Manufacturing process for an insulating panel

Abstract

Method for manufacturing an insulating panel (10) with a device (20) comprising a pressing tool (21) with at least one counter-form (22) and at least one pressing part (23), wherein the counter-form (22) has at least one recess (24) for forming the insulating panel, and the method comprises the following steps: a) Arranging at least one first cover layer (12') in the recess (24) of the counter-mold (22) and arranging at least one second cover layer (12") on a pressing area (25) of the pressing part (23) facing the recess (24); b) Covering the first top layer (12') with at least one liquid plastic material, c) Inserting at least one core layer package consisting of an insulating core (27) with fiber layers arranged on both sides into the recess (24) of the counter-mold (22), such that at least the first of the two fiber layers is in contact with the liquid plastic material; d) Covering the second of the two fiber layers with the liquid plastic material, and e) Pressing the pressed part (23) with the pressing area (25) against the counter-form (22), wherein the core layer package is pressed together with the liquid plastic material and the two cover layers (12', 12") to form the insulating panel, and in which process f) at least one venting insert (26), which serves to remove the air trapped between the counter-mold (22) and the pressing part (23) during the pressing process, is arranged on an edge (28) of the counter-mold (22) adjacent to the recess (24), wherein the venting insert (26) is permeable to air and, in a closed state of the pressing tool (21), connects the recess (24) of the counter-mold (22) to the outside atmosphere, and wherein the venting insert (26) is designed to be liquid-tight, so that it allows trapped air to pass through and retains the liquid plastic material during the pressing process.

Description

[0001] The invention relates to a method for manufacturing an insulating panel. An insulating panel is known, for example, from WO 2010 / 108 615 A1.

[0002] In commercial vehicle construction, metal cover plates are typically used to manufacture insulating panels, which are arranged parallel to each other with a gap between them. A liquid is introduced into this gap and foamed to form an insulating layer. The production of foamed insulating panels is complex and expensive, as the foam must displace and fill the air contained in the gap. Furthermore, there are limitations regarding the shape and size of the insulating panels produced in this way. Such an insulating panel is known, for example, from the aforementioned WO 2010 / 108 615 A1.

[0003] Another option for manufacturing insulating panels is bonded panels, in which prefabricated insulation layers and facing sheets are glued together. Here, too, the shape and size of the insulating panels are subject to limitations. Furthermore, both manufacturing methods require longer waiting times, for example, for the foaming of the cavity or the curing of the adhesive bond.

[0004] Another manufacturing method for insulating panels is, for example, the wet-on-wet process, in which fiberglass mats are embedded in resin, brushed or impregnated with resin, and then cured. In this process, fiberglass mats are arranged layer by layer by hand until the required thickness of the first outer layer is reached. A foam core is then applied, and subsequently, the second outer layer is formed according to the first. While this method can produce insulating panels of higher quality, it is very time-consuming and therefore associated with high costs. Furthermore, it has the disadvantage of being difficult to automate.

[0005] WO 2020 / 109 342 A1 discloses a sandwich composite component with a layered structure. The layered structure comprises a core layer of polymer foam, a reinforcement layer comprising a fiber composite material, and at least one functional layer, wherein the layers of the layered structure are bonded together by material connection, in particular by adhesive bonding.

[0006] DE 11 2015 005 737 T5 describes a multi-layered molding material composite comprising a prepreg which is equipped with a support structure on at least one of its surfaces with a surface coating film.

[0007] DE 81 13 534 U1 discloses a forming press for pressing chipboard.

[0008] WO 99 / 50 060 A1 discloses a sandwich element consisting of a core and plastic cover sheets. The latter are made of low-pressure SMC and completely enclose the core. Manufacturing is carried out using a wet-on-wet process.

[0009] DE 10 2018 129 602 A1 relates to an insulating panel having two parallel outer layers of fiber-reinforced plastic material, which are sprayed onto a core layer and then pressed together to form a sandwich structure. For manufacturing, one side of a press is first treated with a release agent. This side is then sprayed with the fiber-reinforced plastic material, creating the first outer layer.

[0010] DE 33 29 230 A1 describes a method for manufacturing sailboards or surfboards. A foam core, previously coated with impregnated fiber material, is placed in a mold. Before placement, the mold is lined with a thermoplastic film, which serves as a surface layer.

[0011] Furthermore, EP 3 266 580 A1 discloses a method for manufacturing a planar component. In this method, a barrier layer casting compound and a liquid lacquer are first introduced into a tool. Subsequently, a foam core, which has previously been encased in an impregnated mat, is placed into the tool.

[0012] DE 10 2016 104 603 A1 discloses a method for producing a composite component using a press mold. In this method, an open-pore foam body is wrapped with one or more layers of fiber fleece, such that the fiber layers project laterally beyond the parting line of the mold. During a pressing operation, excess resin with which the foam body has been impregnated is displaced laterally out of the mold via the fiber layers.

[0013] The invention is based on the objective of providing a method for manufacturing an insulating panel.

[0014] According to the invention, this problem is solved with regard to the method by the subject matter of claim 1.

