EP3674506B1 - Support element for supporting a window frame - Google Patents

Description

The invention relates to a strip-shaped support element for supporting a window frame, in particular a pre-wall mounting frame.

The invention also relates to a structural section or a building which has at least one support element according to the invention, and to the use of the support element for fire retardancy of a building, e.g. as a fire barrier or to prevent the spread of flames and/or smoke gases upwards along the building facade or in/on a thermal insulation composite system and/or to reduce the temperature rise on a side of the support element facing away from a fire.

Support elements for supporting a window frame, in particular pre-wall mounting frames, have been used for several years in conjunction with thermal insulation composite systems to artificially extend a wall opening for a window outwards. According to EP 2 639 394 A2 A support part made of load-bearing rigid foam is screwed to the side of the wall and serves, particularly on the underside, to support the window frame to be installed. For example, a partition wall forms a gap with the inner wall in which the support element is arranged. The load-bearing support element with a more or less triangular cross-section can be supplemented by an insulating part, which consists, for example, of hard soft foam and together with the support element forms a two-part body with a preferably cuboid cross-section.

EP 2 899 353 A1 provides a support element that enables particularly easy transport and installation. WO 2017/099614 A1 represents a support element according to the preamble of claim 1.

One problem with the use of external thermal insulation composite systems (ETICS), in which pre-wall mounting frames are usually used, is the flammability of the insulating materials often used, which include, for example, polystyrene foam such as expanded polystyrene foam (EPS) or extruded polystyrene foam (XPS). In particular, in the event of a house fire, the flames can spread across the facade or any gaps between the inner wall and the pre-wall to the next floor up, which can create a chimney effect.

WO 2017/077069 describes a functional material that has a thermosetting material such as PUR/PIR or phenolic rigid foam, a binding material for binding the thermosetting material and an additive that is intended to improve the fire behaviour, e.g. expanded graphite. This material is intended to be used, for example, as a thermal insulation element for ETICS, facade insulation or roof insulation, especially as a panel. Coating or impregnation of flammable thermal insulation elements and other construction parts, e.g. sealing tape, with flame retardants is also known in the state of the art, see e.g. EP 3 363 959 A1 , EP 2 963 198 A1 , DE 20 017 102 227 U1 , EP 0 902 062 A1 . DE 20 2012 103 609 U1 describes polystyrene foams that are treated with hexabromocyclododecane (HBCD) as a flame retardant or that are coated with a polyurethane foam shell containing flame retardants such as TCPP (trichloroisopropyl phosphate), TBBPA ester (tetrabromobisphenol ester) or PBDE (pentabromodiphenyl ether).

Fire protection barriers, e.g. made of metal, mineral wool or polymer materials, are already known in the state of the art; their use in thermal insulation is intended to prevent the risk of fire spreading to one of the next higher floors. EP 2 088 253 A shows a fire protection barrier element made of polyurethane foam (PUR foam) and/or polyisocyanurate foam (PIR foam) with a homogeneous density between 26 and 80 kg/m ³ . In Germany, for example, fire protection barriers are required in high-rise buildings every two floors, and in other countries they are sometimes required on every floor.

The present invention is based on the object of improving the fire protection of other structural elements of buildings, e.g. of pre-wall mounting frames, or of contributing to fire protection with the help of such elements already used, in particular in the context of fire barriers.

The invention provides a strip-shaped support element suitable for supporting a window frame with a first longitudinally extending side surface which can be used for bearing against a wall and a second longitudinally extending side surface which runs substantially perpendicular to the first side surface and can be used to support the window frame, wherein the support element is formed from a load-bearing material, and wherein the support element comprises intumescent material on at least one surface in a thickness of at least 10 mm, namely expandable graphite in a proportion of 5-70%.

Expandable graphite can preferably be present in a proportion of 5-20%, more preferably 5-15%. Unless otherwise stated, percentages are always defined as mass/mass in the context of the present invention. Expandable graphite, also called expandable graphite, can be produced from the naturally occurring mineral graphite. A graphite flake consists of layers of carbon atoms arranged in a honeycomb pattern. Within the layers, the atoms are very firmly connected by covalent bonds.

There are only weak binding forces between the layers, so that molecules can be embedded between the graphite layers. By incorporating acids, usually sulfuric acid, graphite is converted into expandable graphite. If expandable graphite is heated, the graphite flakes expand to several times their original volume, depending on the quality, starting at a temperature of around 140°C. The evaporation of the embedded compounds causes the graphite layers to be driven apart like an accordion. The expanded flakes have a "worm-like" appearance and are usually several millimeters long ( Vijay J. Bhagat: Behaviour of expandable graphite as a flameretardant in flexible polyurethane foam Presented at: Polyurethane Foam Association (PFA) Arlington, Virginia, USA, May 10, 2001 ). The expansion rate of expandable graphite is approximately 30-400 cm ³ /g.

The particle size can be between 80% < 75 µm and 80% > 1500 µm. The particle size of the expanded graphite used in the invention is generally over 60% at least 100 µm or at least 500 µm, the average particle size is preferably 500-1500 µm. The larger the particle size, the more expansion pressure is generated in the event of a fire. Large grain sizes (300-1500 µm) are therefore used primarily when a large volume is to be foamed. The particle size can be determined, for example, using a sieve analysis in accordance with DIN 66165.

The starting temperature of the expansion is at least 140°C, preferably at least 160°C, at least 170°C or at least 180°C. The starting temperature of the expansion and expansion rate can be influenced by the fineness of the graphite. When exposed to heat, the expandable graphite expands and forms an intumescent layer on the material surface. This slows down the spread of the fire and counteracts the most dangerous consequences of a fire for humans, the formation of toxic gases and smoke. The proportion of expandable graphite is preferably 5-10%, which is sufficient for the fire-retardant effect. If the proportion of expandable graphite is too high, other negative effects for the desired products come into play, e.g. the high thermal conductivity of graphite ( Öztürk 2012, Highly filled graphite polymer compounds for use in thermal management, dissertation TU Darmstadt ).

