MXPA00011867A - Thermoinsulating packaging for thermosensitive products - Google Patents

Abstract

Said packaging comprises an accessible body (1) having one or more thermoinsulating walls surrounding said thermosensitive product (P) consisting of an envelope (2) made of an open cell type foamed flexible polymer or copolymer, said envelope being delimited by an impermeable inner ply or cloth (3) and an impermeable outer ply or cloth (4), which consist of a metallized plastic sheet forming a barrier against gas and/or liquid diffusion exchange through the envelope (2), and at least one container (5) for a refrigerating element (6) forming an enclosure for the thermosensitive product (P). All elements forming part of said packaging are disposed separately for transportation and storage when they are not being used and have a flat compact configuration. They can be mounted and assembled for utilization by a user at a desired moment.

Description

THERMALLY INSULATED PACKAGING FOR THERMOSENSITIVE PRODUCTS The present invention concerns a thermally insulating packaging for thermosensitive products, such as medicaments, vaccines, laboratory tests, etc., of the type comprising an accessible housing, with one or more thermally insulating walls surrounding said thermosensitive product, together with the which there is an element in general coolant, and whose walls determine a barrier against the passage of substances capable of flow. For a long time, for the transport of thermosensitive products, such as medicines, vaccines, laboratory tests, etc., different devices or packaging have been used, each of them presenting different drawbacks. A very used method is to use a conventional refrigerator of the type used by campers. But, on the one hand, such refrigerators are not designed to maintain low temperatures for many hours, even days, without replacing the refrigerant elements that are deposited in their interior together with the thermosensitive products to be transported, and on the other hand, their rigidity and great volume require a great availability of space, especially during transport and storage when they are not in use, resulting in a general increase in costs.

Another widely used method is to use packaging, which does not need to be especially waterproof, to enclose carbon ice together with the heat-sensitive products to be transported, since the carbonic ice passes directly from the solid to the gaseous state without passing through the liquid state, ie , which is sublimated without wetting the packaging or the contained product. However, the duration of carbonic ice is ephemeral and, in addition, its sublimation produces undesirable gases, which is why many transport companies, including airlines, are prohibited from using it.

At present, packaging is also known consisting of insulating boxes made of rigid polyurethane foam. Such material is a closed cell thermoplastic foam having excellent thermal insulating and water repellent properties together with a very low density. The main drawback of such packaging lies precisely in the rigidity of the material that makes the structure of the entire box occupy a large volume. This is especially inappropriate when the box is not in use, for example, during the transport of the empty packaging between the producer's premises and the user's premises, and during storage, both at the origin and at the user's premises. the moment it fills it and sends it to its place of destination. Accordingly, there is an important demand for a thermally insulating packaging that allows a reduction in its volume, and consequently in its cost, during the transportation and storage operations of said packaging while it is not in use. The object of the present invention is to provide such packaging. This object is achieved, according to the present invention, by providing a thermally insulating packaging for thermosensitive products formed by several components, in which each of said components is capable of being arranged separately adopting a compact, flattened configuration, for its transport and storage when the packaging is not in use, the components being capable of being assembled, assembled, and placed in order of use by the user at a desired time. This is achieved by the use in general, and especially for the thermal insulating component, of flexible materials that allow a folding or unfolding of the components to reduce their volume to a minimum when it is not in use, and consequently transport costs and storage in these circumstances. Said volume reduction is achieved using, as a material of the thermal insulating component, an open cell, flexible foamed copolymer, such as a foam of an isocyanate polymer or a urethane copolymer. The flexibility of said material allows the formation of a shell from several flat panels, two or more of said panels being joined together by split hinge lines forming at least one flat piece, so that said panels and / or flat piece occupy a small space during storage and transport, when they are not in use, being able to be armed by the user for use at a desired time. The thermal insulating properties of the foamed polymeric materials are due to the existence, in said material, of small cells of very low thermal conductivity delimited by thin walls of material. In closed cell foams, a gas from the chemical reaction itself that takes place during its production remains for a long time enclosed within said cells. On the contrary, in the open cell foamed materials, said gas diffuses and mixes with the surrounding air, renewing itself continuously. This is why the heat insulating properties of open cell polymeric foams are lower than those of closed cell foams.

