WO2000070161A1

WO2000070161A1 - Insulating material element made of mineral wool as well as a process for its production and use of the same

Info

Publication number: WO2000070161A1
Application number: PCT/EP2000/004479
Authority: WO
Inventors: Johannes Horres; Michael Becker; Lothar Bihy; Horst Keller
Original assignee: Saint Gobain Isover SA France
Current assignee: Saint Gobain Isover SA France
Priority date: 1999-05-17
Filing date: 2000-05-17
Publication date: 2000-11-23
Anticipated expiration: 2001-11-17
Also published as: DK1099032T3; DE19922592A1; DE60004462D1; AU5394800A; EP1099032B1; EP1099032A1; DE60004462T2; ATE247203T1

Abstract

The invention relates to an insulating material element (1) made of mineral wool, a process for its production and use of the same for insulating surfaces, in particular for the over-rafter insulation of roofs (3), on facades, on ceilings and the like. The insulating material element (1) is designed as a one-piece panel element (10) with at least one insulating part (11) of high heat insulating capacity and at least one load-dissipating fillet (12), which likewise consist of mineral wool and has an increased compressive strength in comparison with the mineral wool material of the insulating part (11). The fillet (12) is permanently bonded to the latter for forming an integral component of the panel element (10). Consequently, the invention provides an insulating material element (1) of which the body exclusively consist of bonded mineral wool and which, in spite of an increased compressive strength in comparison with conventional heat insulating elements, has a good heat insulating capacity. At the same time, on account of the low weight, it can be easily manipulated by one person and can be produced inexpensively.

Description

Insulating material element made of mineral wool as well as a process for its production and use of the same

The invention relates to an insulating material element made of mineral wool, a process for its production and use of the same.

Insulating material elements made of mineral wool are produced by providing mineral fibres generated in a fibre-separating station with a binder and depositing them on a production belt, after which the fibre web produced in this way runs through a heating oven for curing the binder, with pressure being applied at the same time to produce the desired product thickness. By depositing the fibres under the force of gravity, a laminar alignment of the fibres that is substantially parallel to the surface of the production belt is obtained in the web. The compressive strength of the product, and consequently also its tensile strength in the opposite direction of loading, can be set by choosing the thickness compression in the curing oven. If a high apparent density is produced in this way, a good compressive strength is obtained, but a relatively poor heat insulating capacity. If, on the other hand, the web is compressed only little in thickness in the curing oven, a soft product of low compressive strength but good heat insulating capacity is obtained. Moreover, such a product is distinguished by relatively low weight and relatively low production costs, since the use of material per unit volume is a major factor influencing the cost calculation.

To achieve an improvement in the compressive strength under pressure on the major surfaces of such a heat insulating element in panel form without an undesired increase in the apparent density, it is known to re-orientate the main - ~ι

direction of the mineral fibres in such a way that a large part of the mineral fibres stand upright in the panel. For this purpose, it is possible for instance to form lamellar panels by cutting off strips from the product produced on the production belt with a laminar layer of fibres, turning the said strips through 90 and joining them together again. It is also possible to compress the laminar mineral wool material in the main direction of the fibres before the curing of the binder, so that the fibres subjected to the compressive forces stand upright. The production of lamellar panels requires considerable fabrication work, while the compressing operation also entails an increase in the apparent density. In any event, however, the heat insulating capacity is reduced as a result of a relatively large part of the fibres coming to lie in the direction of heat flow and consequently acting to a certain extent as heat bridges.

It is of course possible to improve the compressive or tensile strength of a mineral wool element by corresponding built-in load-dissipating elements, such as for instance spacers of a suitable material. However, in this way foreign materials are introduced into an insulating laver made of mineral wool material constructed in this way, and the said foreign materials may have an adverse effect from many different aspects, whether with respect to fire protection, chemical interactions such as corrosion, formation of condensate and many others besides. In any event, such built-in elements, which must reach from one major surface to the other major surface of the heat insulating element to provide compressive or tensile support, form heat bridges which nullify the heat insulation to a considerable extent.

Against this background, it is the object of the present invention to provide a heat insulating element made of mineral wool for insulating surfaces, in particular for the over-rafter insulation of roofs, in particular steep roofs, or else other surfaces such as building facades, intermediate floors and the like, the body of which element exclusively consists of bonded mineral wool and which, in spite of an increased compressive strength in comparison with conventional heat insulating elements, has a good heat insulating capacity, can be easily manipulated by one person on account of its low weight and as far as possible can be produced inexpensively online.

This object is achieved by Claim 1.

