Sterile cooling compress

(54) Title: COMPRESSA WITH COOLING EFFECT, SAME MANUFACTURING PROCESS AND ITS USE (30) Unionist priority: I8 / 06/2004 fr 0406633 (71) Depositor (s): Patrick Caceres (FR), Franck Caceres (FR ) (72) Inventor (s): PatrickCaceres, FranckCaceres (74) Attorney: Momsen, Leonardos & Cia (57) Summary: COMPRESSA WITH COOLING EFFECT, MANUFACTURING PROCESS AND THEIR USE. The invention relates to a compress with cooling effect, based on particles (6) of a polymer with a high water absorption capacity that is included with a water reserve for its activation in an article (2) that holds, inside an outer sachet (3) watertight, on the one hand, an inner pouch (4) filled with closed water watertight by a wall comprising a frangible area (10), and on the other hand, the compress (1) made in the form of a wrap (5) at least partially permeable to water containing the polymer particles (6) in a dry state. The sachet (3) consists of a material of a nature to keep the pouch (4) and the compress (1) in a sterile state.

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“COMPRESSA WITH COOLING EFFECT, SAME MANUFACTURING PROCESS AND ITS USE”

The present invention relates to the design and production of a compress under sterile presentation which, after activation, has a cooling effect.

A compress is any type of bandage, bandage or similar article that is intended to be applied over the body for a treatment, medical or other operation.

The compress according to the invention is intended to be used for treatment by cryothermia. The effectiveness of cold for the treatment of certain physical ailments has been known for a long time, and notably for relieving pain or causing disintegration of edema. In certain cases, it is necessary that the cold is applied to the part of the body to be treated, respecting sterility conditions. It is thought especially in the case of wounds or areas where the skin is irritated, which are susceptible to becoming infected in contact with microbial agents. In the case of treating such wounds, it is essential that any element placed in contact with the wound is sterile.

The compress according to the invention can be used anywhere that it may be desirable to apply cold to the body, be it human or animal, under sterile conditions. It is particularly advantageous in a hospital environment as in such a medium, it is strict to use only sterile material to prevent the spread of infections as much as possible, and notably hospital infections.

It is known from the prior art that compresses with a cooling effect are intended to be applied over the body. Such compresses, totally advantageous from the point of view of the effectiveness of the applied cold and its comfort of use, were notably conceived from polymers with high water absorption capacity that produce the cold by evaporation and desorption of the absorbed water. The compresses described in US 5 597 577 can be cited as an example. These compresses are composed of absorbent polymer particles enclosed in a textile wrap. In order to exert their cooling action, they must initially be activated, that is, immersed in water so that the polymer particles swell by water absorption. They then exert their cooling effect, by evaporation and desorption of the water absorbed by the polymer. Such compresses are completely adapted for everyday use at home, to relieve pain due, for example, to a ligament or muscle wound, or even a migraine. However, they are not suitable for use in a hospital environment, for example, since they do not appear in a sterile form, and it is, in addition, impossible to activate them in satisfactory sterile conditions.

US 5 447 532 proposes, in order to activate a refreshing compress based on an absorbent polymer, to place it inside a plastic bag, and then pour the water necessary for its activation inside this bag. The bag is then closed for as long as necessary for the water to be absorbed by the pad. This activation process does not allow to obtain a sterile compress. The problem of sterility of the compress is not addressed in this document.

The invention aims to remedy these drawbacks by proposing a system for preparing an absorbent-based compress, which preserves the sterile state of the elements that compose it. This compress can thus be used safely, especially in hospitals. Applied on a part of the body to be relieved, it applies the cold there for a relatively long time.

The cooling effect compress chosen in the framework of the invention is based on particles of a polymer with a high water absorption capacity. Compresses of this type, which are known in the prior art, have a good inertia when resuming temperature, and therefore a good yarn application efficiency. Its operating principle is well known in the prior art. It will be possible notably to refer to the document US 5 597 577 cited above.

