3D vacuum insulation body

Abstract

Method for producing a vacuum insulation body (1), wherein the vacuum insulation body (1) comprises an insulation body (6) comprising a bulk material (14) and an airtight film (12) enclosing the bulk material (14), comprising the following method steps: - Inserting the insulation body (6) into a forming device (5), - forming the insulation body (6) by deep drawing, wherein the insulation body (6) is arranged between a punch and a counterpart and the punch is pressed onto the insulation body (6) so that a trough-shaped insulation body (6) is produced, wherein the punch and / or the counterpart is heated, wherein during the forming and / or after the forming of the insulation body (6) air is drawn out of the insulation body (6) and after the step of drawing air out of the insulation body (6) the airtight film (12) is closed so that a vacuum insulation body (1) is produced.

Description

The invention relates to a method for producing a vacuum insulation body, wherein the vacuum insulation body comprises an insulation body which comprises a bulk material, in particular introduced into a nonwoven bag, and an airtight film, in particular enclosing the nonwoven bag.The invention further relates to a vacuum insulation body and to a thermal insulation vessel or thermal insulation container.Evacuated insulation materials achieve thermal conductivities which are lower by a factor of 5 to 20 than those of aerated conventional insulation materials. It is thus possible to produce compact, highly insulating transport containers for temperature-sensitive goods, highly insulated cooling and freezing appliances or slender insulating structures in the building sector. Evacuated insulating bodies of this kind are typically referred to as vacuum insulating bodies or, if they are in the form of plates, as vacuum insulating panels, VIP for short. Within the scope of this invention, these terms are subsumed under vacuum insulation bodies.For example, DE 20 2017 004 267 U1 discloses vacuum insulation bodies which have a two-dimensional structure or geometry, that is to say are plate-shaped. Correspondingly, such vacuum insulation bodies or vacuum insulation panels are known from DE 10 2008 022 380 A1.Among other things, in cold boxes and other applications involving the insulation of a three-dimensional body, individual panels are used which are then joined together in an abutting manner. This joint at the same time represents a heat bridge, however, since the vacuum bodies arranged in series have an increased heat conduction via the edges and / or air gaps. This leads to a reduction in the insulation performance.DE 10 2004 031 967 A1 shows a method for producing a vacuum insulation body, in which the shape of the insulation body is predefined by the geometry of a film bag or nonwoven bag.DE 10 2004 027 002 A1 discloses a vacuum insulation molded body which comprises a core made of a heat insulation material in a film casing, wherein the film is sealed in a thermally gas-tight manner over its entire contact surface.WO 2007 / 033 836 A1 discloses a method for producing a film-wrapped, powder-filled vacuum insulation body. With an air-permeable but powder dust-impermeable filter material, the bag interior is closed in a dust-tight manner and subsequently evacuated.DE 10 2010 024 951 A1 shows a vacuum insulation body having a non-planar surface. The vacuum insulation body is produced by pressing a flat plate onto a non-flat surface in such a way that it substantially assumes its surface structure.WO 2016 / 082 906 A1 shows a vacuum insulation body, the envelope of which has an outer region and an inner region at least partially surrounding the outer region, wherein the inner region is formed by inverting a film pouch.It is the object of the present invention to provide a vacuum insulation body which is suitable in particular for use in thermal insulation vessels or thermal insulation containers and which, installed in thermal insulation vessels or containers, has a lower thermal conduction and can be produced efficiently.This object is achieved by a method for producing a vacuum insulation body, wherein the vacuum insulation body comprises an insulation body which comprises a bulk material and an airtight film enclosing the bulk material, having the following method steps:introducing the insulation body into a forming device,forming the insulation body by deep drawing, wherein the insulation body is arranged between a punch and a counter piece and the punch is pressed onto the insulation body, so that a trough-shaped insulation body is produced, wherein the punch and / or the counter piece is heated, wherein air is drawn from the insulation body during the forming and / or after the forming of the insulation body and after the step of pulling air from the insulation body the airtight film is sealed, so that a vacuum insulation body is produced.By forming the insulation body so that a trough-shaped insulation body results, it is no longer necessary to put vacuum insulation bodies, which are present as plates, together so that the thermal bridges at the edges are omitted. This provides a very efficient possibility for producing three-dimensional vacuum insulation bodies. In