EP1219755B1 - Insulating board for façades and process for producing the same - Google Patents

Abstract

An insulating plate (1), especially for bracket-mounted, rear-ventilated facades, comprises a base layer (11) and a covering layer (12), both made of the same bound mineral fibers. The covering layer has a greater strength, especially plug passage strength, than the base layer. The fibers of the mineral wool in the covering layer have a different thickness to the fibers of the base layer. The median value d50 of the fiber diameter of the fibers of the covering layer is about 50-100% greater than that of the fibers of the base layer, producing a reinforced three-dimensional supporting framework in the covering layer increasing the plug passage strength. An Independent claim is also included for a method for manufacturing the above insulating plate. Preferred Features: The median value d50 of the fiber diameter of the covering layer is 6-13, preferably 7-10, especially about 8 mu m. The median value d50 of the fiber diameter of the base layer is 3-6, preferably 4-5, especially about 4 mu m.

Description

The invention relates to a method for producing a facade insulation board according to the preamble of claim 1 and a facade insulation board according to claim 2.

Multilayer insulation boards are currently used primarily as facade insulation panels or roof insulation panels. When used as Fassadenträmmplatten, and in particular for curtain, ventilated facades, these are applied directly to the outer wall of a building. Here, the attachment either by gluing or by dowelling, the insulation boards are used for heat and sound insulation. Insofar as they consist of mineral wool, they are classified in accordance with DIN 4102 in the building material class A as non-combustible.

As weather protection such facade insulation panels often carry a glass fleece, whereby they are classified in the building material class A2. As a cladding for the curtain facade then elements of flat glass, ceramic plates and the like can be used.

When using such insulation boards play in addition to their own weight in particular the wind suction forces an essential role, which can cause a lifting of the insulation panels of the outer wall. Usually, therefore, several so-called insulation dowels are used to fix them. However, since the mineral wool material of the insulation boards is sensitive to punctual force, in this case special precautions must be taken so that on the one hand a reliable hold of the insulating board to the wall and on the other hand continue a good insulation effect can be achieved. So it has been shown that mineral wool slabs are better suited with a higher density, to be held reliably by the insulation dowels. However, this is disadvantageous by a higher material usage, which causes additional costs.

Therefore, it has been transferred in practice to form the insulation boards multi-layered, with a base layer with relatively low bulk density for good insulation properties and a good "snuggling" on the wall, even with protruding concrete or mortar residues, and on the outside of this a cover layer with higher density is trained. Such an insulation board is known for example from DE 37 01 592 A1. In this facade insulation board, the cover layer is subjected to additional compression and possibly an additional binder entry, so that just results in a much higher density than in the base layer, by means of a more or less reliable hold of the insulation board by means of several insulation dowels can be achieved on the wall. The reliability of this structure in practice depends on the following factors:

Basically, the fixation of an insulation board improves with it, the more insulation dowels are used on this plate. However, since the attachment of this insulation dowel is very labor-intensive and the insulation dowel this also represent thermal bridges, one is in practice anxious to get as little as possible insulation dowels used.

In particular, occurs in wind suction loads on the problem that the insulation boards are held only by the heads of the insulation dowels on the wall, which is why areas of the insulation boards, which are far away from the heads of the insulation dowel, under the action of the sea can bend away from the wall. As a result, additional thermal bridges can arise at the abutting edges of the individual insulating boards. To counter this, it is desirable that the cover layer has a relatively high flexural strength, so that the inherent stability of the insulating board opposes these suction forces. These adverse phenomena can be counteracted by increasing the bulk densities in the outer layers, which, however, leads to an increase in price. Nevertheless, it must be striven that sufficient bending stiffness of the cover layer so that it does not bulge when wind suction forces occur. Furthermore, a sufficient Dübeldurchzugsfestigkeit must be ensured.

The applied in practice so far insulation boards therefore represent a compromise, in which the base layer has a relatively low density to develop a high insulation effect, and the cover layer due to an additional compression and possibly an additional binder entry has a high density, the Insulating effect contributes less, but is relatively expensive.

A multilayer board is also known from US 5,342,424. This document discloses a method for producing a product consisting of fiber layers, in particular for use as a filter, which has two different layers or layers, wherein the fibers of the individual layers have different diameters.

Furthermore, EP 0 672 803 A1 discloses a facade insulation board and a production method therefor. In this insulation board, in addition to a layer which consists purely of mineral fibers and binder, a second layer is formed in a common chute, which in addition to mineral fibers and other types, contains additional fibers, thereby improving the mechanical properties of the insulation board.