The compress according to the invention is included with a water reserve for its activation in an article that includes inside an external water-tight sachet, the following two elements: on the one hand, an inner bag filled with water and closed watertight by a wall that includes a flexible area; and on the other hand, the compress made in the form of a wrapper at least partially permeable to water containing the polymer particles in the dry state. The sachet consists of a material that keeps the pouch and compress in a sterile state. It is closed in a way that is watertight and microbial germs. The bag containing the water and the different elements that make up the compress are made of materials that are compatible with a sterilization treatment.

The compress wrap containing the water-absorbing polymer particles is advantageously designed in such a way that when the particles are in the dry state, a sufficient volume remains in the wrap to allow the particles to swell by water absorption. Thus, when the particles are in the dry state, the compress is presented in a flattened form, the opposite walls of the wrap being bumped against each other. In contrast, when the particles contained in the envelope absorb water, they swell under the effect of this absorption, and the compress is then presented in a swollen form, with a thickness of the order of a centimeter. When the compress is applied to an individual's body, the water contained in the particles reheats and vaporizes. It is then desorbed from the particles, at the same time as a cooling effect is created.

The different constituents of the article according to the invention are chosen compatible with a sterilization treatment. According to a preferred embodiment of the invention, the external sachet, the internal bag and the compress have in particular the particularity of being compatible with a gamma-sterilization treatment, notably at 20 to 50 kGy, and / or with a beta sterilization treatment.

It is thus advantageously ensured that the article according to the invention, that is, the external sachet containing the compress and the bag filled with water can be subjected to a sterilization treatment. In addition, the material that forms the walls of the external sachet is of a nature to keep the pouch and pad in a sterile state. This material is notably an anti-microbial barrier that prevents any contamination outside the sachet from penetrating the sachet. Thus, once the sterilization treatment has been carried out, the article according to the invention can be safely preserved: the elements it contains, notably the compress and the water bag, are kept there in a sterile state.

In order to be able to use the compress for its cooling effect, it is necessary to activate it. In the beginning, as explained above in the present description, this is accomplished by immersing the compress in water, so that the polymer particles swell by absorbing water, and then placing the compress in the freezer for a few hours. This last step has the objective of decreasing the temperature of the water contained in the particles, and making it pass to the solid state. Thus, when the compress is then applied to the body, before vaporizing, it must first be liquefied. This results in a higher inertia in the temperature rise of the compress.

With the article according to the invention, and in this the present invention proves to be completely advantageous, the activation of the compress is carried out under sterile conditions, and in a very simple way. A pressure is exerted, through the external sachet, on the internal bag, in order to break the frangible zone of the latter. The article according to the invention is advantageously designed in such a way that during this operation there is no risk that it is the external sachet that yields and opens under the effect of this pressure. Thus, according to an advantageous feature of the invention, the outer sachet is closed in a resistant way, and in such a way that it is necessary, to open it, to exert a pressure much greater than that which is necessary to cause the rupture of the zone inside the bag.

Water is released outside the inner pouch, it spills into the sachet, it comes in contact with the compress, it passes through the water-permeable wrap and it is absorbed, and retained by the polymer particles. Once the compress is swollen with water, the entire article can be placed in the cold, notably in the freezer, for a time sufficient to allow the water to cool. In all these stages, the outer sachet is never opened, although the compress and the water it absorbs are permanently in a sterile environment.

Finally, at the desired time for use, the external sachet is opened, preferably respecting optimal sanitary conditions (use of gloves and use of sterile forceps for example), and the compress is extracted from it. It then provides an effective cooling effect.

In accordance with an advantageous feature of the invention, the inner pouch contains a volume of water substantially equal to, and preferably slightly lower than, the volume available in the wrapper to allow the particles to swell through water absorption. It is not taken into account to evaluate this volume the expansion capacity proper to the walls of the envelope when the swollen polymer particles exert pressure on them, this expansion capacity being negligible.

This feature is notably advantageous in that it makes it possible to ensure that a sufficient amount of water will be present in the article to allow the wrap to be completely filled. The compress will thus generate cold at the maximum of its capacity, since it is the amount of water absorbed by the particles that is at the basis of the cooling effect: the more the particles absorbed water, naturally limiting its capacity for intrinsic absorption, and the more the cold effect produced by the compress is long and durable.

