DE69421267T2 - METHOD FOR PRODUCING A MINERAL FIBER INSULATION FABRIC AND SYSTEM FOR PRODUCING A MINERAL FIBER FABRIC - Google Patents

Abstract

A method of producing a mineral fiber-insulating web comprises the steps of firstly producing a first non-wowen mineral fiber web. The first mineral fiber web contains mineral fibers arranged generally in the longitudinal direction of the mineral fiber web. Secondly, the first mineral fiber web is moved in the longitudinal direction of the web and folded parallel with the longitudinal direction and perpendicular to the transversal direction of the first mineral fiber web, so as to produce a second mineral fiber web comprising a central body and opposite surface layers sandwiching the central body, which central body contains mineral fibers arranged generally perpendicular to the longitudinal and transversal directions of the second mineral fiber web and which surface layers contain mineral fibers arranged generally in the transversal direction of the second mineral fiber web. Thirdly, a third non-wowen mineral fiber web being a mineral fiber web of a higher compactness as compared to the second mineral fiber web is produced and adjoin in facial contact with the second mineral fiber web for producing a fourth composite mineral fiber web which is thereupon cured. The method also optionally includes longitudinally compressing and/or transversally compressing the second mineral fiber web. The composite mineral fiber web may additionally be combined with additional mineral fiber webs or coverings for producing a composite mineral fiber web product which is cured in a single curing process.

Description

The present invention relates generally to the technical field of producing mineral fiber insulation boards. Mineral fibers generally include fibers such as rock wool fibers, glass fibers, etc. In particular, the present invention relates to a novel technique for producing a mineral fiber insulation mat from which mineral fiber insulation boards are cut. The mineral fiber insulation boards produced from the mineral fiber insulation mat produced according to the present invention have advantageous properties in terms of mechanical performance, such as elastic modulus and strength modulus, low weight and good thermal insulating properties.

Mineral fiber insulation mats have heretofore been conventionally described as homogeneous mats, i.e., mats in which the mineral fibers making up the mineral fiber insulation mat are generally oriented in a single predominant orientation, which is determined primarily by the orientation of the production line on which the mineral fiber insulation mat is manufactured and conveyed during the process of manufacturing the mineral fiber insulation mat. The product consisting of a homogeneous mineral fiber insulation mat has properties that are determined by the integrity of the mineral fiber insulation mat, which are determined primarily by the bonding of the mineral fibers in the mineral fiber insulation board made from the mineral fiber insulation mat, and which are further determined primarily by the basis weight and density of the mineral fibers of the mineral fiber insulation board.

The advantageous properties of mineral fiber insulation boards of a different structure have already been achieved to some extent, since techniques have been developed for producing mineral fiber insulation boards in which the mineral fibers are aligned in an overall orientation that differs from the orientation determined by the production line, see Published International Patent Application, International Application No. PCT/DK91/00383, International Publication No. WO92/10602, US Patent No. 4,950,355, Swedish Patent No. 441,764, US Patent No. 2,546,230 and US Patent No. 3,493,452. Reference is made to the above-mentioned patent applications and patents.

From the above-mentioned Published International Patent Application, International Publication No. WO92/10602, a method is known for producing an insulating mineral fiber board consisting of interconnected rod-shaped mineral fiber elements. This method involves cutting a continuous mineral fiber mat in its longitudinal direction to form lamellae, cutting the lamellae into desired lengths, rotating the lamellae 90º about the longitudinal axis and bonding the lamellae together to form the board. The method also includes a step for hardening the continuous mineral fiber mat, or alternatively the board consisting of the individual lengths of lamellae bonded together to form the board.

From Swedish Patent No. 441,764 a technique is known for producing mineral fibre boards or panels consisting of rod-shaped elements, the technique being similar to the technique described in the above-mentioned International Patent Application. Thus, according to the technique described in the above-mentioned Swedish Patent, a mat of mineral fibre material is cut into rod-shaped elements of a certain length, which are then turned and assembled into a rod-shaped mineral fibre composite panel structure, the rod-shaped elements being glued together by strands of an adhesive material which are introduced into through-openings of the rod-shaped mineral fibre composite panel structure in a separate manufacturing step.

From US Patent No. 2,546,230 a technique is known for manufacturing mineral fibre panels or slabs consisting of rod-shaped elements. Thus, the technique described in US Patent No. 2,546,230 is very similar to the techniques known from the above-mentioned International Patent Application and the above-mentioned Swedish Patent and includes a separate step for connecting the rod-shaped lamellae by means of a suitable adhesive.

From US Patent No. 3,493,453 a method is known for producing a fibrous layered structure containing filaments or fibers of a polymeric material such as polyethylene terephthalate or polyhexamethyl eaditamide. The method involves producing filaments or fibers of polymeric material by a carding machine from a filament or fiber supply consisting of a porous, elastic wrap of filaments or fibres, collecting the filaments or fibres of polymeric material on a belt to form a continuous mat of filaments or fibres of polymeric material, pressing the mat, cutting the mat into a series of parallel fibre strips containing the filaments or fibres of polymeric material, and rotating the fibre strips through 90º about the longitudinal axis and joining the strips together, while uniformising the strips only by removing a compressive action exerted on the strips during the rotating operation. The mat produced according to this technique described in the above-mentioned US patent is suitable for producing fabrics such as carpets, blankets, bedspreads, bathrobes, etc.

An object of the present invention is to provide a novel method for producing a mineral fiber insulation mat from which mineral fiber insulation panels can be cut, the method making it possible to produce mineral fiber insulation panels in a directly coupled production plant which have a complex composite structure which offers various advantages compared to the homogeneous, one-sidedly oriented mineral fiber-containing panels according to the prior art.

A particular advantage of the present invention relates to the novel mineral fiber insulation board according to the present invention, which is manufactured according to the method of the present invention, which contains less mineral fibers compared to mineral fiber insulation boards according to the prior art and is therefore not as expensive as the mineral fiber insulation boards according to the State of the art, but nevertheless has advantages over state of the art mineral fibre insulation boards in terms of mechanical performance and thermal insulation properties.

A particular feature of the present invention relates to the fact that the novel mineral fiber insulation board according to the present invention, manufactured by the method of the present invention, can be manufactured from less mineral fibers or less material compared to the prior art mineral fiber insulation board and yet has the same mechanical performance and thermal insulating properties as the prior art mineral fiber insulation board, thereby providing a lighter and more compact mineral fiber insulation board product compared to the prior art mineral fiber insulation board product, in which transportation, storage and handling costs are reduced.

The above object, advantage and feature, together with numerous other objects, advantages and features which will become apparent from the following detailed description of the presently preferred embodiments of the invention, are achieved by a method according to the present invention which comprises the following steps:

a) producing a first mineral fibre nonwoven mat which defines a first longitudinal direction parallel to the mineral fibre mat and a second transverse direction parallel to the first mineral fibre mat, wherein the first mineral fiber mat contains mineral fibers generally arranged in the second transverse direction and a first curable adhesive,

b) moving the first mineral fibre mat in the first longitudinal direction of the first mineral fibre mat,

c) folding the first mineral fiber mat parallel to the first longitudinal direction and perpendicular to the second transverse direction to produce a second mineral fiber nonwoven mat, the second mineral fiber mat comprising a central body and surface layers arranged on opposite sides of the central body, the central body containing mineral fibers arranged generally perpendicular to the first longitudinal direction and the second transverse direction and the surface layers containing mineral fibers arranged generally in the second transverse direction,

d) moving the second mineral fibre mat in the first longitudinal direction,

e) creating a third nonwoven mineral fiber mat defining a third direction parallel to the third mineral fiber mat, the third mineral fiber mat containing mineral fibers generally arranged in the third direction and containing a second curable adhesive, the third mineral fiber mat being a higher density mineral fiber mat compared to the second mineral fiber mat,

f) Connecting the third mineral fibre mat to the second mineral fibre mat in surface contact with this to produce a fourth mineral fibre composite mat, and

g) curing the first and second curable adhesives so that the mineral fibers of the fourth mineral fiber composite mat are bonded together, thereby forming the mineral fiber insulation mat.