In addition, WO 99/51535 A1 discloses a mineral wool product improved in terms of the properties of the surface layer (a so-called MMVF fleece), inter alia, for thermal and acoustic insulation and a process for its production. For this purpose, fibers are formed by at least two (cascade) spinner, which have different properties. In this case, the spinners are arranged such that the fleece formed therefrom consists of at least two parallel zones, which are connected to each other. The fleece is then suspended in a subsequent step. For the resulting product, the mean fiber diameters in the zones may be different. Alternatively or additionally, the fiber length, the bead content, the tensile strength, density and / or chemical composition of the fibers may differ from each other.

It is therefore an object of the present invention to improve a method for producing an insulating board, in particular a facade insulation board for curtain, ventilated facades, so that so diverse and optimized in their properties insulation boards can be produced. Another object of the invention is to an insulation board, in particular a facade insulation board for curtain, ventilated façade store to provide that is reliable in commercial dimensions with the least possible use of materials and only a few, especially only one insulation dowel against wind suction and yet inexpensive to attach to the wall.

According to a first aspect of the invention, a method for producing such an insulating board is provided to achieve the object, which has the features of claim 1.

The method according to the invention thus for the first time envisages distributing the melt of a fiber base material to differently operating fiberizing stations and thus forming materially identical primary nonwovens, the fibers having different median values d _{50 of} the diameter. By the method according to the invention, very varied and optimized in their properties can thus produce relatively small procedural changes compared to conventional approaches. Since the method hereby relies on steps that have proven themselves but are newly assembled in this sequence, it is characterized by a high level of process reliability with little preparation effort.

According to a further aspect of the invention, this object is achieved by an insulating board with the features of claim 2. This is particularly characterized in that fibers of the mineral wool in the cover layer have a so-called median d _{50 of} the fiber diameter, which is 50 to 100% larger than that of the fibers of the base layer.

In this case, a median value d _{50 is used} for a distribution function in which particularly asymmetrical distribution curves are present, which is the case with mineral fibers. These distribution curves are known to give the so-called central value or median value. He is the maximum size d ₅₀ , which is less than half of the fiber collective. It is therefore the value of the mean diameter d for which the cumulative curve reaches 50%.

In the case of the abovementioned median value difference of> 50%, it has been advantageously recognized according to the invention that the inherent stability of the insulating board can be significantly increased even with a more cost-effective solution instead of an increase in bulk density, namely the layers having a different average fiber diameter.

This can obviously be attributed to the fact that significantly improved strength properties can be achieved due to the larger average diameter of the fibers in the cover layer, and indeed a reinforced three-dimensional support structure is obtained, which counteracts the dowel pull. At the same time, the bending strength of the cover layer improves by a significant amount, so that the risk of bending of the edge regions of the insulation board is significantly reduced.

The insulation board according to the invention therefore comes with a much smaller number of insulation dowels, with commercial dimensions of, for example, 1250 mm x 600 mm, a single insulation dowel usually sufficient to secure the insulation board reliable. As a result, the costs and installation costs are significantly reduced. At the same time, the number of thermal bridges is reduced by the reduction of the insulating dowels, which also significantly improves the overall insulation properties.

It has further been found according to the invention that this effect already occurs noticeably when the median value d _{50 of} the diameter of the fibers in the cover layer is at least 50% greater than that of the fibers of the mineral wool in the base layer.

Another advantage here is that the mineral wool in the base layer thus has to make a relatively small contribution to the inherent stability of the insulation board, which is why it can be optimized in terms of insulation properties. At the same time, the mineral wool of the base layer can be made sufficiently elastic, thus also of The wall protruding concrete or mortar remnants can be compensated and the main surface of the insulation board nevertheless comes directly into contact with the wall surface.

Since the base and the cover layer are materially the same, there is also a product in which no different materials are combined. This reduces the production costs and also facilitates any recycling or disposal. Finally, this results in no different expansion coefficients, which can lead to a deflection of a multi-layer plate.

Advantageous developments of the insulation board according to the invention will become apparent from the features of the subclaims 3 to 8.

Thus, particularly advantageous properties of the insulating board have been shown when the median d _{50 is} the diameter of the fibers of the cover layer between 6 and 13 microns, while the median d _{50 is} the diameter of the fibers of the base layer between 3 and 6 microns. In these areas, it is possible on the one hand to achieve particularly good insulating properties for the base layer and, on the other hand, to achieve a particularly good strength for the covering layer. In this case, a median d _{50 of} the diameter of the fibers of the cover layer between 7 and 10 microns and in particular at about 8 microns has proven to be particularly advantageous. With regard to the median value d _{50 of} the diameters of the fibers of the base layer, values of between 4 and 5 μm and in particular about 4 μm have been found in practice.

