Fire-retardant panel

Abstract

 Fire-retardant panel, characterized in that it contains a core (1) of foam plastic and an envelope (2) of swelling material in the form of a plate.

Description

[0001] The invention concerns a fire-retardant panel.

[0002] Known fire-retardant panels consist of two walls which are connected to one another at their perimeters and in between which is contained a difficultly flammable and preferably insulating material such as rock wool, chipboard or such. On the sides are provided strips of swelling material, namely a material which swells and forms foam above a certain temperature, for example above 80 to 150°C.

[0003] These panels can form doors or sections of section gates.

[0004] The disadvantage is, however, that these panels are very heavy per unit area. For doors must be used relatively heavy hinges. With section gates, the rails for the sections must be made relatively strong, whereas the length of the sections is very limited in order to prevent them from bending under their own weight.

[0005] The present invention aims to provide a fire-retardant panel which has excellent fire-retardant qualities, but which is extremely light and thus can be used for making doors or sections of section gates without the above-mentioned disadvantages.

[0006] To this aim, the fire-retardant panel according to the invention contains a core of foam plastic and an envelope of swelling material in the form of a plate.

[0007] The foam plastic itself must not be fire-retardant and can be of an ordinary type and thus relatively cheap.

[0008] This foam plastic sticks, preferably in a natural way, to the envelope of swelling material as the synthetic material was injected inside the envelope in a non-foamed or not entirely foamed form and foamed in situ.

[0009] A suitable synthetic material is polyurethane.

[0010] In a special embodiment, the envelope of swelling material is covered at least on the outside of the large sides with a coating.

[0011] Especially in this embodiment, the panel can be used as a leaf or section of a section gate.

[0012] In order to better explain the characteristics of the invention, the following preferred embodiments of a fire-retardant panel according to the invention are described, as an example only without being limitative in any way, with reference to the accompanying drawings, in which:

figure 1 shows a section of a panel according to the invention;

figure 2 shows a section according to line II-II in figure 1;

figure 3 shows a section analogous to that according to figure 2, but for a variant of the embodiment.

[0013] The fire-retardant panel according to figures 1 and 2 consists of a core 1 of plastic foam and an envelope 2 of swelling material.

[0014] The foam plastic of the core 1 is ordinary foam plastic which does not need to be particularly fire-retardant, but which must provide the core 1 sufficient rigidity.

[0015] Suitable synthetic materials are polyurethanes.

[0016] The thickness of the core 1 can vary strongly depending on the application and is situated for example between three and twenty centimetres.

[0017] The swelling material of the envelope is the traditional swelling material which is used nowadays in fire-retardant doors and such and which is applied in the form of a plate.

[0018] Such a swelling material swells and foams when the temperature rises above 80 to 150°C.

[0019] Suitable swelling products are available under the names "Palisol" of BASF and "Interdens" of ETERNIT.

[0020] The envelope 2 must cover the core 1 on all sides. The thickness of the plates of this envelope is situated for example between two and five millimetres.

[0021] The separate plates of swelling material which cover the different sides of the core 1 are secured in relation to one another as they stick to the core.

[0022] This can be done by means of adhesives, but it is preferably the result of the manufacturing method whereby the plates of the envelope 2 are temporarily maintained in their places, for example in a mould, and the synthetic material is injected before the core 1 in a not entirely foamed shape in said envelope 2 and foams in situ.

[0023] Once the plastic foam has cured, it sticks firmly to the plates of the envelope 2.

[0024] If there is a fire on one side of the panel, said plastic foam will burn at a certain temperature, depending on the type of plastic foam of the core 1, but usually below 300°C. However, its place is immediately taken up by the foam formed by the swelling material of the envelope 1, so that the heat-transmission from one side to the other is slowed down.

[0025] The swelling material of the envelope also swells towards the outside and closes off cracks between the panel and neighbouring panels or a frame or a wall.

[0026] The above-described panel does not only have excellent fire-retardant qualities, but is also very light and strong.

[0027] Locally, for example on the large flat sides, or over the entire outer surface can be provided a second plate of swelling material which is glued for example to the innermost plate.

[0028] Instead of this second plate of swelling material, or on top of it, a coating 3 can be provided as represented in figure 3.

[0029] This coating 3 can be made of wood or metal, for example steel or aluminium.

[0030] If basically only the two large sides of the panel are provided with such a coating 3, the narrow sides of the panel at the outside will be mainly formed of swelling material, so that the panel is particularly suitable as a leaf or as a section of a section gate.

[0031] In figure 3, the panel 1-2-3 is represented as a leaf which is mounted, turnable in an opening 5, in a wall 6 by means of hinges 4.

[0032] If during the manufacturing of the panel, synthetic material is injected in the envelope 2, the coating 3 can be part of a mould or formwork in which the envelope 2 is placed or even entirely form this formwork.

[0033] Possibly, the parts of coating 3 can hereby be temporarily held together by means of distance blocks or such.

[0034] The swelling material can be glued to these parts prior to the injection of the synthetic material.

[0035] In this way is obtained a light and solid panel without any heat bridges. Even with a metal coating 3 on either side of the whole which consists of the core 1 and the envelope 2, the panel 1-2-3 has a small weight per unit area of for example 20 to 25 kg/m.

[0036] The present invention is by no means limited to the embodiments described above and represented in the accompanying drawings; on the contrary, such fire-retardant panels can be made in all sorts of variants while still remaining within the scope of the invention.

Claims

1. Fire-retardant panel, characterized in that it contains a core (1) of foam plastic and an envelope (2) of swelling material in the form of a plate.

2. Fire-retardant panel according to claim 1, characterized in that the foam plastic sticks in a natural way to the envelope (2) of the swelling material as the synthetic material was injected inside the envelope (2) in a non-foamed or not entirely foamed form and foamed in situ.

3. Fire-retardant panel according to any of claims 1 and 2, characterized in that the foam plastic is polyurethane.

4. Fire-retardant panel according to claim 1 to 3, characterized in that the envelope (2) of swelling material is covered at least on the outside of the large sides of the panel with a coating (3).

5. Fire-retardant panel according to claim 4, characterized in that the coating (3) is made of metal.

6. Fire-retardant panel according to any of claims 4 and 5, characterized in that in the narrow sides of the panel, swelling material is situated on the outside.

7. Fire-retardant panel according to any of claims 1 to 5, characterized in that it forms a leaf.

8. Fire-retardant panel according to any of claims 1 to 5, characterized in that it forms a section of a section gate.

Drawing