FAÇADE SYSTEM AND INSULATION ELEMENT FOR A FAÇADE SYSTEM

Abstract

The disclosure relates to façade system for a building, in particular an External Thermal Insulation Composite System (ETICS), comprising a thermal and/or acoustic insulation, consisting of at least one insulation element being a bonded mineral fibre product made of mineral fibres, preferably stone wool fibres, and a cured aqueous binder composition, whereby the insulation element is fixed to an outer surface of the building by mechanical fastening elements and/or an adhesive, covered with a rendering, and whereby the aqueous binder composition prior to curing comprises a component (i) in form of one or more oxidized lignins, a component (ii) in form of one or more cross-linkers, a component (iii) in form of one or more plasticizers, and whereby the insulation element has a bulk density between 70 kg/m.sup.3 and 150 kg/m.sup.3.

Claims

1. A façade system for a building, in particular an External Thermal Insulation Composite System (ETICS), comprising a thermal and/or acoustic insulation, consisting of at least one insulation element being a bonded mineral fibre product made of mineral fibres, preferably stone wool fibres, and a cured aqueous binder composition, whereby the insulation element is fixed to an outer surface of the building by mechanical fastening elements and/or an adhesive, covered with a rendering, and whereby the aqueous binder composition prior to curing comprises a component (i) in form of one or more oxidized lignins, a component (ii) in form of one or more cross-linkers, a component (iii) in form of one or more plasticizers, and whereby the insulation element has a bulk density between 70 kg/m.sup.3 and 150 kg/m.sup.3.

2. The façade system according to claim 1, whereby the insulation element has a loss on ignition (LOI) within the range of 2 to 8 wt.-%, preferably 2 to 5 wt.-%.

3. The façade system according to claim 1, having insulation elements with a compression strength between 5 and 90 kPa measured in accordance with European Standard EN 826:2013.

4. The façade system according to claim 1, having insulation elements with a delamination strength between 5 and 100 kPa measured in accordance with European Standard EN 1607:2013.

5. The façade system according to claim 1, wherein the component (i) is in form of one or more ammonia-oxidized lignins (AOL's).

6. The façade system according to claim 1, wherein the component (ii) comprises one or more cross-linkers selected from β-hydroxyalkylamide-cross-linkers and/or oxazoline-cross-linkers.

7. Facadc The façade system according to claim 1, wherein the component (ii) comprises one or more cross-linkers selected from the group consisting of polyethylene imine, polyvinyl amine, fatty amines; and/or one more cross-linkers in form of fatty amides; and/or one or more cross-linkers selected from the group consisting of dimethoxyethanal, glycolaldehyde, glyoxalic acid; and/or one or more cross-linkers selected from polyester polyols, such as polycaprolactone; and/or one or more cross-linkers selected from the group consisting of starch, modified starch, CMC; and/or one or more cross-linkers in form of aliphatic multifunctional carbodiimides; and/or one or more cross-linkers selected from melamine based cross-linkers, such as a hexakis(methylmethoxy)melamine (HMMM) based cross-linkers.

8. The façade system according to claim 1, comprising component (ii) in an amount of 1 to 40 wt.-%, such as 4 to 20 wt.-%, such as 6 to 12 wt.-%, based on the dry weight of component (i).

9. The façade system according to any of the claim 1, wherein component (iii) comprises one or more plasticizers selected from the group consisting of polyethylene glycols, polyethylene glycol ethers, polyethers, hydrogenated sugars, phthalates and/or acids, such as adipic acid, vanillic acid, lactic acid and/or ferullic acid, acrylic polymers, polyvinyl alcohol, polyurethane dispersions, ethylene carbonate, propylene carbonate, lactones, lactams, lactides, acrylic based polymers with free carboxy groups and/or polyurethane dispersions with free carboxy groups.

