WO2011162708A1

WO2011162708A1 - A constructional element, and a method for manufacturing such constructional element

Info

Publication number: WO2011162708A1
Application number: PCT/SE2011/050820
Authority: WO
Inventors: Mikael Olai
Original assignee: Bbi Basic Board Industries Ab
Priority date: 2010-06-22
Filing date: 2011-06-22
Publication date: 2011-12-29
Also published as: EP2585646A1; CN103038427A; EP2585646A4

Abstract

A constructional element is provided. The constructional element comprises two parallel boards of inorganic material being spaced apart by means of a core layer of foam material, wherein each of said boards is attached to said core layer of foam material by means of an adhesive layer, and wherein a third board is attached to one of the boards of inorganic material.

Description

A CONSTRUCTIONAL ELEMENT, AND A METHOD FOR MANUFACTURING SUCH CONSTRUCTIONAL ELEMENT

FIELD OF THE INVENTION

The present invention relates to a constructional element, and a method for manufacturing such constructional element. More particularly, the present invention relates to a self-supporting constructional element having a sandwich structure.

PRIOR ART

Constructional elements are commonly used in building applications to form walls, ceilings or other supporting and isolating structures. Such constructional elements may be manufactured immediately on the building sites, or they may be provided as pre-fabricated modules.

Such pre-fabricated modules include structural insulated panels, often referred to as SIP's, which are formed by two oriented strand boards sandwiching a core of rigid foam plastic insulation. SIP's are known for providing strong, energy efficient and cost effective constructional elements.

However, due to increasing demands on the energy consumption of new houses and buildings, there is a demand for an even more energy efficient and robust constructional element, still providing self-support and being light-weight. Moreover, there is a need for a constructional element allowing the interior area of a house or building to be maximized.

SUMMARY OF THE INVENTION

It is an object of the invention to provide a constructional element that overcomes the above-mentioned drawbacks. Further, an object of the present invention is to provide a constructional element that is resistant to moisture, as well as to provide a constructional element that is resistant to termites and other noxious insects.

An idea is thus to provide a constructional element that acts as an improved climate barrier for a building, while the constructional element is resistant to moisture and mildew. Hence, no organic materials are present whereby the constructional element co-acts as a moisture barrier.

According to a first aspect of the invention, a constructional element is provided. The constructional element comprises two parallel boards of inorganic material being spaced apart by means of a core layer of foam material, wherein each of said boards is attached to said core layer of foam material by means of an adhesive layer, and wherein a third board is attached to one of the boards of inorganic material.

The two boards of inorganic material may comprise MgO which is advantageous in that a cheap and readily available material is used to form

constructional panels showing good building properties.

The third board may be made of gypsum. Hence, the sound insulation and the fire protection is improved.

The foam material may comprise polyurethane and said adhesive layers comprise polyol. Good adhesion as well as improved thermal insulation is thus provided.

The constructional element may further comprise a guiding space arranged within the constructional element for guiding cables and conduits. This is advantageous in that the guiding space may be arranged within the foam material, thus reducing the thickness of the constructional element.

According to a second aspect, a building panel comprising at least two interconnected constructional elements according to the first aspect is provided.

According to a third aspect, a building comprising at least one building panel according to the second aspect is provided.

According to a fourth aspect, a method for providing a constructional element is provided. The method comprises the steps of arranging a first board of inorganic material in a rectangular mold; applying a first adhesive layer onto a planar surface of said first board; arranging a foam distribution onto said adhesive layer; applying a second adhesive layer onto a planar surface of a second board of inorganic material or onto said foam distribution; arranging said second board of inorganic material onto said foam distribution such that said second adhesive layer is arranged between the foam distribution and the second board; and attaching a third board to the first board or the second board.

The foam distribution may have the shape of a rigid board or may be provided in the form of a fluid, in which latter case the method further comprises the step of allowing the foam distribution to harden.

The method may further comprise the step of providing guiding spaces in the form of voids within the foam distribution.

BRIEF DESCRIPTION OF THE DRAWINGS

Hereinafter, the invention will be described with reference to the appended drawings, wherein:

Fig. 1 is a cross-sectional view of a constructional element according to an embodiment;

Fig. 2 is a cross-sectional view of a constructional element according to a further embodiment;

Fig. 3 is a schematic perspective view of a wall assembly comprising a number of constructional elements; and

Fig. 4 is a schematic perspective view of a two-floor building comprising a number of constructional elements.

DESCRIPTION OF EMBODIMENTS

With reference to Fig. 1, a cross-sectional view of a construction element 10 is shown. Two parallel boards of inorganic material, such as MgO 12, 14, are spaced apart by means of a core layer of foam material 16, wherein each of said boards 12, 14 is attached to said core layer of foam material 16 by means of an adhesive layer 18, 20. The core layer 16 is made of polyurethane to some extent, like for example the foam material being distributed by the company Inotan Svenska AB at the date of the present application. Such foam material may also include fire resistant additives, which further improves the properties of the constructional element as well as its suitability for building applications.