It has been found that the use of expanded graphite according to the invention has other advantages in addition to the characteristics that are helpful for fire protection, such as the fact that materials produced with it produce less dust during processing, e.g. when sawing. Materials can therefore also be used to minimize dust formation during processing.

The support element further comprises at least one polymer, preferably thermosetting plastic. A support element with rigid foam, e.g. PUR rigid foam, preferably polyurethane/polyisocyanurate rigid foam, PIT rigid foam or phenolic rigid foam, has particularly good mechanical and thermal insulation properties. In a preferred embodiment, the support element has shredded PUR and/or PIR rigid foam and/or shredded phenolic rigid foam as the thermosetting material, which is bound by a binding material, e.g. liquid or pasty PUR and/or PIR at least when exposed to temperature, preferably also at room temperature (25°C). During production, these components are subjected to temperature and/or pressure, generally both, together with the introduced intumescent material. The particle size of the intumescent material is preferably 0.1-2 times the size of the shredded rigid foam particles, ideally approximately the same size, in order to ensure good miscibility.

Furthermore, fiber materials, e.g. mineral fibers or non-mineral fibers, can be introduced into the starting material before pressing, such as carbon fibers.

In particular, the starting material is pressed in a pressing direction P. Preferably, the starting material, which comprises, for example, expanded graphite, is pressed in a pressing direction P to a bulk density of 500-600 kg/m ^3. In addition to the intumescent material, the support element essentially consists of the polymer, e.g. a PUR/PIR rigid foam as described herein. The proportion of polymer (shredded rigid foam and binding material together) can be, for example, 40-97%, and when combined with expanded graphite, e.g. 70-97%, preferably 80-95% or 90-95%. Since recycled thermal insulation boards can be used as shredded thermosetting material, this can introduce impurities, e.g. film material, such as aluminum, applied to these boards. The support element is preferably halogen-free. The proportion of binding material is usually a maximum of 20%, and the proportion of shredded rigid foam is usually around 60-75%.

Plates produced by the pressing process can be cut into strip-shaped support elements, whereby the production of L-shaped support elements is possible, for example, by milling or by connecting a wider and a narrower element.

In one embodiment, the support element consists of a substantially homogeneous material, i.e. the intumescent material is not only introduced in one or more layers, but continuously, i.e. essentially the whole or the entire support element consists of the mixture with the intumescent material. For example, the support element can consist of a polymer, in particular based on PUR or PUR/PIR, such as a rigid polyurethane foam with expanded graphite (e.g. 5-10%), which can be produced by pressing a starting material by compressing expanded graphite flakes in a polyurethane matrix in a pressing direction P to a bulk density of 500-600 kg/m ^3. In a preferred embodiment, the support element consists of shredded PUR and/or PIR rigid foam which is bound by a binding material, e.g. liquid or pasty PUR and/or PIR. During production, these components, together with the intumescent material, namely expanded graphite, are subjected to pressure and optionally increased temperature in a pressing direction P. The bulk density of the material is, for example, 300-1000 kg/m ³ , 500-600 kg/m ³ , or about 550 kg/m ³ .

Preferably, the material used according to the invention has a fire behavior according to at least a fire reaction class C according to DIN EN 13501-1 and/or corresponding to at least a building material class B1 according to DIN 4102-1 and is therefore considered to be flame-retardant.

The inventors have discovered that in the event of a fire, for example when exposed to flames for 30 minutes at 180°C, the intumescent material expands from a layer approximately 10 mm thick on the side facing the fire and forms an insulating layer. The support element therefore comprises intumescent material on at least one surface with a thickness of at least 10 mm. At least within this thickness, the intumescent material or the particles of intumescent material are distributed essentially homogeneously. In this embodiment, the intumescent material is not coated on the surface of the support element, but embedded in the matrix of the support element.

In a preferred embodiment, at least one layer parallel to the second side surface of the support element comprises the intumescent material, preferably the second side surface of the support element. The second longitudinal side surface of the support element runs essentially perpendicular to the first side surface, which can be used for contact with a wall. The second side surface can be used to support a window frame.

The longitudinal direction is defined by the longest dimension of the strip-shaped element. The strip-shaped element can be present without any connection to other elements, but it can also already be installed, e.g. in a building section, for example as a pre-wall mounting frame for a window or a door.

When installed as a frame, for example as a pre-wall mounting frame, the second side surface of the support element forms the inside of the frame facing the window frame. This means that the surface of this side surface is particularly exposed to flames in the event of a fire, particularly above the window opening, from which flames can erupt in the event of a fire. A fire-retardant or flame-retardant surface according to the invention at this point, which is created by the intumescent effect of the material, e.g. the expansion of the expandable graphite, can thus prevent or at least significantly delay the spread of flames to material located above the window opening, e.g. flammable insulating material of a thermal insulation composite system. Even in the event of a fire that spreads within the thermal insulation composite system, a support element according to the invention thus offers an effective barrier that can prevent or significantly delay further spread upwards.

The expansion of the expanded graphite also effectively prevents the sealing tape, which is generally placed between the casing and the window frame, from having a fire-promoting effect on the side facing the window frame. Any gaps that may arise are sealed by the expansion.

If, alternatively or additionally, a layer parallel to the second side surface of the support element comprises the intumescent material, which is not the second side surface, this is the side facing away from the window opening in the installed state, e.g. the underside of a frame, which also represents an effective horizontal barrier against the upward spread of a fire in or on a building.