The fact that the mineral wool material of an insulating material element according to the invention has load-dissipating fillets of increased compressive strength made of mineral wool maintains the concept of a "monolithic" insulation with bonded mineral wool alone. Nevertheless, an increase in the overall strength is obtained in a way similar to the use of spacers of a different material, for example metal. The insulating material element still has a one-piece character and can be handled like a panel without such fillets as a single, compact part. The one- piece character, fully integrating the fillets, of an insulating panel formed in this way is enhanced by the mineral wool material of the fillets and of the insulating parts having open surfaces and penetrating into one another with these open surfaces when pressed together in the course of making the connection between the fillet and the insulating part, so that the mineral fibres on the respective surface of the insulating part and fillet reach over one another and possibly become hooked, and thus form a particularly intimate bond. Since the fillets can be restricted to a relatively small part of the surface area of the insulating material element, their heat insulating capacity, which is still high but comparatively lower with respect to the insulating part, is of no major significance overall. Nevertheless, their higher strength can be used for the linear support of load-distributing bearing elements such as boards or laths, and if need be provides adequate crush resistance when a person deliberately steps on the fillets, even without load-distributing means. An insulating material element according to the invention may be produced for example by fabrication, with prefabricated portions of the material for the fillets and of the material for the insulating parts being pressed against one another and bonded, for example by means of an adhesive. A particularly advantageous process, especially suitable for the mass production of insulating material elements of this type, is specified in Claim 14. With such a process, fabrication and the associated effort can be avoided, since the material for the fillets, which has been provided with a binder and pretreated in a suitable way, can be brought together with the material for the insulating parts, which has been provided with a binder and pretreated in any desired way, upstream of the curing oven and cured together, so as to obtain a combined sheet in which the material of the fillets and of the insulating parts is integrally bonded at the open flanks of the fibres with the binder for the mineral wool. Insulating material elements of the desired dimensions can then be produced by suitable cut-to-size pieces of the cured sheet.

The insulating material elements may in this way also be provided particularly efficiently on one or both sides with outer layers, in particular with a hard skin, a lamination etc., so that combined insulating material elements for a large number of • applications can be produced continuously on the line, the said elements consisting exclusively of mineral fibres - except possibly for the laminating sheet - with the mineral fibres being bonded with the binder for the mineral wool, even from layer to layer, and thus representing integrally bonded and interlocked units, which however are of an inhomogeneous structure to the extent that the mineral fibres used have at the desired locations the respectively desired properties. In this way, it is thus possible as it were to produce a composite building panel with supports, bracings and outer coverings which consists exclusively of mineral fibres and which undergoes intimate internal bonding and interlocking, consequently giving it stability, without introducing additional material in the course of curing the binder of the mineral wool. By suitable choice of the apparent densities, fibre alignments, fibre thicknesses, binder contents, types of fibre etc., the properties of such a composite panel can be influenced virtually at will and thus adapted optimally to the respective application, it being possible to achieve the greatest possible insulating effect and any required strength with the least possible use of material.

An insulating element according to the invention made of mineral wool acquires particular significance in its use for the over-rafter insulation of a steep roof, since here the work of the roofer on the roof gives rise to quite particular requirements and conditions.

Mineral wool has been extensively used for decades for roof insulation between rafters. Mineral wool is preferred over other insulating materials such as rigid foam because of its good flame retardant properties. It is to be endeavoured also to make use of these properties for the over-rafter insulation if, for visual reasons, the inner side of the roof is to remain visible and the insulation consequently has to be laid on the outer side of the roof in the region above the roof boarding. If in this case it is intended to dispense with the insulation of supports extending through, the insulating layer must absorb the forces acting as a result of the weight of the roof boarding and its load-bearing structure as well as any snow and wind loads, and consequently requires a not inconsiderable compressive strength. With the use of mineral wool, preferred for flame retardant reasons, it has so far only been possible to meet these requirements by making compromises with respect to reduced heat insulating properties, high costs and/or difficult laying procedures with which the roofer is not accustomed.

In this connection, DE 34 37 446 Al disclosed as much as 15 years ago a roof substructure which has rectangular mineral wool panels with a hard outer covering board, which is applied on one side, overlaps the layer of mineral wool on three sides and has on one of these sides a stiffening member fastened to the outer covering board. The stiffening member, made of a compression-resistant material, may in the simplest case be made of wood, but according to the teaching of DE 34 37 446 Al is a composite profiled member comprising a rigid foam profile with a wooden board introduced between the rigid foam profile and the outer covering board for pressure distributing purposes.

