METHOD OF MAKING A FLAT BUILDING COMPONENT

Abstract

The invention relates inter alia to a method of making a thin component (10) in lightweight sandwich construction with a high-quality surface (26).

Claims

1. A method of making a thin component in lightweight sandwich construction with a high-quality surface, the method comprising the following steps of: a) providing a film like substrate; b) introducing the substrate into a lower mold part of a mold; c) providing a granular starting material in the form of loose particles of an expandable particle foam; d) completely expanding the particles; h) baking the expanded particles into a curable particle foam that bonds to the substrate; and i) curing the particle foam to form a molded body with the substrate.

2. The method according to claim 1, wherein the substrate is a thermoformed film.

3. The method according to claim 1, further comprising the step of: k) applying a cover layer to a face of the particle foam directed away from the substrate.

4. The method according to claim 1, further comprising the step of: g) processing of the molded body into a component.

5. The method according to claim 2, wherein the film has a wall thickness of between 0.2 mm and 13 mm.

6. The method according to claim 1, wherein the cured particle foam of step i) has a wall thickness of between 1 cm and 30 cm.

7. The method according to claim 1, further comprising the step of: g) the mold forming the component into a vehicle part for a motor vehicle or for a commercial vehicle or for a trailer.

8. The method according to claim 1, wherein the starting material is expandable EPS, PP or PEEK.

9. The method according to claim 1, further comprising, before step h), the step of: m) positioning of reinforcing elements in the lower mold part such that introduction of the expanded particles into the lower mold part encases the reinforcing elements with the expanded particles.

10. A flat component with a high-quality surface made according to claim 1, the component comprising a substrate to which the cured particle foam is bonded.

11. The component according to claim 10, wherein the film has a wall thickness of between 0.2 mm and 13 mm.

12. The component according to claim 10, wherein the cured particle foam has a wall thickness of between 1 cm and 30 cm.

13. The component according to claim 10, wherein the particle foam is expanded against the substrate.

14. The method according to claim 1, wherein in step b) the substrate is introduced into a cavity of the lower mold part, the method further comprising between steps d) and e) the steps of sequentially: e) introducing the completely expanded particles into the cavity of the lower mold part on top of the substrate, f) closing the mold, g) heating the mold.

15. The method according to claim 1, wherein steps d), h) and i) are carried out in a cavity of the lower mold part.

16. The method according to claim 7, wherein the vehicle part is interior design part, cargo space cover, lining part, engine bonnet, roof element or roof segment, vehicle wall, or vehicle wall element.

17. The method according to claim 1, further comprising the step after step i) of: j) opening the mold and removing the molded body therefrom.

Description

[0065] Other advantages of the invention result from the subordinate claims, which are not cited, and by means of the following description of the embodiments depicted in the drawings.

[0066] Therein:

[0067] FIG. 1 shows, in a partially sectional, schematic view, an embodiment of an oven, into which granular starting material in the form of particles of a particle foam is filled, wherein the granular starting material is unexpanded,

[0068] FIG. 2 shows the oven in FIG. 1 with additionally depicted infrared radiation heating, wherein the particles previously poured in are transferred to a completely expanded state,

[0069] FIG. 3 shows a first mold with lower mold part and upper mold part and a film in a web-shaped, flat state designed as a substrate,

[0070] FIG. 4 shows the closed mold in FIG. 3 with thermoformed film,

[0071] FIG. 5 shows another mold, in which the thermoformed film of FIG. 4 is positioned, wherein the completely expanded particles of the particle foam according to FIG. 2 are filled into the lower mold part,

[0072] FIG. 6 shows the mold in FIG. 5 with additionally depicted upper mold part shortly before complete closure of the mold,

[0073] FIG. 7 shows the mold in FIG. 6 in a completely closed state, wherein a heating device for the mold is additionally depicted,

[0074] FIG. 8 shows the mold in FIG. 7 in the open state with baked and cured particle foam mass,