A further improvement of the inherent stability of the cover layer can also be achieved if it has a higher binder content compared to the base layer. In this case, the ratio of the binder content of the cover layer to the binder content of the base layer in a range between 1.1: 1 and 3: 1, whereby the insulation board according to the invention can be further improved in terms of intrinsically conflicting properties of strength and insulating ability.

In particular, it is possible that the binder content in the top layer between 2.2% and 6% and preferably at about 4%, and that the binder content in the base layer between 2% and 5.5% and preferably at about 3 , 5% lies. The insulation board thus produced has been characterized by a particularly good optimization of their properties.

A further improvement of the properties of the insulation board according to the invention can be achieved, although the raw density ratio between the cover layer and the base layer is set specifically. Thus, the ratio of the bulk density of the cover layer to the bulk density of the base layer in a range between 1.25: 1 and 5: 1 and preferably at 1.5: 1, whereby the intrinsic stability and strength of the cover layer can be further increased.

In particular, it is possible in this case that the bulk density of the cover layer between 40 and 100 kg / m ³ and preferably at about 60 kg / m ³ , and that the apparent density of the base layer between 20 and 80 kg / m ³ and preferably at about 40 kg / m ³ . In these crude density ranges, in practice particularly advantageous properties of the insulating board have been demonstrated, both with regard to the good anchor penetration resistance and flexural strength, and also the insulating properties.

In addition, the cover layer may also be precompressed, which further increases their inherent stability.

Fig. 1

eine perspektivische Ansicht eines Ausschnitts einer vorgehängten, hinterlüfteten Fassade, welche durch mehrere erfindungsgemäße Dämmplatten gebildet ist; und

Fig. 2

einen Vertikalschnitt durch die Anordnung gemäß Fig. 1.

The invention will be explained in more detail in exemplary embodiments with reference to the figures of the drawing. It shows:

Fig. 1

a perspective view of a section of a curtain, ventilated facade, which is formed by a plurality of insulation panels according to the invention; and

Fig. 2

a vertical section through the arrangement of FIG. 1st

As shown in the figures, a plurality of insulation plates 1 which are sealed against each other are fastened respectively to a wall 3 by means of an insulating dowel 2. In addition, each insulation board 1 can also be glued to the wall 3. The insulation boards 1 are in this case in the usual dimensions of, for example, 1250 mm x 600 mm and a thickness of 60 mm, 80 mm, 100 mm or 120 mm before.

On the outside of the facade a plurality of clothing elements 4 is also arranged, which are anchored in a known manner by means of anchor 5 through the insulation boards 1 in the wall. Between the insulation boards 1 and the clothing elements 4 while a ventilation gap is present. On the inside of the wall 3 a Innenputzlage 6 is also arranged.

As can be seen in particular from the dashed line in FIG. 2, the insulation boards 1 each have a base layer 11 and a cover layer 12. Furthermore, the insulation dowel 2 passes through the insulation board 1 and anchored to the Wall 3, wherein a head 21 of the per se conventional insulation dowel 2 comes to rest on the outside of the insulation board 1.

In this case, the head 21 cooperates with the cover layer 12, which has a greater anchor pull-through resistance than the base layer 11. In the present example, the cover layer 12 fibers with a median d ₅₀ diameter of about 8 microns, a binder content of 4% and a bulk density of 60 kg / m ³ on. The base layer 11 has fibers with a median d ₅₀ of diameter of about 4 microns, a binder content of 3.5% and a bulk density of 40 kg / m ³ .

The base layer 11 therefore shows good insulation behavior, while the cover layer 12 has a sufficient inherent strength, so that a tearing at the location of the dowel head 21 is reliably avoided in the expected wind suction forces F _SOG . As can be seen in particular from FIG. 2, such suction forces act on the entire surface of the insulating panel 1. Due to the selected characteristics for the cover layer 12, however, deflection in the edge regions of the insulating panels 1 under the action of the suction forces F _{SOG can be} reliably avoided.

For other application examples, these characteristics can be varied. On the basis of the different design of the median value of the fiber diameter of the cover or base layer provided according to the invention, it is additionally possible for the person skilled in the art to adjust the product characteristics of the insulation board 1 via the binder content of the layers or the respective bulk density.

For the production of the insulating panel 1, two different defibration devices from a melting tank with material of the same basic material for the mineral wool, ie applied with the same glass composition. In this case, a fiberization device produces fibers for the cover layer which have a greater thickness, ie a larger median value d _{50 of} the diameter, than the fibers produced by the other fiberization device for the base layer. Furthermore, more binder is added to the fibers in the top layer defibering device in the chute, as is the case with the fibers in the base layer fiberizer.