10. The façade system according to claim 1, wherein component (iii) comprises one or more plasticizers selected from the group consisting of fatty alcohols, monohydroxy alcohols, such as pentanol, stearyl alcohol; and/or one or more plasticizers selected from the group consisting of alkoxylates such as ethoxylates, such as butanol ethoxylates, such as butoxytriglycol; and/or one or more plasticizers in form of propylene glycols; and/or one or more plasticizers in form of glycol esters; and/or one or more plasticizers selected from the group consisting of adipates, acetates, benzoates, cyclobenzoates, citrates, stearates, sorbates, sebacates, azelates, butyrates, valerates; and/or one or more plasticizers selected from the group consisting of phenol derivatives, such as alkyl or aryl substituted phenols; and/or one or more plasticizers selected from the group consisting of silanols, siloxanes; and/or one or more plasticizers selected from the group consisting of sulfates such as alkyl sulfates, sulfonates such as alkyl aryl sulfonates such as alkyl and/or sulfonates, phosphates such as tripolyphosphates; and/or one or more plasticizers in form of hydroxy acids; and/or one or more plasticizers selected from the group consisting of monomeric amides, such as acetam ides, benzamide, fatty acid amides such as tall oil amides; and/or one or more plasticizers selected from the group consisting of quaternary ammonium compounds such as trimethylglycine, distearyldimethylammoniumchloride; and/or one or more plasticizers selected from the group consisting of vegetable oils such as castor oil, palm oil, linseed oil, tall oil, soybean oil; and/or one or more plasticizers selected from the group consisting of hydrogenated oils, acetylated oils; and/or one or more plasticizers selected from acid methyl esters; and/or one or more plasticizers selected from the group consisting of alkyl polyglucosides, gluconam ides, am inoglucoseam ides, sucrose esters, sorbitan esters; and/or one or more plasticizers selected from the group consisting of polyethylene glycols, polyethylene glycol ethers.

11. The façade system according to claim 1, wherein the component (iii) is present in an amount of 0.5 to 50, preferably 2.5 to 25, more preferably 3 to 15 wt.-%, based on the dry weight of component (i).

12. The façade system according to claim 1, comprising a further component (iv) in form of one or more coupling agents, such as organofunctional silanes in the binder.

13. The façade system according to claim 1, further comprising a component (v) in form of one or more components selected from the group of ammonia, amines or any salts thereof in the binder.

14. The façade system according to claim 1, comprising a further component in form of urea in the binder, in particular in an amount 5 to 40 wt.-%, such as 10 to 30 wt.-%, such as 15 to 25 wt.-%, based on the dry weight of component (i).

15. The façade system according to claim 1, whereby the binder consists essentially of a component (i) in form of one or more oxidized lignins; a component (ii) in form of one or more cross-linkers; a component (iii) in form of one or more plasticizers; a component (iv) in form of one or more coupling agents, such as organofunctional silanes; optionally a component in form of one or more compounds selected from the group of ammonia, amines or any salts thereof; optionally a component in form of urea; optionally a component in form of a more reactive or non-reactive silicones; optionally a hydrocarbon oil; optionally one or more surface active agents; water.

16. An insulation element for a façade system according to claim 1, made of mineral fibres, preferably stone wool fibres, and an aqueous binder composition, whereby the aqueous binder composition prior to curing comprises a component (i) in form of one or more oxidized lignins, a component (ii) in form of one or more cross-linkers, a component (iii) in form of one or more plasticizers and whereby the insulation element has a bulk density between 70 kg/m.sup.3 and 150 kg/m.sup.3.

17. (canceled)

Description

DRAWINGS

[0418] The drawings described herein are for illustrative purposes only of selected embodiments and not all possible implementations, and are not intended to limit the scope of the present disclosure.