[0015] The inventive method produces an insulating panel for a vehicle body, in particular a refrigerated vehicle body, comprising at least one heat-insulating, in particular foamed, core layer, at least two cover layers each made of at least one film, in particular plastic film, and at least two intermediate layers, each formed by at least one fiber layer in a cured plastic material. The intermediate layers are arranged opposite each other between the heat-insulating core layer and the respective cover layer. The intermediate layers firmly, in particular permanently, connect the core layer to the cover layers by means of a press fit.

[0016] The manufactured insulating panel offers several advantages. Due to the formation of the intermediate layers, consisting of at least one fiber layer in the cured plastic material, and the outer layers as films, this insulating panel, unlike conventional insulating panels with, for example, metallic outer layers, has a significantly lower weight. Particularly when used in vehicle bodies, especially refrigerated vehicle bodies, this results in a reduced vehicle unladen weight, enabling increased payload and CO2 savings during operation.

[0017] The films used as top layers have the additional advantage that they can be produced in various colors according to customer requirements and needs. Furthermore, the films are easy to print on. It is also possible to coat the films with another film, particularly by laminating them.

[0018] The intermediate layers each form a fiber-reinforced layer that connects the film to the core layer. Each intermediate layer is designed to firmly bond the top layer or film to the core layer. To achieve this, the cured plastic material of the intermediate layer is in contact with both the film and the core layer. In other words, the cured plastic layer penetrates the fiber layer in such a way that the film and the core layer are permanently bonded by the cured plastic material of the intermediate layer. In other words, the cured plastic material holds the respective film to the core layer.

[0019] The films are firmly bonded to the core layer by pressing the core layer together with the intermediate layers and the films. The individual layers are pressed together in such a way that the liquid plastic material, particularly polyurethane, flows at least partially into the core layer structure or adheres to the structure of the films, thus forming a form-fit and / or material-fit connection between the intermediate layer and the joining partners after the liquid plastic material has cured. The cured plastic material can penetrate the structure of the film and / or the core layer and bond the respective joining partners. The press-fit connection is preferably formed by a combination of form-fit and material-fit connections. The cured plastic material forms a composite material.

[0020] In addition, individual, especially protruding, fibers of the fiber layer can penetrate into the core layer, so that the intermediate layer at least partially engages with the core layer, in particular hooks in.

[0021] During the pressing process, the liquid plastic material is in contact with the film, at least over a surface area. The film may have a treated or modified surface to which the liquid plastic material adheres. This surface may therefore exhibit improved adhesive properties.

[0022] Preferably, the outer layers are each formed by a single film. This simplifies the production of the insulating panel and reduces material costs. Alternatively, the outer layers can each be formed by several films arranged on top of each other. Preferably, the films are elastically deformable, in particular stretchable. This has the advantage that the film, in combination with the intermediate layer, exhibits spring-like properties and thus reduces dent formation in the event of damage.

[0023] The film can be made of plastic. Preferably, the film is a polyurethane plastic film. Alternatively, the film can be made of metal. A composite film made of several plastic and / or metal films is also possible as a top layer.

[0024] During the production of each intermediate layer, the fiber layer is wetted with the liquid plastic material to saturate it. After a curing process, the fiber layer and the cured plastic material together form the intermediate layer, with the fiber layer and the cured plastic material forming a single unit.

[0025] For the purposes of this application, a fiber layer is to be understood as a layer formed from at least one planar, and in particular thin, element made of fibers. The fiber layer can consist of a single planar element or several planar elements arranged one above the other. Glass fibers and / or carbon fibers can be used.

[0026] This type of fiber layer has the advantage that the individual fibers, which form the sheet elements of the fiber layer, can be aligned accordingly during the manufacturing process. For example, the fibers can run predominantly parallel to the corresponding film. This ensures that when the top layer is pressed with the intermediate layer, the fibers lie mostly elongated against the film, thus preventing the individual fiber tips from puncturing the film.

[0027] Within the scope of the application, the core layer is a heat-insulating, central layer in the form of a semi-finished product. In other words, the core layer is prefabricated before the formation of the insulating panel. The core layer is preferably formed by a flat, volumetric element.

[0028] The manufactured insulating panel is constructed as a sandwich panel, with the panels arranged from the outside in as follows: face layer, intermediate layer, and core layer. In other words, the core layer is sandwiched between the two intermediate layers, with each face layer bonded to one of the intermediate layers. The respective intermediate layer is positioned between the core layer and the face layer or foil. The insulating panel exhibits increased stability, improved impact resistance, and enhanced strength. This has the advantage of reducing the panel's susceptibility to hail damage when used outdoors.

[0029] Furthermore, the manufactured insulating panel exhibits low linear expansion in response to temperature differences, which is advantageous, for example, when used in refrigerated vehicle bodies.

[0030] Preferred embodiments of the manufactured insulating panel are specified in the dependent claims.

[0031] In a particularly preferred embodiment, the fiber layer is embedded in the cured plastic material by pressing the individual layers together. In other words, the fiber layer of the respective intermediate layer can be integrated into the cured plastic material. The fiber layer can be at least partially enclosed by the cured plastic material in the intermediate layer. Preferably, the fiber layer is completely enclosed by the cured plastic material in the intermediate layer.

[0032] The hardened plastic material solidifies the fiber layer in its shape, so that the insulating panel has increased stability, especially lateral stability.

