Molded part made of graphite-filled polystyrene and method for its manufacture

Abstract

A molded part, which is designed as a roller shutter box consisting predominantly of graphite-filled polystyrene, wherein the molded part has at least one exposed outer surface, characterized in that the exposed outer surface is formed by a layer (2, 3) of non-graphite-filled polystyrene, which makes up the largest part of the exposed outer surface, wherein at least the flat outer surface of the roller shutter box, which lies on the outside of the building after the roller shutter box has been installed in a building, has the layer of non-graphite-filled polystyrene.

Description

[0001] The present invention relates to molded parts made of graphite-filled polystyrene, wherein the molded part has at least one exposed outer surface and is designed as a roller shutter box. Furthermore, the present invention relates to a method for its production.

[0002] The term “molded part made of graphite-filled polystyrene” is understood to mean a molded part which consists predominantly but not necessarily exclusively of graphite-filled polystyrene.

[0003] For the purposes of this description, an “exposed outer surface” is understood to mean a surface of the molded part which is or may be regularly exposed to intense sunlight or other heat radiation during the intended use of the molded part and / or during its handling and / or storage.

[0004] Graphite-filled polystyrene has been around for some time and is marketed by companies such as BASF under the brand name "Neopor." Graphite-filled polystyrene contains finely dispersed graphite or carbon. In addition to its dark gray, almost metallic color, it offers the advantage over conventional, non-graphite-filled polystyrene, as well as providing even better thermal insulation than regular polystyrene, i.e., polystyrene not filled with graphite particles or a similar substance. This is because thermal radiation is absorbed and / or scattered by small graphite particles in the upper layers of the graphite-filled polystyrene, meaning that thermal or infrared radiation does not penetrate thicker layers as easily as it does with unfilled polystyrene.

[0005] However, the increased absorption of radiant heat also has the disadvantage that the material heats up relatively quickly, particularly in intense sunlight, and may even reach such high temperatures that the polystyrene material is severely degraded and destroyed. Therefore, molded parts made of graphite-filled polystyrene that are intended for use on the exterior of buildings that may be exposed to intense sunlight must be protected from solar radiation, for example, by applying a thin layer of plaster. Even when stored outdoors, and even or especially under protective tarpaulins, such molded parts can be exposed to considerable heat stress, particularly from sunlight, infrared radiation, and thermal radiation from the sun. Therefore, a layer of plaster is often applied prior to installation, i.e.The corresponding pre-formed parts are provided with a thin layer of fine plaster immediately or shortly after production and before installation on a building in order to reduce the direct absorption of thermal radiation in the upper layers of the graphite-filled polystyrene.

[0006] However, this requires considerable additional effort in the production and handling of such molded parts.

[0007] In the case of thermal insulation panels, it is known from CH 699 212 A2 and EP 1 815 077 B1 to use panels with two layers, one layer consisting of white polystyrene and one layer of grey polystyrene, in order to prevent the panels from becoming detached from the facade.

[0008] In contrast to this prior art, the object of the present invention is to provide a molded part made of graphite-filled polystyrene designed as a roller shutter box and a method for its production, by means of which the production as a whole is considerably simplified and made more cost-effective and the products thus manufactured have effective protection against overheating due to thermal radiation.

[0009] With regard to the molded part, this object is achieved by a molded part designed as a roller shutter box, wherein an exposed outer surface of the molded part is formed from a layer of non-graphite-filled polystyrene, which makes up the largest part of the exposed outer surface.

[0010] Preferably, the non-graphite-filled polystyrene surface makes up at least 80 or 90%, and ideally even 100%, of the exposed outer surface.

[0011] With regard to the method, the object underlying the invention is achieved in that a sheet of non-graphite-filled polystyrene is placed against the wall of a foam mold that forms an exposed outer surface of the molded part, the mold is closed and then foamed with graphite-filled polystyrene, and the polystyrene material is bonded in the closed mold by supplying steam to form an integrated molded part. Not only do the graphite-filled polystyrene particles bond to one another, but the graphite-filled polystyrene also bonds to the non-graphite-filled polystyrene, forming a one-piece, coherent molded part, of which at least one exposed outer surface is formed by a layer of non-graphite-filled polystyrene.

[0012] In the case of polystyrene roller shutter boxes, the exposed surfaces are always the surfaces of the molded part facing the exterior of a building. However, the interior surfaces of roller shutter boxes or insulation panels can also be exposed to corresponding solar radiation, for example, during outdoor storage and prior to processing or installation on or in buildings. Therefore, depending on how these parts are handled, the surfaces affected can also be exposed exterior surfaces within the meaning of the present invention.

[0013] However, the invention does not require that every outer surface of a molded part, which could potentially be an exposed outer surface, be formed entirely or partially by a non-graphite-filled polystyrene layer. Rather, it is sufficient for the implementation of the invention if at least one of the outer surfaces of the molded part, which could potentially be an exposed outer surface in the above sense, is formed entirely or partially by a non-graphite-filled polystyrene layer.