Especially when wood is used for the profiled member and a wood chipboard is used for the outer covering board, but also in the case of the composite profile member described, such an insulating panel has a considerable weight, which hinders manipulation of the insulating panel quite considerably during laying on a steep roof and may lead to accidents. This has the result that a roof substructure of this type is not readily accepted by the roofer. Furthermore, the use of rigid foam impairs the good flame retardant properties of mineral wool as the insulating material and leads to inhomogeneity of the material in the roof substructure, which is undesired for a wide variety of reasons. In addition, the structure of this insulating panel is relatively complex and its production is therefore expensive.

A uniform, homogeneous and "monolithic" insulating layer of a roof substructure was disclosed for the first time by DE 36 15 109 Al . Used in this case are insulating panels with an insulating layer of compressed rock wool which has a high compressive strength of over 40 kN/m~ and is provided with a lamination overhanging the edges. These insulating panels can be laid in the accustomed, uncomplicated way, in rows from the eaves to the ridge, can be walked on and have proven very successful in practice.

However, the compressive strength is achieved here by a relatively high apparent density and arrangement of the fibres with preference in the direction of the thickness of the insulating layer, which restricts the heat insulating capacity; as a result, only thermal conductivity group 040 can be attained. For better insulating properties, great insulating thicknesses would therefore have to be chosen, which together with the high apparent density leads to a quite considerable weight of the insulating panels, which in turn hinders their manipulation on a steep roof. Moreover, the high use of material leads to a relatively high price.

In order to achieve a reduced use of material, and consequently a lower price, without sacrificing the homogeneous, "monolithic" character of the insulating layer made of mineral wool alone, EP 682 161 Al has disclosed the inclusion between high-strength mineral wool strips, fastened on the outer side of the roof, of sheets of rolled felt, which have a low compressive strength and low apparent density of, for example, 15 kg/m.3. By introducing the sheets of rolled felt between the pre -fitted mineral wool strips in the manner of a clamping felt, an intimate bond of the materials at the abutting faces, and consequently a uniform insulation of a single material, is achieved, but at the same time the use of material is reduced drastically in the area of the wide sheets of rolled felt, resulting in considerably lower material costs. The high proportion of the surface area accounted for by good heat-insulating rolled felt allows thermal conductivity group 035 to be achieved, so that-lower insulating thicknesses are required.

This procedure too has proven successful in practice, but since the sheets of rolled felt cannot be walked on requires laying from the ridge to the eaves, which is unaccustomed for the roofer and consequently requires explanation, especially as he can no longer work in the accustomed way with panels to be laid but has to manipulate long sheets on the roof while being exposed to wind and weather. It is therefore difficult to gain acceptance for this, especially as an underlay sheet also has to be applied over the entire roof after applying the insulation. In practice, sheets of laminated rolled felt have also been made available, with the underlay sheet being formed by its laminating sheet, with edge strips which can be folded out. Since, in the roll, the lamination must always be on the outside, it comes to lie on the underside of the sheet when the rolled felt is rolled out on the roof, so that the long sheet has to be turned over before it is fitted. This may hinder work on a steep roof in a way which the roofer will accept only unwillingly.

DE 297 23 553 Ul therefore has disclosed a development in which long sheets are avoided by providing, instead of this, handy mineral wool panels of low compressive strength, but good heat insulating capacity, which are fitted between narrow mineral wool strips of the same length and high compressive strength. For forming the underlay sheet, a laminating sheet is fastened to each mineral wool strip, can be laid onto the surface of the adjacent mineral wool panel and then completely covers the latter and overhangs at the edges on two sides, these edge strips having an application of adhesive for adhesive attachment on neighbouring laminating sheets. This means that it is only necessary to manipulate lightweight elements of limited dimensions on the roof, obviating the problem of handling heavy elements or long sheets.

However, it has been found that this system is not readily accepted by workers, since laying is too complex and requires explanation: for laying, initially the first panel is laid at the beginning of the eaves, and then the firm mineral wool strip with the attached lamination is fastened over the panel. The laminating sheet. which flaps in the wind, is then provisionally secured right away by the edge lying opposite the firm strip, by adhesion or by tacking to the eaves themselves. It is recommendable to then initially complete one strip of the insulation, superimposed in alignment, up to the ridge and immediately secure the provisional adhesive attachments of the edges of the laminating sheet of the strip mechanically with a counter-lath. This is likewise a procedure with which the roofer is unaccustomed and which requires explanation. If the roofer works in the customary way, initially completing the first row on the eaves side, cutting off the overhang of the last mineral wool panel and of the last strip and using this with offset on the opposite side at the beginning of the second row, a mechanical securement of the provisional adhesive attachment inevitably only takes place once the entire roof has been provided with the insulation.