[0033] When the individual layers are pressed to form the insulating panel, the fiber layer is impregnated with the still-liquid plastic material, so that after hardening, the fiber layer is firmly, and in particular fixed, within the plastic material. The fiber layer can be embedded in an area facing the film or embedded centrally within the hardened plastic material.

[0034] In a preferred embodiment, the fiber layer is formed by at least one glass fiber mat and / or the cured polyurethane plastic material. In other words, the fiber layer can comprise at least one glass fiber mat. The fiber layer can also comprise several glass fiber mats arranged next to one another. The glass fiber mat can be a woven fabric of glass fibers and / or consist of a plurality of loose glass fibers pressed into a mat. An advantage here is that damage to the insulating panel, particularly to the intermediate layers, can be repaired easily and quickly by hand using a glass fiber filler, thus eliminating the need to replace the insulating panel every time damage occurs.

[0035] Alternatively or additionally, the fiber layer can be formed by at least one carbon fiber mat.

[0036] The cured polyurethane plastic material has advantageously improved elastic properties, thus reducing dent formation in the area of ​​the top and intermediate layers when the insulating panel is damaged. In an embodiment where the core layer, the cured plastic material, and the films are made of polyurethane, recyclability is improved. For example, at the end of their service life, the insulating panels can be shredded and further processed without significant separation effort. In contrast, the components of previously known insulating panels for refrigerated vehicle bodies must be separated in a complex process to enable recycling.

[0037] Furthermore, polyurethane and fiberglass mats are inexpensive to purchase and, unlike metal materials, exhibit increased price stability.

[0038] In a preferred embodiment, the cover layers are each formed by at least one multilayer film. The individual layers of the multilayer film are preferably extruded one on top of the other. The individual layers of the multilayer film preferably have polyurethane as the base material. The individual layers of the multilayer film preferably have different material properties, such as UV resistance, colorfastness, and / or scratch resistance. In addition to the polyurethane as the base material, the layers can contain at least one additive material, in particular an additive, to exhibit the aforementioned material properties. The individual layers are not limited to the aforementioned properties.

[0039] In this embodiment, it is advantageous that the various material properties of the multilayer film are distributed across different film layers. Compared to a top layer made of a single-layer film, the multilayer film does have a greater thickness, but it is generally cheaper to manufacture.

[0040] In the production of the multilayer film, the individual film layers are extruded directly on top of each other. This can be done using an extrusion line in which the various molten material streams are fed together and inseparably extruded one on top of the other to form the multilayer film. Preferably, the multilayer film consists of at least two layers. The multilayer film can also be formed from three or four layers extruded on top of each other. Other variations of the film structure with regard to the number of layers are possible.

[0041] The multilayer film can generally also be referred to as a multi-layered film, with the individual layers forming different film layers.

[0042] In another preferred embodiment, the cover layers, extending outwards from the heat-insulating core layer, particularly perpendicular to a side surface of the core layer, form a final, and especially last, layer of the insulating panel. This has the advantage that the films eliminate the need for a final coat of paint or gelcoat on the insulating panel, as the films serve as the visible surface. This saves costs and reduces solvent emissions. However, a final coat of paint on the films is not precluded.

[0043] The core layer of the insulating panel can be formed in one piece, in particular as a single unit, i.e., from at least one core layer volume element. In other words, the core layer can be formed by a single core layer volume element. Alternatively, the core layer can be formed from several composite core layer volume elements, in particular foamed core layer blocks. In other words, the core layer can be formed from multiple parts.

[0044] The core layer can have various forms. For example, the core layer can have at least one reinforcement, at least one rib, at least one connecting element, and / or at least one molded area. Additionally or alternatively, an insert can be embedded in or formed within the core layer. The insert can be pressed into the core layer.

[0045] A device for manufacturing an insulating panel is disclosed, comprising at least one pressing tool with at least one counter-mold and at least one pressing part. The counter-mold has at least one recess for forming the insulating panel, and the pressing part has at least one pressing area, which in a first of at least two operating positions is arranged opposite the recess. The counter-mold is horizontally movable between the two operating positions to load the recess of the counter-mold layer by layer. The pressing part is vertically movable to press the pressing part against the counter-mold to form the insulating panel. The device can also be referred to as a press.

[0046] The counter-mold forms the part of the pressing tool against which the pressing part is pressed during the pressing process to produce the insulating panel under pressure. The recess of the counter-mold essentially defines the shape of the insulating panel to be produced. The pressing part, together with the pressing area, forms a cover that is pressed against the counter-mold during the pressing process, particularly in the direction of the counter-mold, thus defining another part of the shape.

[0047] The device comprises at least two operating positions, between which the counter-form is horizontally movable. The counter-form can also be referred to as a pendulum form ("shuttle"). In the first operating position, the counter-form is located opposite the pressing area of ​​the pressing part. The first operating position can also be referred to as the pressing position. The pressing part is horizontally fixed, i.e., rigidly arranged in the horizontal direction. The pressing part is movable in the vertical direction, so that the pressing process for forming the insulating panel can take place in the first operating position.

[0048] For the purposes of this application, the vertical direction corresponds to the direction in which the pressing part is moved during operation to press the pressing area against the counter-die. The horizontal direction is orthogonal to the vertical direction.