this case, for example, a vacuum insulation body that is present flat or an insulation body that has not yet been vacuum-formed can be formed in order to be converted into a vacuum insulation body by vacuum forming during the step of forming and / or thereafter.The vacuum insulation body produced according to the invention can also be referred to as a 3D vacuum insulation body.The forming corresponds to a deep drawing. In this case, for example, a stamp is used and a counter piece to the stamp, for example a border, into which the stamp can penetrate. When the punch penetrates into the counterpiece, there is a sufficient distance so that the insulating body or the vacuum insulating body has sufficient space between the punch and the counterpiece to the punch. In the forming process, after the insulating body is introduced into the forming device, the punch is pressed or pressed onto the insulating body and thus penetrates into the counterpart together with a part of the insulating body. Depending on the desired geometry or desired thickness of the final vacuum insulation body, the geometry of the punch and the counter piece is to be designed.Preferably, the bulk material is placed in a nonwoven bag, wherein the airtight film encloses the nonwoven bag. Alternatively, a fleece can also be provided in the region of a vacuuming opening of the airtight film in order to prevent the bulk material from leaking during vacuum drying.Preferably, the vacuum insulation body is removed from the forming device after the sealing of the airtight film. The sealing of the airtight film can also take place before the forming, for example if an already finished vacuum insulation body is used as the starting material for the forming.The method takes place under the action of heat, so that preferably the shaping of the insulation body takes place under the action of heat at a temperature between 40° C. and 200° C., in particular between 60° C. and 150° C., in particular between 70° C. and 90° C. A preferred temperature is 80° C.The preferred temperature will depend on the materials used. In particular, it depends on the material of the airtight film and the bulk material. In order to carry out the process under heat, the vacuum insulation body or the insulation body can be heated before being placed on or introduced into the forming device. The punch or the counterpart thereto or the punch and the counterpart thereto are heated. This measure can support in particular the airtight film enclosing the nonwoven bag with regard to its extensibility, so that damage to the film is prevented.In order to further protect the airtight film enclosing the nonwoven bag during the forming, it is preferred if the film does not closely contact the surface during the production process of the vacuum insulation body, but rather has a certain free surface. For this purpose, it is preferably provided that the airtight film enclosing the nonwoven bag has an area which is 0.3% to 20%, in particular 0.5% to 10%, larger than the area of the nonwoven bag. Preferably, the range is from 0.5% to 3%. This ensures that the airtight film enclosing the nonwoven bag can move relative to the nonwoven during forming, which prevents damage during forming.The forming process preferably takes between 1 s and 20 s, in particular between 3 s and 15 s. The vacuum insulation body produced is preferably held in the forming device for a predeterminable time, so that the latter retains the shape to the greatest possible extent after being removed from the forming device.The object is furthermore achieved by a vacuum insulation body which has been produced by a method according to the invention, wherein the vacuum insulation body comprises a bulk material introduced into an airtight film, wherein the interior of the airtight film is vacuumed and the airtight film is hermetically sealed, wherein the vacuum insulation body is at least partially L-shaped or U-shaped in at least one section.The vacuum insulation body according to the invention makes it possible to produce cooling boxes or thermal insulation vessels or thermal insulation containers which have a better insulation effect.Preferably, the bulk material is placed in a nonwoven bag and the airtight film encloses the nonwoven bag.The vacuum insulation body is preferably trough-shaped.Further preferably, the bulk material comprises granules, powder, fibers and / or granules. Suitable as filling material or bulk material which is introduced into the nonwoven bag is, for example, silica which has preferably been dried before vacuum drying. This material is stable and ensures that the produced shape of the insulation body remains stable. In addition, fibers can also be provided, which in particular increase the stability. For example, cellulose fibers are suitable. In order to improve the insulation properties, a heat radiation (IR radiation) attenuating agent called a darkening agent such as silicon carbide or iron oxide may be added. The fleece bag is air-permeable and at the same time dust-tight. This makes it possible to remove air from the inside of the nonwoven bag and from the vicinity of the bulk material while maintaining the shape and protecting the airtight film enclosing the