The third mineral fiber nonwoven mat, which is connected to the second mineral fiber mat in step f), can be a separate mineral fiber mat. Thus, the first and third mineral fiber mats can be produced by separate production lines, which are connected in step f).

According to a first embodiment of the method according to the present invention, the third mineral fiber nonwoven mat is formed by separating a surface segment layer of the first mineral fiber mat therefrom it and compacting the surface segment layer to produce the third mineral fiber nonwoven mat.

The third mineral fiber mat may additionally be produced by compacting the surface segment layer, comprising the step of folding the surface segment layer to produce the third mineral fiber mat containing mineral fibers arranged generally transversely with respect to the longitudinal direction of the third mineral fiber mat.

According to a further, currently preferred embodiment of the method according to the present invention, the third mineral fiber fleece mat is Separating one of the surface layers of the second mineral fiber mat produced in step c) from the central body thereof and compacting the surface layer to produce the third mineral fiber mat. When the third mineral fiber mat is produced by separating the surface layer from the second mineral fiber mat, the mineral fibers of the third mineral fiber mat retain the general orientation of the mineral fibers of the second mineral fiber mat, ie, the orientation generally in the second transverse direction.

The method according to the present invention preferably further comprises the additional step, similar to step e), of producing a fifth mineral fiber nonwoven mat similar to the third mineral fiber mat, and the step of joining in step f) the fifth mineral fiber mat to the second mineral fiber mat in surface contact therewith, so that the second mineral fiber mat lies between the third and fifth mineral fiber mats in the fourth mineral fiber mat. By producing a fifth mineral fiber nonwoven mat, an integrated mineral fiber composite structure of the fourth mineral fiber mat is achieved, in which structure the central body originating from the second mineral fiber mat lies between opposing, compacted surface layers formed by the third and fifth mineral fiber mats.

The step of folding the first mineral fiber mat is preferably carried out in such a way that continuous corrugations are produced which extend in the first longitudinal direction of the first mineral fiber mat in order to form a precisely structured, folded, second mineral fiber mat. from which the surface layer(s) can be easily separated.

When the third mineral fiber mat is provided as surface layers separated from the second mineral fiber mat, the mineral fibers of the third mineral fiber mat are, as previously discussed, generally oriented along the second transverse direction. Consequently, the third direction may coincide with the second transverse direction and therefore be perpendicular to the first longitudinal direction.

If the third mineral fiber fleece mat is manufactured by a separate production line, the third direction can have any orientation, i.e., can be identical to the first longitudinal direction and therefore perpendicular to the second transverse direction.

The method according to the present invention preferably further comprises the preliminary step of producing a first mineral fibre mat from a base mineral fibre nonwoven mat by arranging the base mineral fibre mat in overlapping layers, so that a more homogeneous and compact mineral fibre mat is obtained compared to the base mineral fibre mat which additionally contains mineral fibres oriented generally along the longitudinal direction of the base mineral fibre mat. By producing the first mineral fibre mat from the base mineral fibre nonwoven mat by arranging the base mineral fibre mat in overlapping layers, the general orientation of the mineral fibres of the base mineral fibre nonwoven mat is shifted from the longitudinal direction of the base mineral fibre mat to the transverse direction of the first mineral fibre nonwoven mat. The base mineral fibre nonwoven mat is preferably arranged in an overlapping relationship generally in the second transverse direction.

According to the technique described in the above-mentioned Published International Patent Application, Application No. PCT/DK91/00383, Publication No. WO 92/10602, the first and second mineral fiber nonwoven mats are preferably subjected to compaction and pressing in order to obtain more compact and homogeneous mineral fiber mats. The compaction and pressing may comprise vertical pressing, longitudinal pressing, transverse pressing and combinations thereof. Thus, the method according to the present invention preferably further comprises the additional step of vertical pressing the first mineral fiber nonwoven mat produced in step a) and preferably produced from the base mineral fiber nonwoven mat as described above.

Furthermore, the method according to the present invention may preferably comprise the additional step of longitudinally pressing the first mineral fiber nonwoven mat produced in step a) and additionally or alternatively the additional step of longitudinally pressing the second mineral fiber nonwoven mat produced in step c). By performing longitudinal pressing, the mineral fiber mat subjected to longitudinal pressing becomes more homogeneous, resulting in an overall improvement in the mechanical performance and, in most cases, the heat insulating property of the longitudinally pressed mineral fiber mat compared to a non-longitudinally pressed mineral fiber mat.

As will be apparent from the following detailed description of the presently preferred embodiments of the present invention, the Mineral fiber insulation boards produced by the method according to the present invention surprisingly have improved mechanical properties and improved mechanical performance, provided that the second mineral fiber nonwoven mat produced in step c) is subjected to transverse pressing, thereby obtaining a homogenization of the mineral fiber structure of the second mineral fiber nonwoven mat. The transverse pressing of the second mineral fiber nonwoven mat leads to a significant improvement in the mechanical properties and performance of the finished mineral fiber insulation boards produced from the second mineral fiber nonwoven mat, which improvement is believed to result from a mechanical rearrangement of the mineral fibers of the second mineral fiber nonwoven mat when the second mineral fiber nonwoven mat is subjected to the transverse pressing, which rearrangement evenly distributes the mineral fibers of the second mineral fiber nonwoven mat throughout the uncured mineral fiber mat.

The method according to the present invention may further preferably and advantageously comprise the step of applying a foil to one side surface or to both side surfaces of the first mineral fibre nonwoven mat and/or applying a foil to one side surface or to both side surfaces of the second mineral fibre nonwoven mat. The foil may be a foil of a plastic material, such as a continuous foil, a woven or nonwoven mesh, or alternatively a foil of a non-plastic material, such as a paper or cloth material. The mineral fibre insulation mat produced by the method according to the present invention may, as previously discussed, be provided with two oppositely arranged mineral fibre mats between which a central body of the mineral fibre insulation composite mat is located. When the mineral fibre insulation mat is manufactured as a three-layer arrangement, one or both outer side surfaces can be provided with similar or identical surface coatings.

The method according to the present invention may further comprise the additional step of pressing the fourth mineral fiber composite web prior to introducing the fourth mineral fiber composite mat into the curing oven. Pressing the fourth mineral fiber composite web may comprise vertical pressing, longitudinal pressing and/or transverse pressing. It is believed that pressing the fourth mineral fiber composite web improves the homogeneity of the final product, since pressing the fourth mineral fiber composite web achieves a homogenizing effect on the central body of the fourth mineral fiber composite web, which central body is formed by the central body of the second mineral fiber nonwoven mat.

