these tests are regrouped in the table in figure 3: 37 ΕΡ 2 533 957 / ΡΤ - with respect to the vertical rolling force, a lower dispersion of the forces with the stoppers of the tests EI to E7 can be verified according to the invention in relation to the EO test, as can be seen by observing the deviation between the D and F curves of the maximum and minimum values. The mean values, which are substantially around 30 daN for the EO test, fall very clearly for the number of assays according to the invention, for example the tests E3 to E6. with regard to the extraction force of the stoppers, it may be noted, on the one hand, a large difference according to the nature of the slip agent A: the results are clearly superior with the slip agent A31. Note the results of the test E7, which are both marked by the poor dispersion of the shear and extraction force values and by the levels of these forces, ideally between 20 and 30 daN. In contrast, commercial natural cork stoppers with a length of 45 mm x 24 mm in diameter, treated with silicones, gave ranges of vertical coring force values between 28 and 50 daN in the bottleneck of dry glass bottles. The dimensions and profiles of bottle necks have previously been measured as scanning the spectrum of tolerances of standards CEN EN 12726: 2000, GME 30. 05 and NF H35-100TR.

Corks from the same batch were treated as in the E7 test and the results obtained with the corks in the same bottles as before gave ranges of introduction values between 25 and 30 daN perfectly centered and with a standard deviation of 2.19 against a standard deviation of 11.71 in the case of commercial stoppers (test E0).

With regard to the values of the extraction forces, these were measured 26 days after stop, always with the same batch of reference bottles.

The cylinders corked with natural cork stoppers 45 x 24 mm commercially treated with silicones (test E0) have extraction values ranging from 20 to 30 daN with a standard deviation of 3.90, which is already remarkable since it is not uncommon to find in the trade values for natural cork extraction 38 ΕΡ 2 533 957 / ΡΤ fluctuating between 10 and 50 daN and even 30 to more than 60 daN in the case of corked stoppers.

In the case of the E7 test, the extraction values range from 23 to 30 daN with a relatively low standard deviation of 2.19. 3 - Corkscrew Dust

At the end of the treatment according to the invention and of the various subsequent operations of corking and extraction, no trace of cork powders appeared, whereas under the usual conditions of use of cork stoppers treated with paraffin or silicones or stoppers significant quantities of cork powders are formed in the bottling lines, in particular during the dispensing and placement of said stoppers. The author of the patent application carried out the test recommended in the Charte des Bouchonniers Liégeurs (Letter of the Cork Rollers), carried out in 4 corks taken at random from a lot. This Charter recommends that the quantity of cork powder should be less than 1,5 mg for top-end corks and 2 mg for standard cork stoppers. It has been found that with the stoppers according to the invention, the amount of deposited dust is almost equal to zero and in any case at least ten times less than in the case of the test stoppers (test E0). 4 The moisture content of the stoppers The author of the patent application controlled the internal hygrometry of the stoppers obtained in the tests according to the invention, as well as the starting relative humidity. All test stoppers exhibit moisture content values measured at 20 ° C, ranging from 4 to 5%, values roughly the same as those of the starting stoppers.

The stoppers of the test E0 also have a moisture content in the same range of values.

In addition, two types of tests were performed: 39 ΕΡ 2 533 957 / ΡΤ 4Α) Outdoor test:

The batches that were used for the introduction and extraction tests were taken and measured after 9 months of storage in the cork manufacturer's original packaging. It should be noted that these stoppers have all the hole of the introduction of the screw thread of the corkscrew used in the extraction tests. The presence of this hole is an attenuating element in the difference between the 'A' lots in commercial natural cork and 'B' impregnated with the treatment product object of the invention.

The results are shown in the table of figure 4.

Commercial natural cork stoppers treated with silicones (EO) have a mean moisture content measured at the beginning of 4.4% and a mean humidity, measured after 9 months, of 5.5%.

Commercial natural cork stoppers treated according to the invention (tests EI to E7) had a mean moisture measured at the beginning after impregnation of 5.2% and after 9 months, this average moisture was always 5.2%.