[0049] In the second operating position, the counter-form to the pressing part is arranged horizontally, in particular laterally, offset in order to fill the recess of the counter-form with components, in particular at least one insulating core and / or at least one fiber layer or at least one core layer package consisting of an insulating core and at least one fiber layer, of the insulating panel to be produced.

[0050] The counter-mold is thus movable between the two horizontal operating positions. This has the advantage of facilitating access for loading the counter-mold and thus reducing effort. Furthermore, the disclosed device has a simple design, which simplifies the production of an insulating panel.

[0051] In a preferred embodiment of the disclosed device, the pressing tool has at least one counterpart that serves as a stationary abutment for the counter-form and absorbs the pressing forces introduced into the counter-form by the pressing part during the pressing process. In other words, the counter-form is vertically supported, at least during the pressing process, to absorb the pressing forces. The counter-form can rest on the stationary counterpart, in particular the tool table, of the pressing tool. Advantageously, the counter-form has a dual function: firstly, as a part defining the shape of the insulating panel, i.e., as the form itself, and secondly, as an abutment, i.e., as a component of the pressing tool. This allows for the elimination of further press components, thus reducing the press's complexity.

[0052] In a further preferred embodiment of the disclosed device, the recess of the counter-mold is trough-shaped and forms a negative mold of the insulating panel to be formed. The recess of the counter-mold can be open on one side, which is closed during the pressing process by the pressing area of ​​the pressing part. The recess essentially forms a final shape of the insulating panel to be formed, with the pressing area of ​​the pressing part completing the final shape of the insulating panel when the counter-mold is closed. In other words, the counter-mold and the pressing area of ​​the pressing part, when the pressing tool is closed, form the complete final shape of the insulating panel to be formed.

[0053] The trough shape of the recess simplifies the loading or insertion of the components of the insulating panel, thus reducing the effort required to manufacture the panel.

[0054] Preferably, the counter-mold and / or the pressed part are formed in one piece. Alternatively, it is possible for the counter-mold and / or the pressed part to be formed in multiple parts.

[0055] Preferably, the disclosed device comprises at least one distribution device for applying a liquid plastic material, in particular polyurethane, which is arranged horizontally between the two operating positions of the counter-mold. In other words, the distribution device is preferably arranged in the transition between the two operating positions, so that the liquid plastic material can be introduced into the recess when the counter-mold changes between the two operating positions. Preferably, the distribution device is designed to apply the liquid plastic material uniformly to the components of the insulating panel arranged in the recess. The distribution device can have at least one nozzle through which the liquid plastic material is applied. Preferably, the distribution device is formed by at least one discharge tube.

[0056] The distribution device allows the counter-mold to be loaded with the liquid plastic material simultaneously when switching between the two operating positions, thus reducing the overall loading time.

[0057] Furthermore, the device has at least one venting insert for removing air trapped between the counter-mold and the pressed part during the pressing process, the venting insert being arranged on an edge of the counter-mold adjacent to the recess. The venting insert is designed to be air-permeable. When the pressing tool is closed, the venting insert connects the recess of the counter-mold to the outside atmosphere, allowing venting to occur during the pressing process.

[0058] The venting insert is made of a material that is air-permeable. It is preferably formed by a soft foam insert. Furthermore, the venting insert is designed to be liquid-tight. In other words, the venting insert allows trapped air or air bubbles to pass through, but retains the liquid plastic material during the pressing process. This results in improved venting and thus prevents the entrapment of air bubbles in the insulation panel as well as material loss due to retention.

[0059] The edge of the counter-form can partially or completely frame the recess. The edge can project outwards from the recess.

[0060] Preferably, the venting insert is arranged around the entire perimeter of the recess. In other words, the venting insert can be designed as a flat insert element positioned at the edge of the counter-mold. The venting insert can be a soft foam mat. Alternatively, several venting inserts can be provided, distributed around the perimeter of the recess. The venting inserts can be evenly distributed between the counter-mold and the pressed part. The venting inserts can also be strip-shaped. The circumferential or distributed arrangement of the venting insert ensures uniform and nearly complete venting of the recess in the counter-mold during the pressing process. This allows for the production of wrinkle-free insulating panels, resulting in improved quality.

[0061] The invention relates to a method for manufacturing an insulating panel, in particular an insulating panel as described above, with a device comprising a pressing tool with at least one counter-mold and at least one pressing part. The counter-mold has at least one recess for forming the insulating panel. The method comprises the following steps: a) Arranging at least one first cover layer, in particular a film, in the recess of the counter-mold and arranging at least one second cover layer, in particular a film, on a pressing area of ​​the pressing part facing the recess. b) Covering the first top layer with at least one liquid plastic material, in particular polyurethane. c) Inserting at least one core layer package consisting of an insulating core with fiber layers arranged on both sides into the recess of the counter-mold, such that at least the first of the two fiber layers is in contact with the liquid plastic material. d) Covering the second of the two fiber layers with the liquid plastic material, in particular polyurethane. e) Pressing the pressed part with the pressing area against the counter-form, whereby the core layer package is pressed together with the liquid plastic material and the two cover layers to form the insulating panel.