nonwoven bag.Preferably, the airtight film enclosing the nonwoven bag has an area which is 0.5% to 20%, in particular 1% to 10%, larger than the area of the nonwoven bag.Preferably, a thermal insulation vessel or thermal insulation container comprises a vacuum insulation body according to the invention.Further features of the invention will become apparent from the description of embodiments of the invention taken in conjunction with the claims and the accompanying drawings. Embodiments according to the invention may fulfil individual features or a combination of several features.Within the scope of the invention, features which are marked "in particular" or "preferably" are to be understood as optional features.The invention is described below without limiting the general concept of the invention on the basis of exemplary embodiments with reference to the drawings, wherein reference is expressly made to the drawings with respect to all details according to the invention which are not explained in more detail in the text. The following are shown: FIG. 1 shows a schematic illustration of a forming device before forming the insulation body, FIG. 2 shows the forming device from FIG. 1 in a position in which the forming of the insulation body has taken place, FIG. 3 shows a formed vacuum insulation body in schematic, three-dimensional representation, FIG. 4 shows a schematic sectional illustration through an insulation body before the forming, and FIG. 5 shows a schematic sectional illustration of a vacuum insulation body before the forming.In the drawings, identical or similar elements and / or parts are each provided with the same reference numerals, so that renewed presentation is omitted in each case.FIG. 1 shows a schematic sectional representation of a forming device 5 which has a punch 2 and a mold 3. The punch 2 can be moved in the direction of movement 4 of the punch 2. For forming, for example in the form of a deep drawing, the punch 2 is moved downwards onto the vacuum insulation body 1 and presses the vacuum insulation body 1 into the mold 3. The punch 2 is then removed again and the formed vacuum insulation body 1 can be removed.This then results in a trough-shaped vacuum insulation body 1, which is illustrated schematically in FIG. 3, for example. In FIG. 3, the trough 10 or the trough emulation can be seen. In addition, a seam 11 can be seen which seals the airtight film 12 enclosing the fleece bag 13.Alternatively, an as yet not vacuum-dried insulating body 6 can also be placed on the mold 3 and correspondingly deformed, wherein during the deformation or thereafter, i.e. still lying in the mold 3, air can be extracted from the insulating body 6, so that a vacuum insulating body 1 is produced. For this case, the seam 5 or a vacuuming opening 17 is then closed as long as the vacuum insulation body 1 is still in the mold 3.FIG. 4 shows an insulation body 6 before vacuuming. An airtight sheet 12 is provided on the outside. This airtight film 12 may be metal-coated, for example, aluminum-coated, and may be referred to as a high-barrier vacuum-tight film 12. Within this vacuum-tight film 12 is provided a non-woven bag 13 which is air-permeable but dust-tight. This serves to prevent bulk material 14, as described above, from being introduced into the fleece bag 13, from exiting the latter. For this purpose, bulk material 14 is first introduced into the fleece bag 13. The nonwoven bag 13 is then sealed at the seam 16. Subsequently, the nonwoven bag 13 is placed in the airtight film 12 which is already hermetically sealed at a seam 15. Air is then removed from the bag formed from the film 12 at the vacuuming opening 17 and the vacuuming opening 17 is closed. A vacuum insulation body 1 is then formed, which is schematically illustrated in a sectional illustration in FIG. 5. A seam 15' is then shown there, at which the airtight film 12 is also closed.Silica (SiO 2). is suitable as the filler material 14. Viscose fibers can also be added, for example with a density of 1.5 g / cm 3. These fibers may have a length of 2 mm to 10 mm. In addition, a darkening agent such as silicon carbide may be used. The airtight film 12 may be a metal-coated plastic such as polyethylene, polyester or polyamide.After the forming, the vacuum insulation body 1 maintains its shape. Particularly preferred is a filler material or a bulk material 14 made of silica, iron oxide and fibers, wherein silica has a proportion of about 2 / 3 and the proportion of iron oxide is five to ten times as large as the proportion of the fibers. The fleece bag 13 is preferably dried for a predetermined time after filling with the bulk material 14.All features mentioned, including those taken alone from the drawings and also individual features which are disclosed in combination with other features, are considered to be essential to the invention alone and in combination. Embodiments according to the invention may be fulfilled by individual features or a combination of a plurality of features.List of reference characters1 Vacuum insulation body 2 Punch 3 Mold 4 Direction of movement of punch 5 Forming device 6 Insulation body 10 Trough 11 Seam 12 Film 13 Non-woven bag 14 Bulk material 15, 15' Seam 16 Seam 17 Vacuuming opening