In view of this first series of results, it seems clear that unlike commercial cork stoppers, the stoppers treated according to the invention did not evolve at all in the course of time, despite the presence of the corkscrew hole at its end higher. 4B - Total immersion test

The two plugs of the EO to E7 tests were immersed for 24 hours in a vessel containing water from the network. At the end of this period and after a 24 hour outdoor drying time, a new series of measurements were performed and the following results appeared:

Commercial natural cork stoppers treated with silicones (EO test) had a moisture measured at the beginning of 4.6 to 5.8%. After immersion and drying, after 48 hours, the measured mean humidity increased from 6.6% to 9.6%. 40 ΕΡ 2 533 957 / ΡΤ

The stoppers of the EI to E7 tests of the invention had a moisture content measured at baseline ranging from 4.7 to 5.4%. After immersion and drying after 48 hours, the average humidity ranged from 5.0 to 5.2%.

In view of these results, the applicant claims that unlike conventional commercial stoppers, stoppers treated according to the invention do not evolve in time, even in the presence of a liquid. The inventor of the patent application has concluded that the stoppers treated according to the invention can equip bottles lying down or not lying down, which is not the case for ordinary commercial stoppers, since these should not under any circumstances stand upright since corks must remain in permanent contact with the liquid, without which cork loses its moisture, hardens and loses its elasticity, and therefore a loss of tightness due to lack of contact force or elastic recovery inside the bottle neck . 5 - Permeability to oxygen The tightness of a stopper is not evaluated solely on the basis of the intrinsic barrier properties of the cork in contact with the inside of a glass tube. It is imperative to use a test representative of the actual sealing conditions of the corked bottlenecks. For this reason, the author of the patent application used the following leakproofness test (see Figure 5). a) a corked bottle is stocked with a natural cork stopper and the bottle body is cut off to remove its lower part. The cut should be straight and as flat as possible so as to be able to place the top of the bottle 601 provided with its stopper 600 in a flat plate 611, typically in stainless steel, in an area where it is pierced to leave passing two pipes 613 and 614. The connection between the lower end of the bottle and the stainless steel plate 601 is made perfectly sealed by placing a thick cord (612) (typically 20 to 30 mm) of epoxy resin. A controlled purity gas, typically pure argon or pure nitrogen, is introduced into the bottle through the tubing (613). This gas is evacuated by the piping 41 ΕΡ 2 533 957 / ΡΤ (614) which is connected to a means for measuring the amount of foreign atoms (for example, oxygen atoms) which are introduced into the bottle (Oxtran type machines ). The assembly is placed in a room (610) and the latter is filled with oxygen. To evaluate the tightness, it is necessary to arrive several tens of days, before beginning to measure the amount of oxygen that has infiltrated inside the bottle. The applicant for the patent has carried out comparative tests for oxygen permeability of corks on bottles, under commercial conditions, which means liquid inside said bottles. A batch of bottles was capped with standard commercial stoppers treated with 45 x 24 mm silicones (E0 test) and another batch of the same dimensions, with stoppers treated with the aid of the material and according to the conditions of the invention (EI tests to E7).

The two types of stoppers were introduced into the bottleneck bottle necks. These were placed for 40 days in an oxygen-containing enclosure.

The analyzes were run with a dry gas (argon) and at room temperature. The following oxygen permeability results were observed:

Test E0 (bottling lot with commercial natural cork stopper): 0,00030 to 0,1227 cm3 / 24 h / bottle.

Test El to E7 (batch of bottled with stopper treated according to the invention): 0.00005 to 0.0050 cm3 / 24 h / bottle.

In view of these results, it appears that: on the one hand, the control stoppers show a very wide dispersion of the results (from 3.10 ~ 4 to 0.12 cm3 Ct / day, which is considerable to compare with the range of 5.10 ~ 5 - 5.10-3 cm3 / day for the stoppers according to the invention, which corresponds to a relatively low dispersion of values, and on the other hand the permeability values fell sharply and were divided by at least 10 42 Ρ Ρ 233 957 / ΡΤ 6 - Liquid marking test

Lots of ten bottles full of wine and corked with natural cork stoppers with a length of 45 mm and a diameter of 24 mm (tests EO to E7) were placed in an oven initially at 30 ° with the elevation of the temperature to levels of 5 ° C up to 60 ° C, the bottles being kept at the temperature of each level for 4 days. At the end of this test, a visual examination as well as a weighing allow to detect a possible leak: a bottle is considered as having a leak if a loss of weight of at least 2 g is observed.