[0062] In step e), the individual layers are pressed together in such a way that the liquid plastic material, in particular polyurethane, flows at least partially into the structure of the core layer or adheres to the structure of the film, thus forming a form-fit and / or material-fit connection between the joining partners. The plastic material can penetrate the structure of the film and / or the core layer and bond the respective joining partners together. The press-fit connection is therefore preferably formed by a combination of form-fit and material-fit connection. The liquid plastic material forms a composite material.

[0063] In general, the method according to the invention can be carried out with a device of the type mentioned above.

[0064] The arrangement of the second cover layer on the pressing area of ​​the pressing part in step a) can alternatively also take place at another time, but before the execution of step e).

[0065] In a preferred embodiment of the method according to the invention, in step a), the first cover layer is held in contact with the recess of the counter-mold. Alternatively or additionally, preferably in step a), the second cover layer is held in contact with the pressing area of ​​the pressed part. In other words, the first cover layer is arranged such that it lies flat against an internally formed contour of the recess of the counter-mold without creases. In other words, the first cover layer forms the contour of the recess. The second cover layer is also arranged such that it lies flat against a contour of the pressing area of ​​the pressed part without creases. The second cover layer forms the contour of the pressing area.

[0066] Preferably, the two cover layers are held in contact without mechanical fastening. To ensure the cover layers remain in contact, an adhesive, in particular a bonding agent, can be provided between the cover layer and the contour of the counter-mold or the pressing area of ​​the pressed part.

[0067] In a further preferred embodiment of the method according to the invention, the first cover layer is drawn against the recess of the counter-mold and / or the second cover layer is drawn against the pressing area of ​​the pressed part, so that the respective cover layer lies flat, in particular without wrinkles. Specifically, the first cover layer is drawn against the contour of the recess without wrinkles and / or the second cover layer is drawn against the contour of the pressing area without wrinkles. The two cover layers are preferably drawn against the mold by means of a vacuum applied by at least one vacuum system. In other words, the two cover layers are drawn against the respective mold contour by means of a vacuum. This has the advantage that the arrangement of the cover layers, which are preferably flexible, in particular elastic, plastic films, is carried out in a simple manner without the need for additional steps to attach the films.This significantly simplifies the manufacturing process. Furthermore, the assembly process can be easily automated.

[0068] Preferably, the counter-mold is moved horizontally between two operating positions for loading, with steps a) and e) being performed in the first operating position and step c) being performed in the second operating position. Changing the counter-mold from the first to the second operating position improves its accessibility for inserting the core layer package. In the second operating position, the counter-mold is horizontally offset from the pressed part. In the first operating position, the counter-mold is in the pressing position, i.e., directly opposite the pressed part. Loading the counter-mold in the first operating position is therefore difficult.

[0069] Preferably, the first coating layer is covered with the liquid plastic material, particularly by spraying, as the counter-mold moves from the first to the second operating position. In other words, during the horizontal process, the first coating layer is covered with the liquid plastic material simultaneously as the counter-mold moves from the first to the second operating position. These parallel process steps significantly reduce the loading time for the counter-mold.

[0070] Preferably, the second fiber layer is covered with the liquid plastic material, particularly by spraying, as the counter-mold is moved from the second to the first operating position. In other words, the second top layer is covered with the liquid plastic material simultaneously during the horizontal process of moving from the second to the first operating position. These parallel process steps further reduce the loading time for the counter-mold.

[0071] In step b), the first cover layer can be coated with the liquid plastic material across the entire width of the recess in the counter-mold. Alternatively or additionally, in step d), the second fiber layer can be coated with the liquid plastic material across the entire width of the insulating core. This has the advantage that complete wetting of the first cover layer and / or the second fiber layer already occurs in steps b) and d). This saves further work steps, thus simplifying the process.

[0072] Furthermore, in the inventive method, at least one venting insert is arranged between the counter-mold and the pressed part, wherein, during pressing, the air trapped between the counter-mold and the pressed part escapes through the venting insert until the liquid plastic material seals the venting insert. Specifically, the venting insert can be placed between the first cover layer and the pressed part or the second cover layer. Alternatively, it is possible for the venting insert to be arranged in at least one section of the first cover layer between the counter-mold and the pressed part or the second cover layer. During pressing in step e), the venting insert enables improved venting and thus prevents the entrapment of air bubbles in the insulating panel as well as material loss due to retention.

[0073] In this process, the venting insert is positioned at an edge of the counter-mold adjacent to the recess. The venting insert can project into the recess of the counter-mold. During pressing in step e), the venting insert connects the recess of the counter-mold to the outside atmosphere, allowing venting to occur during the pressing process.

[0074] In a further preferred embodiment of the method according to the invention, in step e) the fiber layers with the liquid plastic material each form an intermediate layer which firmly, in particular inseparably, connects the respective cover layer and the insulating core to form the insulating panel.

[0075] Preferably, in step e), the pressing area of ​​the pressed part is pressed against the counter-mold for a predetermined period of time, in particular a curing time, whereby the liquid plastic material cures to form the intermediate layer. During curing, the plastic material solidifies and binds the fiber layer, thus forming the intermediate layer.

[0076] Preferably, after step e), the pressed part is detached from the counter-mold, the formed insulating panel is removed from the counter-mold, and steps a) to e) are then repeated to form another insulating panel.