The overcoat fiberizer provides a uncured binder topcoat primary web which is compressed in a subsequent precompacting step.

Thereafter, the precompacted primary web for the cover layer is combined with the primary web leaving the other fiberizer for the base layer. The two primary nonwovens are then passed through a tunnel oven serving as a curing device for curing of the binder. With this step, the two primary nonwovens are connected to each other at the same time.

The thus formed, multi-layer insulating element is then further processed in a separating device of conventional design, not shown here by means of transverse and / or longitudinal sections to insulation boards 1 with predetermined dimensions.

To set the desired according to the particular application characteristics of the insulation board 1, the fiberizing stations for the individual primary webs can be chosen such that a desired ratio of the median value d ₅₀ of the diameters of the fibers of the cover layer to the median value d ₅₀ of the diameters of the fibers of the base layer providable is , Furthermore, the addition of binder in the chute can also be varied. In addition, the degree of precompression of the primary nonwoven for the cover layer and possibly also precompression of the primary nonwoven for the base layer can influence the achieved density ratio between the cover layer and the base layer.

Since the individual fibers of the cover layer already have improved tensile and compressive strength properties over the fibers of the base layer due to their larger dimensions, it is also possible to design both layers with the same density. The improvement of the properties of the insulation board as regards the anchor pull-through strength is then achieved solely by the more stable fibers in the cover layer.

Claims (8)

1. Method for manufacturing an insulating board (1), comprising the steps:

   - melting fibrous base material in a melting tank (101),

   - dividing the melt into at least two melt strands,

   - supplying one melt strand to a first shredding station (103) for a base layer (11) of the insulating board (1), shredding the melt and producing a primary web, provided with uncured binding agent, for the base layer (11) with fibres, the diameters of which have a predetermined first median value d₅₀,

   - supplying another melt strand to a second shredding station (102) for a cover layer (12) of the insulating board (1), shredding the melt and producing a primary web, provided with uncured binding agent, for the cover layer (12) with fibres, the diameters of which have a predetermined second median value d₅₀ which is greater by 50 to 100% than the first median value of the fibre diameter of the base layer (11),

   - bringing together the primary webs of the base and cover layers,

   - curing the binding agent forming a multilayer insulating element, and

   - separating insulating boards (1) from the insulating element.
2. Insulating board (1), especially for curtain-type, rear-ventilated façades, which can be produced by the method according to claim 1, comprising a base layer (11) and a cover layer (12) which are each formed from physically identical bonded mineral fibres, the cover layer (12) having a greater strength, especially pin-insertion strength, than the base layer (11), fibres of the mineral wool in the cover layer (12) having different thicknesses from the fibres of the base layer (11), specifically in such a way that the median value d₅₀ of the fibre diameters of the fibres of the cover layer (12) is greater by 50 to 100% than that of the fibres of the base layer (11), as a result of which a reinforced three-dimensional support structure is formed to increase the pin-insertion strength.
3. Insulating board according to claim 2, characterised in that the median value d₅₀ of the diameters of the fibres of the cover layer (12) is between 6 and 13 µm, preferably between 7 and 10 µm and especially roughly 8 µm, and
   in that the median value d₅₀ of the diameters of the fibres of the base layer (11) is between 3 and 6 µm, preferably between 4 and 5 µm and especially roughly 4 µm.
4. Insulating board according to claim 2 or 3, characterised in that the cover layer (12) and the base layer (11) have differing binding agent contents, the ratio of the binding agent content of the cover layer (12) to that of the base layer (11) being in a range between 1.1:1 and 3:1.
5. Insulating board according to claim 4, characterised in that the binding agent content in the cover layer (12) is between 2.2% and 6% and preferably approx. 4%, and
   in that the binding agent content in the base layer (11) is between 2% and 5.5% and preferably approx. 3.5%.
6. Insulating board according to one of claims 2 to 5, characterised in that the cover layer (12) and the base layer (11) have a differing bulk density, the ratio of the bulk density of the cover layer (12) to the bulk density of the base layer (11) being in a range between 1.25:1 and 5:1 and preferably about 1.5:1.
7. Insulating board according to claim 6, characterised in that the bulk density of the cover layer (12) is between 40 and 100 kg/m³ and preferably approx. 60 kg/m³, and
   in that the bulk density of the base layer (11) is between 20 and 80 kg/m³ and preferably approx. 40 kg/m³.
8. Insulating board according to one of claims 2 to 7, characterised in that the cover layer (12) is precompressed.

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