SK283915B6 - Process and apparatus for the production of a mineral fibreboard - Google Patents

Abstract

In a continuous process for the production of a bonded mineral fibreboard a fleece is compressed in the thickness direction to a first thickness substantially without simultaneous longitudinal compression and then compressed in length, no further thickness compression preferably taking place before the bonding of the fleece. During the longitudinal compression the precompressed fleece is clamped to a thickness in the range of between approximately 1 and 1.3, preferably between 1 and 1.1 of the nominal thickness of the finished product. The preferably single-stage longitudinal compression to 2 to 10 times the weight/unit area of the precompressed fleece is substantially carried out so as to avoid any pleating of the fleece and prevent any break-out of the fleece between the longitudinal compression unit (19; 19') and the bonding station (25). A multiply bonded mineral fibreboard may be obtained by longitudinally compressing of fleece and then dividing it into two or more layers, subjecting at least one of these layers to thickness and/or longitudinal compression and then recombining them.

Description

Technical field

The invention relates to a process for the continuous production of bonded mineral fiber boards and to an apparatus for carrying out the process.

BACKGROUND OF THE INVENTION

Various improvements in the production of mineral fiber boards have been disclosed in recent years. A substantial improvement in the properties of mineral fiber boards can be achieved, for example by reorienting the fibers in the manufacturing process so that the fibers are aligned predominantly perpendicular to the large surfaces of the board. As a result, it is possible to increase the compressive and tensile strength perpendicular to the plane of the slab.

Various methods are known in which the fibers are reoriented so that the article obtains a corrugated arrangement, but usually a higher efficiency is obtained when the finished article is substantially free of corrugation. There are many disclosed methods for longitudinally compressing a fibrous web to produce either a corrugated product or a non-corrugated product. Such a method is described in DE 16 35 620. It is clear from the description and the drawing that the extent of longitudinal compression is quite small (maximum 35%, as shown in the examples), and that it can be accompanied by a slight increase in thickness during longitudinal compression .

Many methods including longitudinal compression also include significant compression to thickness, after longitudinal compression and before final curing. In EP 133 083, for example, the web is subjected to substantial longitudinal compression in many stages and then subjected to compression to the thickness at the entrance to the curing oven. The final product has a substantially isotropic fiber orientation.

Other methods of longitudinal compression, designed to prevent undulations, are described, for example, in U.S. Pat. Nos. 4,567,078, WO 91/14816 and WO 94/16164.

It would therefore be desirable to develop a longitudinal compression method which avoids substantial curling of the starting web but which results in a significant improvement in properties, as compared to properties achievable by known methods. In particular, it should be desirable to produce mineral fiber boards with improved physical properties, such as improved compressive and tensile strength, and improved insulation values. In particular, it should be desirable to achieve these better results with less use of raw materials such as reduced fiber and binder.

SUMMARY OF THE INVENTION

Said objectives are achieved by a process for the continuous production of bonded mineral fiber sheets having a thickness of t of a web of a thickness greater than 2 t. wherein in this manner the web is deeply compressed, substantially without simultaneous longitudinal compression, to a first thickness and to a basis weight w, then the web is longitudinally compressed, turning to a second thickness, thereby forming a longitudinally compressed web, further forming the longitudinally compressed web conveyed to a bonding station to form a bonded fiber board according to the invention, the principle being that the first thickness is in the range of 0.8 to 1.5 t, in particular in the range of 0.9 to 1.3 t, the second thickness is in the range of I up to 1.3 t, in particular 1 to 1.1 t, the longitudinal compression is carried out continuously or in one or several stages, without the corrugation of the web and forms a longitudinally compressed web having a basis weight of 2 to 10 w and the web is forcibly held against tearing, when conveyed between the longitudinal compression stage and the coupling stage.

Since the compressed web has a basis weight of 2 to 10 w, it can be reasonably asserted that the longitudinal compression can be performed at about 0.5 to 0.1 of the original web length.

The invention also encompasses a method of continuously manufacturing bonded mineral fiber boards, in which the fiber felt is pre-compressed in a thickness direction to a thickness of 1 to 3 thicknesses of the final product (especially substantially the same thickness as the nominal thickness of the final product) and then subjected to longitudinally compressing by means of at least two pairs of conveyors, driven at different speeds, to form the longitudinally compressed felt, and then joining at a bonding station to a bonded mineral fiber plate according to the invention, the essence of which is the felt thickness in the longitudinal compression stage; upstream of the bonding station is about 0.9 to 1.3 of the thickness of the final product, wherein the longitudinal compression is performed substantially without compression to a thickness, wherein the longitudinal compression is performed to 0.5 to 0.1 of the original length, which compression is performed at a a continuous compression zone, and the felt is held to prevent tearing between the longitudinal compression unit and the coupling station.

The invention further encompasses a novel device as defined in the claims. Since the web is in a certain longitudinal compression, it is subjected to some bulging outside the conveyor through which the web is conveyed, and a suitable means must be used to force the web to break (ie bulging outside the support device) when conveyed between the longitudinal compression unit; connecting station. The means may be a belt, rollers or other guides which will adequately limit the longitudinally compressed web in the desired longitudinal path and prevent significant deviation of the web from the desired path.

Surprisingly, it has been found that in a novel way, products with significantly better properties can be produced compared to the prior art. Unlike known products, new products differ in a very homogeneous density. The fibers are uniformly felted and no preferred fiber orientations can be detected (Fig. 12). On a larger scale, it has been found that the random orientation of the fibers is arranged in a partial wavy pattern.

Significant savings in material resources have been achieved by the process according to the invention compared to conventional production methods. In particular, the amount of fibers required to achieve specific physical values may be up to 15 to 25% lower. Products made by the new manufacturing process are therefore much lighter than conventional products having the same physical properties. Since production costs depend substantially on the amount of fibers used, significant savings can also be achieved in a new way.

In the preliminary compression stage, the relatively thin web is pre-compressed to a basis weight w (kg / nT) and then further compressed to a final weight, in a longitudinal compression unit, which may also be referred to as an optimization unit. Contrary to expectation, this extremely high compression of the pre-compressed web to 2 to 10 times, in particular 2 to 6 times the weight of the pre-compressed web, results in virtually no corrugation of the web surface. Multiplying the basis weight of the web or felt can be achieved by suitable longitudinal compression of the web with substantially equal distances between the top and bottom of the web.

EN 283915 Β6 lawyers, for example according to the nominal thickness of the final product.