The core layer 16 is attached to the boards of MgO 12, 14 by means of an adhesive, forming a layer 18, 20 between the boards 12, 14 and the core layer 16. The adhesive may for example be based on polyol, or any other suitable adhesive known per se may be used.

A gypsum board 22 is arranged adjacent to one of the MgO boards 14 for forming a wall surface facing an interior space. As is shown in Fig. 1, the gypsum board 22 is attached directly to the MgO board 14, e.g. by means of adhesive, screws, bolts, or by any other suitable fastening means.

According to another embodiment being shown in Fig. 2, the gypsum board 22 is attached to the MgO board 14 by means of a plurality of joists 24. The joists 24 are preferably arranged vertically at a distance from each other, wherein the distance corresponds to constructional standards. For example, the distance between two joists 24 may be 45, 60, or 90 cm. The joists 24 may be made by wood or by other suitable materials, such as Al. The constructional element 10 may be provided in different sizes, depending on the application. For example, the dimensions may be 132 * 1200 * 2400 mm, wherein the thickness of each MgO board 12, 14 may be 9 mm. A constructional element according to the particular size is light-weight, resistant to mold and mildew, fire-resistant, and strong.

To this end it should be understood that Figs. 1 and 2 are not to scale.

In further embodiments, the constructional element 10 comprises interior spaces 30 for guiding cables and conduits along the walls. Again with reference to Fig. 1, a space 30 is formed as a hollow cylinder extending within the foam material 16. With reference to Fig. 2, the interior space 30 is formed by the distance between the gypsum board 22 and the adjacent MgO board 14, i.e. the space between the joists 24 and the boards 22, 14.

In a yet further embodiment, the interior space 30 between the the joists 24 and the boards 22, 14 may be filled with insulating material. Hence, further interior guiding spaces may be provided either within the additional insulating material, or in the foam distribution.

In Fig. 3, two constructional elements 10a, 10b are assembled to form a wall structure 100. The two constructional elements 10a, 10b are assembled in an angle, and should thus be represented as a part of a wall of a house or a building.

Each constructional element 10a, 10b has interior spaces 30, 40a, 40b. A first space 30 is formed within the constructional elements 10a, 10b for guiding electrical cables from a power grid to a main socket 32. Consequently, the constructional element 10b has a through hole extending through the gypsum board and the adjacently arranged MgO board to the space 30. The guiding space 30 extends along the constructional elements 10a, 10b, and is branched inside the constructional element 10a for allowing connection to the power transmission line (not shown).

Interior spaces 40a, 40b are also provided for housing cold and hot water conduits, and connectors 42a, 42b are provided on the constructional element 10b. Consequently, through holes extending through the gypsum board and the adjacent MgO board are also provided.

The interior spaces 30, 40a, 40b may be formed between the MgO board and the adjacent gypsum board in case joists are used. In another embodiment, the interior spaces 30, 40a, 40b are formed as 3-dimensional voids within the foam material.

In the embodiment in which the gypsum board is attached directly to the MgO board without the provision of joists, the arrangement of conduits and cables may be as follows: i) the guiding spaces 40a, 40b for water conduits are provided as cavities, or voids, within the foam material of the constructional elements, ii) electrical switches are mounted directly on the gypsum board and made wireless, as is well known in the art, and iii) electrical cables are arranged in the skirting and within voids in the foam material and the main sockets are mounted directly on the gypsum board. For iii), external consoles may be provided for hiding the cables from the skirting to the main sockets.

All cables and conduits in a house or a building may be provided in an efficient manner according to the embodiment described above. This is shown in Fig. 4, wherein two floors of a building 200 are shown. Three different types of pre-manufactured constructional elements are used; a first constructional element 210 having no interior spaces, a second constructional element 212 having an interior space 222 for guiding electrical cables 232, and a third constructional element 214 having interior spaces 224, 225 for guiding water conduits (not shown). The interior spaces 222, 224, and 225 are preferably formed as voids within the foam material of the constructional elements. More preferably, the interior spaces 224, 225 are provided at the construction site. However, they may also be formed as the space obtained between joists and the gypsum board and an adjacent MgO board.

An electrical cable 232 is extending within the constructional elements 212 and may be branched at the interface between two adjacent constructional elements 212.

The electrical cable 232 may then be guided within a skirting 240 that extends along the lower part of the constructional elements 210, 212, 214. Main sockets 242 are provided and mounted directly on the gypsum boards of the constructional elements 210, 212, 214.

The constructional elements 214 are further provided with connectors 244 for connecting equipment to the water conduits inside the spaces 224, 225. Although it may be possible to also arrange the conduit spaces 224, 225 at other angles within the foam material of the constructional elements, vertical arrangement is preferred due to facilitated plumbing.

In another embodiment, a default constructional element is provided having a number of vertical interior spaces extending from the bottom of the constructional panel up to a certain distance from the bottom end, the distance being in the range of 10 to 30 cm. The number of such interior spaces may be e.g. two or three, and they may be connected by means of a recess provided in the foam material along the bottom end of the constructional element. Such constructional element is advantageous in that it provides for a flexible handling, since the positions of the interior spaces define the lateral positions of main sockets. This means that an electrical cable may be guided along the bottom end in the provided recess, and further guided into one of the vertical spaces. A construction worker may then easily drill a hole in the panel at the desired height of the vertical interior space such that the electrical cable may be pulled out and attached to a main socket on the panel.