Claims

Method for producing a vacuum insulation body (1), wherein the vacuum insulation body (1) comprises an insulation body (6) comprising a bulk material (14) and an airtight film (12) enclosing the bulk material (14), having the following method steps: - introducing the insulation body (6) into a forming device (5), - forming the insulation body (6) by deep drawing, wherein the insulation body (6) is arranged between a punch and a counter piece and the punch is pressed onto the insulation body (6) so that a trough-shaped insulation body (6) is produced, wherein the punch and / or the counter piece is heated, wherein air is drawn from the insulation body (6) during forming and / or after forming of the insulation body (6) and after the step of drawing air from the insulation body (6) the airtight film (12) is sealed, so that a vacuum insulation body (1) results.Method according to claim 1, characterised in that the bulk material (14) is introduced into a fleece bag (13), wherein the airtight film (12) encloses the fleece bag (13).Method according to Claim 1 or 2, characterized in that the vacuum insulation body (1) is removed from the forming apparatus (5) after the airtight film (12) has been sealed.Method according to one of Claims 1 to 3, characterized in that the shaping of the insulation body (6) is carried out under the action of heat at a temperature between 40°C and 200°C, in particular between 60°C and 150°C, in particular between 70°C and 90°C.Method according to one of Claims 2 to 4, characterized in that the airtight film (12) enclosing the nonwoven bag (13) has an area which is 0.5% to 20%, in particular 1% to 10%, larger than the area of the nonwoven bag (13).Method according to one of Claims 1 to 5, characterized in that the forming process takes between 1 s and 20 s, in particular 3 s to 15 s, wherein, in particular after the forming, the vacuum insulation body (1) produced is held in the forming apparatus (5) for a predeterminable time.Vacuum insulation body (1) produced according to a method according to one of Claims 1 to 6, comprising a bulk material (14) introduced into an airtight film (12), wherein the interior of the airtight film (12) is vacuumed and the airtight film (12) is hermetically sealed, characterized in that the vacuum insulation body (1) is at least partially L-shaped or U-shaped in at least one section.Vacuum insulating body (1) according to claim 7, characterised in that the bulk material (14) is introduced into a non-woven bag (13) and the airtight film (12) encloses the non-woven bag (13).Vacuum insulation body (1) according to claim 7 or 8, characterised in that the vacuum insulation body (1) is trough-shaped.Vacuum insulation body (1) according to one of claims 7 to 9, characterised in that the bulk material (14) comprises granules, powder, fibres and / or granules.Vacuum insulation body (1) according to one of Claims 8 to 10, characterized in that the airtight film (12) enclosing the nonwoven bag (13) has an area which is 0.3% to 20%, in particular 0.5% to 10%, larger than the area of the nonwoven bag (13).A thermal insulation vessel or thermal insulation container comprising a vacuum insulation body (1) according to any one of claims 7 to 11.

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