Although longitudinal compression of the web can be achieved by a series of sequential steps, the longitudinal compression of the web is preferably a one-stage process, wherein the basis weight of the longitudinally compressed web and bonded board is 2 to 6 times, especially 2.5 to 5 times, and most preferably 2.5 to 3. 5 times the weight of the pre-compressed web. The resulting product has high compressive strength and good insulating value.

The longitudinal compression is preferably performed by feeding the web by the first conveyor to the second conveyor, wherein the second conveyor is driven at a lower speed than the first conveyor. The conveyor device may consist of a belt, roller or chain conveyor. Preferably, roller conveyors are used, since these conveyors achieve a total micro-density that is extremely homogeneous. In particular, the diameter of the rollers and the spacing between the rollers are such that the nonwoven or ripple of the web can be substantially neither ruptured. In particular, the distance between the two adjacent rollers is 1 to 50 mm, more preferably 2 to 30 mm, and in the most preferred embodiment less than 20 mm. The permissible roll distance depends essentially on the fleece density, the degree of longitudinal compression in the compression unit, and the thickness of the board produced. Products of different thickness and high density can be produced with a small roller distance. Although the rollers may be individually driven, in a preferred embodiment they are joined to groups, each group having a row of rollers.

In the process according to the invention, products with a density of in particular approximately 40 to 200 kg / m ³ can be produced. In a particularly preferred variant, after longitudinal compression, the web is expanded in the conveying direction. For this purpose, for example, the web can be first compressed to a higher pressure, for example 20 to 40% relative to the desired density of the final product, and then released by stretching. This helps to prevent undesirable undulations of the web. The overall micro-density can also be improved. Pressure relief by stretching may be particularly important in the case of high density products, for example products with a density greater than 140 kg / m ³ . The compression and release operation may also be repeated.

The web may consist of glass wool, mineral wool or other synthetic fibers. However, the web consists mainly of chemical glass fibers, in particular mineral fibers, and contains an uncured binder. The binder content by weight may be about 0.7 to 7%, often 1 to 4%. In particular, the binder is curable in a curing oven. The bonding of the web can also be effected by reinforcing the fibers of the web itself or by felting, instead of or in addition to bonding by curing the binder.

Mineral fibers with an average length of about 0.3 to 50 mm, in particular 0.5 to 15 mm, and a thickness of about 1 to 12 μτη, in particular about 3 to 8 µm, are preferably used. Mineral fibers with an average length of about 2 to 10 mm, in particular about 2 to 6 mm, and an average thickness of about 1 to 12 µm, in particular about 3 to 6 or 7 µm, can also be used. The average length of the mineral fibers, which is usually shorter than the length of the glass fibers, is generally 2 to 4 mm, and the average diameter value is 3 to 4 µm.

During laying of the web on the conveyor, the predominant fiber orientation is preferably altered or partially compensated. This can be achieved, for example, by means of a spinning device adapted to swing obliquely to the conveying direction or by air deposition. In this way, the density distribution of the web can be improved and the fiber orientation can be changed, which has a beneficial effect on the mechanical properties of the resulting product. The primary web is preferably deposited on the collecting belt in layers by means of a rocking belt adapted to rock at an angle to the conveying direction. Thus, a primary web is formed by transverse lapping. In this way, the fibers are partially reoriented, and the homogeneity (transverse distribution) of the web deposited on the collecting belt can be improved.

Advantageously, 2 to 60 layers, in particular 2 to 40 to 50 layers, may be superimposed. This creates a certain reorientation of the fibers.

The fibers may deviate, for example transversely from the conveying direction, while the compression, in particular the longitudinal compression, can be performed simultaneously.

According to a particularly preferred variant, the thickness of the longitudinally compressed web is divided into two or more web auxiliary layers, parallel to the main webs of the web, while to prevent any deformation in the thickness direction, the web auxiliary layers are retained on opposite web webs. The at least one nonwoven web is compressed in the thickness direction and / or in the longitudinal direction, and the nonwoven webs are then joined and subsequently bonded. In this way, a multi-layer product can be produced.

Although the adherence of the nonwoven webs is normally satisfactory due to curing of the binder, the mating surfaces of the nonwoven webs may be sprayed or impregnated with the binder prior to bonding. In principle, the bonded nonwoven layers held together by suitable means can be compressed once more to a thickness. However, these webs are preferably longitudinally compressed prior to bonding. This longitudinal compression can be performed in a ratio of 1.1: 1 to a maximum of 2: 1. The size of the contact surfaces can be increased by a final longitudinal compression so that the bonding of the web layers is improved.

Although the new device may have individually driven rollers, in particular it is equipped with at least two groups of rollers, with two or more rollers. In particular, the compression unit is provided with at least about 10 to 12 rollers to compress the fibrous batt. Thus, the compressed felt can advantageously form a corrugated fiber structure. Further preferred embodiments are defined in the subclaims. The invention also encompasses a method for continuously manufacturing single-layer or multi-layer fiber boards, in which the fiber felt is pre-compressed by at least two pairs of conveyors driven at different speeds, further compressed longitudinally or longitudinally and thicknesswise and then consolidated according to the invention. that the fiber batt is pre-compressed to 1 to 3, usually 1 to 1.5 times the nominal thickness of the finished product, and then compressed in length or only lengthwise in the optimization unit by means of conveyors equipped with two opposing groups of rollers, each group it has two or more rollers, wherein the longitudinal compression is performed to 0.5 to 0.1 of the original length in the continuous or quasi-continuous compression region, and wherein the thickness of the finished product is achieved in the optimization unit.

The invention also encompasses an apparatus for carrying out the described method, comprising at least one fiber felt collecting strip, a pre-compression stage for compressing the fiber felt, at least two conveyors arranged in succession, and driven at different speeds for longitudinal or longitudinal and thickness compression of the fibrous of a felt and a curing oven for consolidating a longitudinal and rake compressed felt according to the invention, wherein the optimization unit consists of conveyors equipped with two opposing groups of rollers, each group having two or more rollers of metal, with continuous operation being achieved or a quasi-continuous compression region passing through a row of rollers or groups of rollers.

A preferred variant wherein the longitudinally compressed web is divided into two or more nonwoven webs, at least one of which is then longitudinally compressed prior to reconnection, is a manufacturing method having a wider usability and value than the method used only as the second stage in The method of the invention described above.