Other critical points for the spread of fire are joints that can be located between the frame and an optional pre-wall in the building. Combustible insulating materials located between the wall and the pre-wall can ignite quickly in the event of a fire, and if no further structural measures have been taken, the fire can spread very quickly upwards in this gap. For example, due to different distances between the wall and the pre-wall or to ensure ventilation behind the pre-wall, there are often joints in a building between the frame and Prefabricated walls are often several centimetres wide, e.g. 10-200 mm. According to the invention, the vertical spread of fire through these joints can be prevented or at least significantly delayed. The penetration of smoke through such joints can also be minimised.

According to the invention, the support element can comprise intumescent material on at least one surface, which is a third side surface running in the longitudinal direction, which borders the second side surface on the side opposite the first side surface. The third side surface preferably runs parallel to the first side surface, e.g. in the case of an L-shape of the support element. This side can thus face a prefabricated wall when installed. When the expandable graphite expands on this side surface, a joint potentially located there is advantageously closed, so that the spread of flames through the joint can be prevented. This advantage also applies when the support element is triangular in shape, albeit to a lesser extent depending on the angle.

Preferably, substantially all surfaces (e.g. at least 90% of the area) or all surfaces of the support element comprise the intumescent material. Optionally, the first side surface, which may be used for abutment against a wall, does not comprise any intumescent material, since the wall is generally not made of a combustible material.

The intumescent material can be present in a thickness of 11-50 mm, 12-40 mm, 15-30 mm, or 10-20 mm. The proportion of expandable graphite is then preferably between 5 and 20%.

Preferably, at least all surfaces of the support element other than the first side surface or all surfaces of the support element comprise the intumescent material.

However, as the inventors were able to show, it is not necessarily necessary for intumescent material to be included further inside. The support element can therefore have a layered construction. In one embodiment, the support element comprises at least one layer that has a load-bearing capacity that exceeds the load-bearing capacity of the material on the surface that comprises the intumescent material. Such an internal layer with a high load-bearing capacity can, for example, have a compressive stress at 10% compression according to DIN EN 826 of 2 to 15 MPa, preferably 4 to 8 MPa or particularly preferably 6 to 8 MPa. It can, for example, contain fiber material, such as carbon fibers and/or glass fibers. Otherwise, carbon fibers lose significant load-bearing capacity in the event of a fire, which can be prevented according to the invention. Alternatively, the inner material can have essentially the same load-bearing capacity as the outer material. Optionally, the inner material consists of the same material as the outer layer(s), except for the intumescent material. In this case, the layered structure primarily leads to a reduction in costs, since less intumescent material needs to be used.

A layered construction can be produced by connecting (e.g. gluing, screwing) different layers. However, it is also possible to produce a layered construction by, for example, adding a binding material, e.g. liquid or pasty PUR and/or PIR, to different layers of shredded PUR and/or PIR rigid foam on the outside in the presence and on the inside in the absence of intumescent material (e.g. expanded graphite) and, during production, subjecting them to pressure and optionally increased temperature in a pressing direction P that runs perpendicular to the direction of the layers. The outer layers with intumescent material have a thickness of at least 10 mm. Support elements according to the invention can be produced from panels produced in this way.

The support element is made of a load-bearing material, i.e. it has a total load-bearing capacity or compressive strength that is at least sufficient to support a window. Preferably, the compressive stress at 10% compression according to DIN EN 826 is 2 to 15 MPa, in particular 4 to 8 MPa or 6 to 8 MPa.

As the inventors have determined, the pressing direction P during the production of the raw material for the support element has an influence on the structure of the raw material and thus also on the properties of the support element in the event of a fire. For support elements made of a homogeneous material as well as for layered constructions, different orientations are possible depending on the manufacturing process. In particular, the support element can be designed such that the pressing direction P relevant during production is aligned perpendicular to the first side surface of the support element or that the pressing direction P relevant during production is aligned perpendicular to the second side surface of the support element.

In the context of the invention, it was found that the expansion of the intumescent material on a surface perpendicular to the pressing direction P results in a greater expansion in the event of fire than on a surface parallel to the pressing direction P. The expansion of expandable graphite on a surface perpendicular to the pressing direction P causes, when exposed to flame after 30 minutes, as described herein, expansion of expandable graphite from an approx. 1 cm thick layer on the surface, which leads to the formation of an approx. 8 cm thick insulating layer with expanded graphite. In contrast, expansion of expandable graphite on a surface parallel to the pressing direction P when exposed to flame after 30 minutes, as described herein, leads to expansion of expandable graphite from an approx. 1 cm thick layer on the surface, which leads to the formation of an approx. 4 cm thick insulating layer with expanded graphite.

Therefore, within the scope of the invention, the support element is preferably designed such that the pressing direction P is aligned perpendicular to the second side surface of the support element. The support element can in particular comprise rigid polyurethane foam, preferably with 5-10% expanded graphite, which can be produced by pressing a starting material in which expanded graphite flakes are pressed in a polyurethane and/or polyisocyanurate matrix in a pressing direction P to a bulk density of 500-600 kg/m ³ , wherein the pressing direction P is aligned perpendicular to the second side surface of the support element. In the event of a fire, this has two significant advantages:
Firstly, a particularly thick insulating layer of expanded graphite forms on the surfaces of the support element which, as described herein, are particularly important for fire protection, in particular for preventing the upward spread of flames, and which are aligned parallel to the second surface of the support element. This prevents or at least significantly delays burn-through.

On the other hand, expansion takes place in the direction of the wall and the prefabricated wall, which is sufficient to seal any joints that may be present there. Nevertheless, the expansion and thus the pressure on the wall or prefabricated wall are weaker than if the support element were aligned in the opposite direction. This means that the structural integrity of the adjacent building elements is less stressed. In the event of a fire, there is less movement in the building structure. Cracks in the prefabricated wall, for example, which could cause the fire to spread or parts to fall down, are minimized.