Therefore, in order to take advantage of the flexibility of open-cell foam in terms of the possibility of reducing the volume of the packaging when it is not in use, without losing thermal insulation capacity, it is necessary to provide a complementary device to prevent the diffusion of gases and / or liquids through such material. For this purpose, according to the present invention, an internal waterproof layer or canvas and an external waterproof layer or canvas are provided which completely delimit the walls of said envelope on both sides. Said layers or canvases take the form of respective internal flexible pouch and external flexible pouch, with shapes and dimensions that conform respectively to the interior and exterior dimensions of the thermal insulation enclosure, when it is assembled. Said bags are susceptible, once placed, to be closed by any known method that provides a sufficient seal, such as a heat seal, by a multiple hem of its embouchure, by bending and pinching a section of its embouchure, by means of a ring clamp or by means of a tongue-and-groove closing section of its embouchure. The material of said bags consists of a sheet of metallized plastic, composed of a layer of polyethylene and a laminated aluminum layer, the thickness of the polyethylene layer of the external bag being greater than that of the inner bag. The aluminum layer guarantees an excellent seal against the diffusion of gases while the polyethylene layer forms a barrier against accidental spills of the cooling element or the product transported inside, and against possible penetrations of liquid from the outside. In addition, the polyethylene and aluminum laminate has very good mechanical strength properties. With this arrangement, when the envelope of foamed material is assembled and with the internal and external flexible bags placed and closed, an enclosure of thermally insulating walls is constituted which defines an interior enclosure for housing the thermosensitive product together with a cooling element, which typically consists of in water with an additive to lower its freezing temperature. Said additive may be a salt, such as sodium chloride. Such a cooling element is contained in at least one container comprising a flattened, flexible plastic bag, with opposite walls linked together by welding points, provided with partially sealed welding lines defining articulation lines of different pliable panels . Said bag comprises an openable stopper and is supplied empty of water but containing a sufficient quantity of said additive, so that, when it is not in use, it occupies a small space during storage and transport. When its use is foreseen, said bag is capable of being filled with water by the user, agitated to dissolve the additive, cooled to freeze its content and subsequently folded by said articulation lines to form said cooling enclosure for the thermosensitive product. In a preferred embodiment of the invention, the package comprises two of said cooling bags, equal to each other, each with articulation lines defining three of said fillable panels, both bags being capable of bending in a "U" and of coupling together to mutually form said enclosure according to a rectangular prismatic configuration, of suitable dimensions to be housed in said inner enclosure defined by the aforementioned thermoinsulating enclosure. The thermosensitive product to be transported is deposited inside said cooling enclosure. The entire assembly is protected by an outer shell formed by a conventional cardboard box, such as corrugated cardboard, armable. Preferably, the outer surfaces of said cardboard box, which admit inscriptions or graphics, are of a light color to avoid the maximum absorption of thermal radiation from the outside. These and other features will become more apparent from the following detailed description of an embodiment of the heat insulating packaging according to the invention, with references to the accompanying drawings, in which: Fig. 1 is a partial view, in section enlarged cross section, which illustrates the arrangement of the different components that make up the packaging of the invention; Fig. 2 is a perspective view of a flat piece integral with the heat insulating envelope of Fig. 1; Fig. 3 is an exploded perspective view of the heat insulating envelope of Fig. 1; Figs. 4 and 5 respectively illustrate internal and external flexible bags constituting the respective impermeable layers or canvases of Fig. 1; Fig. 6 is a plan view of the coolant container of Fig. 1; and Fig. 7 is an exploded perspective view of the cooling enclosure of Fig. 1 made by two containers like that of Fig. 6. In the cross-sectional view of Fig. 1 a corner of the thermally sealed packaging is shown. insulator for thermosensitive products according to the present invention. Such thermosensitive products can be, for example, drugs, vaccines, laboratory tests, etc. The packaging comprises an accessible casing 1, insulating walls constituting a casing 2 made of an open-cell flexible foamed polymer or copolymer, with an internal impermeable layer or canvas 3 and an external impermeable layer or canvas 4 delimiting said casing 2, each of said layers or canvases 3, 4 being composed of a sheet of metallized plastic which forms a barrier against the exchange by diffusion of gases and / or liquids through the casing 2. The casing 2 defines a suitable internal enclosure to locate the heat-sensitive