Cut the web to thickness into the nonwoven layers and compact one of them and then reconnect and cure them as already known from CA-A-1057183, WO 88/00265 and EWP-A-277 500. The known methods have a number of disadvantages. For example, the backsheet of the web is often only pre-compressed so that the finished product has a relatively low compressive strength. Although the compressive strength can be improved perpendicularly by the corrugation of the web, the flexural strength deteriorates. These methods also have the disadvantage that the bottom web of the web is only subjected to weak compaction and substantially no rearrangement of the fiber orientation, except for possible corrugations.

According to another aspect of the invention, there is provided a continuous process for producing bilayer or multilayer bonded mineral fiber webs from a mineral fiber web, by pre-compressing the web, feeding the pre-compressed web to the splitter, splitting the web into two sub-webs, furthermore, these nonwoven webs are re-bonded and conveyed to the bonding station where the web is bonded, according to the invention, which is characterized in that the mineral fiber web is compressed longitudinally and / or thickness-compressed (especially compressed longitudinally) in the compression unit, in front of the distributor, avoiding tearing of the stretched nonwoven layers between the compression unit and the coupling station by the retaining means.

In an example of a preferred embodiment of the method of manufacture, a method for continuously producing mineral fiber boards with two or more boards of different density is provided, wherein the method is pre-compressing the fibrous batt, further pre-compressing the fibrous batt to the splitting device, further splitting the fibrous batt into a plurality of auxiliary layers consisting of at least one auxiliary layer in the thickness direction, further the auxiliary layers are bonded and transported to a bonding station where the felt is bonded, according to the invention, which is characterized in that the fiber felt is compressed longitudinally for the splitting device in the compression unit, without compressing to a thickness in the continuous compression region in which the nominal thickness of the product is maintained, while preventing the tensile nonwoven webs from breaking between the compression unit and the coupling station by the holding means.

Also provided is a new apparatus for continuously producing mineral fiber webs connected from a mineral fiber web, consisting of means arranged one after the other in a conveying direction on a pre-web compressor, from the first web means for conveying the web to the splitter, from the splitter to the web splitter. two or more nonwoven webs, from means for compressing at least one nonwoven web in the thickness direction, second conveying means for subsequently joining the auxiliary layers and transporting them to the bonding station where the web is bonded, from the bonding station for bonding the compressed web, according to The invention is based on the fact that the first means of transport comprise a compression unit which is provided with at least two pairs of conveyors arranged one after the other in the conveying direction, and that the device is provided with means to prevent tearing bursts. The fleece between the compression unit and the coupling station.

The method and apparatus according to these aspects of the invention differ from the known methods and apparatus essentially in that the pre-compressed web is further compressed in the thickness and / or longitudinal direction, in particular in the longitudinal direction, by the compression unit so that the webs produced may have a relatively high density and different fiber structure prior to cutting. This has the advantage, for example in the case of double-layer boards, that the lower density layer, in contrast to conventional layers, has better compressive and tensile strength perpendicular to the main surface. Therefore, a specific tensile and compressive strength can be achieved with less material, in particular less fiber, compared to known methods.

Therefore, in order to prevent the stretched web layers from tearing or wrinkling between the compression unit and the coupling station, the device is preferably provided with suitable holding means and / or conveyors for holding the web layers to the main surfaces.

To form a highly compacted upper layer, the at least one slit web layer may be compressed to a thickness. In this way, a higher puncture resistance is achieved. Advantageously, one non-woven layer of the web, compressed to a thickness, can also be compressed longitudinally. Twisting the reoriented fibrous batt when compressed to thickness may induce compensation for the resulting elongation.

In order to improve the bond between the fleece auxiliary layers, the contact surfaces of the fleece auxiliary layers can additionally be provided with a binder before they are joined. In many cases, the quality of the binder originally applied to the fibers is already sufficient to achieve good bonding between the nonwoven layers when the binder is cured. Another possibility to improve the bond between the fleece auxiliary layers is to longitudinally compress the bonded layers before curing the binder. By shrinking these layers, for example in a ratio of 1.1: 1 to a maximum of 2: 1, it is possible to increase the contact area and thereby obtain a better bond between the layers.

One of the problems associated with the continuous production of bilayer or multilayer products may be the soiling of the belt knife used from the binder adhering to the fibers. According to a preferred variant of the process according to the invention, it is therefore proposed to continuously clean the distributor device. This can be done, for example, by means of a solvent stream, for example water, directed towards the cutting edge of the band knife.

The longitudinal compression is preferably performed by passing the web through a compression unit provided with a series of pairs of conveyors arranged one after the other in the conveying direction, wherein the speed of the at least one conveyor pair is lower than the speed of the previous pair of conveyors. The pre-compressed web is preferably longitudinally compressed in at least one stage. Longitudinal compression allows the fibers to be reoriented, so that compressive strength and tensile strength perpendicular to the major surfaces are particularly improved. Material resources can be saved as a result of the optimization of the fiber structures.

For the manufacture of products having a corrugated fiber structure, it is advantageous to adjust the distance of the opposing conveyors from the pairs of conveyors to approximately 0.5 to 0.1 distances of the following conveyors, the conveying path defined by the two pairs of conveyors being substantially aligned in line and peripheral speed of at least the immediately following pair. of conveyors is lower than the peripheral speed of the previous pair of conveyors. In this way, nonwoven layers with a corrugated fiber structure can be produced (FIG. 2).

Before entering the compression unit, the web is already compressed to about 0.8 to 1.5, in particular 0.9 to 1.3 times the nominal thickness, and most preferably to the nominal thickness of the finished product so that substantially only longitudinal compression is performed by conveyors of the compression unit. Longitudinal compression takes place in a continuous compression region in which the nominal thickness of the product is maintained. Surprisingly, a very homogeneous overall micro-density can be achieved if the web is already pre-compressed to approximately the nominal thickness of the finished product before the compression unit, and then compressed only longitudinally. The mineral fiber web is preferably longitudinally compressed at a factor of 2 to 10, more preferably 2.5 to 5, and in a particularly preferred embodiment for a factor of about 2.5 to 3.5. In some cases, for example, when the density of the bottom auxiliary layer of the finished product is less than about 100 kg / m ³ , simultaneous longitudinal and thickness compression may be recommended. The degree of thickness compression is preferably less than 2, and in particular less than 1.5.