[0077] The method according to the invention is not limited to the sequence mentioned above. It is possible for the first fiber layer to be arranged with the first cover layer as early as step a). In this case, the first cover layer can first be arranged in the recess, and then the first fiber layer can be placed in the recess onto the first cover layer. In other words, the first fiber layer is arranged on top of the first cover layer after it has been inserted. It is also possible for the first cover layer and the first fiber layer to be arranged together in the recess. In this alternative variant, the core layer assembly is inserted in step c) with only the second fiber layer, which is then covered with the liquid plastic material in step d). Here, the core layer assembly consists of the core layer or insulating core and the second fiber layer.

[0078] Further advantages of the method for manufacturing an insulating panel are described in relation to the insulating panel and the apparatus. In addition, the method may alternatively or additionally incorporate one or a combination of several of the features previously mentioned in relation to the insulating panel and the apparatus.

[0079] The invention is explained in more detail below with reference to the accompanying drawings. The illustrated embodiments represent examples of how the manufactured insulating panel and the disclosed device can be designed.

[0080] These show, Fig. 1 a schematic diagram of an insulating panel produced using the method according to the invention, shown in exploded view; Fig. 2 a top view of a counterpart of a device for the method according to the invention; and Fig. 3 a cross-section of the device according to Fig. 2 along a section line AA.

[0081] In the following, the same reference numbers are used for identical and equivalent parts.

[0082] Fig. Figure 1 shows a schematic diagram of an insulating panel 10 for a vehicle body, manufactured according to a production method according to the invention. The insulating panel 10 is used, for example, as a thermal insulation panel, preferably in refrigerated vehicle construction for the production of a refrigerated vehicle body. The insulating panel primarily serves as a thermally insulating wall element and / or as a thermally insulating floor element and / or as a thermally insulating ceiling element and / or as a thermally insulating door element. Other applications are possible.

[0083] The insulating panel 10 has a heat-insulating core layer 11, two cover layers 12 and two intermediate layers 14. According to Fig. 1. The outer layers 12 of the insulating panel 10 are each designed as a film 13. The films 13 can be arranged on one side, both sides, or on several sides of the core layer 11. The films 13 can completely encase or encapsulate the core layer 12.

[0084] The cover layers 12 are each formed by a single film. The single film can be a multilayer film whose layers have different material properties. The multilayer film preferably consists of at least two film layers extruded one above the other. Alternatively, it is possible that the cover layers 12 are each formed by several films 13 arranged next to one another. Specifically, the film 13 is a plastic film made of polyurethane. Hereinafter, the cover layers 12 are each referred to as plastic film 13'.

[0085] Furthermore, the intermediate layers 14 are according to Fig. 1. Each fiber layer is formed from a single layer of fibers embedded in a cured plastic material. The fiber layer is embedded in the cured plastic material. The fiber layer consists of a glass fiber mat. Alternatively, the fiber layer can be formed from several glass fiber mats arranged next to each other.

[0086] The cured plastic material is cured polyurethane. The fiber layer or glass fiber mat is embedded in cured polyurethane. The intermediate layers 14 according to Fig. Each of the following consists of a glass fiber mat integrated into cured polyurethane. The intermediate layers 14 each form a fiber-reinforced, in particular glass fiber-reinforced, layer. Hereinafter, the cured plastic material is referred to as cured polyurethane.

[0087] The insulating panel 10 according to Fig. The core layer 11 is formed by pressing together the individual layers 11, 13', 14. The core layer 11 is firmly bonded to the plastic films 13' by means of the intermediate layers 14 via a press fit. The cured polyurethane acts as a composite material, firmly bonding the plastic films 13' to the core layer 11. The bond between the core layer 11, the intermediate layers 14, and the plastic films 13' is permanent. In other words, the individual layers 12, 13', 14 can only be separated by destroying the individual layers 12, 13', 14 of the insulating panel 10.

[0088] The intermediate layers 14 are arranged opposite each other on the core layer 11. The plastic films 13' are arranged opposite each other on the intermediate layers 14. In other words, each intermediate layer 14 is located between the core layer 11 and the plastic film 13'. The insulating panel 10 according to Fig. 1 is therefore designed as a sandwich panel, wherein the individual layers 12, 13', 14 are arranged from the outside inwards in the sequence plastic film 13', intermediate layer 14 and core layer 11 and pressed together.

[0089] The plastic films 13' form a final, and in particular last, layer of the insulating panel 10 on the outside. Specifically, the plastic films 13' extend outwards from each side surface 15 of the core layer 11, perpendicular to the side surface 15, forming a final layer. The plastic films 13' are thus arranged on the outside of the insulating panel 10. Painting the plastic films 13' is nevertheless possible.

[0090] According to Fig. 1. The core layer 11 can be formed from composite core layer volume elements, in particular foamed core layer blocks. In other words, the core layer 11 can be formed in multiple parts. Alternatively, the core layer 11 can be formed in one piece, in particular as a single unit. In other words, the core layer 11 can be formed by a single core layer volume element.

[0091] According to the Fig. 2 and Fig. Figure 3 shows a device 20 according to an exemplary embodiment. The device 20 serves to manufacture an insulating panel 10 according to Fig. 1.

[0092] The device 20 comprises a pressing tool 21 with a pressing part 23 and a counter-mold 22, which is movable in a horizontal direction H. The counter-mold 22 has a recess 24, which forms a negative mold of an insulating panel 10 to be formed.