product P to be transported, next to which there is an element in general refrigerant 6 enclosed in a container 5. Both said casing 1, accessible, and said casing 2, said layers or internal and external canvases 3, 4 and said container 5 for said cooling element 6 are arranged, during transport and storage when not in use, separately, adopting a compact configuration to planada, being susceptible to be armed, assembled, and placed in order of use by the user at a desired time. Preferably, said flexible foamed polymer or copolymer is a foam of an isocyanate polymer or of an open cell urethane copolymer. Precisely in order to counteract the adverse effects of open-cell foams with regard to thermal insulation, said metallized plastic sheets applied on both sides on the walls of the casing 2 are provided. Said sheets 3, and 4 comprise a layer of polyethylene and a laminated aluminum layer, which prevent the gas inside the foamed polymeric material from diffusing into the surrounding air and at the same time they constitute a hermetic barrier against liquids. The thickness of the polyethylene layer of the outer sheet 4 is greater than that of the inner sheet 3. Said shell 2 of foamed copolymer comprises at least six panels 8 of beveled edges 9 capable of being interconnected to form a rectangular prismatic body that defines the aforesaid indoor enclosure. In Figs. 2 and 3 illustrate an embodiment of such shell 2 in which it is formed by two of said flat pieces 11, each integrating two articulated panels 8, and two other pieces of single panel 12. The flat pieces 11 comprise an articulation splitting line 10 separating the two panels 8, being able to be folded by said articulation 10 adopting an "L" shape, and of coupling between each other and with said single panel pieces 12 to form said rectangular prismatic body . It is evident that, although in this example said prismatic body is achieved by means of two pieces of double panel and two pieces of single panel, it could also be formed from pieces with other configurations, such as two pieces of three panels, one piece of four panels and two pieces of single panel, and up to a single piece of six articulated panels. However, the common feature to all of them lies in their flat configuration, so that said flat pieces 11, 12 occupy a small space during storage and transport when they are not in use, and can even be compressed given their flexible foamed constitution, being able to be assembled by the user for use at a desired time . In order to materialize in a practical, economical and easy-to-place manner the contribution of said inner impermeable layer or canvas 3 and said external impermeable layer or canvas 4 delimiting inside and outside the envelope 2, said layers or canvases 3, 4 are formed respectively by an internal flexible bag 13 and an external flexible bag 14 (see Figs 4 and 5) of sizes respectively adjusted to the internal and external dimensions of the casing 2 once assembled, and capable of being closed once placed. Obviously said bags can be transported and stored, when not in use, in a folded position so that they occupy a minimum space. The closure of said inner and outer bags 13, 14, once placed, can be done by any known method, such as by thermowelding, by a multiple hem of its embouchure, by bending and pinching a section of its mouthpiece, by means of a ring clamp or through a tongue and groove closing section of its embouchure. In Figs. 6 and 7 the said container 5 is illustrated, of the generally cooling element 6, which comprises a plastic bag 15 flattened, flexible, with opposite walls linked together by welding points 16, provided with partially sealed welding lines 17 which define articulation lines of different fillable panels 18. The cooling element 6 used comprises common water and an additive 7 to lower its freezing temperature. As an additive, a salt, such as sodium chloride, is typically used. The bag 5 comprises an openable plug 19 and is supplied empty of water but containing said additive 7, so that it occupies a small space during storage and transportation when it is not in use, being capable of being filled with water by the user, stirred, cooled to freeze its contents and subsequently folded by said articulation lines 17 to form a cooling enclosure for the thermosensitive product P at a desired time. In the illustrated embodiment, two of said bags 15, equal to each other, are used, each with two articulation lines 17 defining three of said fillable panels 18, being capable of bending in a "U" shape and of coupling with each other. to form said enclosure according to a rectangular prismatic configuration. It is evident that this configuration could be achieved with another number of bags by integrating different numbers of panels that can be filled in a manner analogous to that previously explained with reference to the envelope 2. Finally, all the aforementioned elements, properly assembled and assembled, are arranged inside of said casing 1 (partially illustrated in cross-section in Fig. 1) formed, in a preferred embodiment, by a conventional cardboard box which, like all other elements, can be transported and stored separately in flattened form when not It is in use, so it occupies a minimum space. In order to determine the capacity of the packaging, according to the present invention, a series of tests have been carried out to maintain a low temperature in its interior.