Although the conveyors of the compression unit may be conveyor belts, the conveyors are in a particularly preferred embodiment designed as roller conveyors. Unlike conveyor belts, the rollers have the advantage that the web is repeatedly expanded and compressed by the rollers during compression. As a result, the products surprisingly have a very homogeneous micro-density (density divided in a small volume unit) and very good mechanical properties, such as compressive and tensile strength and puncture resistance, for products with significantly reduced weight compared to conventional products. The fibers are uniformly corrugated and no preferred fiber orientation can be detected (Fig. 11). On an enlarged scale, it has been found that the random orientation of the fibers is partially arranged in a wavy pattern. This type of fibrous structure is referred to by the inventor as a wavy fibrous structure. Another desirable effect is to compact the surface of the nonwoven layers, which is achieved by means of rollers.

Although each individual roller may be individually steerable, in a preferred embodiment each roller conveyor consists of two opposing groups, each of at least two rollers, each conveyor roller being driven at the same peripheral speed. Since the rollers are joined into groups of at least two rollers, the compression unit and its control are greatly simplified.

Preferably, the web is expanded in the conveying direction upstream of the distributor device. By unwrapping the web, unwanted undulations or rupture of the web can be prevented. for example when transferred from a compression unit to a distributor device.

The web may consist of glass wool, mineral wool or other synthetic fibers. However, the web consists mainly of mineral fibers and contains an uncured binder. The binder content may be about 0.7 to 4% by weight. In particular, the binder is curable in a curing oven. However, the bonding of the web can also be effected by reinforcing the fibers of the web itself or by felting.

Mineral fibers with an average length of about 0.3 to 50 mm, in particular 0.5 to 15 mm, and a thickness of about 1 to 12 µm, in particular about 3 to 8 µm, are preferably used. Mineral fibers with an average length of about 1 to 10 mm, in particular about 2 to 6 mm, and an average thickness of 2 to 10 µm, in particular about 3 to 7 µm, can also be used. The average length of the mineral fibers, which is usually shorter than the length of the glass fibers, is generally 2 to 4 mm, and the average diameter value is 3 to 4 µm.

During laying of the web on the conveyor, the predominant fiber orientation is preferably altered or partially aligned. This can be achieved, for example, by means of a spinning device adapted to swing obliquely to the conveying direction or by air deposition. In this way, the density distribution of the web can be improved and the fiber orientation can be changed, which has a beneficial effect on the mechanical properties of the resulting product. The primary web is preferably deposited on the collecting belt in layers by means of a rocking belt adapted to rock at an angle to the conveying direction. In this way, the fibers are partially reoriented and the homogeneity (transversal distribution) of the web deposited on the collecting belt can be improved.

Advantageously, 2 to 60 layers, in particular 2 to 40 to 50 layers, may be superimposed. This creates a certain reorientation of the fibers.

The fibers may deviate, for example transversely from the conveying direction, while the compression, in particular the longitudinal compression, can be performed simultaneously.

The invention also relates to a device according to the features of claim 27. The essence of the device according to the invention is that an additional compression unit is arranged between the pre-compression stage and the separating device for further thickness or longitudinal compression of the web, in particular longitudinal compression, and reorienting the fibers. The conveyor belts serve to maintain the fiber structure already obtained and to prevent any deviation or puncture of the stretched web.

In the subclaims, further preferred embodiments, according to one preferred embodiment, of the at least one splitting device and the subsequent holding device are adjustable independently of each other, perpendicular to the strip surface in the region of the multilayer unit, so that the device can be used selectively to produce monolayer or multilayer products. The means for compressing the at least one auxiliary layer of the web are preferably provided with at least two independently driven conveyor pairs. Thus, the slit web of the web can also be compressed longitudinally. The conveyor pairs are preferably formed by roller conveyors, the distance between the rollers being adjustable. Due to this arrangement, the nonwoven webs can be compressed as thickly as they are longitudinal.

The connecting station is preferably formed by a curing oven, in front of which there are cooled feed rollers. In this way, any adhesion of the binder to the rollers can be prevented and clogged. In a preferred embodiment, the peripheral speed of the conveying means between the splitter and the coupling station and the peripheral speed of the conveyor belts in the furnace are individually adjustable so that, for example, the nonwoven can also be compressed and released before the curing furnace.

BRIEF DESCRIPTION OF THE DRAWINGS

BRIEF DESCRIPTION OF THE DRAWINGS 1 shows a mineral wool product produced by compression to a thickness and with fibers oriented substantially parallel to the surface; FIG. 2 shows a corrugated product, with most of the fibers arranged perpendicular to the surface, FIG. Fig. 3 shows a bilayer product whose upper layer has an increased density; 4 shows a product with substantially homogeneous density and randomly oriented fibers; FIG. Fig. 5 shows an article wherein the randomly oriented fiber layer is combined with an increased density layer; 6 is a simplified drawing of a device for producing single-layer mineral fiber boards, wherein FIG. 6a) it is a machine shown in continuous operation and with a continuous compression region; and FIG. 6b) is shown in a single-stage operation; FIG. 7 is a diagram showing the principle of machinery for the continuous production of monolayer or multilayer mineral fiber boards of varying density, wherein in FIG. 7a) the machine is shown in continuous operation and with a continuous compression region; and FIG. 6b) is shown in a single-stage operation; FIG. 8 shows a detail of the compression unit, FIG. 9 is a side view of the compression unit of FIG. 8, FIG. 10 is a plan view of the compression unit of FIG. 8, FIG. 11 shows a fracture region where FIG. 11a) this region is shown with a board having substantially parallel oriented fibers, and in FIG. 10b) and 10c) for mineral wool slabs produced in a novel manner and spaced apart from each other, perpendicular to the plane of the slabs, in FIG. 12 is a perspective cross-sectional view of a two-layer board, the fibrous structure of which is shown to an enlarged scale; and FIG. 13 schematically illustrates the various possible arrangements of four pairs of conveyors arranged one after the other in the conveying direction.

DETAILED DESCRIPTION OF THE INVENTION

In FIG. 1 to 5 show the fiber orientations that often occur with soft boards. Boards whose fibers are arranged parallel to the surface (Fig. 1) have comparable weak mechanical properties. In order to compensate for this disadvantage, the fibers are often reinforced with binder and their density is increased.

Products with fibers oriented perpendicular to the surface can be obtained if the board shown in FIG. 1 is cut into strips, the strips are rotated 90 [deg.], And then arranged in a bundle. This type of production is complex and therefore uneconomical. According to another type of production, the fleece is corrugated (according to FIG. 2). These products have significantly better compressive and tensile strength, perpendicular to the plane of the board, than with boards of the type shown in FIG. 1. Corrugated fiber boards may be bent and may therefore be used in insulating tubes or for lining in curved areas. On the other hand, they have the disadvantage that these products tend to break along the undulations and also have inadequate puncture resistance. Another disadvantage of these known products of this type is that there may be noticeable variations in density in the board.