Furthermore, it also provides that the amount of polymer particles present in the entire envelope will be sufficient to absorb all the water contained in the bag, the fact of introducing in the latter an amount of water exactly equal, or even slightly lower, to the remaining volume. available in the compress wrap, it ensures that all water released from the internal pouch will penetrate and be retained in the wrap. Thus, there will be no volume of free water left inside the sachet. This is particularly advantageous, since the water that remained free in the sachet could, during the stay of the article in the freezer, freeze on the external surface of the compress, and stick on the latter. This would then result in certain damage to the end user of the compress.

According to preferred embodiments in industrial practice, the invention responds to the following characteristics, employed separately or in each of its technically operative combinations.

These characteristics take into account the fact that the compress, which is intended to be applied on the skin, and even on sensitive areas, such as wounds, must respect safety conditions for the user. Thus, all its constituents, and especially the polymer particles, are non-toxic to the organism.

In addition, the characteristics of the article according to the invention notably allow to respond to supplementary objectives of the invention, which are to ensure a good efficiency of the applied cold, as well as a good comfort of the compress once activated.

In these preferred embodiments of the invention, the polymer particles are present in the envelope in an excess of 400 to 800%, and preferably about 600% in relation to the amount that would be exactly needed to fill the envelope when the particles are completely swollen by water absorption.

Thus, a number of particles of absorbent polymer that are considerably higher than that which would normally be required for the compress to produce its full cooling effect are placed in the wrapper. This feature advantageously allows to ensure that, even if during the sterilization treatment a part of the particles is degraded, a quantity of active particles will always remain in the wrapper, that is, able to absorb a large amount of water and keep it in order not to release it if not in the vapor state, thus causing the application of an intense and durable cold by the compress.

In the preferred embodiments of the invention, the polymer particles used have a water absorption capacity of about 60 times their volume. For an inner volume envelope equal to 100 ml, the amount of polymer particles in the dry state contained in the envelope is between 6 and 13 ml, preferably approximately equal to 10 ml. The associated internal bag contains a volume of water equal to the complement of this volume of particles to reach 99 ml. It is thus advantageously ensured that sufficient operating polymer particles remain after the sterilization treatment to obtain an effective compress cooling effect. In addition, the four parameters that are the inner volume of the wrapper, the absorption capacity of the polymer particles and their quantity in the dry state present in the wrapper, providing for a large excess to solve the problem of partial degradation of the particles during sterilization , and finally the volume of water associated inside the external sachet, are advantageously chosen, in connection with each other, in order to obtain a maximum compress cooling capacity, at the same time as good wearing comfort.

In preferred embodiments of the invention, the polymer is a cross-linked sodium polyacrylate. Such a polymer is non-toxic to the organism.

According to an advantageous feature of the invention, the wrap is made of a water-permeable non-woven fabric and strong enough to not sag under the forces exerted on it by the polymer particles that swell under the effect of water absorption. It is also advantageous in the context of the invention to provide that the material constituting the wrapper allows water to pass through, but that it does not retain it. Then, the walls of the wrap, and therefore the outer surface of the compress that is intended to come into contact with the body, become dry. This results in better comfort for the user since the sensation he experiences at the skin level, when the compress is applied there, is that of a dry cold.

With the same objective of ensuring a good comfort of use of the compress, in preferred embodiments of the invention, the external sachet is airtight and the water bag and the compress are packed there under vacuum.

For this purpose, the external sachet is made of an airtight material. Any material that has this characteristic can be used in the framework of the invention, with the essential condition that it also constitutes a barrier against microbial germs. It is preferred, for practical reasons, to use an external sachet consisting of a plastic material that is such that it ensures a tightness to microbes, air and naturally to water in order to avoid the risk of leakage. In addition, the outer sachet is closed tightly to the three elements that are water, microbial agents and air, notably through continuous welding lines.

Vacuum packaging advantageously prevents a layer of ice from forming on the external surface of the compress during the latter's stay in the freezer. In fact, the air inside the sachet always contains traces of moisture. If a large amount of air is allowed to remain inside the sachet, when the article is placed in the freezer, this moisture condenses on the surface of the compress, and when cooling, a layer of ice forms there. This layer of ice is a source of damage to the compress user.