Results: EO test stoppers showed a leakage rate of 5%, whereas stoppers of all EI to E7 tests according to the invention had a leakage rate of 0%. 7 - Measurement of the barrier effect to harmful molecules 7-1 Procedure: a - selection of 15 natural corks b - maceration of the 15 corks in a hydroalcoholic solution with 15% by volume of ethanol, acidified to pH, 3,5 for three days at the temperature environment c - analysis and determination of contaminating haloanisols

The contaminant haloanisol contents in the hydroalcoholic solution were determined by SPME (Solid Phase Micro Extraction) and by SBSE (Stir Bar Sorptive

Extraction): 7-2 Evidence of the barrier effect of the treatment according to the invention

Different batches of LI to L5 stoppers were variously contaminated with haloanisols. In each of these batches a first sample of 15 stoppers was used to determine the pre-treatment haloanisole content and a second sample of 15 stoppers was treated with the E7: 43 ΡΡ 533 957 / ensaio assay, then the content in haloanisole after treatment. The following table indicates the levels found in ng / 1 (nanograms per liter):

Before treatment After treatment Efficacy in% LLl 85.9 15.7 7 82 L2 38.1 7.0 82 L3 22.7 1.9 92 L4 19.3 1.5 92 L5 8.2 0.7 91

It will be appreciated from this table that the treatment according to the invention can effectively be applied to relatively polluted stoppers having a haloanisole content of about 23 ng / l, knowing that the detection limit is 2 ng / l.

On the other hand, when it is known that the usual haloanisole contents of the so-called natural or so-called commercial capped stoppers are around 10 ng / l, it is thus clear that the invention allows to guarantee for stoppers a haloanisole content below the limit of detection of 2 ng / l. 8 - Sensory analysis tests The author of the patent application also conducted sensory and taste tests of water, in which the stoppers had been previously immersed for at least 24 hours, each in a glass of water considered organoletically neutral. It was found that after a number of significantly representative tests: - at least 80% of the commercial cork stoppers (test E0), produced odors and tastes the cork making the water hardly drinkable. 100% of the stoppers treated with the material and according to the treatment of the invention (tests EI to E7) did not induce any olfactory detectable organoleptic deviation or by tasting the water. F) General conclusions 44 ΕΡ 2 533 957 / ΡΤ

All controls and tests performed comparatively and regrouped in the preceding 8 rubrics have shown that the stoppers obtained by the treatment according to the invention have properties always superior to those of the stoppers. The invention enables economically to manufacture a wide variety of corks with properties and performances adapted to the particular requirements of each type of wine to be conditioned in the bottle, in particular by joining said liquid composition of all types of additives, such as TiC> 2, SiC> 2, SiO 2, talc, clays, kaolin, barium sulfate.

LIST OF REFERENCES

Cork stopper ............................................... ...... 100

Bottle................................................. ............. 101 Coverage Capsule ................................. ................ 102 Liquid in the bottle .............................. 103

Cell structure of cork ......................................... 200

Cork recess ............................................... 201

Composite film 'L + P' ........................................... .. ^ Left section of cork stopper .......................................... .. 300a ^ Right cut of cork stopper .......................................... 300b

External composite film .......................................... 301

Inner film or coating (with dye) .................................... 304

Portion of bottle ............................................... ..... 600

Bottleneck ............................................... 601

Watertight enclosure ................................................ ... 610

Metal watertight plate .............................................. 611

Sealing material strand .................................... 612

Gas inlet pipe ............................................. 613

Gas outlet pipe ............................................. 614

Dryer reactor ................................................ 800

Ballast ballast reactor .............................................. 800a

Cylindrical dryer reactor ................................... 800b

Trunco dryer dryer reactor ......................................... 800c

Outer wall ................................................ ...... 801

Central perforated wall basket .................................... 802 Central shaft ...... ................................................... 803 45 ΕΡ 2 533 957 / o Hollow and perforated central shaft ...................................... 803 '

Air inlet under pressure Pi ......................................... 804

Vacuum P2 Pressure Pipe ........................................ 805

801 upper flap ................................... 806

801 lower flap ................................... 807

802 hatch ............................................... 808

Hot air evacuation .............................................. 809

Feeding and emptying pipes ............................. 810

Stoppers to be treated - lot of stoppers ..................................... 900