The tests have been carried out on two different packaging specimens, namely: Type I, designed to maintain temperatures of -20 ° C (-4 ° F); and Type II, designed to maintain temperatures of 0 ° C (32 ° F), whose characteristics are reflected in Table 1 below: Table 1 Characteristics of the packagings In these tests, EKS 21 standardized cooling elements have been used, that is to say that the containers described above have not been used in relation to the drawings. Accordingly, the dimensions of the enclosure refer to the dimensions of the inner enclosure of the thermally insulating enclosure. The test conditions for Type I packaging were as follows: Specimen: Type I: for temperatures of -20 ° C (-4 ° F) Refrigerant: 22 EKS 21 refrigerant elements Eutectic temperature: approx. -21.1 ° C (-6 ° F) Refrigerant energy: 2600 kJ Sample: Ice-filled test tube (diameter: 24 mm, length: 90 mm, volume: approx 40 cm3) Thermocouple transducer Fe-Co Temper. ext. 23 ° C (73 ° F) The results of the increase in temperature as a function of time are shown in Table 2.

Table 2 Increase in temperature as a function of time for Type I packaging 2.0 (0.08) -24.9 (-12.8) 18.5 (0.77) -22.6 (-8.7) 21.0 (0.88) -22.4 (- 8.3) 90.0 (3.75) -22.0 (-7.6) 96.0 (4.00) -22.0 (-7.6) 114.5 (4.77) -20 , 7 (-5.3) 118.5 (4.94) -20.3 (-4.5) 121.0 (5.04) -19.8 (-3.6) The test conditions for Type II packaging were as follows: Specimen: Type II: for temperatures of 0 ° C (32 ° F) Refrigerant: 8 EKS 21 refrigerant elements Eutectic temperature: approx. 0 ° C (32 ° F) Refrigerant energy: 1340 kJ Sample: Test tube full of ice (diameter: 24 mm, length: 90 mm, volume: approx 40 cm3) Thermocouple transducer Fe-Co Te per. ext 23 ° C (73 ° F) The results of the increase in temperature as a function of time are shown in Table 3.

Table 3 Increase in temperature as a function of time for Type II packaging 42.0 (1.75) -0.5 (31.1) 44.0 (1.83) -0.6 (30.9) 46.0 (1.92) -0.6 (30.0) ) 72.0 (3.00) -0.6 (30.9) 110.0 (4.58) -0.3 (31.5) 113.5 (4.73) 2.1 (35.8) ) 114.5 (4.77) 3.6 (38.5) 115.5 (4.81) 6.3 (41.5) 116.5 (4.85) 6.2 (43.2) 117 , 5 (4.90) 7.0 (44.6) The results of the tests show that both in the Type I packaging and in the Type II packaging, the desired limit temperatures of -20 ° C (-4 ° F) and 0 ° C (32 ° F) respectively, they are not exceeded until more than 4 days have passed since the start of the tests. The total thermal permeability coefficient (k-value) of the packages is calculated as the quotient between the cooling capacity and the product of the average surface geometric area and the temperature difference between the interior and exterior surfaces. The cooling capacity is given by the quotient between the cooling energy used and the period of time of maintenance of the cooling temperature.