[0014] In a preferred embodiment of the invention, the layer not formed from graphite-filled polystyrene is a substantially flat layer. This facilitates production using a polystyrene sheet inserted into a mold, which defines the respective layer in the finished molded part. Since at least thin polystyrene sheets are also more or less bendable, the non-graphite-filled polystyrene layer can alternatively form a concave or convex surface, provided the radius of curvature of this surface is not too small, and is generally, for example, more than 10 cm.

[0015] It is advantageous if the layer consisting of a polystyrene sheet is molded directly onto the surface of a graphite-filled polystyrene part. This is achieved by placing the polystyrene sheet in a mold and then filling the mold with graphite-filled polystyrene particles, followed by hot steam treatment. This causes the individual graphite-filled polystyrene particles to bond to each other, creating a continuous, solid bond at the interface between the polystyrene sheet and the graphite-filled polystyrene particles.

[0016] In addition, the side of the polystyrene plate inserted into the mold facing the graphite-filled surface of the molded part can be structured in order to achieve an even stronger connection with the graphite-filled polystyrene material.

[0017] Furthermore, it is advisable for the exposed outer surface of the non-graphite-filled polystyrene layer to be textured, i.e., with elevations and / or depressions. This is particularly useful if the exposed outer surface is on the outside of a building and this side is also to be plastered, because this way the applied plaster adheres better to the textured polystyrene surface than to a non-textured surface.

[0018] The thickness of the non-graphite-filled polystyrene layer should be between 2 and 10 mm, in particular approximately 5 mm. The applicant has found that a correspondingly thin layer of non-graphite-filled polystyrene is readily sufficient in most cases to prevent overheating and subsequent deformation or degeneration of the graphite-filled polystyrene material beneath the non-graphite-filled polystyrene layer, even in direct sunlight.

[0019] If necessary, the surface area of ​​the non-graphite-filled polystyrene layer can be slightly smaller than the underlying graphite-filled polystyrene surface to be protected. This means that on the exposed side, parts of the graphite-filled polystyrene material, for example, a narrow, elongated strip, are exposed and remain visible on the outer surface. However, it would also be equally possible to provide the outer surface of the non-graphite-filled polystyrene layer with a corresponding identification in the mold, for example, in the form of a specific pattern of indentations or elevations, which serve as a marker for the fact that only the externally visible layer of the roller shutter box or other molded part consists of non-graphite-filled polystyrene, while the interior of the molded body consists entirely of graphite-filled polystyrene.

[0020] With regard to the method, a variant of the invention is therefore preferred in which the polystyrene plate is already placed against a structured wall of the foaming mold, so that the structure of the wall is transferred to the inserted polystyrene plate. For a better bond between the two polystyrene materials, the side of the inserted polystyrene plate facing the interior of the foaming mold can of course also be structured.

[0021] It is understood that, in the case of roller shutter boxes, corresponding thin sheets of non-graphite-filled polystyrene can also be inserted into a mold on both opposite sides of a roller shutter box in order to have an outer polystyrene layer both towards the inside and outside of the building, which protects the underlying graphite-filled polystyrene material from overheating and deformation.

[0022] It is understood that the molded part may also have other integrated components in addition to one or more outer surfaces made of non-graphite-filled polystyrene.

[0023] Roller shutter boxes in particular can have reinforcing sheets or grilles, as well as plaster edges and other connecting elements such as profile strips along the edges of the roller shutter box as well as corresponding bearings for roller shutter shafts and guide elements for roller shutter curtains.

[0024] Further advantages, features and possible applications of the present invention will become clear from the following description of a preferred embodiment and the associated figures. Fig. 1 shows a perspective view of a roller shutter box, partly in section, with a polystyrene layer made of non-graphite-filled polystyrene applied on the outside and the inside and Fig. 2 shows the cross-section of a corresponding roller shutter box.

[0025] How to Fig. 1, the roller shutter box 10 according to the invention consists predominantly of graphite-filled polystyrene material 1, which is formed into a cuboid-shaped box with a U-shaped recess in cross-section for receiving a roller shutter curtain and a roller shutter shaft.

[0026] On the outside of the roller shutter box, designated 4, which is generally essentially flush with the outside of a building, the layer of graphite-filled polystyrene is typically somewhat thinner than on the opposite inside of the roller shutter box, since the roller shutter boxes made of a corresponding heat-insulating material are primarily intended to better protect the interior of the building against heat loss, whereas the roller shutter itself runs on the outside of a window or door and the slit-shaped opening through which the roller shutter passes is in any case connected to the U-shaped cavity which serves to accommodate the roller shutter curtain.

[0027] It goes without saying that the roller shutter box can take on very different cross-sectional shapes and, for example, can be made of polystyrene in one piece and closed except for a narrow gap on the underside, or it can be simply L-shaped or composed of several parts.

[0028] One can also see multiple angled reinforcement plates 7 inside and near the outer walls of the roller shutter box, which primarily serve to increase the rigidity and load-bearing capacity of the roller shutter box and which deliberately extend predominantly only in the vertical direction and have no connection to each other in the horizontal direction in order to avoid the formation of thermal bridges from the inside to the outside or vice versa in the roller shutter box.