Since the support element according to the invention itself has a good thermal insulation effect, it can be used without additional insulation. However, the support element according to the invention is preferably used together with an insulating part which can be connected to the support element in order to improve the thermal insulation ability. The insulating part is preferably made of foam or mineral wool, preferably of hard soft foam. This foam should preferably be self-supporting. Examples of materials that can be used are thermal insulation materials such as polystyrene, Styrodur, Styrofoam, Styrofoam or Neopur. The insulating part can be made of soft foam, e.g. hard soft foam.

In order to facilitate installation work on site, at least one through hole for receiving a fastening element for fastening the support element to the wall can already be provided through a first leg of the support element, running from the inner side surface to the first side surface. In this way, the craftsman is spared the step of creating the through hole on the construction site.

A geometry that is particularly preferred within the scope of the invention is when the support element is essentially L-shaped in cross section. This ensures that slanted surfaces on the support element are avoided, which make handling more difficult when creating through holes or when inserting fastening elements into the through holes.

In a variant, the support element can also be essentially T-shaped in cross section, or cuboid-shaped.

Typically, the second leg has the second side surface and the first and second side surfaces also intersect at the same angle at which the second leg protrudes from the first leg. This is particularly true for the design of the support element with an L-shaped cross section.

However, it is also possible for the first leg to also have the second side surface, which is then arranged adjacent to the first side surface. This design is inevitable for the support element with a T-shaped cross-section, but can also be present for the support element with an L-shaped cross-section.

In one embodiment, the invention provides a frame, such as a pre-wall mounting frame, comprising support elements according to the invention, each having a surface comprising intumescent material. The frame can be part of a building section.

The invention also relates to a building section with a wall, at least one support element according to the invention arranged laterally from the wall, which is fastened to the wall by means of at least one fastening element, so that the first side surface of the support element rests against the wall, and a window frame which is at least partially supported on the second side surface of the support element.

A building section equipped with support elements according to the invention usually comprises a wall, a partition wall and a gap arranged between the wall and the partition wall. The support elements according to the invention are generally arranged in the gap between the wall and the partition wall and fastened to the wall by means of fastening elements. A window frame is arranged adjacent to the gap and rests on the second side surfaces of the support elements. There can also be just one support element, which is arranged below the window frame and thus bears the weight of the window. As an alternative to the partition wall, a thermal insulation layer attached to the wall can also be provided, which has an opening for a window. The support element then protrudes into this thermal insulation layer. The building section can have a thermal insulation composite system, a ventilated facade or a double-shell masonry.

Preferably, a building according to the invention comprises a building section according to the invention and has a thermal insulation composite system, a ventilated facade or a double-shell masonry and generally at least one window.

A structural section or a building according to the invention can also comprise a plurality of support elements according to the invention. In one embodiment of the structural section, support elements can advantageously be designed to be horizontally continuous, e.g. by connecting them directly to one another. At least one surface of the support element forms a horizontally continuous fire barrier. This can be achieved by designing a substantially horizontally continuous window front that is installed with support elements according to the invention. Alternatively, it is possible to design only one support element to be continuous.

Alternatively, the support elements according to the invention are spaced apart from one another, with a fire-retardant layer being introduced horizontally between the support elements, wherein the layer can comprise mineral wool or another flame-retardant material.

Such fire barriers can be installed on every floor or every second floor of the building.

The invention also relates to the use of a strip-shaped support element or structural section according to the invention for fire protection of a building. In one embodiment, this use serves to prevent or at least significantly delay the spread of flames and/or smoke gases upwards, in particular in thermal insulation composite systems, a ventilated facade or a double-shell masonry.

In another embodiment, this use serves to minimize the temperature rise on a side of the support element facing away from a fire. As described in the example section, it was found within the scope of the invention that the temperature rise on a side of the support element facing away from a fire is significantly lower than with a support element according to the prior art, in particular at joints. Support elements according to the invention can thus be used so that, preferably when exposed to flames (e.g. at 180°C according to DIN 1366-4), the temperature rise at joints between adjacent support elements on the side facing away from the flame is minimized, whereby it is preferably less than 55°C after 25 minutes.

Fig. 1

zeigt Querschnittsansichten einer ersten Ausführungsform des erfindungsgemäßen Stützelements, wobei die untere Darstellung ein Isolierteil während des Verschwenkvorgangs darstellt.

Fig. 2

zeigt eine schematische Querschnittsansicht eines Bauwerksabschnitts, der eine Einbausituation des Stützelements aus Fig. 1 zeigt.

Fig. 3a bis 3e

zeigen Ansichten von alternativen erfindungsgemäßen Stützelementen.

Fig. 3f bis 3h

zeigen Ansichten von nicht erfindungsgemäßen Stützelementen.

Fig. 4a und 4b

zeigen von einer Seite (im Bild oben) für 30 min beflammte Ausführungsformen erfindungsgemäßer Stützelemente mit homogen verteiltem Blähgraphit.

Fig. 5a, 5b und 5c

zeigen das Ergebnis der Beflammungsexperimente an Ausführungsformen erfindungsgemäßer Stützelemente mit homogen verteiltem Blähgraphit mit einer expandierten Graphitschicht auf der beflammten Seite.

Fig. 5d

zeigt den Aufbau der Beflammungsexperimente. Die Pfeile geben die Beflammungsrichtung in verschiedenen Experimenten an.

Fig. 6a und 6b

zeigen die unterschiedliche Bildung von Isolierschichten bei Expansion des Graphits aus einem erfindungsgemäßen Stützelement je nach Ausrichtung zur Pressrichtung.

Further advantages and properties of the support element according to the invention will become apparent from the following description with reference to the drawings.