Table 4 Thermal permeability coefficient (value k) The knowledge of the thermal permeability coefficient makes it possible to calculate the required cooling capacity, ie the number and type of cooling elements, as well as the maintenance period at a desired temperature for each type of packaging. A person skilled in the art could introduce some changes and variations without departing from the scope of the present invention, which is defined by the appended claims.

Claims (9)

1. - Thermally insulating packaging for thermosensitive products such as medicines, vaccines, laboratory tests, etc. of the corresponding type: an accessible casing (1), with one or more thermally insulating walls surrounding said thermosensitive product (P) next to which there is a cooling element (6) and whose walls form a barrier against the passage of susceptible substances of flowing, said insulating walls being constituted from a shell (2) made of a flexible foamed polymer or copolymer, of open cell, with an inner impermeable layer or canvas (3) and an outer impermeable layer or canvas (4) which delimit said envelope (2), each of said layers or canvases being composed of a sheet of metallized plastic forming a barrier against the exchange by diffusion of gases and / or liquids through the envelope (2), said housing being (1) accessible, said envelope (2), said inner and outer layers or canvases (3,4), arranged during transport and storage, when not in use, separately, adopting a configuration n compact flattened, being able to be assembled, assembled, and placed in order of use by the user at a desired time, characterized in that said cooling element (6) comprises at least one container (5) which also adopts a compact flattened configuration for its transport and storage, when it is not in use, and in that said inner impermeable layer or canvas (3) and said outer impermeable layer or canvas (4) delimiting said envelope are formed respectively by an internal flexible bag (13) and by an outer flexible pouch (14) of sizes respectively adjusted to the interior and exterior dimensions of the enclosure (2), once assembled, and capable of being closed once placed.

2. Thermally insulating packaging, according to claim 1, characterized in that the closure of said inner and outer bags (13) and (14) once placed is made by thermowelding by a multiple hem of its mouth, by bending and pinching a Section of its embouchure by means of a clamp ring or by means of a tongue and groove closing section of its embouchure.

3. Thermally insulating packaging, according to claim 1, characterized in that said container (5) which is at least one, which houses the cooling element (6) comprises a plastic bag (15) flattened, flexible, with opposite walls linked between yes by means of welding points (16), provided with intermittent welding lines that define articulation lines (17) to form a cooling enclosure for the thermosensitive product (P).

4. Thermally insulating packaging, according to claim 3, characterized in that it comprises two of said bags (15), equal to each other, each with articulation lines (17) defining three of said foldable panels (18), allowing the panels of each bag (15) bending in a "U" shape, so that two of said bags (15) can be coupled together to form an enclosure according to a rectangular prismatic configuration.

5. Thermally insulating packaging, according to claim 3 or 4, characterized in that said bag (15) comprises a plug (19) practicable, and is supplied empty of water, but containing an additive (7), so that it occupies a space Reduced during storage and transport, when not in use, and allows the user to fill it with water, shake it, freeze it and use it at a desired time.

6. Heat insulating packaging, according to claim 5, characterized in that said additive (7) is sodium chloride.

7. Thermally insulating packaging, according to claim 1, characterized in that said flexible foamed copolymer shell (2) comprises at least six panels (8) with beveled edges (9) capable of being interconnected to form a rectangular prismatic body defining an enclosure inside, it being provided that two or more of said panels (8) are joined to each other by a split hinge line (10) forming at least one flat piece (11), so that said panels (() and / or flat piece ( 11) occupy a small space during storage and transport, when they are not in use, being able to be assembled by the user for use at a desired time

8. Thermally insulating packaging, according to claim 7, characterized in that said enclosure (2) comprises two of said flat pieces (11), equal to each other, each one defining two articulated panels (8), and two other single panel pieces (12), the flat pieces (11) being able to fold in shape

9. "Heat-insulating packing" according to any one of the preceding claims, characterized in that said housing is "L" and coupled to each other and with said single panel parts (12) to form said rectangular prismatic body. (1) is formed by a conventional cardboard box, such as corrugated cardboard.