[0075] FIG. 9 shows the molded body removed from the mold in FIG. 8 with an indication of separation lines, along which protruding regions of the substrate are separated,

[0076] FIG. 10 shows another embodiment of a molded body or a component according to the invention formed according to the inventive method with an additional layer on the face of the cured particle foam mass directed away from the substrate,

[0077] FIG. 11 shows another embodiment of a component according to the invention in a depiction according to FIG. 10, wherein the pore structure of the cured particle foam is depicted purely for illustrative purposes in a modified manner compared with FIG. 10,

[0078] FIG. 12 shows another embodiment to illustrate the method according to the invention in a depiction according to FIG. 5, wherein a mold is depicted in an open state, into which completely expanded, loose particles have been filled, wherein the volume of the particles poured into the mold is greater than the volume of the cavity in the mold, and

[0079] FIG. 13 shows, in a depiction according to FIG. 12, the closed mold with compression of the loose, granular expanded particles in FIG. 12 to illustrate a volume reduction achieved in the mold accompanied by the already performed step of baking.

[0080] embodiments of the invention are described by way of example in the following description of the figures, also with reference to the drawings. For the sake of clarity hereeven so far as different embodiments are concernedidentical or comparable parts or elements or regions are designated by the same reference characters, in some cases with the addition of small letters.

[0081] Features that are described, depicted or disclosed only in relation to one embodiment can be provided in the scope of the invention also in any other embodiment of the invention. embodiments modified in such a way are also comprised by the invention, even if they are not depicted in the drawings.

[0082] All disclosed features are themselves essential to the invention. The disclosure content of the associated priority documents (copy of the earlier application) and the cited printed publications and the described devices of the prior art are hereby also fully included in the disclosure of the application, also for the purpose of including individual or multiple features of the subject matters disclosed there in one or more claims of the present application. Such modified embodiments are also comprised by the invention, even if they are not depicted in the drawings.

[0083] embodiments of components that have been made according to the method according to the invention are designated in their totality by 10 in FIGS. 8, 9, 10, 11 and 13.

[0084] The method of making such a component 10 is to be presented below starting out from FIG. 1:

[0085] According to FIG. 1, a container 12 is depicted into which a granulate 11 of a particle foam is filled. The individual granulate particles, which are designated by the reference characters 30a, 30b, 30c as an example, are unexpanded and represent the starting material of making a particle foam. The individual materials that can be used according to the inventive method will be considered in detail elsewhere.

[0086] According to FIG. 2, the container 12 is part of an oven 13, in which the granulate particles 30a, 30b, 30c can be completely expanded:

[0087] To this end a heater 14, in particular an infrared heater 14, is provided, which by the use of infrared rays 15 (indicated) introduces a predetermined radiation output into the oven 13, in order to achieve a certain temperature or a certain temperature range. The granulate particles 30a, 30b, 30c are exposed in the oven 13 to the influence of temperature for a predetermined time, and foam completely. It is recognized that the individual particles 30a, 30b, 30c of FIG. 1 gain considerably in volume and mutate according to FIG. 2 into completely expanded particles 31a, 31b, 31c.

[0088] Let it be noted that the figures should naturally not be understood as being to scale, only that the process of expanding and the volume increases are to be depicted by way of example.

[0089] The completely expanded particles 31a, 31b, 31c are still loose, in particular not joined to one another. During the process of expanding according to FIG. 2, it can be achieved by additional measures, such as shaking the container 12, for example, stirring, the use of chemicals, or introduction of chemicals into the container 12 etc. that the particles 31a, 31b, 31c do not connect to one another or do not mainly connect to one another but are still transportable as a loose, free-flowing or pourable mass. This mass is filled according to FIG. 5 into a lower mold part 23 of a mold 17b.