Natural cork stoppers ............................................ 900a

Corks corked ....................................... 900b

Corkscrew retention net bag .............................. 901

Reservoir or pressure vessel ............................... 902

Fluid liquid composition ............................................ 903

Reservoir cover ............................................... 904

Measurement of applied pressure ......................................... 905

Reservoir under depression ........................................... 902 '

Net composition ................................................ ... 903 '

Reservoir cover ............................................... 904 '

Vacuum measurement applied ............................................... 905 '

Desorbed liquid composition ........................................ 906

Dryer................................................. ............ 910 Access port ................................. 911

Polymer extraction pump ........................................ 912

Vertical Oven-Conduit .............................................. 920

Corks to be dried and polymerized ......................................... 921

Turbine................................................. 922

Heating resistors .......................................... 923

Bottom grid ................................................ ...... 924

Top grille ................................................ 925

Taipal ................................................. 926

Horizontal evacuation pipe ............................................. 927

Stopper ready to be used ................................. 928

Conditioning bag ...................................... 929

Lisbon, 2013-07-26

Claims (15)

Treatment of natural cork stoppers (900) comprising successively the following steps a, c and d: a) a batch is provided with a plurality of natural stoppers (900a) and impregnated said batch is in a liquid composition CP (903) comprising at least one polymeric material P, under a pressure Pi greater than atmospheric pressure PA, in order to obtain a batch said impregnated, c) thereafter said impregnated batch is dried , in order to obtain said dried batch, (d) finally, said dried batch is subjected to a heat treatment, so as to obtain a batch of said treated stoppers (928), each stopper (928) having a &quot; composite film &quot; (204, 301, 304) of L cork impregnated with polymeric material P, symbolically represented by &quot; L + P &quot;. Treatment of natural cork stoppers (900) according to claim 1 further comprising a vacuum treatment step b), inserted between said steps a) and c) in succession to steps a) to d) the following: a) a batch is supplied with a plurality of natural stoppers and the batch is impregnated in a liquid CP composition comprising at least one polymeric material P, under a pressure Pi greater than atmospheric pressure PA, in order to obtaining a batch impregnated, b) then said impregnated batch is treated under vacuum P2 < PA so as to obtain a vacuum treated batch, c) thereafter, said impregnated batch is dried in order to obtain said dried batch, d) finally, said dried batch is subjected to a heat treatment. ΕΡ 2 533 957 / ΡΤ 2/5 A treatment according to any one of claims 1 to 2, wherein, in step a), said batch of stoppers (900a) is immersed in a first pressure resistant container (902) containing said liquid composition (903) and (902) is placed under pressure with an air pressure Pi of between 2 and 6 bar, and preferably of 3 to 5 bar, said air pressure Pi being applied inside said first vessel (902) a duration of from 1 to 15 minutes and preferably from 3 to 10 minutes. A treatment according to any one of claims 2 to 3 in which, in step b) of the treatment, said impregnated batch is treated under vacuum in a vacuum-tight container (902 ') with a pressure P2 ranging from 0.1 to 4 mbar and preferably ranging from 0.5 to 1.5 millibar. A treatment according to any one of claims 1 to 4, wherein, in step c) of the treatment, after being returned to the free air, the batch of vacuum-treated stoppers, once introduced into a dryer 910, is dried in vacuo. cycles, each cycle comprising a drying step for 0.5 to 5 minutes, for example 1 to 3 minutes, with a number of cycles comprised between 1 and 5 and preferably comprised between 2 and 3, and a flanking step between each drying step, having a duration of between 3 seconds and 1 minute and preferably between 5 seconds and 30 seconds and during which the stoppers change position and place inside the drum of the dryer 910. A treatment according to any one of claims 1 to 5, wherein in step d) of the treatment, after having extracted the batch of stoppers (921) from the dryer (910) in step c) of the treatment, said batch of stoppers (921) is treated in an enclosure (920), with a flow of hot air at a velocity of between 3.0 and 20.0 meters per second, and preferably between 5.0 and 10.0 meters per second, in a manner to form said heat treatment, said heat treatment being particularly intended to ΕΡ 2 533 957 / ΡΤ 3/5 to remove a solvent from said liquid composition CP, when said liquid composition CP comprises a solvent. A treatment