Fig.1

shows cross-sectional views of a first embodiment of the support element according to the invention, wherein the lower illustration shows an insulating part during the pivoting process.

Fig.2

shows a schematic cross-sectional view of a structural section showing an installation situation of the support element from Fig.1 shows.

Fig. 3a to 3e

show views of alternative support elements according to the invention.

Fig. 3f to 3h

show views of support elements not according to the invention.

Fig. 4a and 4b

show embodiments of support elements according to the invention with homogeneously distributed expandable graphite, flamed from one side (in the picture above) for 30 minutes.

Fig. 5a, 5b and 5c

show the result of the flame experiments on embodiments of support elements according to the invention with homogeneously distributed Expanded graphite with an expanded graphite layer on the flamed side.

Fig. 5d

shows the setup of the flame experiments. The arrows indicate the direction of flame in different experiments.

Fig. 6a and 6b

show the different formation of insulating layers during expansion of the graphite from a support element according to the invention depending on the orientation to the pressing direction.

In Fig.1 a first embodiment of the support element according to the invention for supporting a window frame is shown. The support element 2 is angular in cross section. An insulating part 4 with a cuboid cross section can be connected to the support element 2. The insulating part 4 can also be designed differently or be omitted entirely.

The support element 2 extends primarily in a longitudinal direction. The length of a support element 2 in the longitudinal direction can be freely selected and is preferably between 10 and 150 cm. The support element 2 can be formed in one piece or consist of two parts that are firmly connected to one another. In the embodiment shown, the support element 2 is L-shaped in cross section. The shape of the support element 2 can also be cuboid-shaped or have a beveled surface. The support element 2 is made of a load-bearing material that is suitable for bearing the load of the window frame without deforming.

It is preferred if the material of the support element 2 has a compressive stress at 10% compression according to DIN EN 826 in the range of 2 to 15 MPa, in particular in the range of 4 to 8 MPa. The bulk density of the material should be in the range of 100 to 1,200 kg/m ³ , preferably between 350 and 800 kg/m ³ . The thermal conductivity of the rigid foam material should be in the range of 0.05 to 0.2 W/mK, preferably in the range of 0.06 to 0.15 W/mK. The material is dimensionally stable and compression-stable under the load of the window.

The support element 2 has a first longitudinally extending side surface 6 which is designed to rest against a wall 8 ( Fig.2 ). The first side surface 6 is part of a first leg 10 of the support element 2. The support element 2 also has a second longitudinally extending side surface 12 which is substantially perpendicular to the first side surface 6 and serves to support a window frame 34 ( Fig.2 ). In the embodiment shown, the second side surface 12 is part of a second leg 16 of the support element 2, which is connected to the first leg 10 and protrudes from the first leg 10 at an angle. In the example shown, the angle is 90°. The The first side surface 6 and the second side surface 12 abut one another along an edge and also intersect at the same angle as the two legs 10, 16, i.e. here at 90°. The second side surface 12 and the third side surface 45 also abut one another along an edge and intersect at an angle of 90° in the preferred embodiment shown.

In the first leg 10, one or preferably several through holes 18 can be provided, which allow the passage of one or more fastening elements 20 ( Fig.2 ), for example screws. Each through hole 18 thus runs through the first leg 10 of the support element 2 from an inner side surface 22, which is opposite the first side surface 6, to the first side surface 6. As can be seen from Fig.2 As can be seen, each fastening element 20 serves to fasten the support element 2 to the wall 8.

It is also possible that no through hole 18 is provided in the first leg 10 of the support element 2, but that the through hole is only made on site in the support element 2 by the craftsman.

The insulating part 4 is arranged in the area of the inner side surface 22 of the first leg 10 of the support element 2. It is preferably made of foam or mineral wool, particularly preferably of hard soft foam. As a rule, such foams are self-supporting, but cannot bear any load. Examples of such materials are polystyrene, Styrodur, Styrofoam, Styrofoam or Neopur, with densities < 100 kg/m ³ , preferably < 50 kg/m ³ , which are considered thermal insulation materials. The compressive strength of such thermal insulation materials is preferably at most 50% of the compressive strength of the load-bearing rigid foam preferably used for the support element 2, as a rule less than 20%.

The insulating part 4 is pivotably connected to an outer edge region of the first leg 10 of the support element 2. It can also be pivotably connected to an outer edge region of the second leg 16 of the support element 2. In Fig.1 Above, an insulating position of the insulating part 4 is shown, in which the insulating part 4 at least largely covers the inner side surface 22 of the first leg 10 of the support element 2, in the present case even completely. In this position, the insulating part 4 preferably lies against both the first leg 10 and the second leg 16 of the support element 2. It is particularly preferred if the support element 2 and the insulating part 4 complement each other to form a rectangular cross-sectional shape. The combination of support element 2 and insulating part 4 is preferably also transported in this insulating position.

Fig.1 below shows the pivoting insulating part 4, which is on its way to a working position in which it contacts the inner side surface 22 of the first leg 10 of the support element 2 is at least largely exposed. In the working position of the insulating part 4, the fastening elements 20 can be introduced unhindered into the through holes 18. If there are no through holes 18 in the support element 2, the craftsman also has unhindered access to the first leg 10 of the support element 2 in the working position of the insulating part 4 and can create the through holes 18 there before inserting the fastening elements 20 through the through holes 18 into the wall 8. The swivel angle between the working position and the insulating position of the insulating part 4 is generally between 60 and 120°, but is not subject to any restrictions. The swiveling connection between the insulating part 4 and the support element 2 is preferably formed by a flexible adhesive strip 24 which is glued to both the insulating part 4 and the support element 2. In the Fig.1 In the embodiment shown, the adhesive strip 24 is designed to directly overlap an abutting edge between the support element 2 and the insulating part 4. However, many other arrangements of the adhesive strip 24 are also possible.