In order to provide a more homogeneous and compact mineral fiber mat which is fed into the curing oven in step g), the method according to the present invention preferably further comprises the additional step of compacting the fourth mineral fiber composite mat before introducing the fourth mineral fiber composite mat into the curing oven. By compacting the fourth mineral fiber composite mat, the homogeneity of the final product is improved, since compacting the fourth mineral fiber composite mat achieves a homogenizing effect on the central body of the fourth mineral fiber composite web, whereby the central body is formed by the central body of the second mineral fibre fleece mat.

The step g) of curing the first curable adhesive, as well as optionally the second and third curable adhesives, can be carried out in a number of different ways, depending on the type of curable adhesive(s), for example, by simply exposing the curable adhesive(s) to a curing gas or atmosphere, such as the atmosphere, by exposing the curable adhesive(s) to radiation, such as UV radiation or IR radiation. When the curable adhesive(s) are thermosetting adhesives, such as conventional resin-based adhesives commonly used in the mineral fiber industry, the process for curing the curable adhesive(s) includes the step of introducing the mineral fiber mat to be cured into a curing oven. The curing process is then carried out by a curing oven. Other alternative curing devices may include IR emitters, microwave emitters, etc.

Plate segments are preferably cut from the hardened mineral fiber insulation mat produced in step g) by cutting the hardened, fourth mineral fiber composite mat into plate segments in a separate production step.

The above-mentioned objective, advantage and features, together with numerous other objectives, advantages and features, are further achieved by a plant for producing a mineral fiber insulation mat, comprising:

a) first means for producing a first mineral fiber nonwoven mat defining a first longitudinal direction parallel to the mineral fiber mat and a second transverse direction parallel to the first mineral fiber mat, the first mineral fiber mat produced containing mineral fibers arranged generally in the second transverse direction and containing a first curable adhesive,

b) second means for moving the first mineral fibre mat in the first longitudinal direction of the first mineral fibre mat,

c) third means for folding the first mineral fiber mat parallel to the first longitudinal direction and perpendicular to the second transverse direction to produce a second mineral fiber nonwoven mat, the second mineral fiber nonwoven mat comprising a central body and surface layers disposed on opposite sides of the central body, the central body containing mineral fibers disposed generally perpendicular to the first longitudinal direction and the second transverse direction, and the surface layers containing mineral fibers disposed generally in the second transverse direction,

d) fourth means for moving the second mineral fibre mat in the first longitudinal direction,

e) fifth means for producing a third mineral fibre nonwoven mat defining a third direction parallel to the third mineral fibre mat, the third mineral fibre mat produced containing mineral fibres which are generally oriented in the third direction and containing a second curable adhesive, wherein the third mineral fibre mat is a mineral fibre mat with a higher density compared to the second mineral fibre mat,

f) sixth means for connecting the third mineral fibre mat to the second mineral fibre mat in surface contact therewith to produce a fourth mineral fibre composite mat, and

g) seventh means for curing the first and second curable adhesives so that the mineral fibers of the fourth mineral fiber composite mat are bonded together, thereby forming the mineral fiber insulation mat.

The plant of the present invention may advantageously comprise any of the above-mentioned features of the process according to the present invention.

The present invention will now be described in more detail with reference to the accompanying drawings, of which:

Fig. 1 is a schematic and perspective view showing a first production step for producing a mineral fiber insulation mat from a mineral fiber molding melt;

Fig. 2 is a schematic and perspective view showing a production step for compacting a mineral fiber insulation mat;

Fig. 3, 4, 5 and 6 are schematic and perspective views showing four alternative techniques for folding a mineral fibre insulation mat parallel to the longitudinal direction of the mineral fibre insulation mat;

Fig. 7 is a schematic and perspective view showing a production step for separating a surface layer of the folded mineral fiber insulation mat made according to the techniques disclosed in Figs. 3-6 and a production step for densifying the surface layer;

Fig. 8 is a schematic and perspective view showing a production step for transversely pressing a mineral fiber insulation mat produced in the production step shown in Fig. 7;

Fig. 9 is a schematic and perspective view showing the production step of bonding a surface layer, preferably a densified surface layer, to a mineral fiber insulation mat, or preferably a remaining part of a mineral fiber insulation mat, manufactured according to the techniques disclosed in Figs. 3-6 and from which a surface layer has been separated according to the technique disclosed in Fig. 7;

Fig. 10 is a schematic and perspective view showing a production step for curing a mineral fiber insulation mat and a production step for separating the cured mineral fiber insulation mat into plate segments;

Fig. 11 is a schematic and perspective sectional view showing the folded Mineral fiber insulation mat made according to the techniques disclosed in Figs. 3-6;

Figures 12 and 13 are diagrams showing the production parameters of a direct-coupled production facility producing general building insulation panels from a mineral fiber insulation mat made according to the teachings of the present invention, and

Figures 14 and 15 are diagrams similar to the views of Figures 12 and 13, respectively, showing the production parameters of a direct-coupled production line producing thermally insulating mineral fiber roofing panels from a mineral fiber insulation mat made according to the teachings of the present invention.

In Fig. 1, a first step for producing a mineral fiber insulation mat is disclosed. The first step involves forming mineral fibers from a mineral fiber molding melt mass which is prepared in a furnace 30 and fed from a chute 32 of the furnace 30 to a total of four rapidly rotating spinning wheels 34 to which the mineral fiber molding melt mass is fed as mineral fiber molding melt flow 36. While the mineral fiber molding melt flow 36 is fed to the spinning wheels 34 in a radial direction with respect thereto, a cooling gas flow is simultaneously fed to the rapidly rotating spinning wheels 34 in the axial direction thereof, thereby forming individual mineral fibers which are ejected or sprayed from the rapidly rotating spinning wheels 34, as shown by the reference numeral 38. The mineral fiber spray 38 is formed on a continuously operated first conveyor belt 42 which forms a primary mineral fiber insulation mat 40. A thermosetting adhesive is also added to the primary mineral fiber insulation mat 40 either directly to the mineral fiber insulation mat 40 or at the ejection stage of the mineral fibers from the spinning wheels 34, ie, at the formation stage of the individual mineral fibers. The first conveyor belt 42 consists, as can be seen from Fig. 1, of two conveyor belt sections. A first conveyor belt section which is inclined with respect to the horizontal direction and with respect to a second, substantially horizontal conveyor belt section. The first section represents a collection section, while the second section represents a conveying section through which the primary mineral fiber insulation mat 40 is conveyed to a second and a third continuously operated conveyor belt, designated by the reference numerals 44 and 46, respectively, which are operated synchronously with the first conveyor belt 42, wherein the primary mineral fiber insulation mat 40 comes to lie between two adjacent surfaces of the second and third conveyor belts 44 and 46, respectively.

The second and third conveyor belts 44 and 46, respectively, are connected to a fourth conveyor belt 48, which is a collection conveyor belt on which a secondary mineral fiber insulation mat 50 is collected when the second and third conveyor belts 44 and 46, respectively, are pivoted over the upper surface of the fourth conveyor belt 48 in the transverse direction with respect to the fourth conveyor belt 48. The secondary mineral fiber insulation mat 50 is then formed by placing the primary mineral fiber insulation mat 40 in overlapping ratio in the transverse direction of the fourth conveyor belt 48.

By producing the secondary mineral fiber insulation mat 50 from the primary mineral fiber insulation mat 40 as disclosed in Figure 1, a more homogeneous secondary mineral fiber insulation mat 50 is produced as compared to the less homogeneous primary mineral fiber insulation mat.