In FIG. 3 shows a bilayer product whose upper layer has an increased density. These products are suitable for applications requiring high wear resistance or increased surface protection. Due to the high density of the topsheet, the average density may be reduced.

In FIG. 4 shows an article with a substantially isotropic fiber orientation, substantially randomly oriented fibers. These products have excellent mechanical properties, such as high compressive strength and wear and puncture resistance, and high tensile strength perpendicular to the plane of the board. Their thermal conductivity is substantially the same as that of the products of FIG. 1. These products are generally lighter than comparable products having substantially parallel fibers for comparable or improved mechanical properties.

In FIG. 5 shows an article in which the advantages of the increased density top layer and the fiber structure of FIG. In particular, it is an object of the invention to further improve the properties of the products of the type shown in FIG. 4 and 5.

The device 11 'shown in FIG. 6, for carrying out the manufacturing process, it consists of a pre-compression stage 17 'and an optimization or compression unit 19' adjacent to the pre-compression stage 17 ', in the conveying direction F, and consisting of two pairs of felt conveyors 30, 32 or a web, and also from the conveyor belt 40 and the pressure belt 42 and from the feed rollers 63, 65 for conveying the compressed web to the curing oven 25. Finally, conveyor belts 67, 67 'are arranged in the curing oven 25 to ensure passage and holding of the compressed web. on opposite major surfaces during curing of the binder.

The pre-compression stage 17 'consists of a lower conveyor belt 27 and a pressure belt 29. By means of the pre-compression stage 17', the nonwoven preferably deposited in the layers on the collection belt 15 is pre-compressed to such an extent that the web designated 20 can be the pressure belt 29 is adjustable for this purpose.

The pair 30,32 of the conveyors of the compression unit 19 'consists of an upper and a lower group 30', 30, 32 ', 32 rollers, each group consisting of six rollers 39. Each upper and lower group 30', 30, 32 ', The 32 rollers have a separate drive (not shown in detail) so that the conveyors can be driven at different speeds relative to each other. Also, the upper groups of rollers 30 ', 32' are height adjustable so that the device 11 'can be used to produce products of different thickness. The distance between the upper and lower groups 30 ', 30, 32', 32 'of the rollers is particularly the same.

In carrying out the method of the invention, the web is pre-compressed to a nominal thickness of the finished product and then compressed longitudinally at a conveyor distance corresponding approximately to the nominal thickness of the finished product. In these circumstances, the conveyor 30 is driven at a first speed and the conveyor 32 is driven at a second speed, which is typically no higher than half the first speed, so that a corresponding longitudinal compression of the web 20 is achieved. extend after longitudinal pressing. This step may prevent the heavily compressed web from rippling or tearing up when conveying to the curing oven 25.

Downstream of the compression unit 19 is a conveyor belt 40 and a retaining belt 42, forcibly holding the compressed web against breakage, i. j. The holding device 42 consists of a relatively unwinding unwinding belt which is positioned on the web of the web. The feed rollers 63, 65 are arranged in front of the curing oven 25 and can be cooled. The distance between the lower and upper groups of rollers is preferably adjusted to approximately the nominal thickness of the finished product. This has the advantage that the fiber orientation once set in the compression unit 19 no longer changes.

The device 11 shown in FIG. 7 differs from the device shown in FIG. 6 essentially in that the compression unit 19 has four conveyors, each with four rollers. The apparatus may be provided with a multiple unit which may be used for the production of multilayer boards and may in principle be used together with the apparatus 11 '. For simplicity, the same components are used for the same components

The reference numerals in the following description, as in the description of the device 11 '.

The device 11 shown in FIG. 7 for the production of mineral fiber plates essentially consists, when arranged in the conveying direction F, of a rocking belt 13 and a collecting belt 15 for respectively storing and receiving the fibers produced by the fiber production unit (not shown in detail), and a preliminary compression stage; an optimization or compression unit 19 for forming a felt or web 20 having optimized fiber orientation and homogeneity. An optional multiple unit 21 is provided downstream of the compression optimizing unit 19, which may be used to produce multi-layer mineral fiber boards. Downstream of the multiple unit 21 are conveying means which grip the compressed web on opposite main surfaces and convey it to a coupling station, for example a curing oven 25.

Said production unit serves for the continuous production of fibers, in one of the known ways, for example in a cascade spinning process. A binder (not shown) is sprayed onto the fibers produced, also known as the primary web, and transported by a conveyor (not shown) to the rocking belt 13. This belt is located above the collecting belt 15 and is pivoted transversely to the conveying direction of the collecting belt 15. however, also a different orientation of the rocking movement is possible, for example in the conveying direction. As a result of the rocking movement, the primary web 26 is deposited in a transverse overlap, as can be seen in FIG. 7, to the collection belt 15 advancing, depending on the speed of the collection belt and the frequency of the oscillations. However, other means, such as gas nozzles, may be used to create the most irregular orientation of the fibers on the collecting belt. As a result of the forward movement of the collecting strip 15, the fibers are oriented predominantly at an angle to the conveying direction. When viewed from above, the two layers of webs extend substantially transverse to each other.

The pre-compression stage 17 consists of a lower conveyor belt 27 and a pressure belt 29. The pressure belt is height adjustable so that the primary web 26 can be pre-compressed in various stages.

Each upper and lower groups 31 ' 33 ', 33; 35 ', 35; 37 ', 37 of the rollers of the conveyor pairs 31, 33, 35, 37 have a separate drive, which is not shown in detail in FIG. 7. In particular, the drives used are infinitely variable to a certain extent, so that, for example, the upper and lower groups of rollers may have different peripheral speeds. A slightly higher peripheral speed of the upper group of rollers is needed, for example, when this group is positioned not horizontally but at an angle to the lower group of rollers.

Fig. 8 to 10 show an exemplary embodiment of a compression unit 19 wherein conveyors with groups 3 ', 31; 33 ', 33; 35 ', 35; The rollers 37 ', 37 provided with rollers 39 are arranged on a support structure 71. Sprockets 115 are arranged at one end of each roller 39 (FIG. 10). In each case, four or five rollers 39 are interconnected by drive chains (not shown) and form a group of rollers. Each roller group is provided with a drive 117 ', 117, 117', 117, 118 ', 118, 118', 118.