In addition to the adhesive strip 24, many other possibilities for implementing the pivoting connection between the insulating part 4 and the support element 2 are also conceivable for the expert. For example, the insulating part 4 and the support element 2 could be connected to one another via another elastic element, the insulating part 4 could also be laminated directly to the support element 2 over a small area, or another mechanical pivoting connection could be implemented between the insulating part 4 and the support element 2.

In the illustrated embodiment Fig.1 a second adhesive strip 26 is also provided, which connects the edge area of the second leg 16 of the support element 2 to the insulating part 4. This adhesive strip 26 should at least be easily detachable from the support element 2, since it must be detached from the support element 2 before the insulating part 4 is pivoted into the working position ( Fig.1 below). Preferably, the adhesive strip 26 is reusable, so that it can be reattached to the support element 2 after the support element 2 has been attached to the wall 8 and the insulating part 4 has been pivoted back into the insulating position. Instead of the second adhesive strip 26, the detachable connection between the insulating part 4 and the second leg 16 of the support element 2 can also be realized in another way.

If the pivotable connection is formed between the second leg 16 of the support element 2 and the insulating part 4, the detachable adhesive connection between the insulating part 4 and the support element 2 is logically present between the insulating part 4 and the first leg 10 of the support element 2.

In principle, however, the pivoting connection between the insulating part 4 and the support element 2 can also be the only connection between these two components. The insulating part 4 should then remain in the insulating position without external influence, for example by being releasably wedged between the inner side of the support element 2, which runs perpendicular to the inner side surface 22, and the pivot connection due to a suitable choice of the size and shape of the support element 2 and the insulating part 4.

The insulating part 4 can also be designed such that the surface of the insulating part 4 arranged adjacent to the inner side surface 22 of the support element 2 provides sufficient space for the parts of the fastening elements 20 that may protrude from the inner side surface 22 (not shown in the drawing).

In Fig. 2 the installation situation of a support element 2 according to the invention is sketched, wherein the orientation of the support element 2 represents the installation situation below the window opening. On the other three sides of the window opening, the support element 2 must be rotated accordingly. The building section 28 shown comprises, in addition to the wall 8 to which the support element 2 is attached by means of the fastening elements 20, usually also a pre-wall 30, which is usually formed by a thermal insulation material. This pre-wall 30 is ventilated from behind and the support element 2 according to the invention is arranged in the gap 32 between the wall 8 and the pre-wall 30. The pre-wall 30 is usually connected to the wall 8 by means of webs, projections or pins. The window frame 34 is usually arranged adjacent to the gap 32 and is supported on the second side surface 12 of the support element 2. Sealing elements 36, for example made of PUR foam, can also be inserted between the window frame 34 and the support element 2. Likewise, sealing elements 38, for example made of PUR foam, can be arranged between the window frame 34 and a projection of the partition wall 30 that projects beyond the height of the support element 2.

The strip-shaped support elements are usually arranged around the entire window opening. However, one or more support elements can also be installed just below the window opening, as this is where the main weight of the window rests.

If the window frame 34 is surrounded on all sides by support elements according to the invention, the one or more support elements on the underside of the window opening will usually be connected to the wall 8 by means of screws or the like. At this point, but especially also on the other sides of the window opening, an adhesive connection between the support element 2 and the wall 8 may be sufficient under certain circumstances. The adhesive connection can also be advantageous in addition to the fastening by means of the fastening elements 20. The adhesive can preferably also serve as a diffusion brake at the same time.

Usually, the length of a support element corresponds exactly to the corresponding length or width of the window opening. However, several support elements can also be lined up on each side of the window opening. As a rule, the individual support elements are mitred and either lie flush against one another or are preferably attached to one another, in particular glued.

In Fig. 3a to 3h Further alternatives of the support elements according to the invention are shown.

The support element 2 made of Fig. 3a corresponds to the support element made of Fig.1 with the difference that there is no insulating part. It is provided with intumescent material throughout. The other described embodiments also lack an insulating part, but it could be present in each case.

The support element 2 made of Fig. 3b corresponds to the support element made of Fig. 3a with the difference that it is not L-shaped in cross section, but wedge-shaped with a bevel on a side facing away from the first side surface 6. The shape of the bevel can be varied as desired. It is also conceivable that the support element 2 is cuboid-shaped in cross section.

The support element 2 made of Fig. 3c corresponds to the support element made of Fig. 3a with the difference that not the entire support element is provided with intumescent material, but only a layer 47 with intumescent material is provided on the second side surface 12. The remaining layer 46 has no intumescent material. The layer 47 is at least 10 mm thick. The intumescent material, namely expanded graphite, is preferably present in layer 47 in a proportion of 5-20%. With this design, a particularly strong expansion of the intumescent material upwards in the direction of the window frame is ensured in the event of a fire.

The support element 2 made of Fig. 3d corresponds to the support element made of Fig. 3c with the difference that the layer 47 with intumescent material is arranged on the third side surface 45, which faces away from the first side surface 6. Otherwise, the same parameters apply to the layer 47 as to Fig. 3c This design ensures that the intumescent material expands particularly strongly to the side (to the right in the picture) in the direction of the pre-wall in the event of a fire.

The support element 2 made of Fig. 3e corresponds to the support element made of Fig. 3c with the difference that a further layer 47 with intumescent material is arranged on the side facing away from the second side surface 12.

The non-inventive support element 2 made of Fig. 3f corresponds to the support element made of Fig. 3c with the difference that the layer 47 with intumescent material is thinner, preferably with a thickness of between 0.25 mm and 10 mm, more preferably between 0.5 mm and 5 mm, even more preferably between 1 mm and 3 mm. If the intumescent material is expandable graphite, it is preferably present in the layer 47 in a proportion of 20-70%, more preferably in a proportion of 30-60%.