according to any one of claims 1, 2, 3, 4 and 6 in which in step a) of the treatment a batch of so-called fill-up stoppers 900b is supplied and vacuum-locating step b) is suppressed. A treatment according to any one of claims 1 to 7, wherein said liquid composition CP (903) comprises, in addition to said polymeric material P, at least one additive A intended to favor the sliding of the stopper in contact with the glass, so that said treated stopper has a &quot; skin &quot; composition represented symbolically by &quot; L + P + A &quot;. A treatment according to any one of claims 1 to 8 wherein said liquid composition CP 903 forms an emulsion or an aqueous phase dispersion of at least one polymeric material P being selected from the polymer materials: ) suitable for contact with food, b) suitable for forming a barrier with respect to said harmful molecules, said polymeric material P being preferably an emulsion of acrylic polymers in aqueous medium or an aqueous composition based on EVOH, copolymer of ethylene and vinyl alcohol. A treatment according to any one of claims 1 to 9 comprising: a) a said first succession of at least steps a), c) and d) from a first polymer composition CPi, typically formed by said liquid composition CP comprising said polymeric material P so as to form said first impregnation, b) and a complementary treatment comprising, for example, said second succession of at least the steps a), c) and d) from said second liquid polymeric composition CP2, said at least said second polymeric composition CP2 said additive A adapted to favor the slides of said stoppers, so as to form said second impregnation, so that said treated stopper display a &quot; skin &quot; composition composite symbolically represented by &quot; L + P / A &quot;. A treatment according to any one of claims 1 to 10 wherein said liquid composition CP (903), CPi or CP2 comprises an elastomeric material E selected from: butyl rubber, nitrilic rubber, thermoplastic elastomers such as SIS ( styrene-isoprene-styrene), SBS (styrene-butadiene-styrene), SEBS (Styrene-ethylene-butylene-styrene), MS Polymer (Modified Silicon Polymer) or PDMS (polydimethylsiloxane). A treatment according to any one of claims 8 to 1 in which said additive A intended to promote the sliding of the stopper in contact with the glass is an anionic emulsion wax, typically based on paraffin wax or carnauba wax, or a silicone resin when said first liquid polymeric composition CPi comprises said aqueous composition based on EVOH, so as to cover said EVOH based polymeric material with a bed which in turn forms a water barrier and an agent said additive A being an additive A2 constituting said second liquid polymeric composition CP2, said second liquid polymeric composition being then free of EVOH. A treatment according to any one of claims 1 to 12 in which said liquid composition CP (comprises a micronised mineral filler B which forms a barrier, in particular to diffusion of the gases, said mineral filler being chosen from: silica SiO 2 , a SiO2 silicon oxide (with &lt; 2), TiO2 titanium oxide, micronized clay, kaolin, barium sulfate. A cork stopper obtained by the treatment according to any one of claims 1 to 13, characterized in that ΕΡ 2 533 957 / ΡΤ 5/5 has on its entire accessible surface, outer surface and inner surface of the cavities or recesses of said stoppers, a cork surface area L, comprising a penetration of said polymeric material P into its mass with an incorporation of said polymeric substance P into the cork, so that said treated stopper comprises a composite film (204, 301, 304) of composition represented symbolically by &quot; L + P &quot;, said composite film (204, 301, 304) having a thickness of at least 10 Âμm and up to 1 mm depending on the local hardness or porosity of natural cork or of its constituents and optionally characterized in that said cork surface area L forming said composite film (204, 301, 304) comprises , in addition to the incorporation of said polymeric substance P in the cork and the incorporation of said additive A, the incorporation of at least one auxiliary chosen from: a micronized mineral filler B forming a barrier, namely to diffusion of gases, an elastomeric resin E . A cork stopper according to claim 14 in which said cork surface area L forming said composite film (204, 301, 304) comprises, in addition to incorporating said polymeric substance P into the cork, the incorporation of the said additive A intended to favor the sliding of the stopper in contact with the glass, so that said treated stopper presents a composite film of composition symbolically represented by &quot; L + P + A &quot; or by &quot; L + P / A &quot; according to which said additive A is incorporated into said polymeric material P or copper said polymeric material P and optionally characterized in that said cork surface area L forming the composite film (204, 301, 304) comprises, in addition to the incorporation of said polymeric substance P in the cork and the incorporation of said additive A, the incorporation of at least one auxiliary chosen from: a micronized mineral filler B which forms a barrier, namely to diffusion of the gases, an elastomeric resin E. -07-26