It should be noted that the overall orientation of the mineral fibers of the primary mineral fiber insulation mat 40 is parallel to the longitudinal direction of the mat 40 and the conveying direction of the first conveyor belt 42. In contrast to the primary mineral fiber insulation mat 40, the overall orientation of the mineral fibers of the secondary mineral fiber insulation mat 50 is substantially perpendicular and transverse to the longitudinal direction of the secondary mineral fiber insulation mat 50 and the conveying direction of the fourth conveyor belt 48.

In Fig. 2, a station for compacting and homogenizing an incoming mineral fiber insulation mat 50' is shown, the station for compacting and homogenizing the incoming mineral fiber insulation mat 50' to produce an outgoing mineral fiber insulation mat 50", the outgoing mineral fiber insulation mat 50" being more compact and homogeneous compared to the incoming mineral fiber insulation mat 50'. The incoming mineral fiber insulation mat 50' may be the secondary mineral fiber insulation mat 50 produced in the station shown in Fig. 1.

The compaction station comprises two sections. The first section comprises two conveyor belts 52" and 54", which are arranged on the upper side surface and the lower side surface of the mineral fiber insulation mat 50', respectively. The first section essentially forms a section in which the mineral fiber mat 50' entering the section is subjected to a height compression, which leads to a reduction in the overall height of the mineral fiber mat and a compression of the mineral fiber mat. The conveyor belts 52" and 54" are thus arranged in such a way that they are inclined from an inlet end on the left side of Fig. 2, at which inlet end the mineral fiber mat 50' enters the first section, to an outlet end from which the height-pressed mineral fiber mat is delivered to the second section of the compaction station.

The second section of the compaction station comprises three sets of rollers 56' and 58', 56" and 58" and 56''' and 58'''. The rollers 56', 56" and 56''' are arranged on the upper side surface of the mineral fiber mat, while the rollers 58', 58" and 58''' are arranged on the lower side surface of the mineral fiber mat. The second section of the compaction station provides a longitudinal pressing of the mineral fiber mat, wherein the longitudinal pressing causes a homogenization of the mineral fiber mat, since the mineral fibers of the mineral fiber mat are rearranged into a more homogeneous structure compared to the initial structure. The three roller sets 56' and 58', 56" and 58" and 56''' and 58''' of the second section are rotated at the same rotational speed, which is however lower than the rotational speed of the conveyor belts 52" and 54" of the first section, whereby the longitudinal pressing of the mineral fiber mat. The vertically and longitudinally pressed mineral fiber mat is output from the compaction station shown in Fig. 2 and is designated by the reference number 50".

It should be noted that the combined elevation and longitudinal pressing compaction station shown in Fig. 2 can be modified by removing either of the two sections, i.e., the first section forming the elevation pressing section or, alternatively, the second section forming the longitudinal pressing section. By removing either of the two sections of the compaction station shown in Fig. 2, a compaction section is provided which performs a single compaction or pressing operation, thus obtaining an elevation pressing station or, alternatively, a longitudinal pressing station. Although the elevation pressing section has been described with conveyor belts and the longitudinal pressing section has been described with rollers, both sections can be formed with belts or rollers. Likewise, the elevation pressing section can be formed with rollers and the longitudinal pressing section can be formed with conveyor belts.

Four alternative techniques for folding a mineral fiber insulation mat in the longitudinal direction of the mineral fiber insulation mat are disclosed in Figs. 3, 4, 5 and 6. In Figs. 3, 4, 5 and 6, the mineral fiber insulation mat 50" may be the outgoing mineral fiber insulation mat 50" shown in Fig. 2 or the mineral fiber insulation mat 50 produced in the station shown in Fig. 1.

In Fig. 3, the mineral fiber insulation mat 50" is brought into contact with a pressure roller 51, by which a continuous film 99 made of a thermoplastic material is applied to the upper side surface of the mineral fiber insulation mat 50". The continuous film made of the thermoplastic material is fed from a roll 98. After the continuous film 99 has been applied to the upper side surface of the mineral fiber insulation mat 50", the mineral fiber insulation mat 50" and the continuous film 67 applied thereto are pressed through a corrugated funnel 60', the funnel comprising two oppositely arranged corrugated guide plates 64' and 66' and two oppositely arranged end walls, one of which is designated by the reference numeral 62'. It is obvious that the foil 99 must have an elasticity that allows folding of the foil 99 and the mineral fiber insulation mat 50". The end walls of the corrugated funnel 60' and the corrugations of the corrugated funnel plates 64' and 66' converge from an inlet end of the corrugated funnel 60' to its outlet end. When the mineral fiber insulation mat 50" and the foil 99 applied thereto are pressed through the corrugated funnel 60', the mineral fiber insulation mat is folded in its longitudinal direction, whereby a corrugated and longitudinally folded mineral fiber insulation mat 50''' is obtained.

In Fig. 4, an alternative technique for producing the corrugated and longitudinally folded mineral fiber insulation mat 50''' from the flat mineral fiber insulation mat 50" is disclosed. The technique disclosed in Fig. 4 differs from the technique previously described with reference to Fig. 3 in that a funnel 60" is used, the funnel 60" differing from the corrugated funnel 60' shown in Fig. 3 in that the funnel 60" comprises flat, oppositely disposed walls, one of which is designated by the reference numeral 64", and curved end walls, one of which is designated by the reference numeral 62".

In Fig. 5, another alternative technique for producing a longitudinally folded mineral fiber insulation mat 50''' from the planar mineral fiber insulation mat 50" is shown. The corrugated and longitudinally folded mineral fiber insulation mat 50''' is produced according to the technique shown in Fig. 5 by a roller assembly 60''' which includes planar end walls 62''' which serve the same purpose as the planar end walls 62' and the curved end walls 62" shown in Figs. 3 and 4, respectively, i.e., the purpose of directing the outer edges of the planar mineral fiber insulation mat 50" to the corrugated and longitudinally folded form of the mineral fiber insulation mat 50'''. The roller assembly 60''' further includes a total of eight roller sets, each roller set including two rollers arranged on opposite sides of the mineral fiber insulation mat. In Fig. 5, two rollers designated by the reference numeral 68. The roller sets define a tapered arrangement which converges from an inlet end of the roller assembly 60''' to its outlet end, with the corrugated and longitudinally folded mineral fiber insulation mat 50''' being fed from the outlet end. The tapered shape serves to facilitate the corrugation and longitudinal folding of the flat mineral fiber insulation mat 50"in to support the shape of a folded mineral fiber insulation mat 50''' shown in Fig. 5.

In Fig. 6, another alternative technique for manufacturing a longitudinally folded mineral fiber insulation mat 50''' is shown. According to the technique disclosed in Fig. 6, a station 60"" is used, the station comprising a combined vertical/longitudinal pressing station and a transverse folding station. Thus, the station 60"" comprises a total of six roller sets, three sets of which are formed by the three roller sets 56', 58'; 56", 58"; and 56''', 58''' previously discussed with reference to Fig. 2.