Although the roofer can step on the firm mineral wool strips, a neighbouring part of the soft mineral wool panel may easily be pressed in as a result, with the result that the laminating sheet is subjected to tensile stress and the adhesive bond on the overhanging edge is lost. In particular when there is wind, it is consequently repeatedly necessary for flapping-up laminating sheets to be provisionally fixed again. An added hindrance is that, if a lateral adhesive bond of the edge strip is lost, the exposed edge of the laminating sheet lying thereunder over the next insulating panel is accessible to wind, so that this laminating sheet may be lifted off by a strong gust of wind and its provisional adhesive attachment may become detached, and so on, so that this insulation can in practice only be fitted when there is largely no wind. These difficulties impede the working process and are not accepted by the roofer. The roof substructure of DE 297 23 553 Ul has therefore not been adopted in practice.

On the basis of the roof substructure of DE 36 15 109 Al, it is consequently a further object of the invention to provide a roof substructure of this generic type which retains the described advantages of this known roof substructure that has proven successful in practice, but makes working with the roof panels on the slope of a roof significantly easier and reduces the cost.

This object is achieved by the characterizing features of Claim 23. In this case, recourse is initially made to the concept of the previous attempted solutions of EP 682 161 Al and of DE 297 23 503 Ul, according to which part of the homogeneous insulating layer consists of mineral wool of reduced compressive strength and lower apparent density, in order to reduce the use of material and consequently the price of the insulating panels, and consequently of the roof substructure. By contrast with the teaching of DE 36 15 109 Al and of DE 297 23 553 Ul, however, the principle is maintained here that individual, one-piece rectangular panels are used and can be laid in rows from the eaves to the ridge, in a manner with which a roofer is accustomed. In comparison with the generic prior art, the manipulation of the insulating panels on a steep roof is made significantly easier here, however, by the fact that the weight of the individual insulating panels is considerably less due to the reduced use of material. Laying from the eaves to the ridge is made possible without any problem by the fact that the insulating panels can be walked on and the laminating sheets are firmly connected by their upper sides, in other words cannot be lifted off by the wind. The roofer can step on the fillet regions of the panels, and any pressing in of the laminating sheet does not lead to detachment of an edge connection of the laminating sheet to neighbouring laminating sheets because of the adhesive bonding on the upper side of the insulating part, such detachment moreover possibly leading at most to a wind-induced lifting-off of the edge strip and not for instance of the entire laminating sheet. The insulating part is relatively compression-resistant, because of the laminar arrangement of fibres in the direction of its major surface, and is thus capable of additionally securing the fillet arranged above it against slipping, even when the roof has a great inclination.

By contrast with the teaching of DE 297 23 553 Ul , use is not made of individual elements which are joined together to form a complete element in panel form only when they are on the roof, but instead prefabricated one-piece panels with lamination fastened on them are made available from the outset by the fillet and insulating part being integrally bonded to each other, in particular adhesively bonded. This dispenses with the inconvenience of a large number of laying steps with repeatedly required, intermittent securement of the lamination against wind by means of counter-laths, it instead being possible, as in the generic prior art, for the insulating panels to be laid simply side-by-side without having to fear any disturbances from the wind.

This has the overall effect of producing a roof substructure which can be laid in the same, accustomed way as the generic roof substructure, but makes the laying work easier by reducing the weight of the insulating panels considerably and reducing their price by reduced use of material. This provides for the first time a roof substructure with a homogeneous insulating layer made of mineral wool material which can compete in terms of price with roof substructures of other materials, for example with rigid foam, and nevertheless can be laid or fitted without any problem and in the accustomed way, so that it is accepted on the part of those owning and working on buildings, and therefore for the first time provides in practice the advantages of a homogeneous insulation on a mineral wool basis without painful eompromises in the area of costs or the area of laying difficulties. The most important thing of all is that this provides for the first time an insulating element uniformly made of mineral wool for roof substructures which is classified in thermal conductivity group 035, increasing considerably the quality of the insulation.

Further details, features and advantages of the invention emerge from the following description of exemplary embodiments with reference to the drawing, in which: Figure 1 shows a schematic representation of a production line for the production of an insulating material element according to the invention;

Figure 2 shows a first embodiment of an insulating material element according to the invention;

Figure 3 shows a second embodiment of an insulating material element according to the invention;

Figure 4 shows a third embodiment of an insulating material element according to the invention;

Figure 5 shows a fourth embodiment of an insulating material element according to the invention; and

Figure 6 shows a plan view of part of a roof substructure which has insulating material elements according to Figure 5, but without roof covering.

An insulating material element 1, several embodiments of which are shown in Figures 2 to 5, has a panel element 10 with at least one insulating part 11, with a high heat insulating capacity, and at least one load-dissipating fillet 12, with an increased compressive strength in comparison with the insulating part 11.