[0090] The production of the substrate 21 is to be explained first by means of FIGS. 3 to 4:

[0091] According to FIG. 3, a first mold 17 is provided that comprises an upper mold part 18 and a lower mold part 19. The relevant mold parts can be designed as a female mold and a male mold. A film 20 in a flat, web-like state is recognized in FIG. 3, thus in a starting state. FIG. 3 shows the mold in an open state.

[0092] As a result of closing the mold, the film 20 is thermoformed from the flat state. Any spatial contour can be applied to the film by the thermoforming process. The thermoforming process can be supported by temperature in a conventional manner that is not depicted in the figures. Alternatively to the stamping/swaging process of the mold 17 in FIG. 3, blow-molding processes or other forming processes, in which the film is heated and brought into its final form by suction, can be considered for the thermoforming process.

[0093] Following the opening of the mold 17 from the state in FIG. 4, the thermoformed film 21 can be removed and supplied to another mold. Such a second mold 17b is depicted in FIGS. 5 to 8.

[0094] It is also comprised by the invention when the film 21 remains in the lower mold part 19 following the thermoforming process, and only the upper mold part is exchanged. Let it be assumed below that starting out from FIG. 5, the thermoformed film 21 has been introduced into another, second lower mold part 23 of another mold 17b.

[0095] According to FIG. 5, the free-flowing or pourable mass of completely expanded particles 31a, 31b, 31c is introduced into the lower mold part 23 into a cavity 22 that is used to receive the completely expanded particles 31a, 31b, 31c and that faces the rear face 35 of the thermoformed film 21. The second lower mold part 23 and the cavity 22 provided for it can be filled manually or mechanically or aided by machine until a predetermined volume or a predetermined mass of completely expanded particles 31a, 31b, 31c is positioned and in particular also distributed in the cavity 22.

[0096] A delivery or outputting device, not shown in the figures, can be provided here that distributes the particles uniformly along the cavity 22 like a supply head.

[0097] The mold 17b is then closed. To this end an upper mold part 24 is moved starting out from a state according to FIG. 6, in which the mold 17b is still partly open, to a closed state. The cavity 22 is now closed on all sides.

[0098] FIG. 7 indicates a heater 25 that maintains a temperature of the mold 17b, preferably both of the lower mold part 23 and the upper mold part 24. The mold temperature is selected according to the materials used for the particle foam.

[0099] In consequence of the temperature influence and if applicable also in consequence of a pressure influence as a result of closing the mold, the completely expanded particles 31a, 31b, 31c are baked with one another and with the film 21. The baked particle foam mass is formed in particular homogeneously.

[0100] A honeycomb structure is recognizable, only indicated by way of example in FIG. 8. This should likewise only be understood schematically, and is intended to indicate the dimensional stability and the homogeneity: in fact, the structure of the baked particle foam will be formed irregularly. Another comparable structure is shownlikewise purely schematicallyby FIG. 11:

[0101] Here instead of the framework structure of FIG. 8 there is shown an irregular, approximately polygon-like structure in the schematic sectional representation.

[0102] FIG. 8 makes it clear that the completely expanded particles 31a, 31b, 31c according to FIG. 7 are baked to a continuous particle foam mass of a substantially homogeneous nature, wherein no or substantially no further free spaces remain between individual expanded particles 31a, 31b, 31c. FIG. 7, on the other hand, still indicates such free spaces, designated 36 by way of example.

[0103] Let it be noted that even if the overall volume of the expanded particles 31a, 31b, 31c is reduced on baking, or is not or not substantially changed, the contours of the individual particles 31a, 31b, 31c may very well be subjected to changes.

[0104] Following the baking of the particles 31a, 31b, 31c with one another, the baked particles are designated by the reference characters 32a, 32b, 32c by way of example in the embodiments of FIGS. 8, 9, 10, 11 and 13.