[0093] As in Fig. As can be clearly seen in Figure 3, the recess 24 is trough-shaped. The recess 24 has a circumferential boundary surface 29 and a side wall boundary surface 31. During the pressing process to form the insulating panel 10, the circumferential boundary surface 29 defines the shape of the insulating panel 10 all around, and the side wall boundary surface 31 defines a first side wall shape 27 of the insulating panel 10. The recess 24 of the counter-mold 22 thus defines the circumferential shape as well as the first side wall shape 27 of the insulating panel 10 to be formed.

[0094] As in Fig. As shown in Figure 2, the recess 24 of the counter-form 22 has a rectangular shape in plan view. The counter-form 22 also has a rim 28 that adjoins the recess 24. The rim 28 extends around the entire recess 24. The rim 28 has a contact surface 32 against which the pressing part 23 is pressed during the pressing process against the counter-form 22. The contact surface 32 extends around the entire recess 24.

[0095] Fig. Figure 2 further shows several venting inserts 26, which are arranged distributed around the circumference of the recess 24. The venting inserts 26 are strip-shaped and, during the pressing process, i.e., when the pressing tool 21 is closed, connect the recess 24 to the outside atmosphere. The venting inserts 26 are air-permeable. Furthermore, the venting inserts 26 are liquid-tight. According to the Fig. 2 and Fig. The venting inserts 26 are each formed by a soft foam insert. The venting inserts 26 allow air trapped in the pressing tool 21 during the pressing process to escape, preventing unwanted air inclusions in the insulating panel 10.

[0096] In the device 20 according to Fig. In section 2, the vent inserts 26 are arranged on each longitudinal side of the counter-form 22. Specifically, the vent inserts 26 are arranged on the contact surface 32 of the counter-form 22 and project into the recess 24. The vent inserts 26 abut the circumferential boundary surface 29 of the recess 24. The vent inserts 26 are arranged in a uniformly distributed manner. Specifically, the vent inserts 26 are arranged symmetrically around a central (imaginary) plane of the counter-form 22.

[0097] Fig. Figure 3 shows the counter-form 22 in a first operating position, in which the counter-form 22 is arranged opposite the pressing part 23. In the installed position, the counter-form 22 is arranged below the pressing part 23. The pressing part 23 is movable in the vertical direction V and is arranged horizontally in a fixed position. The counter-form 22 is relatively displaceable in the horizontal direction relative to the pressing part 23. The vertical direction V corresponds to the direction in which the pressing part is moved during operation for pressing and releasing. The horizontal direction H is orthogonal to the vertical direction V.

[0098] The device 20 includes a second operating position to which the counter-form 22 is moved for loading. In the second operating position, the counter-form 22 is horizontally offset from the pressing part 23.

[0099] The pressing part 23 of the pressing tool 21 has a pressing area 25 facing the recess 24. The pressing area 25 forms a pressing surface 33, which defines a second side wall shape 34 of the insulating panel 10 to be formed. In the closed state of the pressing tool 21, the pressing part 23 presses the pressing surface 33 against the contact surface 32 of the counter-form 22.

[0100] The following describes an embodiment of the inventive method for manufacturing the insulating panel according to the invention. Fig. 1 using the device according to Fig. 2 and Fig. 3 described. Initially, the counter-form 22 of the press tool 21 is in the first operating position, i.e., directly opposite the press part 23. The press part 23 is detached from the counter-form 22 and the recess 24 of the counter-form 24 is empty.

[0101] In a first process step, a first plastic film 13' is arranged as a first cover layer 12' in the recess 24 of the counter-mold 22. The first plastic film 13' is drawn against an inner contour of the recess 24, so that it lies flat against the contour without creases. A second plastic film 13' is then arranged as a second cover layer 12' on the pressing area 25 of the molded part 23. The second plastic film 13' is also drawn against the pressing area 25, so that it lies flat against the pressing area 25 without creases. The arrangement of the second plastic film 13' on the pressing area 25 of the molded part 23 can also be carried out at a later time, but must be done before the layers are pressed together.

[0102] Next, the counter-form 22 is moved from the first operating position to the second operating position, whereby, during the movement of the counter-form 22, the first plastic film 13' is covered with liquid polyurethane. Specifically, the first plastic film 13' is covered with liquid polyurethane across its entire width during this process.

[0103] Subsequently, a core layer package, consisting of a heat-insulating core layer 11 and two glass fiber mats pre-arranged on the core layer 11, is inserted into the recess 24. In this process, the first of the two glass fiber mats, in particular the lower one, comes into contact with the liquid polyurethane already introduced.

[0104] After the counter-mold 22 has been loaded with the core layer package, the counter-mold 22 is moved again from the second operating position to the first operating position, whereby a second, in particular the upper, of the two glass fiber mats is covered with the liquid polyurethane during the process. The second glass fiber mat is covered with the liquid polyurethane over the entire width of the core layer package.

[0105] Before the pressing process, several venting inserts 26 are arranged at the edge 28 of the counter-mold 25, as in Fig. 2 and Fig. 3 described how to enable venting of the closed pressing tool 21 during the pressing process.