On the other hand, by applying a reduced pressure inside the sachet, most of the moisture that is present there is suppressed, and because of this fact, the formation of the ice layer is avoided. In practice, a pressure that corresponds to about 95% air vacuum, applied by means of conventional low pressure delivery devices, is sufficient for this purpose.

In addition, the fact of placing the interior of the sachet under reduced pressure offers other advantages, due to the fact that in these circumstances, the walls of the external sachet are applied against the respective surfaces of the water bag and the compress.

On the one hand, this reduces the risk of opening the outer sachet when pressure is applied to the article to cause the frangible area of ​​the inner pouch to rupture. In effect, when a reduced pressure is applied to the interior of the sachet, the walls of the latter are applied against the water bag: the efforts are therefore transmitted directly to those of the bag. The rupture of the latter is, therefore, favored.

On the other hand, when the polymer particles swell, and the compress increases in thickness, the walls of the external sachet applied against the walls of the wrap constitute a reinforcement for the latter, thus allowing them to better resist the forces exerted on them by the particles.

Finally, placing under reduced pressure also has the effect of applying the water pouch against the dressing surface, and then favoring the penetration of water released from the pouch directly into the dressing.

The wrap of the compress according to the invention can have different shapes and different dimensions. Thus a whole range of compresses can be declined, each being adapted to a particular application.

In preferred embodiments of the invention, the opposite faces of the compress wrap are connected together in different longitudinal lines, so as to form a plurality of elongated compartments in which the polymer particles are homogeneously distributed. This embodiment advantageously allows to obtain a high contact surface of the compress with the skin, although the application of the cold is homogeneous over the whole area of ​​skin on which the compress is applied.

According to an advantageous secondary feature of the invention, the longitudinal lines are made by ultrasonic welding in continuous lines or in a cross arm. This advantageously allows to obtain a tightness in the passage of the polymer particles from one compartment to another. The welding lines obtained are, moreover, mechanically resistant to the tensile stresses exerted on them by the polymer particles that swell by absorbing water.

The invention also relates to a process for manufacturing the article for the presentation in sterile form of a compress based on polymer particles with a high water absorption capacity.

This process is characterized by the following steps.

A compress is initially prepared in the form of a wrapper containing the polymer particles.

Then, the compress, as well as the internal bag filled with water, is introduced into the outer sachet.

Reduced pressure is applied to the inside of the sachet, and the sachet is sealed tightly.

Finally, the set is sterilized by treatment with gamma rays, at 20 to 50 kGy. Sterilization can also, in preferred embodiments of the invention, be carried out by beta rays.

According to the invention, the compress is then activated and used as follows:

Without opening the outer sachet, pressure is applied to the pouch to fracture its frangible area. The water thus released from the internal bag is allowed to penetrate the compress.

The article is then placed, optionally, in the cold, notably in a freezer, for a time notably between 15 and 90 minutes. This step allows to increase the cooling capacity of the compress.

Finally, the external sachet is opened at the time of use to remove the sterile compress with cooling effect.

Then, the compress can be applied over the desired body part, with complete safety, as it responds to the required sterility conditions.

The compress according to the invention is particularly adapted for single use.

The invention will now be more fully described in the framework of preferred features and their advantages, referring to figures 1 to 4 in which:

- Figure 1 represents a top view of an article according to the invention, prior to the activation of the compress it contains:

figure 2 shows the article of figure 1 in cross-section according to the AA plane;

- figure 3 shows the article in figure 2, in a vacuum presentation,

- and figure 4 represents an overview of an activated compress ready for use at the outlet of the external sachet.

The compress 1 according to the invention is presented as an integral part of an article 2, as illustrated in figure 1.

Article 2 consists of an external sachet 3, which is both water and air tight, and which constitutes an anti-microbial barrier. The walls of sachet 3 are, for example, made of a plastic material that constitutes an anti-microbial barrier, notably a polyamide / polyethylene mixture. Such a material has the particularity of being compatible with a gamma sterilization treatment. This means that, on the one hand, this material is not degraded during such a sterilization treatment, and that, on the other hand, it lets the gamma rays pass, thus allowing an effective sterilization of the elements contained in the external sachet 3. It preserves then the elements it contains in a sterile state.