The strip-shaped layer 47 with intumescent material in Fig. 3f is fabric-like, foil-like or paper-like. The layer 47 is in its original state preferably in the form of a roll, which is unwound and glued onto the layer 46. In the embodiment according to Fig. 3f In the event of a fire, a particularly strong expansion of the intumescent material upwards towards the window frame is guaranteed.

The non-inventive support element 2 made of Fig. 3g corresponds to the support element made of Fig. 3f with the difference that the layer 47 with intumescent material is arranged on the third side surface 45, which faces away from the first side surface 6. Otherwise, the same parameters apply to the layer 47 as to Fig. 3f This design ensures that the intumescent material expands particularly strongly to the side (to the right in the picture) in the direction of the pre-wall in the event of a fire.

The non-inventive support element 2 made of Fig. 3h corresponds to the support element made of Fig. 3f with the difference that the layer 47 with intumescent material covers only a part of the second side surface 12.

The layer 47 of the embodiment of the Fig. 3d is also with the layers 47 of the embodiment of Fig. 3c or 3e In addition, different thin layers 47 can be combined with different thick layers 47. For example, the thin layer 47 can be made of Fig. 3g with the thick layer 47 of Fig. 3c be combined.

In principle, all side surfaces or any selection of side surfaces can be completely or partially covered with a layer 47 of intumescent material.

The measures taken with regard to Fig. 3b The geometries of the support element 2 described above can also be used in all of these embodiments.

In all of the above-mentioned variants, one or more layers 47 can also extend only over a part of the respective side surface.

Examples of production Example 1A: Support element with water glass

The inert sodium or potassium silicate (10-20%) is mixed with the base material, e.g. a PUR rigid foam or a PUR/PIR rigid foam and optionally one or more additives, e.g. a hardener, to form a homogeneous mass. The mixture is pressed in a mold and cured by heat. Plates can be cut and processed into strip-shaped support elements according to the invention.

Example 1B: Support element with expanded graphite

PUR and/or PIR rigid foam, which has been shredded to a maximum particle size of approx. 5 mm, preferably approx. 1 mm, and which comes from production residues and/or recycled material, e.g. old insulation boards, is mixed with 5-10%, preferably 7.5% expanded graphite (average particle size approx. 1 mm) and PUR-based binding material in a ratio of 1:5, calculated on the mass of the shredded rigid foam, e.g. in liquid form. The mixture is placed in a board mold and subjected to temperature and pressure in a pressing direction P perpendicular to the surface of the boards, so that a rigid foam material with a bulk density of approx. 550 kg/m ³ is produced. The thickness of the boards is preferably 2-7 cm.

Alternatively, shredded rigid foam parts, expanded graphite flakes and binding material can be added alternately in layers (e.g. by sprinkling) and then pressed.

Hardened plates resulting from the pressing process are cut into strip-shaped parts, and L-shaped support elements 2 are produced according to Fig. 3a are produced by connecting a wider and a narrower element, wherein in both elements the pressing direction P is preferably perpendicular to the second surface 12, which is suitable for supporting the window frame 24 (see Fig.1 ). The connection is made by gluing and/or mechanical fastening using nails, screws or metal staples.

Example 1C: Support element with expanded graphite-containing layer

In the Fig. 3c In the alternative embodiment shown, the upper layer 47 of the manufactured plate (ie a surface perpendicular to the pressing direction P) is provided with a thickness of at least 10 mm, preferably 15 mm, of expanded graphite, the remainder of the support element not being expanded graphite.

The strip-shaped support elements are manufactured as described in Example 1B.

Fire tests

According to the test criteria of DIN1366-4, support elements 2 according to the invention made of PUR/PIR rigid foam with expanded graphite, produced according to Example 1B, with a thickness of 30 mm or 50 mm were flame-treated at 180°C (see structure Fig. 5d ) and the temperature increases on the opposite side were measured in comparison to corresponding rigid foam without expanded graphite after 5, 15 and 25 minutes.

On the side facing away from the flame, the temperatures were measured directly on the material after 5, 15 and 25 minutes, in test applications on the ceiling (Table 1-4) and wall (Table 5-6). The measured temperature increases (in Kelvin, starting temperature 23°C) are shown in the following tables (Table 1, 3, 5: measurement on the surface of the elements, Table 2, 4, 6: measurement on the joint).

Ceiling:

Table 1: 30 mm, area Material without expanded graphite Material with expanded graphite Measuring point 3.29 4.03 4.10 4.14 3.01 3.07 3.08 3.14 5min 1 0 1 0 1 1 1 7 15 minutes 15 23 26 2 22 21 24 29 25 min 52 52 52 20 43 43 48 53 Table 2: 30mm on joint without expandable graphite with expandable graphite Measuring point 3.32 4.07 3.04 3.11 5min 4 2 2 10 15 minutes 30 32 17 35 25 min 117 158 45 56 Table 3: 50mm, area Material without expanded graphite Material with expanded graphite Measuring point 4.11 4.17 4.18 4.24 3.15 3.21 3.22 3.28 5min 0 0 0 0 0 0 3 3 15 minutes 1 3 2 2 2 3 4 4 25 min 11 11 17 11 9 9 12 12 Table 4: 50mm on joint without expandable graphite with expandable graphite Measuring point 4.14 4.21 3.18 3.25 5min 1 2 0 3 15 minutes 2 4 3 4 25 min 20 18 12 12

Wall:

Table 5 30mm area Material without expanded graphite Material with expanded graphite Measuring point 1.15 1.21 1.22 1.28 1.29 7.07 7.08 7.14 5min 8th 0 5 1 8th 1 8th 5 15 minutes 19 22 30 20 33 25 30 30 25 min 57 50 52 49 57 44 49 50 Table 6: 30mm on joint without expandable graphite with expandable graphite Measuring point 1.18 1.25 1.32 7.11 5min 2 1 2 3 15 minutes 30 22 30 25 25 min 80 67 50 45

The temperature rise, particularly at the joints, was significantly reduced on both ceilings and walls by the use of expanded graphite in the support elements 2 used. For example, after 25 minutes, the temperature of the rigid foam without expanded graphite on the ceiling rose by an average of 137.5°C at the joint, while for material with expanded graphite the temperature rose by an average of only 50.5°C. On the wall, the temperature of the rigid foam without expanded graphite rose by an average of 73.5°C at the joint, while for material with expanded graphite the temperature rose by an average of only 47.5°C. The temperature rise, particularly at the joints, was therefore significantly reduced by the inventive use of support elements with expanded graphite.