It may be produced, for example, by a production line 2 according to the representation in Figure 1. For this purpose, the production line 2 includes a production belt 21, on which the mineral wool material is fed to the production line from a fibre-separating station in the form of a web, from which the insulating parts 11 of the insulating material elements 1 are then formed. This web, which is provided with a still uncured binder, may in this case be slit over the entire thickness by means of a cutting device 22 at at least one predetermined position of its width and be spread by a following spreading device 23 in such a way that the mineral wool material which has been pretreated in another way and is intended for the forming of a load-dissipating fillet 12 of the panel elements 10 can be introduced between the separated portions of the web.

The mineral wool material for a fillet 12 may be taken from the same fibre - separating station as the material for an insulating part 11. The mineral wool material for a fillet 12 is in this case pre-compacted by means of a customary compressing installation 24, with rollers of respectively reduced speed arranged one behind the other, and is turned through 90 before introduction between the portions of the slit web in such a way that a high proportion of the mineral fibres is arranged in the direction of the thickness of the panel element 10.

In a following pressing roller device 25, the combined, but still uncured, web is levelled to an equal material thickness. By means of a multiple compressing installation 26, as for example described in detail in the German patent application with the application number P 19860040.2 of the same applicant, it is also possible, according to Figure 1, for an outer layer 13, in particular a hard skin, of individually pretreated mineral wool material with an uncured binder to be applied to the combined web. In Figure 1 it is also shown that, before the curing of the binder, web-like laminations 14 may also be applied to the combined web on both sides. However, these must be of an open-cell character, in order that the hot air circulating in a downstream curing oven 27 can pass through the lamination.

In the downstream curing oven 27, the insulating parts 11, the fillets 12, the outer layer 13 and, if applicable, the laminations 14 are then pressed against one another and adhesively bonded to one another during the curing of the binder. The insulating part 11 and the fillet 12 are in this case also passed through the curing oven 27 as a unitary sheet, in a way not represented in Figure 1 and with pressing laterally applied. The insulating material sheet consequently formed as an endless product is finally cut to length into rectangular insulating material elements 1.

In the process explained with reference to Figure 1 for the production of an insulating material element 1, further modifications are also possible.

For instance, it is possible to dispense with the outer layer 13 and/or one or both laminations 14. Furthermore, the lamination 14 may also be applied and attached by means of an adhesive after the panel element 10 has left the curing oven 27, a so-called tunnel oven, which is the case in particular with laminations which are temperature-sensitive and not suitable for the hot air of the curing oven to pass through. Furthermore, the combined web may also be subjected to further compression before curing.

Moreover, it is also possible to dispense with turning of the mineral wool material for the fillet 12 before insertion between the portions of the slit web, if for example a higher apparent density of the fillet material is considered adequate to provide sufficient stability for the panel element 10 in the final state without a reorientation of its mineral wool fibres.

Furthermore, a plurality of cutting devices 22 and spreading devices 23 may also be provided in order to arrange a plurality of fillets 12 in the insulating material element 1. On the other hand, however, it is also possible to dispense with the cutting device 22 and the spreading device 23, if the fillet 12 is to be joined onto the insulating part 11 laterally on one or both sides. Exemplary embodiments of insulating material elements 1 are shown in Figures 2 to 5.

In the case of the insulating material element 1 according to Figure 2, the fibres of the insulating parts 11 and of the fillets 12 of the insulating element 10 have an alignment with respect to one another that is substantially at right angles. The mineral wool of the insulating parts 11 is in this case aligned substantially parallel to the insulating surface and has an apparent density of between 20 and 70 kg/m3. so that it is possible to realize a low weight and a high heat insulating capacity. The mineral wool material of the fillets 12, on the other hand, is compacted and has a compressive strength of less than 40 kN/m.2. In this case, a high proportion of the mineral wool of this fillet 12 is aligned in the direction of the thickness of the insulating material element 1. The insulating material element 1 according to Figure 3, on the other hand, has insulating parts 11 which have been compressed before the insertion of the fillet material.

In the case of the insulating material elements 1 according to Figures 2 and 3, it can be seen that the fillets 12 and each insulating part 11 are in each case of the same length. -Furthermore, the fillets 12 and the insulating parts 11 are arranged parallel to one another. The width of the insulating parts 11 of the insulating material element 1 is in this case a multiple of the width of the fillets 12, each fillet 12 having at least approximately a rectangular shape in plan view.