In the preferred embodiment of the invention shown in the figure, the walls of the sachet 3 are transparent, although visible through them. This advantageously allows you to even monitor the status of the elements contained in sachet 3.

Inside sachet 3, compress 1 and a bag 4 filled with water are arranged.

The compress 1 is made in the form of a wrap 5 inside which particles 6 of a polymer with a high water absorption capacity are arranged, initially in the dry state. Particles 6 are devoid of toxicity.

These are polymer particles that cause the cooling effect produced by the compress, according to a known general principle. Particles 6, when they are activated, that is, when they are swollen by the water they have absorbed, and they eventually suffered a stay in a cold environment, generate cold by vaporization and desorption of the absorbed water.

Polymer particles 6 advantageous in the framework of the invention have a water absorption capacity approximately 60 times its volume. This embodiment is notably limited to cross-linked polyacrylate particles, however, it is not limiting the invention.

The wrapper 5 containing the particles 6 is made of a water-permeable non-woven material. This material is compatible with a gamma sterilization treatment, which implies that, on the one hand, it resists such a treatment, and on the other hand, it does not block the passage of gamma rays, thus allowing the sterilization of particles 6 inside the wrapper.

Furthermore, the material constituting the wrap has a good resistance to the pressure that is exerted on the walls of the wrap by the polymer particles when the latter swell due to water absorption, and therefore expand very quickly.

The wrap is notably made of polypropylene.

The amount of particles 6 in the dry state included in the wrap is such that there is still a large free volume inside the wrap to allow the particles to swell under the effect of water absorption. Thus, the wrapper is presented in an almost flat form when the polymer particles are in the dry state, while it has a thickness that can be several centimeters when the particles are swollen with water.

Furthermore, the amount of particles 6 in the dry state included in the wrap 5 is greater than the amount that would be just needed to fill the wrap completely when the particles are swollen filled with water. It is notably between 400 and 800% of this quantity.

In other words, as an example, for a wrap with an internal volume equal to 100 ml, and particles of polymer with a water absorption capacity equal to 60 times its volume, if 1.65 ml of particles are introduced into the wrap, a Once swollen with water, they would occupy a volume 60 times greater, that is, approximately equal to 100 ml. The amount of 1.65 ml of particles in the dry state would therefore be the amount just needed to fill the 100 ml of internal volume of the envelope when the particles are completely swollen with water.

According to the invention, a quantity of polymer particles 6 is introduced four to eight times greater, and preferably six times greater. Thus, always in the example of a wrapper with an internal volume of 100 ml, 6 to 13 ml, preferably approximately 10 ml, of polymer particles in the dry state are introduced. The corresponding mass quantity of particles is easily accessible, according to a calculation available to the specialist, from the mass by volume of the particular polymer chosen.

This makes it completely advantageous to ensure that, even if during the sterilization of the compress, there is a degradation of a part of the polymer particles, or a partial destruction of the crosslinking, there is always enough particles left to fill the bag completely after absorption. of water, and apply an effective cold.

On its edges, the envelope is closed by welding lines 7 in order to prevent particles 6 from escaping from there.

The welding lines 7 are relatively wide, notably between 3 and 7 mm in width, which increases their resistance to the stress exerted on them by the polymer particles 6 that swell when they absorb water. The welding technique used is preferably ultrasonic welding, in continuous lines or cross arms. However, any other welding technique that allows to obtain a good resistance of the welding line made is also usable in the framework of the invention.

The compress wrap 5 is preferably made to form a plurality of elongated compartments 8, within which the particles 6 are evenly distributed. In the embodiment shown in the figure, the wrapper forms six compartments. This shape allows to obtain a homogeneous contact surface of the compress with the body on which it must be applied, and this over the entire surface of the compress.

Any other form of the envelope or compartments also falls within the framework of the invention.