The upper and lower roll group 31 ', 31' of the first pair of conveyor 31, taken in the conveying direction (arrow F in Fig. 9), is vertically adjustable. Vertical adjustment of the upper roller group 31 'is performed by a drive member 81 which drives the spindles 73, 73' by means of the propeller shafts 77, 77 '.

To vertically adjust the lower pair of the conveyor 31, a drive member 83 is used which drives the spindles 75, 75 'by means of cardan shafts 79, 79'.

Unlike the first roller group 31 ', 31 ”, the position of the remaining roller groups is either not adjustable or only adjustable together (at the upper group). As is clear in particular from FIG. 8 and 9, the three rear lower roller groups 33, 35, 37, gripped in the conveying direction, are mounted on the fixed frame 85, while the three upper roller groups 33 ', 35', 37 'are mounted on the vertically adjustable frame 87. the frame 87 is vertically adjustable at the top of the support structure 71. The vertical guidance of the adjustable frame 87 is secured by a linear guide 93 on the stands 95.95 ', 97.97'. The vertical adjustment of the adjustable frame 87 is provided by a drive member 103 which drives the spindles 89, 89 ', 91, 91' arranged in pairs on the support structure 71 by means of cardan shafts 99, 99 ', 101, 101'.

The upper roller groups 33 ', 35', 37 ', the last of which has five rollers 39, are disposed on the support rails 105 rotatably connected to the adjustable frame 87 by a pivot pin 107. In the embodiment shown, the front end of the track 105 is braked. in the conveying direction, connected to the adjustable frame 87 by another pair of spindles 109, 109 '. By adjusting the spindles 109, 109 'it is possible to swing the support rails 105 up or down from the horizontal direction, so that, for example, a track can be formed which tapers in the conveying direction F. Spindles 109, 109' are also connected by cardan joints 111, 111 '. here again, one actuator 113 is sufficient to adjust them.

In FIG. 12 shows various ways in which four pairs of conveyors can in principle be arranged. However, the setting of FIG. 13b and 13c cannot be performed by the compression unit of FIG. 8 to 10. The arrangement of the roller groups 31 ', 31, 33', 33, 35 ', 35, 37', 37 according to FIG. 12d is suitable, for example, when light products are to be produced.

An optional multiple unit 21 is provided downstream of the optimization unit 19 comprising a series of conveyor pairs, which in the embodiment shown is a dual density device. This device consists of a distribution device 41, for example a band saw or a band knife, shown only in the outline of FIG. 7, for separating the compressed web into two sub-webs 43 and 45. The multiple unit 21 is also provided with conveyors 47, 49, 50, 51, for example conveyor belts, which strengthen the compressed auxiliary layers 43 and 45 of the web to a thickness. Any gaps arising for geometric reasons between the manifold and, for example, the conveyor belt 49 or 50 may be bridged, where possible, by guide plates. In this way, the rupture of the web layer 43, which is compressed in different degrees, is prevented.

In particular, the splitting device 41 and the following conveyor 49 are adjustable in height so that the web exiting the compression unit 19 can be cut into the lower and upper webs 43, 45 of the web, in virtually any thickness. In addition, the splitter 41 and the conveyor belt 49 may also be displaced independently of each other and upwardly so as to be located outside the fleece transport range. The conveyor belt 49 then serves as a retaining belt. Due to its vertical adjustability, the device 11 can optionally be used to produce single-layer or multi-layer boards. In principle, the device may comprise a plurality of splitting devices and corresponding holding strips to allow the production of boards with three or even more layers. Also, the distance between the upper and lower rollers is adjustable so that outer layers of different thicknesses can be produced.

SK 283915 Β6

A pair of conveyors 53, 54 arranged downstream of the conveyors 50, 51 serve to compress to a thickness and longitudinally compress the upper auxiliary layer 45 of the web. In particular, the pair of conveyors 53, 54 is provided with rollers 55, which in each case are connected to form an upper and a lower group of rollers, each having three rollers. The pairs of conveyors 53, 54 are arranged to be driven at different peripheral speeds, so that the elongation that may occur as a result of the compression to the thickness can be compensated by subsequent longitudinal compression. Also, the distance between the upper and lower rollers is adjustable so that outer layers of different thicknesses can be produced.

The compressed topsheet 45 'of the web is reconnected to the bottomsheet 43 by conveyor belts, chutes or guide plates (not shown in detail). In most cases, it is possible to dispense with the retaining strip for the highly compressed topsheet 45 'of the web. In the area where the upper auxiliary layer 45 and the lower auxiliary layer 43 of the fleece meet, a binder dispensing device 57 is provided. With this arrangement, it is possible to apply a binder to the contact surfaces of the upper auxiliary layer 45 'and / or the lower auxiliary layer 43 of the web so as to achieve better bonding after curing of the binder. In most cases, especially when no elongation has been compensated, dispensing devices can be dispensed with.

The bonded upper and lower sub-webs 43 and 45 'of the web are co-compressed by the feed belts 59 and 61, and the feed rollers 63, 65 and conveyed thereto to the curing oven 25. The peripheral speeds of the feed belts 59, 61 and feed rollers 63, 65 are preferably individually adjustable so that the compression or release of the compressed webs 43 and 45 'may be performed as desired. In particular, at least the feed rollers 63, 65 can be cooled. Conveyor belts 67, 67 'are provided in the curing oven 25, which are air-permeable. The conveyor belts 67, 67 'hold the layers 43 and 45' together during the curing process, thereby substantially defining the nominal thickness of the finished slabs. The conveyor belts 67, 67 'as well as the conveyors 59, 61, 63, 65 are vertically adjustable and can therefore be adjusted to the thickness of the web supplied from the multiple unit 21 or from the compression unit 19.

The production of a multi-layer board may be carried out as follows: Primary fleece fed from a collection chamber (not shown) and provided with a binder and, in the case of wool from mineral fibers, usually weighing 200 to 800 g / m ² , in particular 200 to 400 g / m ² an approximate average thickness of 15 to 20 mm, often up to 75 mm, is fed to the rocking belt 13. This belt places the primary web on the collecting belt 15, which moves continuously forward. Depending on the speed of the collecting belt 15 and the oscillation frequency of the rocker belt 13, a greater or lesser number of fleece layers are formed on the collecting belt in the vertical direction. The number of layers is selected according to the desired board properties, such as weight, compressive strength, etc., of the final product. The number of layers also depends on the fiber arrangement, ie the individual state of fiber processing between the fiber processing unit and the curing oven. Typically 2 to 40 to 50 layers are deposited on the collecting belt 15.