[0029] How to use both Fig. 1 as well as in Fig.2, both the outer side 4 and the inner side 5 of the roller shutter box are predominantly formed from a layer 2 or 3, respectively, which consists of non-graphite-filled polystyrene, while the cross-section of the roller shutter box otherwise consists of graphite-filled polystyrene material 1 - apart from the integrated reinforcing sheets 7 and edge profiles 8, 9.

[0030] The lower edges of the roller shutter box are also formed by profile strips or profile rails 8, 9, which, like the panels 2, 3 and the reinforcing elements 7, are inserted into the mold and fixed therein before the mold is filled with polystyrene particles and foamed or fused into an integrated part by hot steam.

[0031] In the illustrated embodiment, the surfaces or (unfilled) polystyrene plates 2, 3 do not extend over the entire outer surface 4 or inner surface 5 of the roller shutter box, but rather a narrow strip at the upper edge of the roller shutter box remains uncoated on both the outer and inner sides, which serves the sole purpose of making visible the fact that the roller shutter box is otherwise and predominantly made of graphite-filled polystyrene material.

[0032] However, these narrow strips do not necessarily have to be present and the polystyrene panels 2, 3 could also be identified by appropriate structuring or labelling on their outer side as parts of a roller shutter box consisting largely of graphite-filled polystyrene material.

[0033] The coating according to the invention, especially on the outside of the roller shutter box, ensures that the graphite-filled polystyrene material does not heat up excessively even in direct sunlight, but is sufficiently insulated so that the material does not degenerate or deform due to the effects of heat.

[0034] At the same time, such roller shutter boxes made of graphite-filled polystyrene material offer the advantage of improved thermal insulation while maintaining the same dimensions. Conversely, compared to conventional roller shutter boxes made of non-graphite-filled polystyrene or another material, the wall thicknesses and overall cross-sectional dimensions of the roller shutter box could be kept smaller without compromising the thermal insulation performance compared to conventional products.

[0035] The advantage of inserting thin polystyrene panels (made of non-graphite-filled polystyrene material) is that the roller shutter box is provided with relatively little effort and is immediately and integrally with its own external thermal insulation, which protects the more sensitive, graphite-filled polystyrene material from excessive exposure to thermal radiation.

[0036] For the purposes of original disclosure, it is pointed out that all features as they become apparent to a person skilled in the art from the present description, the drawings, and the dependent claims, even if they were specifically described only in conjunction with certain other features, can be combined both individually and in any combination with other features or groups of features disclosed herein, unless this has been expressly excluded or technical circumstances make such combinations impossible or pointless. A comprehensive, explicit presentation of all conceivable feature combinations and an emphasis on the independence of the individual features from one another are omitted here solely for the sake of brevity and readability of the description.

Claims

[1] Moulded part which is designed as a roller shutter box consisting predominantly of graphite-filled polystyrene, wherein the moulded part has at least one exposed outer surface, characterized by in that the exposed outer surface is formed by a layer (2, 3) of non-graphite-filled polystyrene which makes up the largest part of the exposed outer surface, wherein at least the flat outer surface of the roller shutter box which lies on the outside of the building after the roller shutter box has been installed in a building has the layer of non-graphite-filled polystyrene. [2] Moulded part according to claim 1, characterized by that the layer (2, 3) is at least a flat layer. [3] Moulded part according to claim 1 or 2, characterized by that the layer consists of a polystyrene plate which is molded directly onto the surface of a graphite-filled polystyrene part. [4] Moulded part according to one of claims 1 to 3, characterized bythat the side of the polystyrene plate facing the graphite-filled surface is structured for a stronger connection with the graphite-filled polystyrene surface. [5] Moulded part according to one of claims 1 to 4, characterized by that the exposed outer surface of the non-graphite-filled polystyrene layer is structured, ie formed with elevations and / or depressions. [6] Moulded part according to one of claims 1 to 5, characterized by that the thickness of the polystyrene layer is between 2 and 10 mm, in particular about 5 mm. [7] A method for producing molded parts according to any one of the preceding claims, wherein the molded part has at least one exposed outer surface, characterized bythat a plate of non-graphite-filled polystyrene is placed on the wall of a foaming mold corresponding to the exposed surface, the foaming mold is closed, foamed with graphite-filled polystyrene and the polystyrene is bonded in the mold by supplying steam to form an integrated molded part. [8] Method according to claim 7, characterized by that the polystyrene plate is placed on a structured wall of the foaming mold. [9] Method according to claim 8 or 9, characterized by that a polystyrene plate is used which is structured on the side facing the interior of the foam mold. [10] Method according to claim 9, characterized by that polystyrene panels are placed on at least two walls of the foaming mold. [11] Method according to one of claims 7 to 10, characterized bythat in addition to at least one polystyrene plate, further components to be integrated into the molded part are arranged in the foam mold.

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