The station 60"", shown in Fig. 6, further comprises three sets of rollers, of which a first set is formed by two rollers 152' and 154', a second set is formed by two rollers 152" and 154", and a third set is formed by two rollers 152''' and 154'''. The rollers 152', 152", 152''' are arranged on the upper side surface of the mineral fiber insulation mat 50", as are the rollers 56', 56", 56'''. The rollers 154', 154", 154''' are arranged on the lower side surface of the mineral fiber insulation mat 50", as are the rollers 58', 58", 58'''. The three roller sets 152', 154'; 152", 154"; and 152", 154''' serve the same purpose as the belt arrangements 52" and 54" previously discussed with reference to Fig. 2, i.e., the vertical compression of the mineral fiber insulation mat 50" entering the station 60"".

The three height-pressing roller sets 152', 154';152",154'''; and 152", 154''' are provided with a rotational speed which is identical to the speed of the mineral fiber insulation mat 50" entering the vertical pressing section of station 60"". The three sets of rollers which form the longitudinal pressing section, ie, the rollers 56', 58';56",58"; and 56''' and 58''', are operated at a reduced rotational speed which determines the longitudinal pressing ratio.

To create the longitudinal folds of the mineral fiber insulation mat 50" entering the station 60"" shown in Fig. 6, four crankshaft assemblies designated by the reference numerals 160', 160", 160''', 160"" are provided. The crankshaft assemblies have identical constructions and in the following description a single crankshaft assembly, the crankshaft assembly 160" will be described since the crankshaft assemblies 160', 160''', 160"" are identical to the crankshaft assembly 160" and include elements identical to the elements of the crankshaft assembly 160" and are designated by the same reference numerals but to which a single, double or triple prime has been added.

The crankshaft assembly 160" includes a motor 162" that drives a gear assembly 164" from which an output shaft 166" extends. A total of six gears 168" of identical shape are attached to the output shaft 166". Each of the gears 168" meshes with a corresponding gear 170". Each of the gears 170" represents a drive gear of a crankshaft lever system, which further includes an idler gear 172" and a crankshaft lever 174". The crankshaft levers 174" are arranged so that they from a retracted position to a raised position between two adjacent rollers on the lower right side of the mineral fiber insulation mat 50" entering the station 60"" and are designed to cooperate with the crankshaft levers of the crankshaft lever system 160' arranged on the upper right side of the mineral fiber insulation mat 50" entering the station 60"".

Likewise, the crankshaft levers of the crankshaft lever systems 160''' and 160"", which are arranged on the upper and lower left sides, respectively, of the mineral fiber insulation mat 50", which runs into the station 60"", are designed to cooperate in a manner described below.

As can be seen from Fig. 6, a first set of crankshaft levers 174', 174", 174''', 174"" of the crankshaft lever systems 160', 160", 160''' and 160"" is arranged between the first and second roller sets 152', 154' and 152", 154". Likewise, a second set of crankshaft levers is arranged between the second and third roller sets 152", 154" and 152''', 154'''.

The crankshaft levers of each of the six crankshaft lever sets have identical widths. Within each of the crankshaft lever systems 160', 160", 160''' and 160"", the first crankshaft lever is the widest crankshaft lever and the width of the crankshaft lever within each crankshaft lever system decreases from the first crankshaft lever to the sixth crankshaft lever, which is positioned behind the sixth roller set 56''', 58'''.

The motors of the crankshaft lever assemblies 160', 160", 160''', 160"" rotate the crankshaft levers of a particular crankshaft lever set synchronously with the other three crankshaft levers of the crankshaft lever set in question. The crankshaft levers of all six crankshaft lever sets are further operated synchronously and in synchronism with the speed of the mineral fiber insulation mat 50" entering the station 60"". The widest or first set of crankshaft levers are configured to begin folding the mineral fiber insulation mat 50" while crankshaft levers 174" and 174"" of crankshaft lever systems 160" and 160"" respectively are raised from positions below the lower side surface of the mineral fiber insulation mat 50" and brought into contact with the lower side surface of the mineral fiber insulation mat 50" and while crankshaft levers 174' and 174''' of crankshaft lever systems 160' and 160''' respectively are simultaneously lowered from positions above the upper side surface of the mineral fiber insulation mat 50" and brought into contact with the upper side surface of the mineral fiber insulation mat 50".

Further rotation of the output shafts 166', 166", 166''' and 166"" causes the crankshaft levers of the first set of crankshaft levers to be moved to the center of the mineral fiber insulation mat 50", thereby creating a fold in the center of the mineral fiber insulation mat 50". As the crankshaft levers of the first set of crankshaft levers reach the center position, the crankshaft levers of the crankshaft lever systems 160' and 160''' are raised, while the crankshaft levers of the Crankshaft lever systems 160" and 160"" are lowered and consequently lose contact with the upper or lower side surface of the mineral fiber insulation mat 50".

As the mineral fiber insulation mat 50" continues to move through the station 60"", the next or second set of crankshaft levers creates a second and a third fold of the mineral fiber insulation mat 50", with the second or third fold being located on an opposite side of the first fold, after which the third, fourth, fifth and sixth sets of crankshaft levers create additional folds in the mineral fiber insulation mat, thereby creating an overall longitudinally folded mineral fiber insulation mat.

The width of the crankshaft levers of each crankshaft lever set, the gear ratio of the gear assemblies 164', 164", 164''' and 164"", the gear ratio of the gears 168 and 170 and the speed of the mineral fiber insulation mat 50" entering the station 60"" are coordinated with each other and with the rotational speed of the vertical pressing and longitudinal pressing sections of the station to produce the longitudinally folded, vertically and longitudinally pressed mineral fiber insulation mat 50'''.

The integration of the vertical pressing section, the longitudinal pressing section and the longitudinal folding section into a single station, as previously described with reference to Fig. 6, is by no means obligatory for the operation of the longitudinal folding crankshaft system previously described with reference to Fig. 6. Thus, the vertical pressing section, the longitudinal pressing section and the longitudinal folding section can be separate, but the Incorporation of all three functions reduces the overall size of the manufacturing plant. It should be noted that folding the mineral fiber mat, as previously described with reference to Figs. 4, 5 and 6, causes compaction and pressing of the mat in the transverse direction, which further achieves homogenization of the mat compared to the unfolded, incoming mat.

11, a vertical sectional view of the corrugated and longitudinally folded mineral fiber insulation mat 50''' is shown. The corrugated and longitudinally folded mineral fiber insulation mat 50''' comprises a central core or body 28 and two oppositely disposed surface layers 24 and 26, the surface layers 24 and 26 being separated from the central core or body 28 of the corrugated and longitudinally folded mineral fiber insulation mat 50''' along imaginary separation lines 20 and 22, respectively. The surface layers 24 and 26 of the corrugated and longitudinally folded mineral fiber insulation mat 50''' consist of segments of the folded mineral fiber insulation mat, the segments containing mineral fibers oriented substantially transversely with respect to the longitudinal direction of the corrugated and longitudinally folded mineral fiber insulation mat 50'''. The corrugated and longitudinally folded mineral fiber insulation mat 50''' is made from the secondary mineral fiber insulation mat 50 by folding the secondary mineral fiber insulation mat 50, optionally after the secondary mineral fiber insulation mat 50 has been compacted as described below with reference to Fig. 8, and the general orientation of the mineral fibers of the secondary mineral fiber insulation mat 50 is thus maintained within the segments of the corrugated and longitudinally folded mineral fiber insulation mat 50''', which segments together form the surface layers 24 and 26.