The deposition of the primary web 26 by the rock band 13 not only creates a good transverse distribution of the fibrous material on the collecting belt 15, but also contributes to a uniform orientation of the fibers and to a certain homogenization thereof. Further, the orientation of the fibers can be controlled by changing the direction of travel of the rocker belt.

The deposited web is subjected to pre-compression in the pre-compression stage 17. Pre-compression is typically performed so that the web can still be clamped by the rollers of the first pair of conveyors (a nominal thickness plus a maximum of about 40% of the roller diameter is required). Certain deviations of the web after pre-compression are desirable so that sufficient adhesion between the web and the rollers is achieved at the inlet of the compression unit to provide the desired fiber reorientation. Since, for products with a density of only approximately 80 and 90 kg / m ³ , the expansion forces present in the web during longitudinal compression are much lower, a slight thickness compression, except longitudinal compression, is usually required in the manufacture of these products to adjust the desired tension and avoid undesirable undulations of the fleece surface.

In the case of duplication, i. i.e., when the primary web is deposited in layers, the web surface has steps showing varying degrees. These steps can be compensated at least partially in the preliminary compression stage 17 by driving the upper belt 29 at a slightly higher speed than would be necessary for further transport.

The partially smoothed web may be subjected to further smoothing in the compensation unit 19. For this purpose, for example, the first and second pairs of conveyors may be adjusted so that they are not aligned. It is also possible for any additional pairs of conveyors to be set in an unbalanced configuration. This misalignment causes the conveyed web to be subjected to bending or lateral deflection which may cause the web surface to be smoothed. The smoothing effect may be increased when the second pair of conveyors runs a little slower than the first pair.

In particular, longitudinal compression in a ratio of 2: 1 to 6: I (depending on the peripheral speeds of the first and last pairs of conveyors 31 and 37) is performed in a compression unit 19, with a roller spacing substantially corresponding to the nominal board thickness. thickness). However, in the case of lighter products, longitudinal compression, together with simultaneous thickness compression, may be advantageous. In the case of a single speed, each pair of conveyors 31, 33 and 35, 37 may be driven together with a single drive.

Although conveyor belts may be used for compression, rollers are preferred because there is a relatively lower tendency to corrugate fleece surfaces, even at a significant degree of longitudinal compression. The web may be longitudinally compressed longitudinally by means of rollers 39, without apparent undulations on its surface. The only possible explanation for this phenomenon is that there is little adhesion between the rolls and the fleece. The rollers also effect the reorientation of the fibers, since the web between the rollers may increase somewhat in volume, but in any case without curl. The result is a good compaction of the fibrous web inside and on the surface.

In the multiple unit 21, the compressed web may be divided into two or more sub-layers 43, 45. It is also possible to omit the multiple unit or to place it outside the conveying path and feed the web with optimized fiber structure directly to the curing oven.

The separation of the web 20 is effected by a band saw or a band knife in a manner known per se. The topsheet 45 of the fiber-optimized web is then subjected to thickness and longitudinal compression. In this case, the fibers of the upper nonwoven layer 45 are further compacted by thickness and then longitudinal compression. The upper nonwoven web 45 'compressed to the thickness of the web then returns to the continuously advancing lower nonwoven web 43.

The compressed webs 41, 45 ', in particular the lower stretched layer 43, are guided between the compression unit 19 and the curing oven 25 by means of conveyors 47, 49, 59, 61, 63, 65, formed for example by belts by a chain or roller system, in particular conveyor belts. preventing any breakage or bulging.

In the curing oven 25, the binder is cured in the web. Curing takes place at a temperature of 180 to 300 ° C, in particular about 200 to 150 ° C. The binder also provides a firm bond between the low and high overall density layers 43, 45 'of the web.

To improve the adhesion of the webs 43, 45 ', a solid or liquid adhesive (dispensing device 57) may be applied to their interface at a multiple unit prior to joining them.

Alternatively or additionally, the bond between the webs 43, 45 'of the web may be improved if the webs somehow contract before entering the curing oven 25, particularly in a ratio of 1.1: 1 to 2: 1. Depending on the degree of contraction, this may result some ripple of these layers. As a result of the shrinkage, the size of the contact area is increased and thus the adhesion / felting of these layers can be improved.

By means of the device according to the invention described, the web or felt is compressed longitudinally, in particular in one step. Alternatively, the device can also be controlled, such that a series of compression zones or a continuous compression zone is formed during compression.

Thickness of the invention

Thickness compression: 1.8: 1 to 1.1: 1

Longitudinal press: 3: 1

Compressive strength at 10% deflection: 0.25 to 0.030 N / mm ²

Tear-off strength. _{nnlOÄT /} 2 _,,,, . 0.013 to 0.018 N / mm (division into layers):

Example 3

Board type:

Fibrous material:

Plate thickness:

Outer layer thickness: Underlayer thickness: Average total density: Average total density of outer layer:

Total density of the base layer:

binder:

Average fiber length: Average fiber diameter: Pre-compression:

Thickness compression:

Longitudinal Press:

Compressive strength at 10% deflection:

Tear strength (division into layers):

Diameter of rollers used 2-layer mineral wool 100 mm about 20 mm about 80 mm about 90 kg / m ³ 155 kg / m ³ kg / m ³ modified phenol resin about 3 to 4 mm to 4 µm about 1.8 to 1.5 nominal thickness

1.5: 1 to 1.1: 1: 1

0.25 to 0.030 N / mm ²

0.013 to 0.018 N / mm ² mm

Example 1

Board type:

Fibrous material:

Plate thickness:

Average total density:

binder:

Average fiber length:

Average fiber diameter:

Preloading:

Longitudinal Press:

Compressive strength at 10% deflection:

Tear strength (division into layers):

single-layer mineral wool 100 mm approx. 90 kg / m ³ modified phenolic resin 3 to 4 mm 3 to 4 pm approximately to nominal thickness: 1 0.035 N / mm ² 0.020 N / mm ²

Example 2 Board type: dvojvrstvox Fibrous material: mineral wool Plate thickness: 100 mm Outer layer thickness: about 20 mm Substrate thickness: about 80 mm Average total density: about 90 kg / m ³ Average total density of outer layer: 155 kg / m ³ Total density of the base layer: 75 kg / m ³ binder: modified phenol resin Average fiber length: 0.5 to 10 mm Average fiber diameter: 3 to 6 pm Preloading: approximately 1.5 nominal

Compared to boards that do not have optimized fiber structure and density, the weight of boards produced by the novel process can be reduced by up to 25 to. 40% with otherwise substantially the same mechanical properties. The tensile strength perpendicular to the plane of the plate has improved considerably, as is evident from the highly structured fracture region (Figs. 11b to 11c).