The compartments 8 are delimited from each other by welding lines 9. These welding lines are made in a similar way to the welding lines 7 made at the ends of the casing 5. It follows from this that intermediate welding lines 9 have a high resistance to the forces that can be exercised on them.

It is thus advantageously ensured that even if one of the fibers of the material constituting the wrap is degraded during the gamma or beta sterilization treatment, the welding lines 7 and 9 will only be weakened, and that they will remain sufficiently resistant after the sterilization to preserve its integrity throughout the use of the compress.

Inside the outer sachet 3, a bag 4 filled with water is associated with the compress 1.

The pouch 4 consists of a water-tight material, which is also, as well as the materials that make up the walls of the external sachet 3 and the wrap 5 of the compress, compatible with a gamma-sterilization treatment. Thus, on the one hand, this material is not degraded by gamma rays, and, on the other hand, it does not constitute an obstacle to its passage, although the water contained within the bag 4 can be sterilized by such a treatment.

The walls of the pocket 4 are notably made of a plastic material. They are, for example, made of polyethylene.

Bag 4 is closed hermetically, notably by welding. The welds made are strong enough to not sag when the article is handled for transport. However, at least one of the welds is designed in such a way that it can yield, at least in part, under the effect of pressure that will be exerted by the user on the outer surface of the bag. For example, at least one of the welds 10 is less than 0.5 mm wide, at least in one of its zones.

Thus, when it is desired that the water contained in the pouch 4 is spread out of this pouch, a very high pressure exerted with the hand on the pouch allows to break the frangible area 10 of the pouch, and to release the water. In all other cases, if lower forces are accidentally exerted on the bag, there is little or no risk that it will break.

The amount of water contained in the pouch 4 is approximately equal, and preferably slightly less, to the volume that remains free in the wrap 5 of the pad once the polymer particles 6 have been introduced there. Thus, always for an example of a wrap 5 with a volume equal to 100 ml, if this wrap contains, for example, 10 ml of polymer particles 6 in the dry state, then a water bag containing 90 ml of water will be associated , or preferably 89 ml. Thus, it is advantageously ensured that the totality of water contained in the pouch 4 can still penetrate the envelope 5 where it will be absorbed by the polymer particles.

An article according to the invention is manufactured as follows:

A pad 1 is prepared, in the form, for example, of a set of compartments each comprising a suitable amount of polymer particles 6 in the dry state.

A pouch of water 4 is prepared independently, taking care to have a frangible zone on its surface, and notably at the level of a welding line 10. Bag 4 contains only the appropriate amount of water, which is determined by a side of the internal volume of each of the compartments 8, and, on the other hand, of the amount of polymer particles 6 included in each of the compartments and of the water absorption capacity of these particles. In addition, it is advantageous that bag 4 contains as little air as possible.

The compress 1 and the pouch 4 are then inserted in an external sachet 3 that is sufficiently bulky to contain them placed flat on top of each other. Thus, the article shown in section according to the AA plane in Figure 2 is obtained.

A reduced pressure is then applied to the inside of the sachet, and the sachet is closed. The closing of sachet 3 is notably accomplished by welding. The welding line 11 is wide and resistant, in order, on the one hand, to ensure water and air tightness of the sachet, and on the other hand, to ensure that when the user presses on the surface of the sachet 3 in order of breaking the internal water bag 4, it will still be the frangible zone 10 of the latter that will break, and not the welding line 11 that closes the sachet. This is further favored by the fact that reduced pressure was applied to the interior of the sachet, although the pressure exerted on the surface of sachet 3 is directly transmitted to that of bag 4. For safety reasons, it is advantageous to provide that a double weld be performed to close sachet 3.

The article is then presented in the configuration shown in figure 3. The water bag 4 is applied against the surface of the pad 1. The walls of the external sachet 3 are glued against the surfaces of the pad 1 and the bag 4.

Once this operation is carried out, the article 2 is submitted to a sterilization treatment by gamma rays, or by beta rays. The interior of sachet 3, and thus compress 1 and water in bag 4, is then taken sterile. None of the elements included in the sachet is damaged, with the exception of a portion of the particles 6 whose crosslinking is destroyed. However, particles remain to operate to ensure the application of an effective cold.