[0105] The plurality of the particles 32a, 32b, 32c baked with one another in fact forms a homogeneous particle foam mass 33 overall or a homogeneously expanded particle foam. This can also cure within a short time according to FIG. 8, in particular by cooling of the mold to a temperature below the melting temperature of the particle foam mass, so thatas indicated in FIG. 8the mold can be opened and the upper mold part 24 can be raised from the lower mold part 23. Now the molded body 10 thus formed can be removed from the mold form.

[0106] As a result of the process of bakingin a closed moldthe particle foam bonds durably and firmly to the inside 35 of the molded film 21. A light, bend-proof and load-bearing and yet inexpensively producible composite is provided by this.

[0107] According to FIG. 9, projection regions 34a, 34b of the film 21 can be detached if necessary along the separation lines 29a, 29b.

[0108] The embodiment of FIG. 10 shows the rear face 27 of the component 10 that can be provided with an additional layer 28, e.g. of plastic.

[0109] Comprised by the invention are also components in which, instead of a thermoformed film 21 of ABS or PMMA, a thin film of polyethylene or polypropylene, or in particular also so-called slush skins are used as a substrate.

[0110] The face 26 of the thermoformed film 21 directed away from the cured particle foam mass 33 can form a high-quality surface. Since conventional known and proven materials can be reverted to for the provision of a thermoformed film 21, pertinent surface properties corresponding to those of conventional materials can be achieved.

[0111] It is also comprised by the invention when the surface 26 of the substrate 21 is subjected to separate processing in order to provide a high-quality surface. Thus processing steps such as polishing, lacquering, steaming, roughening, wetting etc. can be considered.

[0112] In FIG. 8 the wall thicknesses W1 of the thermoformed film 21 or of the substrate and W2, namely the wall thickness of the cured particle foam mass 33, are indicated as an example. The wall thickness W1 can be between 0.2 mm and 13 mm, and the wall thickness W2 between 1 cm and 30 cm.

[0113] Comprised in particular by the invention are components that are designed as caravan wall elements. For example, wall sections of a caravan trailer or a caravan, or complete wall elements of a caravan, can be used in automotive construction with the use of the method according to the invention.

[0114] Further comprised by the invention are embodiments that provide that, before filling of the cavity 22 with completely expanded particles 31a, 31b, 31c, reinforcing elements are placed in the cavity 22.

[0115] The reinforcing elements, which are not depicted in the figures, can have e.g. reinforcing fibers. As a result of filling the cavity 22 with completely expanded particles 31a, 31b, 31c, the particles are evenly distributed and encase the reinforcing elements on multiple sides, preferably on all sides. The finished component 10 comprises a cured particle foam mass that securely encloses the reinforcing elements. Due to the positioning of the reinforcing elements, tensile forces in particular can be transmitted and intercepted.

[0116] According to the embodiment in FIG. 12, it is clear that the interior 22 of the mold 17b can have a certain volume. The volume of the expanded particles 31a, 31b, 31c that are introduced into the mold can be greater in the implementation variant in FIGS. 12 and 13, on the other hand. The volume of the particles 31a, 31b, 31c is therefore greater in total than the volume of the cavity 22.

[0117] As a result of closing the mold 17b, thus by completion of a movement towards one another by the upper mold part 24 relative to the lower mold part 23, the loose granular particle foam mass of the expanded particles 31a, 31b, 31c can be compressed, and then the step of baking can be carried out under pressure. A reduction can be achieved here in the volume of the particle foam mass.

[0118] Following the volume reduction, thus after carrying out the step of baking and following curing, the volume of the particle foam mass naturally corresponds to the volume of the interior 22 of the mold.

[0119] FIG. 13 shows the particle foam mass in the baked and cured state, therefore shortly before opening of the mold for the purpose of removing the molded body 10 formed in this way.

[0120] In the embodiment in FIGS. 12 and 13 the mold is overcharged in this respect with expanded particles 31a, 31b, 31c. The degree of overcharging can be between 100% and 150%, for example, advantageously between 105% and 115%, relative to the volume of the interior 22 of the mold 17b.