Specially adapted joints may be provided for connecting the constructional elements to each other. Such joints and/or openings may be designed similar to what has been developed with regards to structural insulated panels, i.e. wall-to-wall panel connections, foundation connections, roof-to-roof panel connections, 2^nd-floor connections, eaves, or wall openings. Preferably, the joints are designed to prevent the formation of thermal bridges within the wall.

In a preferred embodiment, each constructional element comprises a recess in the foam material that extends along the edge of the constructional element. For example, the recess may have the form of a half cylinder being divided along its longitudinal axis. When two constructional elements are being attached to each other, the recesses of each constructional element are aligned and a separate piece having a shape corresponding to the aligned recesses, i.e. a cylinder, is introduced into the closed space formed by the two aligned recesses. The separate piece may for example be made of the same material as the foam material; however other suitable materials known per se may also be contemplated. This embodiment is advantageous in that the risk of thermal bridges is avoided, or at least reduced.

The recesses may have other shapes, such as a V-shape such that a separate piece having an X-shape may be introduced into the aligned recesses. Such embodiment is advantageous in that the separate piece contributes to the attachment of the constructional elements which may be useful during the mounting.

According to a yet further embodiment, the inorganic board facing the outer environment may be covered by an exterior layer, e.g. rendering components such as EPS cladding systems. This is advantageous in that it decreases the risk of humidity in the foam material.

In the following, a method for manufacturing a constructional element will be described. The method comprises a first step of arranging a first board of MgO in a rectangular mold. In this mold, the board of MgO is arranged horizontally. In a next step, a first adhesive layer is applied onto the upper planar surface of board, and a foam distribution is subsequently arranged on the MgO and the adhesive layer. A second adhesive layer is thereafter applied onto a planar surface of a second board of MgO or onto said foam distribution, and the second board of MgO is attached to the foam distribution such that said second adhesive layer is arranged between the foam distribution and the second board.

Preferably, the mold is extending upwards from the first board of MgO such that the second board of MgO is prevented from sliding on top of the core layer. After the adhesive is hardened, the sandwich construction, i.e. the semi-finished

constructional element is removed from the mold.

The foam distribution may have the shape of a rigid board, or the foam distribution may be a fluid. In the latter case, the method further comprises the step of allowing the foam distribution to harden before the second board of MgO is arranged on the core layer.

The method further comprises the step of attaching a board of gypsum to one of the MgO boards. This step may be done either by attaching the gypsum board directly to the MgO board by means of adhesive, screws or similar, or by using joists as intermediate components. This step may be performed at the construction site, or immediately after the second board of MgO has been attached to the core layer of foam material.

In a preferred embodiment the step of arranging the foam distribution comprises forming an interior space within the foam distribution. In case the foam distribution is supplied in the form of a rigid board, the interior space may be formed by drilling through holes in parallel with the MgO boards. On the other hand, if the foam distribution is supplied in the form of a fluid to be hardened, the interior space may be provided by arranging hollow pipes in parallel with the already provided MgO board when the fluid foam is introduced within the mold. The pipes may either be left within the foam material or be drawn out when the foam has hardened.

Claims

1. A constructional element comprising two parallel boards of inorganic material being spaced apart by means of a core layer of foam material, wherein each of said boards is attached to said core layer of foam material by means of an adhesive layer, and wherein a third board is attached to one of the boards of inorganic material.

2. The constructional element according to claim 1, wherein the two boards of inorganic material comprises MgO.

3. The constructional element according to claim 1 or 2, wherein the third board is made of gypsum.

4. The constructional element according to claims 1 to 3, wherein said foam material comprises polyurethane.

5. The constructional element according to any one of claims 1 to 4, wherein said adhesive layers comprise polyol.

6. The constructional element according to any one of claims 1 to 5, further comprising a guiding space arranged within the constructional element for guiding cables and conduits.

7. A building panel, comprising at least two interconnected constructional elements according to any one of claims 1 to 6.

8. A building, comprising at least one building panel according to claim 7.

9. A method for providing a constructional element, comprising the steps of: arranging a first board of inorganic material in a rectangular mold;

applying a first adhesive layer onto a planar surface of said first board;

arranging a foam distribution onto said adhesive layer;

applying a second adhesive layer onto a planar surface of a second board of inorganic material or onto said foam distribution; arranging said second board of inorganic material onto said foam distribution such that said second adhesive layer is arranged between the foam distribution and the second board; and

attaching a third board to the first board or the second board.

10. The method according to claim 9, wherein said foam distribution has the shape of a rigid board.

11. The method according to claim 9, wherein said foam distribution is a fluid and said method further comprises the step of allowing the foam distribution to harden.

12. The method according to any one of claims 9 to 11, further comprising the step of providing guiding spaces in the form of voids within the foam distribution.