The central core or body 28 of the corrugated and longitudinally folded mineral fiber insulation mat 50''' is comprised of segments of the corrugated and longitudinally folded mineral fiber insulation mat 50''', the segments being folded perpendicular to the segments of the surface layers 24 and 26 of the mineral fiber insulation mat 50'''. The mineral fibers of the central core or body 28 of the corrugated and longitudinally folded mineral fiber insulation mat 50''' are thus oriented substantially perpendicular to the longitudinal direction as well as the transverse direction of the corrugated and longitudinally folded mineral fiber insulation mat 50'''.

The corrugated and longitudinally folded mineral fiber insulation mat 50''' shown in Fig. 9 and manufactured according to the techniques previously discussed with reference to Figs. 3, 4, 5 and 6 is further processed in a station shown in Fig. 7, in which station the surface layer 24 is separated from the central core or body 28 of the corrugated and longitudinally folded mineral fiber insulation mat 50''' along the imaginary separation line 20 shown in Fig. 9. The separation of the surface layer 24 from the remainder of the mineral fiber insulation mat is accomplished by a cutting tool 72, while the remainder of the mineral fiber insulation mat is carried and conveyed by a conveyor belt 70. The cutting tool 72 may be a fixed cutting tool or knife or, alternatively, be a transversely reciprocating cutting tool. The surface layer 24 severed from the mineral fiber insulation mat is diverted from the path of travel of the remainder of the mineral fiber insulation mat by a conveyor belt 74 and is passed from the conveyor belt 74 to three sets of rollers comprising a first set of rollers 76' and 78', a second set of rollers 76" and 78" and a third set of rollers 76''' and 78''', which three sets of rollers together form a compaction or pressing section similar to the second section of the corresponding station previously described with reference to Fig. 2.

Fig. 8 shows a cross-pressing station, which is designated in its entirety by the reference numeral 80. In station 80, the central core or body 28, or alternatively the corrugated and longitudinally folded mineral fiber insulation mat 50''' produced in one of the stations previously described with reference to Figs. 3, 4, 5 and 6, is brought into contact with two conveyor belts 85 and 86 which define a constriction in which the mineral fiber insulation mat is cross-pressed, and brought into contact with a total of four surface finishing rollers 89a, 89b, 89c and 89d which, together with like rollers not shown in the drawing and arranged opposite the rollers 89a, 89b, 89c and 89d, serve to assist in cross-pressing the central core or body 28. The conveyor belts 85 and 86 are mounted on rollers 81, 83 and 82, 84 respectively.

From the cross-pressing station 80, a cross-pressed and compacted central core or body 28' is fed. As the central core or body 28 is passed through the cross-pressing station 80 and formed into the cross-pressed central core or body 28', the core or body is held by rollers which constitute an input roller 87 and an output roller 88.

Although the central core or body 28 that passes into the cross-pressing station 80 preferably consists of the previously described central core or body that has been severed from the mineral fiber insulation mat 50" as previously described with reference to Fig. 7, the mineral fiber insulation mat 50" may alternatively be processed in the station 80 shown in Fig. 8.

Provided that the central core or body 28 or the mineral fiber insulation mat 50''' being cross-pressed in the station 80 is provided with an upper surface layer such as the foil 99 previously described with reference to Fig. 3, the foil must have a structure compatible with the cross-pressing of the mat-foil assembly. Thus, the foil applied to the upper side surface of the mineral fiber insulation mat 50" as shown in Fig. 3 must be compressible and conformable to the reduced width of the cross-pressed central core or body 28' or the cross-pressed mineral fiber insulation mat exiting the cross-pressing station 80.

When compaction of the separated surface layer 24 is completed, as previously described with reference to Fig. 7, the compacted surface layer 24 is returned to the remainder of the mineral fiber insulation mat or central core or body, which has preferably been cross-pressed as previously described with reference to Fig. 8, and bonded into facing contact with the upper surface of the central core or body 28 as shown in Fig. 9.

In Fig. 9, a roller set comprising a roller 79' and a roller 79" arranged on the upper and lower side surfaces of the surface layer 24, respectively, forms a roller set by which a surface film 99' fed from a roller 98' is applied to the upper surface of the compacted surface layer 24. From the rollers 79' and 79", the surface layer 24, which is an integral mineral fiber insulation mat of higher density compared to the central core or body 28, is shifted to the upper surface of the central core or body 28 by two rollers 77' and 77". The roller 77" is arranged below the surface layer 24 and represents a turning roller, while the roller 77', which is positioned above the upper side surface of the surface layer 24, is used to press the densified surface layer 24 in facing contact with the upper side surface of the central core or body 28 which is carried and conveyed by the conveyor belt 70 also shown in Fig. 7. After the densified surface layer 24 has been placed in surface contact with the upper side surface of the central core or body 28, a mineral fiber insulation mat assembly is obtained and this assembly is designated in its entirety by the reference numeral 90.

In Fig. 9, another foil 99" is shown in dashed line. This foil is fed from a roll 98". The foil 99" may be a continuous foil or, alternatively, a grid foil, i.e., a foil similar to the surface foil 99' previously described. It must be emphasized, however, that the foils 99, 99' and 99" optionally represent features that may be omitted if an integral mineral fiber insulation mat structure is to be created. Alternatively, one or more of the above-mentioned foils or all of the foils may be included in various embodiments of the mineral fiber insulation mat made in accordance with the teachings of the present invention.

It should be noted that the densified surface layer 24 separated from the mineral fiber insulation mat 50''' as shown in Fig. 7 may alternatively be provided by a separate production line, wherein one of the production stations shown in Figs. 3, 4, 5 and 6 may be directly connected to the production station shown in Fig. 9, optionally via the production station shown in Fig. 8, thus eliminating the production station shown in Fig. 7. Preferably, the production station shown in Fig. 7 is designed to separate two surface layers from the central core or body 28 to produce two separate surface layers separated from opposite side surfaces of the central core or body 28, the surface layers being processed according to the technique previously described with reference to Fig. 7 to produce two high density surface layers which are processed according to the technique previously described with reference to Fig. 9. technique to the central core or body 28 at its opposite surfaces, whereby the central core or body 28, which has preferably been cross-pressed as previously described with reference to Fig. 8, is sandwiched between two opposite surface layers similar to the surface layer 24 shown in Fig. 9.

In Fig. 10, the mineral fiber insulation mat assembly 90 is moved through a curing station consisting of a curing oven comprising opposed curing oven sections 92 and 94 which generate heat to heat the mineral fiber insulation mat assembly 50 to an elevated temperature so that the thermosetting adhesive of the mineral fiber insulation mat assembly is cured and the mineral fibers of the central core or body of the assembly and the mineral fibers of the densified surface layer or layers are bonded together to form an integral, bonded mineral fiber insulation mat which is cut into plate-like segments by a knife 96. When the film 99 and optionally the continuous films 99' and 99" are provided, the thermoplastic material of the films 99, 99' and 99" is also melted, thereby providing additional bonding of the mineral fibers of the mineral fiber insulation mat. In Fig. 10, a simple plate-like segment 10" is shown comprising a central core 12 and an upper layer 14. The upper layer 14 consists of the densified surface layer 24, while the core 12 consists of the central core or body 28 of the corrugated and longitudinally folded mineral fiber insulation mat 50''' shown in Fig. 9.

example 1

A thermal insulation panel consisting of a mineral fiber insulation mat manufactured by the process according to the present invention as previously described with reference to Figs. 1-10 is manufactured according to the specifications set out below:

The process comprises steps similar to those previously described with reference to Figures 1, 2, 6, 7, 8, 9 and 10. The production capacity of the plant is 5000 kg/h. The basis weight of the primary mat produced in the station disclosed in Figure 1 is 0.4 kg/m² and the width of the primary mat is 3600 mm. The density of the central core or body 28 is 20 kg/m³. The rates of longitudinal compression produced in two separate stations similar to the station disclosed in Figure 2 are 1:1 and 1:2 respectively and the rate of transverse compression produced in the station disclosed in Figure 8 is 1:2. The finished panel comprises a single surface layer with a basis weight of 1 kg/m². The rate of longitudinal compression of the surface layer is 1:2. The thickness of the surface layer is 10.00 mm and the density of the surface layer is 100 kg/m³. The width of the mineral fiber insulation mat manufactured in Fig. 1 is 1800 mm.