Because of the properties of the material that makes up the walls of sachet 3, no contamination agent can then penetrate the interior of the sachet. The article can thus be safely preserved, preserving the sterility of the elements contained in the sachet.

When it is desired to use compress 1 for its cooling effect, it is sufficient, without opening sachet 3, to press on the sachet's surface in order to exert pressure on the wall of the bag 4, and cause the frangible zone 10 to rupture, and because of that the release of the water contained in the bag 4.

The water then spreads inside the sachet, and it penetrates very naturally inside the compress 1, where it is absorbed by the polymer particles 6. The water is naturally distributed between the different compartments 8. However, a homogeneous and quick is favored when the article is kept in a position such that the water bag is located above the compress, and approximately centered on the latter, at the moment when the pouch ruptures 4.

Then, the swelling of the compartments 8 is observed. The particles that swell by absorbing water exert a relatively high pressure on the walls of the envelope 5 that contains them. The walls of the external sachet 3, which are glued against the surface of the compress 1, fit a part of these mechanical stresses exerted on the wrap 5, thus constituting a reinforcement for the latter, and thus increasing its resistance to these stresses.

When the water, which was contained in bag 4, completely penetrated the compress, which in practice is done in just a few minutes, the article is placed, always without opening it, in a cold environment, notably in a freezer. It is kept in this place for 15 to 90 minutes, according to the power of the freezing material used, in order to ensure the cooling of the water absorbed in the polymer particles, and its transformation into ice. This will allow to obtain a better inertia of the compress in raising the temperature during its use.

Due to the reduced pressure applied inside the sachet, there are only a few traces of moisture in the air that surrounds the compress. Therefore, no ice deposits are formed by moisture condensation on the compress surface during the freezer stay. The compress surface is dry, which will make it more comfortable to use. In addition, it will not wet the skin, and notably the wound on which it will be applied, which will favor a quick healing of the latter.

The article 2 is then removed from the freezer. The compress 1 present inside it is activated, which means that it produces its cooling effect. It is entirely sterile. It is then enough for the user to open sachet 3, respecting all appropriate sterility conditions, and remove the compress from there. The latter is then presented in the form of chorizo, as shown in Figure 4. It is ready to be applied over the body to provide its cooling effect there safely.

It is particularly suited for single use, and can be discarded after use.

As an example, a compress according to the invention consists of particles of cross-linked sodium polyacrylate with a water absorption capacity equal to 60 times its volume. The compress consists of six elongated sausages, like the one illustrated in the figures. Each compartment has an internal volume of 23 ml and contains 2.7 ml of polymer particles. The associated internal pouch contains 120 ml of water.

The compress is prepared under sterile presentation in the article according to the invention, and activated according to the process described above.

After a 90-minute stay in the freezer, the compress is extracted from the outer sachet. Its outer surface is dry, although it offers good wearing comfort when applied over the body.

It maintains a temperature between 3 and 12 ° C for 60 minutes.

These performances are equivalent to those of compresses prepared and activated in a classic way, which are not submitted to sterilization prior to their use.

The foregoing description clearly explains how the invention makes it possible to achieve the objectives it has set itself. In particular, it provides a compress under sterile presentation, which has an effective cooling action and good wearing comfort.

However, it emerges from the foregoing that the invention is not limited to the modes of execution that have been specifically described and represented in the figures and that they extend in reverse to any variant that passes through the bias of equivalent means.

In particular, the compress that was described above has only a cooling action. Of course, it is also possible to integrate an active treatment agent of the medical or paramedic type into the dressing. The active agent may notably be initially present in the water contained in the internal pouch, in which case it penetrates the compress at the same time as the water. It can also be present in solid form, inside the envelope, in mixture with the polymer particles. When the compress is applied to the body, the active agent has its effect there. A double effect, cooling and treatment, is then advantageously obtained. Examples of active agents usable in the framework of the invention, provided that they are compatible with the chosen sterilization treatment, are the following: antiseptics, anti-inflammatory, local anesthetics, anti-edemics, and healing.

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