[0419] The disclosure is illustrated in the accompanying drawings in which

[0420] FIG. 1 shows a first embodiment of a facade system according to the disclosure;

[0421] FIG. 2 shows a diagram showing the delamination strength of an insulation element used in an ETICS compared to the delamination strength of an insulation element according to the prior art;

[0422] FIG. 3 shows a diagram showing the delamination strength of an insulation element used in an ETICS after ageing compared to the delamination strength of an insulation element according to the prior art after ageing;

[0423] FIG. 4 shows a diagram showing the compression strength of an insulation element used in an ETICS compared to the compression strength of an insulation element according to the prior art;

[0424] FIG. 5 shows a diagram showing the compression strength of an insulation element used in an ETICS after ageing compared to the compression strength of an insulation element according to the prior art after ageing

[0425] FIG. 6 shows a second embodiment of a mounted insulation element being part of an ETICS according to the present disclosure;

[0426] FIG. 7 shows a third embodiment of a mounted insulation element being part of an ETICS according to the present disclosure;

[0427] FIG. 8 shows a fourth embodiment of a mounted insulation element being part of an ETICS according to the present disclosure;

[0428] FIG. 9 shows a fifth embodiment of a mounted insulation element being part of an ETICS according to the present disclosure; and

[0429] FIG. 10 shows a sixth embodiment of a mounted insulation element being part of an ETICS according to the present disclosure;

[0430] FIG. 11 shows a section from a possible lignin structure;

[0431] FIG. 12 shows different lignin precursors and common interunit linkages;

[0432] FIG. 13 illustrates the at least four groups of technical lignins available in the market;

[0433] FIG. 14 shows a summary of the properties of the technical lignins.

[0434] Corresponding reference numerals indicate corresponding parts throughout the several views of the drawings.

DETAILED DESCRIPTION

[0435] Example embodiments will now be described more fully with reference to the accompanying drawings.

[0436] FIGS. 1 and 6 to 10 show different embodiments of façade systems (ETICS) according to the disclosure each comprising a thermal and/or acoustic insulation of at least one insulation element, mechanical fasteners 4 and a rendering 13 (not shown in FIGS. 7 to 10). The insulation element comprises at least a bonded mineral fibre or mineral wool product made from mineral fibres and a binder. In the following said insulation element is also referred to as mineral wool insulation plate 2, or insulation plate 2, or insulating composite plate 12 containing mineral wool and aerogel. Other embodiments of the insulation element comprise a plate 3 representing an aerogel particle fibre composite, further below also referred to as aerogel containing plate 3.

[0437] A first embodiment of a façade system is shown in FIG. 1 represented by an insulation sub-system 1 as a part of the ETICS comprising a mineral wool insulation plate 2 at a building wall 5 and mounted by a mechanical fastener 4 into the building wall 5 holding the insulation plate 2. The insulation plate 2 is glued (not shown) to the wall 5. The part of the ETICS is shown in cross section displaying the mechanical fastener 4. The mechanical fastener 4 is a polyamide based hollow dowel 7 with a metal screw 6 inserted in the hollow dowel 7. The dowel 7 has a head 8 in shape of a round plate with a diameter of preferably around 90 mm. The head 8 exerts a pressure on the surface of the insulation plate 2 and there is a slight indentation 9 into the surface due to the static hold force of the mounted screw 6. The total system of fastener 4 and insulation plate 2 forming an insulation sub-system which is mechanically rigid and resistant to wind loads.

[0438] The insulation shown in FIG. 1 consists of insulation plates 2 made from mineral wool and each having a rectangular major surface onto which a rendering is applied. The rendering 13 is made from two layers of mortar and the layer being in direct contact to the insulation plate is a so-called base coat.

[0439] Instead of a one layered insulation plate 2 multilayered insulation plates can be used, each having at least two layers of different density. These insulation plates are so-called dual-density plates and are shown in a second embodiment according to FIG. 6.

[0440] The insulation plate 2 may also be a mineral wool lamella plate which consists of several lamellas of mineral wool glued together in their length direction to form the plate and where the mineral fibre direction is predominantly perpendicular to the major surface as is conventional for such mineral wool lamella plates. The thickness is 100 mm and the width by length is 400 by 1200 mm and the density of the mineral wool plate is 75 kg/m.sup.3.