The production parameters used are listed in Tables A and B below: Table A

A = Speed of belt 42 of the spinning chamber

B = Speed of belt 48

C = speed of belt 70 after the first longitudinal pressing (Fig. 2)

D = speed of belt 70 after transverse pressing (Fig. 8)

E = speed of belt 70 after the second longitudinal pressing (Fig. 2)

F = Speed of belt 70 before the curing oven (Fig. 5) Table B

G = Weight per unit area of the mineral fibre insulation mat on Band 42

H = weight per unit area of the mineral fibre insulation mat after the first longitudinal pressing (Fig. 2)

I = Weight per unit area of the mineral fibre insulation mat after transverse pressing (Fig. 8)

J = weight per unit area of the mineral fibre insulation mat before the second longitudinal pressing (Fig. 2)

K = weight per unit area of the mineral fibre insulation mat after the second longitudinal pressing (Fig. 2)

L = Weight per unit area of the mineral fiber insulation mat before the curing oven

Fig. 12 shows a diagram showing the correspondence between the parameters listed in Table A. The reference numerals used in Fig. 12 refer to the parameters listed in Table A.

Fig. 13 shows a diagram showing the correspondence between the parameters listed in Table B. The reference numerals used in Fig. 13 refer to the parameters listed in Table B.

Example 2

A composite roof panel made from a mineral fiber insulation mat made by the process of the present invention as previously described with reference to Figures 1-10 is produced according to the specifications set out below:

The process comprises steps similar to those previously described with reference to Figures 1, 2, 6, 7, 8, 9 and 10. The production capacity of the plant is 5000 kg/h. The basis weight of the primary mat produced in the station disclosed in Figure 1 is 0.6 kg/m² and the width of the primary mat is 3600 mm. The density of the central core or body 28 is 110 kg/m³. The rates of longitudinal compression produced in two separate stations similar to the station disclosed in Figure 2 are 1:3 and 1:2 respectively and the rate of transverse compression produced in the station disclosed in Figure 8 is 1:2. The finished board comprises a single surface layer having a basis weight of 3.57 kg/m². The rate of longitudinal compression of the surface layer is 1:2. The thickness of the surface layer is 17.00 mm and the density of the surface layer is 210 kg/m³. The width of the mineral fiber insulation mat produced in Fig. 1 is 1800 mm. The production parameters used are shown in Tables C and D below: Table C

A = Speed of belt 42 of the spinning chamber

B = Speed of belt 48

C = speed of belt 70 after the first longitudinal pressing (Fig. 2)

D = speed of belt 70 after transverse pressing (Fig. 8)

E = speed of belt 70 after the second longitudinal pressing (Fig. 2)

F = Speed of belt 70 before the curing oven (Fig. 5) Table D

G = Weight per unit area of the mineral fibre insulation mat on Band 42

H = weight per unit area of the mineral fibre insulation mat after the first longitudinal pressing (Fig. 2)

I = Weight per unit area of the mineral fibre insulation mat after transverse pressing (Fig. 8)

J = weight per unit area of the mineral fibre insulation mat before the second longitudinal pressing (Fig. 2)

K = weight per unit area of the mineral fibre insulation mat after the second longitudinal pressing (Fig. 2)

L = Weight per unit area of the mineral fiber insulation mat before the curing oven

Fig. 14 shows a diagram similar to that of Fig. 12, showing the correspondence between the parameters previously listed in Table C.

In Fig. 15 a diagram similar to that of Fig. 13 is presented, showing the correspondence between the parameters previously listed in Table D.

Example 3

The significance of longitudinal and transverse compression of the mineral fibre insulation mat is shown in the data given in the following Table E: Table E

The mineral fiber insulation boards according to the present invention clearly show an increased compressive strength and an increased elastic modulus compared to a conventional thermal insulation board. However, the mechanical performance of the mineral fiber insulation boards according to the present invention is further increased if the mineral fiber mat from which the Insulation panels produced are subjected to longitudinal and transverse pressing, as previously discussed with reference to Fig. 2 and Fig. 8.

Claims (32)