[0106] In the first operating position, the pressing process now takes place. The pressing part 23 moves in the vertical direction V towards the counter-form 22 and presses the pressing area 25, or the pressing surface 33, against the contact surface 32 of the counter-form 22 in such a way that the core layer package with the liquid polyurethane and the two plastic films 13' is compressed. By pressing together the individual layers 11, 13' and the liquid polyurethane, the trapped air is displaced and discharged to the outside through the venting inserts 26. Venting continues until the liquid polyurethane blocks the venting inserts 26 in the recess 24 and thus seals them.

[0107] The press part 23 exerts a contact pressure until a predetermined curing time for the liquid polyurethane has been reached. Afterwards, the press part 23 is moved in the opposite vertical direction V, thus opening the press tool 21. The insulating panel 10 is now fully formed, with the intermediate layers 14 consisting of the cured polyurethane and the embedded glass fiber mats. The two plastic films 13' are permanently bonded to the core layer 11 by the intermediate layer 14. Reference symbol list 10 insulating panels 11 Core layer 12 top layers 12' first top layer 12" second top layer Slide 13 13' plastic film 14 intermediate layers 15 Side surface of the core layer 20 Device 21 Press tool 22 Opposite form 23 Pressed part 24 Exclusion 25 Pressing area 26 vent insert 27 first side wall shape 28 rand 29 Perimeter boundary area 31 Side wall boundary surface 32 Contact surface 33 Pressing surface 34 second side wall shape H horizontal direction V vertical direction

Claims

[1] Method for manufacturing an insulating panel (10) with a device (20) comprising a press tool (21) with at least one counter-form (22) and at least one press part (23), wherein the counter-form (22) has at least one recess (24) for forming the insulating panel, and the method comprises the following steps: a) Arranging at least one first cover layer (12') in the recess (24) of the counter-mold (22) and arranging at least one second cover layer (12") on a pressing area (25) of the pressing part (23) facing the recess (24); b) Covering the first top layer (12') with at least one liquid plastic material, c) Inserting at least one core layer package consisting of an insulating core (27) with fiber layers arranged on both sides into the recess (24) of the counter-mold (22), such that at least the first of the two fiber layers is in contact with the liquid plastic material; d) Covering the second of the two fiber layers with the liquid plastic material, and e) Pressing the pressed part (23) with the pressing area (25) against the counter-form (22), wherein the core layer package is pressed together with the liquid plastic material and the two cover layers (12', 12") to form the insulating panel, and in which process f) at least one venting insert (26), which serves to remove the air trapped between the counter-mold (22) and the pressing part (23) during the pressing process, is arranged on an edge (28) of the counter-mold (22) adjacent to the recess (24), wherein the venting insert (26) is permeable to air and, in a closed state of the pressing tool (21), connects the recess (24) of the counter-mold (22) to the outside atmosphere, and wherein the venting insert (26) is designed to be liquid-tight, so that it allows trapped air to pass through and retains the liquid plastic material during the pressing process. [2] Method according to claim 1, characterized by , that in step a) the first cover layer (12') is held against the recess (24) of the counter-form (22) and / or in step a) the second cover layer (12") is held against the pressing area (25) of the pressing part (23). [3] Method according to claim 1 or 2, characterized by, that the first cover layer (12') is drawn against the recess (24) of the counter-form (22) and / or the second cover layer (12") is drawn against the pressing area (25) of the pressing part (23), so that the respective cover layer (12', 12") lies flat, in particular without wrinkles. [4] Method according to any one of the preceding claims, characterized by , that the counterform (22) is moved horizontally between two operating positions for loading, with steps a) and e) taking place at the first operating position and step c) taking place at the second operating position. [5] Method according to claim 4, characterized by , that the first top layer (12') is covered, in particular sprayed, with the liquid plastic material when the counter-form (22) is moved from the first to the second operating position. [6] Method according to claim 4 or claim 5, characterized by, that the second fiber layer is covered, in particular sprayed, with the liquid plastic material when the counter-form (22) is moved from the second to the first operating position. [7] Method according to any one of the preceding claims, characterized by , that in step b) the first cover layer (12') is covered with the liquid plastic material over the entire width of the recess (24) of the counter-form (22) and / or in step d) the second fiber layer is covered with the liquid plastic material over the entire width of the insulating core (27). [8] Method according to any one of the preceding claims, characterized by , that in step e) the fiber layers with the liquid plastic material each form an intermediate layer (14) which firmly, in particular indissolubly, connects the respective top layer (12', 12") and the insulating core (27) to form the insulating panel. [9] Method according to any one of the preceding claims, characterized by, that in step e) the pressing area (25) of the pressing part (23) is pressed against the counter-form (22) for a predetermined period of time, in particular curing time, whereby the liquid plastic material cures to form the intermediate layer (14). [10] Method according to any one of the preceding claims, characterized by , that after step e) the pressed part (23) is detached from the counter-form (22), the formed insulating panel is removed from the counter-form (22) and then steps a) to e) are repeated to form another insulating panel. [11] Method according to any of the preceding claims, wherein the at least one liquid plastic material is polyurethane. [12] Method according to any of the preceding claims, wherein the at least one first cover layer (12') is a film (13) and / or wherein the at least one second cover layer (12") is a film (13). [13] Method according to claim 12, wherein the individual fibers of the fiber layer are aligned such that they run predominantly parallel to an associated film (13).

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