[0441] A plate 3 (FIG. 6) can be present, representing an aerogel particle fibre composite comprising stone fibres, aerogel particles and a means for binding the constituents and covering the insulation plate 2.

[0442] FIG. 6 shows an insulation sub-system like in FIG. 1 with the amendment that the insulation plate 2 shown in FIG. 6 is a dual density mineral wool plate which has a surface layer 10 of about 20 mm thickness of a compacted mineral wool layer with a density of about 160 kg/m.sup.3 and a layer 11 of about 120 mm thickness of mineral wool layer with a density of about 90 kg/m.sup.3; the layer 11 with the lower density is facing the wall 5 and the layer 10 with the higher density is facing the plate 3. The plate 3 improves the thermal performance of the ETICS and may be connected to insulation plate 2 by using an adhesive which might be the binder used in the insulation plate 2. Furthermore, the binder used in the plate 3 being a matrix of mineral fibres and additives, such as aerogel particles, can be identical with the binder used in the insulation plate 2. The plate 3 increases the insulation properties of the ETICS. Plate 3 can be connected to the insulation plate 2 by an adhesive which can be the binder used in the insulation plate 2.

[0443] FIG. 7 shows an insulation sub-system comprising an plate 3 provided on the building wall 5 and arranging a insulation plate 2 on top of the plate 3 and mounting a mechanical fastener 4 into the wall 5 holding both the plates 2, 3; the plate 3 is glued (not shown) to the wall 5 and can be identical to the plate 3 according to FIG. 6. The part of the ETICS is shown in cross section displaying the mechanical fastener 4. The mechanical fastener 4 is a polyamide based hollow dowel 4 with a metal screw 6 inserted in the hollow element 7 and the dowel 4 has a head 8 in shape of a round plate with a diameter of preferably around 60 mm. The head 8 exerts a pressure on the surface of the insulation plate 2 and there is an indentation 9 into the surface due to the static hold force of the mounted screw 6 and the mineral wool of the insulation plate 2 is compressed between the fastener head 8 and the surface of the aerogel containing plate 3. The total system of fasteners, insulation plate 2 and plate 3 is mechanically rigid and has improved properties over a sub-system exclusively consisting of mineral wool plates; the pull-through resistance is in particular improved and the insulation plate 2 provides a mechanical protection to the aerogel containing plate 3 due to its resilient characteristics.

[0444] The insulation shown in FIG. 7 consists of two plates 2, 3 each having a rectangular major surface of substantially the same length and width as the other plate 2, 3 and where the two plates 2, 3 are being placed commensurate so that the two plates 2, 3 substantially exactly cover each other. The insulation plate 2 is in this example a mineral wool laminar plate of the stone wool type where the mineral fibre direction is predominantly parallel to the major surface. The thickness of the insulation plate 2 is 40 mm and the width by length is 625 by 800 mm and the density of the insulation plate is 120 kg/m.sup.3. The aerogel containing plate 3 is in this example an aerogel matrix composite comprising polymer fibres in an aerogel matrix.

[0445] FIG. 8 shows an insulation sub-system 1 like in FIG. 7 with the amendment that the insulation plate 2 shown in FIG. 7 is a dual density insulation plate 2 of the stone wool type shown in FIG. 6, too, which has a surface layer 10 of about 20 mm thickness of a compacted mineral wool layer with a density of about 160 kg/m.sup.3 and a layer 11 of about 60 mm thickness of mineral wool layer with a density of about 90 kg/m.sup.3; the layer 11 with the lower density is facing outwards.