By forming the fillets 12 with a compressive strength of at least 40 kN/m2, a sufficient stability is provided at the insulating material element 1, also allowing for example the insulating material element 1 to be walked on in the regions of the fillets. Furthermore, the load-dissipating fillets 12 stiffen the insulating material element 1 , so that it does not sag, i.e. bow, as a floor panel. The load-dissipating fillets 12 also advantageously make it possible to use apparent densities of 20 to 70 kg/m3 for the insulating parts 11, in order nevertheless to obtain an adequate strength of the overall insulating material element. The essential basic idea of the present invention is "as much in terms of statics as necessary and as little in terms of insulating material as possible", i.e. optimum heat insulating capacity with lowest possible weight. In the interaction of these components, the insulating material element 1 therefore has good compressive strength with at the same time good heat insulating properties, these measures also leading to a reduction in material consumption, and consequently costs.

The insulating material element 1 according to Figure 4 has, as a further variant, an outer layer 13 comprising a so-called hard mineral wool skin, with an apparent density of over 200 kg/m.3. This outer layer makes it possible, for example, for this insulating material element 1 to be used for insulating flat roofs, since it can be walked on. Furthermore, an insulating material element of this type is also suitable as a facade insulating panel, in which case the outer layer 13 then serves as a plaster underlay.

As already emerges from the description of the process for the production of the insulating material element 1, the latter may also be provided on at least one of its major surfaces with a surface-area-bonded lamination 14, which however is not represented in Figures 2 to 4.

Shown in Figure 5, finally, is a fourth variant of an insulating material element 1, which is explained in connection with its use for an over-rafter insulation of roofs 3.

In this respect, Figure 6 shows a perspective representation of an insulating layer 30 comprising a plurality of insulating material elements 1 according to the invention, as shown in Figure 5, arranged in series with one another and in a surface-covering manner. The insulating material element 1 according to Figure 5 or 6 has here a load-dissipating fillet 12, which is arranged at the edge and is adhesively attached laterally to a single insulating part 11, i.e. forms with the latter a one-piece panel element 10. The insulating material element 1 has, furthermore, on an upper side a laminating sheet 14, which overhangs the insulating part 11 or the fillet 12 on two sides. This laminating sheet 14 may in this case consist, for example, of a plastic-coated polyester spunbonded web and is open with respect to diffusion, but at the same time designed such that it is water-repellent (impervious to driving rain) and crush-resistant when stepped on. Since the laminating sheet 14 overhangs by a predetermined amount on one longitudinal side and one end side of each insulating material element 1, overlapping edges are produced with respect to the corners, respectively covering over the joints of abutting insulating material elements 1. The laminating sheet 14 is adhesively attached on the panel element 10 in spots or strips by means of a special adhesive.

According to the representations in Figure 6, an insulating layer 30 of this type, comprising insulating material elements 1, can be arranged on the roof 3, in particular a steep roof. The roof 3 contains rafters 31, onto which a closed roof boarding 32 is applied. Applied over this is an airtight and diffusion-resistant, film- like vapour barrier 33, which in the present example comprises a customary bituminous roofing sheet according to DIN 52143. Applied in a surface-covering manner on the vapour barrier 33 are a plurality of the insulating material elements 1 according to Figure 5, for forming the insulating layer 30. In this case, the overlapping edges of the longer side of the laminating sheets 14 of each insulating material element 1 respectively face in the direction of the eaves, so that rain water etc. can run down in the direction of the eaves.

Fastened exactly over each rafter 31, above the insulating layer 30. are also counter-laths 34, by means of so-called screw-type nails, which reach through the insulating material elements 1 etc. into the respective rafters 31 and fix the counter-laths 34 on the rafter 31. Also arranged over the counter-laths 34 are roof laths 35. on which roofing panels (not shown) can be arranged. In this case, the weight of the structure comprising the counter-laths 34 and the roof laths 35 in the fitted state is substantially absorbed by the fillets 12, whereas the entire load dissipation of the covered roof takes place through the screw-type nails.

For further details on the construction of such a roof substructure, reference is made to the content of DE 36 15 109 Al of the same applicant, so that there is no need here for any further comments.

As can be seen in particular from Figure 6, the load-dissipating fillets 12 of the panel elements 10 of the insulating material elements 1 are respectively arranged on the insulating material element 1 on the roof-ridge side and are parallel to the ridge. Each fillet 12 has in the present case an apparent density of at least 140 kg/m3 and a width of 1/8 to 1/5 of the width, measured in the direction of fall of the insulating material element 1. The mineral wool of the insulating part 11, on the other hand, has only an apparent density of 20 to 70 kg/m3 and in the present case 50 kg/m3, which advantageously makes possible a thermal conductivity classification in group 035.

When using the insulating material element 1 for a roof substructure it has been found that a compressive strength of the fillets 12 of over 80 kN/m.2, and in particular of over 100 kN/m2, is advantageous in order to withstand the loads in particular when the roof insulation is walked on. On the other hand, it has been found that the compressive strength of the fillets 12 should be below 200 kN/m2, and in particular below 180 kN/m.2, to keep the total weight of the insulating material element 1 in a range which allows good handling. For the apparent density of the insulating part 11 , values of between 30 and 60 kg/m3 and preferably between 40 and 50 kg/m3 have proven to be most suitable.