1. A method for producing a mineral fiber insulation mat, comprising the following steps: a) producing a first mineral fiber nonwoven mat (50") defining a first longitudinal direction parallel to the first mineral fiber mat (50") and a second transverse direction parallel to the first mineral fiber mat (50"), the first mineral fiber mat (50") containing mineral fibers generally arranged in the second transverse direction and containing a first curable adhesive, b) moving the first mineral fiber mat (50") in the first longitudinal direction of the first mineral fiber mat (50"), c) folding the first mineral fiber mat (50") parallel to the first longitudinal direction and perpendicular to the second transverse direction to produce a second mineral fiber nonwoven mat (50'''), wherein the second mineral fiber mat (50''') comprises a central body (28) and surface layers (24, 26) disposed on opposite sides of the central body (28), the central body (28) containing mineral fibers disposed generally perpendicular to the first longitudinal direction and the second transverse direction, and the surface layers (24, 26) containing mineral fibers disposed generally in the second transverse direction, d) moving the second mineral fibre mat (50''') in the first longitudinal direction, e) creating a third nonwoven mineral fiber mat (24) defining a third direction parallel to the third mineral fiber mat (24), the third mineral fiber mat (24) containing mineral fibers arranged generally in the third direction and containing a second curable adhesive, the third mineral fiber mat (24) being a higher density mineral fiber mat compared to the second mineral fiber mat, f) connecting the third mineral fiber mat (24) to the second mineral fiber mat (50''') in surface contact therewith to produce a fourth mineral fiber composite mat (90), and g) curing the first and second curable adhesives so that the mineral fibers of the fourth mineral fiber composite mat (90) are bonded together, thereby forming the mineral fiber insulation mat. 2. The method of claim 1, wherein the third mineral fiber nonwoven mat (24) is formed by separating a surface segment layer of the first mineral fiber mat (50") therefrom and compacting the surface segment layer to produce the third mineral fiber nonwoven mat (24). 3. The method of claim 2, wherein compacting the surface segment layer comprises the step of folding the surface segment layer so that the third mineral fiber mat is produced which contains mineral fibers which are arranged generally transversely with respect to the longitudinal direction of the third mineral fiber mat (24). 4. The method of claim 1, wherein the third mineral fiber nonwoven mat (24) is formed by separating one (24) of the surface layers (24, 26) of the second mineral fiber mat (50''') from its central body (28) and compacting the one (24) of the surface layers (24, 26) to produce the third mineral fiber mat (24). 5. A method according to any one of claims 1-4, comprising the additional step, similar to step e), of producing a fifth mineral fiber nonwoven mat similar to the third mineral fiber mat (24), and the step of joining in step f) the fifth mineral fiber mat to the second mineral fiber mat (50''') in surface contact therewith, so that the second mineral fiber mat (50''') lies between the third and fifth mineral fiber mats in the fourth mineral fiber mat (90). 6. The method of any of claims 1-5, wherein the folding of step c) comprises folding the first mineral fiber mat (50") to create continuous corrugations extending in the first longitudinal direction of the first mineral fiber mat (50"). 7. Method according to one of claims 1-6, wherein the third direction is perpendicular to the first longitudinal direction. 8. Method according to one of claims 1-6, wherein the third direction is identical to the first longitudinal direction. 9. The method of any of claims 1-8, comprising the preliminary step of making the first mineral fiber mat (50") from a base mineral fiber nonwoven mat (40) by arranging the base mineral fiber mat in overlapping layers. 10. The method of claim 9, wherein the base mineral fiber nonwoven mat (40) is arranged in overlapping relationship generally in the second transverse direction. 11. The method according to any one of claims 1-10, further comprising the additional step of height-compacting the first mineral fiber fleece mat (50") produced in step a). 12. The method according to any one of claims 1-11, further comprising the additional step of longitudinally compacting the first mineral fiber nonwoven mat (50") produced in step a) and additionally or alternatively the additional step of longitudinally compacting the second mineral fiber nonwoven mat (50''') produced in step c). 13. The method according to any one of claims 1-12, further comprising the additional step of transversely compacting the second mineral fiber fleece mat (50''') produced in step c). 14. The method according to any one of claims 1-13, comprising the additional step of compacting the fourth mineral fiber composite mat (90) before introducing the fourth mineral fiber composite mat (90) in step g) into a curing oven (92, 94). 15. Method according to one of claims 1-14, further comprising the step of applying a film (99', 99") to one side surface or to both side surfaces of the first mineral fiber fleece mat (50") and/or applying a film (99', 99") to one side surface or to both side surfaces of the second mineral fiber fleece mat (50'''). 16. The method of any of claims 1-15, further comprising the step of cutting the cured fourth mineral fiber composite mat (90) into plate segments (10', 10"). 17. Plant for producing a mineral fiber insulation mat, comprising: a) first means (30, 44) for producing a first nonwoven mineral fiber mat (50") defining a first longitudinal direction parallel to the first mineral fiber mat (50") and a second transverse direction parallel to the first mineral fiber mat (50"), the first produced mineral fiber mat (50") containing mineral fibers arranged generally in the second transverse direction and containing a first curable adhesive, b) second means (48) for moving the first mineral fiber mat (50") in the first longitudinal direction of the first mineral fiber mat (50"), c) third means (60, 60", 60''', 60"") for folding the first mineral fiber mat (50") parallel to the first longitudinal direction and perpendicular to the second transverse direction to produce a second mineral fiber nonwoven mat (50'''), the second mineral fiber nonwoven mat (50''') comprising a central body (28) and surface layers (24, 26) disposed on opposite sides of the central body (28), the central body (28) containing mineral fibers disposed generally perpendicular to the first longitudinal direction and the second transverse direction, and the surface layers (24, 26) containing mineral fibers disposed generally in the second transverse direction, d) fourth means (70) for moving the second mineral fiber mat (50''') in the first longitudinal direction, e) fifth means (72) for producing a third nonwoven mineral fiber mat (24) defining a third direction parallel to the third mineral fiber mat (24), the third mineral fiber mat (24) produced containing mineral fibers arranged generally in the third direction and containing a second curable adhesive, the third mineral fiber mat (24) being a higher density mineral fiber mat compared to the second mineral fiber mat, f) sixth means (77') for connecting the third mineral fiber mat (24) to the second mineral fiber mat (50''') in surface contact therewith to produce a fourth mineral fiber composite mat (90), and g) seventh means (92, 94) for curing the first and second curable adhesives so that the mineral fibers of the fourth mineral fiber composite mat (90) are bonded together, thereby forming the mineral fiber insulation mat. 18. Plant according to claim 17, wherein the fifth means (72) for producing the third mineral fiber nonwoven mat (24) is designed such that a surface segment layer of the first mineral fiber mat (50") is separated therefrom and the surface segment layer is compacted to produce the third mineral fiber nonwoven mat (24). 19. The plant of claim 18, wherein the fifth means (72) for compacting the surface segment layer is arranged such that the surface segment layer is folded so as to produce the third mineral fiber mat containing mineral fibers arranged generally transversely with respect to the longitudinal direction of the third mineral fiber mat (24). 20. Plant according to claim 17, wherein the fifth means (72) for producing the third mineral fiber fleece mat (24) is designed such that one (24) of the surface layers (24, 26) of the second mineral fiber mat (50''') is separated from its central body (28) and one (24) of the surface layers (24, 26) is compacted to produce the third mineral fiber mat (24). 21. The system of any of claims 17-20, further comprising eighth means similar to the fifth means for producing a fifth mineral fiber mat similar to the third mineral fiber mat (24), and ninth means for joining the fifth mineral fiber mat to the second mineral fiber mat (59"") in surface contact therewith so that the second mineral fiber mat (50''') lies between the third and fifth mineral fiber mats in the fourth mineral fiber mat (90). 22. Installation according to one of claims 17-20, wherein the third means (60, 60", 60''', 60"") is designed for folding the first mineral fiber mat (50") so that continuous corrugations extending in the first longitudinal direction of the first mineral fiber mat (50") are produced. 23. Installation according to one of claims 17-22, wherein the third direction is perpendicular to the first longitudinal direction. 24. Installation according to one of claims 17-22, wherein the third direction is identical to the first longitudinal direction. 25. Plant according to one of claims 17-24, wherein the first means (30, 44) for producing the first mineral fiber mat (50") from a base mineral fiber nonwoven mat (40) are formed by arranging the base mineral fiber mat in overlapping layers. 26. The system of claim 25, wherein the first means (30, 44) for arranging the base mineral fiber nonwoven mat (40) in overlapping relationship are generally in the second transverse direction. 27. Plant according to one of claims 17-26, further comprising tenth means (52", 54") for height-compacting the first mineral fiber fleece mat (50") produced by the first means. 28. Plant according to one of claims 17-27, further comprising eleventh means (56', 56", 56''', 58', 58", 58''') for longitudinally compacting the first mineral fiber fleece mat (50") produced by the first means (30, 44) and additionally or alternatively twelfth means for longitudinally compacting the second mineral fiber fleece mat (50''') produced by the third means (60', 60" 60''', 60""). 29. Plant according to one of claims 17-28, comprising thirteenth means (80) for transversely compacting the second mineral fiber fleece mat (50''', 28) produced by the third means (60', 60" 60''', 60"", 28). 30. Plant according to one of claims 17-29, comprising fourteenth means (52", 54", 56', 56", 56''', 58', 58", 58''', 80) for compacting the fourth mineral fiber composite mat (90) before the hardening of the fourth mineral fiber composite mat (90) by the seventh means (92, 94). 31. System according to one of claims 17-30, further comprising fifteenth means (77') for applying a film (99', 99") to one side surface or to both side surfaces of the first mineral fiber fleece mat (50") and/or for applying a film (99'; 99") to one side surface or to both side surfaces of the second mineral fiber fleece mat (50'''). 32. Plant according to one of claims 17-31, further comprising sixteenth means (96) for cutting the hardened fourth mineral fiber composite mat (90) into plate segments (10', 10").