[0446] FIG. 9 shows an insulation sub-system 1 comprising an insulation plate 2 of mineral wool at the building wall 5 and arranging an aerogel containing plate 3 on top of the insulation plate 2 and arranging a further insulation plate 2 on top of the aerogel containing plate 3; the three plates 2, 3 are mounted with a mechanical fastener 4 into the wall 5 holding the plates 2, 3. Additionally the insulation plate 2 can be connected to the wall 5 by an adhesive and further adhesives can be present between the insulation plates 2 and the plate 3. Such adhesive can be the binder used in the insulation plate 2. The part of the ETICS is shown in cross section displaying the mechanical fastener 4. The mechanical fastener 4 is a polyamide based hollow dowel 7 with a metal screw 6 inserted in the hollow dowel 7 and the dowel 7 has a head 8 in shape of a round plate with a diameter of preferably around 60 mm.

[0447] The head 8 exerts a pressure on the surface of the insulation plate 2 and there is an indentation 9 into the surface due to the static hold force of the mounted screw and the mineral wool of insulation plate 2 is compressed between the fastener head 8 and the surface of the plate 3.

[0448] The total system of fasteners 4, the sandwich of the aerogel and mineral fibres containing plate 3 and the two outside layered insulation plates 2 is mechanically rigid and has improved properties over a sub-system exclusively consisting of mineral wool plates; the pull-through resistance is in particular improved but also the overall weight is lowered.

[0449] The insulation shown in FIG. 9 consists of three plates 2, 3 all having a rectangular major surface of substantially the same length and width as the other plates 2, 3 and where the three plates 2, 3 are being placed commensurate so that the three plates substantially exactly cover each other. The insulation plates 2 are in this example mineral wool laminar plates of the stone wool type where the mineral fibre direction is predominantly parallel to the major surfaces. The thickness is 80 mm and the width by length is 625 by 800 mm and the density of the mineral wool plate 2 is 100 kg/m.sup.3. The plate 3 is in this example an aerogel particle fibre composite comprising aerogel particles and a means for binding the constituents.

[0450] FIG. 10 shows an insulation sub-system 1 comprising an insulating composite plate 12 containing mineral wool and aerogel; the plate is mounted with a mechanical fastener 4 into the wall 5 holding the composite plate 12. The part of the ETICS is shown in cross section displaying the mechanical fastener 4. The mechanical fastener 4 is a polyamide based hollow dowel 7 with a metal screw 6 inserted in the hollow dowel 7 and the dowel 7 has a head 8 in shape of a round plate with a diameter of preferably around 60 mm.

[0451] The head 8 exerts a pressure on the surface of the composite plate 12 and there is an indentation 9 into the surface due to the static hold force of the mounted screw 6 and the composite plate 12 is compressed between the fastener head 8 and the surface of the composite plate 12.

[0452] The total system of fasteners 4, mineral wool-aerogel-composite plate 12 is mechanically rigid and has improved properties over a sub-system exclusively consisting of mineral wool; the pull-through resistance is in particular improved but also the overall weight is lowered.

[0453] The insulation shown in FIG. 10 has a rectangular major surface. The thickness is 120 mm and the width by length is 625 by 800 mm and the density of the composite plate 12 is 100 kg/m.sup.3.

[0454] The binder used in the insulation element 2, 3, 12 and/or for the connection of the insulation elements 2, 3, 12 to each other comprises a first component in form of one or more ammonia-oxidized lignins.

[0455] The diagram according to FIG. 2 shows absolute values of the delamination strength of an insulation element according to the disclosure (graph C.sub.2) compared with the delamination strength of an insulation element containing one of the assignees prior art non-added formaldehyde binder shown in graph B.sub.2 and the delamination strength of an insulation element containing traditional phenol-urea-formaldehyde binder shown in graph A.sub.2.

[0456] The delamination strength is measured according to EN 1607:2013 and the first initial measurement is carried out on unaged samples immediately or shortly after production of the insulation element. This initial testing and the respective average result of a representative number of samples is illustrated at time ‘0’ on the x-axis of the diagram. Said time ‘0’ corresponds with day ‘0’ respectively the start of the accelerated ageing test according to the following description below.