Furthermore, the overhanging edges of the lamination 14 in the region of the side facing the body of the insulating material element 1 may be coated with adhesive which can be activated in a known way during fitting.

The insulating material element 1 may in this case consist entirely of rock wool or glass wool .

However, the insulating material element 1 according to the invention can be used not only for the over-rafter insulation of roofs 3, and in particular steep roofs, but also - as already mentioned - for the insulation of other surfaces such as building facades, intermediate floors and the like. Moreover, they may also be used in the area of air-conditioned rooms as inlays for modules for cold stores, for example, and as an inlay for fire doors or for modular walls in the building of industrial sheds.

The invention consequently provides a one-piece insulating material element 1 made of mineral wool as well as a process for its production which is designed on the basis of "as much in terms of statics as necessary and as little in terms of insulating material as possible".

Claims

Insulating material element (1) made of mineral wool for the insulation of surfaces, in particular for the over-rafter insulation of roofs (3), on facades, on ceilings and the like, which is designed as a one-piece panel element (10) with at least one insulating part (11) of high heat insulating capacity and at least one load-dissipating fillet (12), likewise made of mineral wool, which has an increased compressive strength in comparison with the mineral wool material of the insulating part (11) and is permanently bonded to the latter for forming an integral component part of the panel element (10).

Insulating material element according to Claim 1, characterized in that the fillet (12) and the insulating part (11) are of the same length.

Insulating material element according to Claim 1 or 2, characterized in that a plurality of fillets (12) and/or insulating parts (11) are arranged in parallel with one another.

4. Insulating material element according to one of Claims 1 to 3, characterized in that the compressive strength of the mineral wool of the fillet (12) is at least 40 kN/m2.

5. Insulating material element according to one of Claims 1 to 4, characterized in that the mineral wool of the fillet (12) has a high proportion of mineral fibres lying in the direction of the thickness of the panel element (10).

6. Insulating material element according to one of Claims 1 to 5, characterized in that the width of the insulating parts (11) of the panel element (10) is a multiple of the width of the fillets (12) of the panel element (10).

7. Insulating material element according to one of Claims 1 to 6, characterized in that each fillet (12) has at least approximately a rectangular shape in plan view.

8. Insulating material element according to one of Claims 1 to 7, characterized in that each insulating part (11) has an apparent density of between 20 and 7 kg/m3.

9. Insulating material element according to one of Claims 1 to 8, characterized in that the insulating part (11) has a laminar layered structure of the mineral fibres parallel to the major surfaces of the panel element (10).

10. Insulating material element according to one of Claims 1 to 9, characterized in that the panel element (10) is provided on at least one of its major surfaces with an outer layer (13) made of mineral wool permanently fastened thereto.

11. Insulating material element according to Claim 10, characterized in that the outer layer (13) is formed as a hard mineral wool skin with an apparent density of over 200 kg/m3.

12. Insulating material element according to one of Claims 1 to 11 , characterized in that the insulating material element (1) is provided on a least one of its major surfaces with a surface-area-bonded lamination (14).

13. Insulating material element according to one of Claims 1 to 12, characterized in that it consists entirely of rock wool or glass wool.

14. Process for the production of an insulating material element (1) according to one of Claims 1 to 13,

• in which mineral wool material is generated in at least one fibre- separating station and provided with a binder and is deposited on a production belt for the formation of a web, after which the web is cured, while at the same time undergoing compression, to the desired material thickness and apparent density in a curing oven (27),

• in which part of the mineral wool material forming the insulating material element (1) is intended for the forming of insulating parts (11) of the insulating material element (1) and another part of the mineral wool material, after different pretreatment, is intended for the forming of load-dissipating fillets (12), and

• in which the mineral wool material serving for the forming of insulating parts (11) is arranged side-by-side with the mineral wool material serving for the forming of the fillets (12) and they are pressed against one another and fed in this form to the curing oven (27).

15. Process according to Claim 14, characterized in that the mineral wool material for the insulating part (11) made available in the fibre-separating station as a coherent web is slit and spread at those positions of its width at which fillets (12) are to be inserted, in that the pretreated mineral wool material for the fillets (12) is inserted between the strips spread in this way for the formation of insulating parts (11) and, after closing the gaps by applying lateral pressure, is passed as a unitary sheet through the curing oven (27).