Fig. 4a and 4b show support elements according to the invention with homogeneously distributed expanded graphite with an original thickness of 3 cm that have been exposed to flames from one side (in the picture above) for 30 minutes. 1 cm of the material used in the invention produces a graphite layer of approx. 8 cm.

Fig. 5a to 5c show top views of the flamed side of support elements according to the invention with homogeneously distributed expanded graphite with an expanded graphite layer on the flamed side. In Fig. 5a-5c the arrows point to the joints between adjacent components. Fig. 5d shows the setup of the flame experiments. In Fig. 5d The arrows indicate the direction of flame in different experiments. Depending on the arrangement (cf. Fig. 5d , schematic drawing in the cross-sectional plane), the expanded graphite layer protrudes significantly above the plane of the concrete elements between the support elements, while the element was flush with it before flame exposure (especially Fig. 5b ).

In Fig. 6a On the left is a part of a 30 mm thick support element sawn from one side after 30 minutes of flame exposure, in which the pressing direction P, indicated by the arrow, runs horizontally. The expansion in the pressing direction P is approximately twice as large (approx. 8 cm) as the expansion on the side perpendicular to the pressing direction, here the side exposed to the flames on the right (approx. 4 cm). Fig. 6b shows the sample rotated by 90°C. It was thus determined that the expansion of the intumescent material on a surface perpendicular to the pressing direction P causes a greater expansion in the event of a fire than on a surface parallel to the pressing direction P.

Claims (13)

1. A strip-shaped support element (2) suitable for supporting a window frame (34) with a first side surface (6) extending in a longitudinal direction which can act as an abutment on a wall (8), and a second side surface (12) extending in the longitudinal direction which extends substantially perpendicular to the first side surface (6) and can be used to support the window frame (34), wherein the support element (2) is formed from a load-bearing material,
   characterized in that
   the support element (2) comprises, on at least one surface, an intumescent material, namely expandable graphite in a proportion of 5-70%, with a thickness of at least 10 mm.
2. The strip-shaped support element (2) according to claim 1, characterized in that the support element (2) further comprises rigid foam selected from the group comprising polyurethane rigid foam, preferably polyurethane/polyisocyanurate rigid foam.
3. The strip-shaped support element (2) according to claim 1 or 2, characterized in that at least one layer parallel to the second side surface (12) of the support element (2) comprises intumescent material, preferably the second side surface (12) of the support element.
4. The strip-shaped support element (2) according to any one of the preceding claims, characterized in that the support element (2) comprises intumescent material on at least one surface, which is a third side surface (45) extending in the longitudinal direction adjoining the second side surface (12) on the side opposite the first side surface, wherein the third side surface (45) preferably extends parallel to the first side surface (6) .
5. The strip-shaped support element (2) according to any one of the preceding claims, characterized in that it has a layered construction, wherein it comprises at least one outer layer (47) with intumescent material and at least one layer (46) without intumescent material.
6. The strip-shaped support element (2) according to claim 5, characterized in that the layer (47) with intumescent material is fastened to the layer (46) without intumescent material by adhering and/or screwing.
7. The strip-shaped support element (2) according to any one of claims 1 to 5, characterized in that the intumescent material is expandable graphite in a proportion of 5-20%, preferably in a proportion of 5-10%.
8. The strip-shaped support element (2) according to any one of claims 1 to 4, characterized in that it comprises intumescent material throughout and that the intumescent material is expandable graphite in a proportion of 5-20%, preferably in a proportion of 5-10%.
9. The strip-shaped support element (2) according to claim 8, characterized in that it comprises polyurethane rigid foam with 5-10% expandable graphite, manufacturable by pressing a starting material in which expandable graphite flakes are pressed in a polyurethane and/or polyisocyanurate matrix in a pressing direction P, wherein the pressing direction P is oriented perpendicularly to the second side surface (12) of the support element (2).
10. A section of a building structure (28) comprising a wall (8),

    at least one support element (2) according to any one of the preceding claims arranged laterally to the wall (8) and fastened to the wall (8) by means of at least one fastening element (20), so that the first side surface (6) of the support element (2) rests against the wall (8), and

    a window frame (34) that is supported at least partially by the second side surface (12) of the support element (2) .
11. The section of a building structure (28) according to claim 10, characterized in that it comprises a plurality of support elements (2) according to any one of claims 1 to 9, wherein

    a) support elements (2) are directly connected to one another horizontally, so that the at least one surface that comprises intumescent material forms a horizontally running continuous fire protection barrier and/or

    b) a fire-resistant layer is introduced horizontally between the support elements (2), wherein the layer is selected from the group comprising mineral wool.
12. A building comprising a section of a building structure (28) according to claim 10 or 11, wherein the building preferably has a thermal insulation composite system, a ventilated facade or a cavity wall.
13. Use of a strip-shaped support element (2) according to any one of claims 1 to 9 or a section of a building structure according to claim 10 or 11 as a fire barrier in a building, optionally for reducing the temperature increase on a side of the support element (2) facing away from a fire.

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