[0457] In order to determine the ageing resistance of mineral fibre products exposed to moisture and heating during the service life of constructions, such mineral fibre products with focus on mechanical properties are subjected to accelerated ageing. The ageing resistance is defined as the ability of the product to maintain the original mechanical properties, and it is calculated as the aged strength in per cent of the original strength. The test procedure follows the so called Nordtest method NT Build 434: 1995.05, extended to 28 days. The aim of said method is to expose insulation materials to accelerated ageing due to increased temperature and heat. It is applicable to all insulation materials manufactured as insulation boards. The method is not predictive i.e. it is not intended for assessment of the service life, but it is a precondition for a satisfactory performance that ageing due to this method does not cause major changes in the properties of the materials under investigation. Experiences over more than two decades with the Nordtest method have proven to deliver reliable data to ensure satisfactory mechanical performance of inter alia mineral fibre products as insulation elements for use in facade systems.

[0458] According to the method, a representative number of test specimens are exposed to heat-moisture action for 7, 14 and 28 days at 70±2° C. and 95±5% relative humidity (RH) in a climatic chamber. Subsequently, the specimens are placed at 23±2° C. and 50±5% RH for at least 24 hours and upon drying are prepared for testing of mechanical performance, like e.g. the delamination strength is measured according to EN 1607:2013, or compression strength according to EN 826:2013 as will be described further below.

[0459] The relative ageing resistance is then calculated in % of and based on the initial absolute value measured at time ‘0’.

[0460] Results are documented and illustrated for 7, 14 and 28 days of accelerated ageing.

[0461] With respect to the figures and examples given here, the insulation element is a bonded mineral fibre facade product, commercially available at the assignee or affiliated companies which has been produced with the different binder types mentioned and tested for its mechanical properties. The product in question provides a target density of around 145 kg/m.sup.3 and a loss on ignition (LOI) of approx. 3.8 wt.-%.

[0462] The following Table I shows the delamination strength [kPa] EN 1607 according to FIG. 2.

TABLE-US-00010 TABLE I 0 days 7 days 14 days 28 days A.sub.2 38.6 28.4 27.9 26.9 B.sub.2 32.1 23.7 21.1 15.3 C.sub.2 33.4 25.7 23.5 21.8

[0463] Table I shows the absolute delamination strength of the insulation element according to the disclosure (C.sub.2) compared to an insulation element containing a phenol-formaldehyde binder (A.sub.2) and to an insulation element containing a non-added formaldehyde binder (B.sub.2). The corresponding graphs are shown in FIG. 2.

[0464] The following Table II shows the relative delamination strength according to table I in % of initial according to FIG. 3.

TABLE-US-00011 TABLE II 0 days 7 days 14 days 28 days A.sub.3 100.0 73.6 72.1 68.7 B.sub.3 100.0 75.2 67.1 48.3 C.sub.3 100.0 77.5 71.1 66.2

[0465] Table II shows the relative delamination strength of the insulation element according to the disclosure (C.sub.3) compared to an insulation element containing a phenol-formaldehyde binder (A.sub.3) and to an insulation element containing a non-added formaldehyde binder (B.sub.3). The corresponding graphs are shown in FIG. 3.

[0466] In Tables I and II it can be seen that the delamination strength of the insulation element according to the disclosure is very close to the delamination strength of the insulation element containing a phenol-formaldehyde binder. Furthermore, it can be seen that the loss of delamination strength of the insulation element containing a non-added formaldehyde binder increases much more than the delamination strength of the insulation element according to the disclosure. Furthermore, the delamination strength of the insulation element according to the disclosure is very close to the delamination strength of the insulation element containing a phenol-formaldehyde binder. From FIGS. 2 and 3 it can be seen that the graphs C.sub.2/C.sub.3 and A.sub.2/A.sub.3 are approximately parallel to each other.