16. Process according to Claim 14 or 15, characterized in that the mineral wool for the forming of the fillets (12) is compressed before combining with the mineral wool for the forming of the insulating parts (11), the insertion of the mineral wool material for the fillets (12) taking place in such an alignment that the mineral wool fibres re-orientated by the compression stand upright in the combined web.

17. Process according to Claim 16, characterized in that the combined web is subjected to further compression.

18. Process according to one of Claims 14 to 17, characterized in that, before entering the curing oven (27), an outer layer (13), in particular a hard skin, made of individually pretreated mineral wool material with an uncured binder is fed to the upper side and/or underside of the combined web and runs through the curing oven (27) together with the combined web.

19. Process according to Claim 18, characterized in that a laminating sheet (14) is applied onto the upper side and/or underside of the combined mineral wool sheet.

20. Process according to Claim 19, characterized in that, before entering the curing oven (27), the laminating sheet (14) is applied onto the web and is cured together with the latter in the curing oven (27) and, as a result, is bonded to the web.

21. Process according to Claim 19, characterized in that, after the combined sheet has left the curing oven (27), a film-like laminating sheet is applied and attached by means of adhesive.

22. Process according to Claim 21. characterized in that the cured combined sheet is cut to length for the forming of rectangular panels.

23. Roof substructure for rafters (3) covered with roofing panels,

• with an insulating layer (30) made of mineral wool in the form of rectangular insulating panels (1) arranged directly next to one another and made of bonded mineral wool, free from supports made of any- other type of material, which are laid on a boarding (32) that is arranged on rafters (31) and covered by a film-like vapour barrier (33). and which are respectively covered on the upper side by means of a water-repellent, crush-resistant laminating sheet (14) which at two mutually neighbouring panel edges laterally protrudes over the latter and overlaps the edges of the laminating sheets (14) of the neighbouring insulating panels (1), as well as

• with counter-laths (34) which are arranged thereupon, extend from the ridge to the eaves and bear roof laths (35), characterized

• in that each insulating panel (1) has a fillet (12) made of mineral wool which lies on the roof-ridge side, is parallel to the ridge, has a compressive strength of at least 40 kN/m2, has a high proportion of mineral fibres lying in the direction of the thickness of the insulating panel and has a width of less than half the width of the insulating panel, measured in the direction of fall, as well as

• a rectangular insulating part (11) made of mineral wool, of significantly lower compressive strength with an apparent density of between 20 and 70 kg/m3, which has a high proportion of mineral fibres lying parallel to the major surface of the insulating panel (1) and completes the insulating panel (1), • in that the laminating sheet (14) projects over the edge of the insulating panel (1) lying opposite the fillet (12), and

• in that the fillet (12) and the insulating part (11) are permanently bonded to each other, in particular by adhesive bonding, for the formation of one-piece insulating panels (1).

24. Roof substructure according to Claim 23, characterized in that the compressive strength of the fillets (12) is over 80 kN/m2, in particular over 100 kN/m2.

25. Roof substructure according to Claim 23 or 24, characterized in that the compressive strength of the fillets (12) is below 200 kN/m2, in particular below 180 kN/m.2.

26. Roof substructure according to one of Claims 23 to 25, characterized in that the apparent density of the insulating part (11) is between 30 and 60 kg/m3, in particular between 40 and 50 kg/m3.

27. Roof substructure according to one of Claims 23 to 26, characterized in that the overhanging edges of the laminating sheet (14) are coated in the region of their side facing the body of the insulating panel (1) with adhesive which can be activated during fitting.

28. Roof substructure according to one of Claims 23 to 27, characterized in that the laminating sheet (14) is bonded to the insulating panel (1) lying thereunder by the binder of the mineral wool of the insulating panel.

29. Roof substructure according to one of Claims 23 to 27, characterized in that the laminating sheet (14) is adhesively bonded to the insulating panel (1) lying thereunder in spots or strips by means of a special adhesive.

30. Roof substructure according to one of Claims 23 to 29, characterized in that the laminating sheet (14) consists of a material which is resistant to tension and tearing and preferably open with respect to diffusion, in particular a plastics film reinforced with glass fibre mat.

31. Use of an insulating material element according to one of Claims 1 to 13 or of an insulating material element produced according to one of Claims 14 to 22 as an initial product for combination with other materials.

32. Use of an insulating material element according to one of Claims 1 to 13 or of an insulating material element produced according to one of Claims 14 to 22 as a floor panel which can be laid in grid rails.

33. Use of an insulating material element according to one of Claims 1 to 13 or of an insulating material element produced according to one of Claims 14 to 22 as an inlay for fire doors, modular walls and the like.

34. Use of an insulating material element according to one of Claims 1 to 13 or of an insulating material element produced according to one of Claims 14 to 22 as a facade insulating panel.