[0467] From Table II and FIG. 3 the relative delamination strength of the insulation element according to the disclosure (graph C.sub.3) compared to insulation elements containing a phenol-formaldehyde binder (graph A.sub.3) or insulation elements containing a non-added formaldehyde binder (graph B.sub.3). All insulation elements to be compared were exposed to an ageing process according the before standing description.

[0468] Furthermore, it can be seen from Table II and from FIG. 3, that the values of delamination of the insulation element according to the disclosure are approximately equal to the values of delamination of the insulation element containing phenol-formaldehyde binder A.sub.3.

[0469] The following Table III shows the absolute compression strength [kPa] EN 826 according to FIG. 4.

TABLE-US-00012 TABLE III 0 days 7 days 14 days 28 days A.sub.4 82.6 65.5 63.9 61.3 B.sub.4 66.3 55.1 51.4 43.9 C.sub.4 71.5 58.5 56.1 54.0

[0470] Table III shows the absolute compression strength of the insulation element according to the disclosure (C.sub.4) compared to an insulation element containing a phenol-formaldehyde binder (A.sub.4) and to an insulation element containing a non-added formaldehyde binder (B.sub.4). The corresponding graphs are shown in FIG. 4.

[0471] FIG. 4 shows the compression strength of an insulation element according to the disclosure (graph C.sub.4) compared with the compression strength of an insulation element containing mineral fibres and a non-added formaldehyde binder shown in graph B.sub.4 and the compression strength of an insulation element containing mineral fibres and a phenol-formaldehyde binder shown in graph A.sub.4.

[0472] The compression strength is measured according to EN 826:2013 and it can be seen, that the compression strength is measured immediately after production of the insulation element, and seven, fourteen and twenty-eight days after production of the insulation element 4.

[0473] Whereas the compression strength of the insulation element according to the disclosure is very close to the compression strength of the insulation element containing a phenol-formaldehyde binder (A.sub.4) it can be seen that the loss of compression strength of the insulation element containing a non-added formaldehyde binder (B.sub.4) increases much more than the compression strength of the insulation element according to the disclosure. Furthermore, the compression strength of the insulation element according to the disclosure is very close to the compression strength of the insulation element containing a phenol-formaldehyde binder (A.sub.4). It can be seen that the graphs C.sub.2 and A.sub.2 are approximately parallel to each other.

[0474] The following Table IV shows the relative compression strength according to table III in % of initial according to FIG. 5.

TABLE-US-00013 TABLE IV 0 days 7 days 14 days 28 days A.sub.5 100.0 80.5 78.5 75.2 B.sub.5 100.0 83.2 77.8 66.6 C.sub.5 100.0 82.5 79.0 76.1

[0475] Table IV shows the relative compression strength of the insulation element according to the disclosure (C.sub.5) compared to an insulation element containing a phenol-formaldehyde binder (A5) and to an insulation element containing a non-added formaldehyde binder (B5). The corresponding graphs are shown in FIG. 5.

[0476] From FIG. 5 the relative compression strength of the insulation element according to the disclosure (graph C5) compared to insulation elements containing a phenol-formaldehyde binder (graph A.sub.5) or insulation elements containing a non-added formaldehyde binder (graph B.sub.5). All insulation elements to be compared were exposed to an ageing process containing the steps as described before.

[0477] Furthermore, it can be seen from FIG. 5, that the values of compression strength of the insulation element according to the disclosure are approximately equal to the values of compression strength of the insulation element containing phenol-formaldehyde binder.

[0478] The foregoing description of the embodiments has been provided for purposes of illustration and description. It is not intended to be exhaustive or to limit the disclosure. Individual elements or features of a particular embodiment are generally not limited to that particular embodiment, but, where applicable, are inter-changeable and can be used in a selected embodiment, even if not specifically shown or described. The same may also be varied in many ways. Such variations are to be regarded as a departure from the disclosure, and all such modifications are intended to be included within the scope of the disclosure.