The products according to the invention can be used for any purpose intended for synthetic fibers, for example for sheets and webs used for thermal insulation, for fireproofing and fire protection or for soundproofing and sound control or in suitable form in horticulture as a vegetation medium.

Claims (38)

PATENT CLAIMS 1. A method for the continuous production of bonded mineral fiber sheets having a thickness t2 of a web having a thickness greater than 2 t, in which the web is deeply compressed substantially without simultaneous longitudinal compression, to a first thickness and to a basis weight w; being pressed to a second thickness to form a longitudinally compressed web, such longitudinally compressed web is fed to a curing oven (25) where the web is joined to form bonded mineral fiber plates, characterized in that the web is compressed deeply on the first a thickness which is in the range of 0.8 to 1.5 t, preferably in the range of 0.9 to 1.3 t, then pressed longitudinally to a second thickness which is in the range of 1 to 1.3 t, preferably 1 to 1, 1 t, wherein the longitudinal compression is carried out continuously or at least in one step without undulating the web, thereby producing a longitudinally compressed web having a basis weight of 2 to 10 w, which is it forcibly retains against tearing during transport between the longitudinal compression and the curing oven (25). Method according to claim 1, characterized in that the longitudinal compression of the web is carried out in one step. Method according to claim 1 or 2, characterized in that the longitudinally compressed web and the joined board have a basis weight of from 2 to 6 w, preferably 2.5 to 4 w. Method according to claims 1 to 3, characterized in that the longitudinal compression of the web is performed by feeding the web to the first conveyor pairs (30) to the second conveyor pair (32), the second conveyor pair (32) being driven at a lower speed than the first conveyor pair (30). 30) conveyors, each pair (30, 32) comprising two opposing roll groups (30 ', 30), each comprising at least two spaced rollers (39). Method according to claim 4, characterized in that the opposing roller groups of the at least one conveyor pair (30, 32, 31, 33, 35, 37) are driven at different speeds. Method according to claims 1 to 5, characterized in that the breakage of the web is prevented by the retaining means in guiding the web between the longitudinal compression and the curing oven, the retaining means comprising a belt, rollers or guide which prevents significant deviation from the intended path. Method according to claim 4, characterized in that tearing the web between the longitudinal compression and the curing oven (25) is prevented by feeding the web with another pair of conveyors after the second pair of conveyors (32). Method according to the preceding claims, characterized in that the web is stretched longitudinally after compression. Method according to the preceding claims, characterized in that the web is formed of chemical glass fibers, in particular of fibrous mineral wool, and comprises an uncured binder, which binder is cured by heating in a curing oven (25). Method according to the preceding claims, characterized in that the web is formed by cross-lapping. Method according to the preceding claims, characterized in that the longitudinally compressed web is divided in front of the curing oven (25) parallel to the main surfaces into two or more non-woven layers, each of the non-woven layers being forcedly held against tearing as they pass to the curing oven, and wherein the at least one nonwoven web layer is compressed to a thickness or length, then the auxiliary layers are joined and joined in the curing oven (25). Method according to claim 11, characterized in that the mating surfaces of the nonwoven layers are provided with a binder before they are joined. Method according to claim 11 or 12, characterized in that the bonded nonwoven layers are compressed longitudinally in front of the curing oven (25). 14. A method for continuously manufacturing bonded mineral fiber plates, wherein the fiber felt is pre-compressed in a thickness direction to a thickness of 1 to 3 thicknesses of the finished product, then compressed longitudinally using at least two pairs of conveyors driven at different speeds to form a longitudinally compressed felt. which is then joined in a curing oven (25) to a bonded mineral fiber board, characterized in that the thickness of the felt in the longitudinal compression stage and before the curing oven (25) is 0.9 to 1.3 thickness of the finished product, longitudinal compression is performed substantially without compression in the thickness direction, wherein the longitudinal compression is performed to 0.5 to 0.1 of the original length, this compression is performed in the continuous compression region, and the felt is prevented from breaking between the longitudinal compression unit (19, 19 ') and a curing oven (25). Method according to claim 14, characterized in that the thickness of the felt in the longitudinal compression region is substantially the same as the thickness of the finished product. Method according to one of Claims 1 to 15, characterized in that before the web is fed into the curing oven (25), the web is fed to a separating device (41), wherein the web is divided into at least two auxiliary layers (43, 45). , the at least one sub-layer (45) is compressed in the thickness direction, followed by joining the sub-webs (43, 45) and feeding them to a curing oven (25) in which the web is joined and tearing the stretched sub-webs (43, 45) between the compression unit (19) and the curing oven (25) is prevented by retaining means. Method according to claim 16, characterized in that the at least one fleece auxiliary layer (45) is longitudinally compressed. Method according to claim 16 or 17, characterized in that the contact surfaces of the nonwoven layers (43, 45) are provided with a binder before they are joined. Method according to claims 16 to 18, characterized in that the joined auxiliary layers (43, 45j) are compressed longitudinally prior to joining. Method according to claims 16 to 19, characterized in that the distributor device (41) is continuously cleaned. Apparatus for carrying out the method according to claim 1, comprising conveying means for conveying the web to the curing oven (25), a pre-compression stage (17) for compressing the web in the thickness direction, a longitudinal web compression unit (19, 19 ') arranged behind the web. a pre-compression step (17) for compressing the web in the thickness direction, a curing oven (25) for joining the longitudinally compressed web, characterized in that there are means for preventing the web from tearing between the pressing unit (19, 19) and the curing oven (25); the longitudinal compression unit (19, 19 ') comprises at least two conveyor pairs (30, 32) disposed one behind the other in the conveying direction (F), each conveyor pair (30, 32) consisting of two opposing groups of at least two rollers (39) the opposing groups of rollers (39) form a conveying path of the conveying direction (F) of the web, the apparatus further comprising drive means for driving the rollers (39). 39) each group having substantially the same peripheral speed, means for controlling the peripheral speeds of the rollers (39) of each individual group independently of the roller speed (39) in each other group, and means for adjusting the distance between the opposing groups (30 ', 30, 32') , 32) the rollers of the conveyor pairs (30, 32) independently of the distance of the rollers (39) of the other conveyors. Apparatus according to claim 21, characterized in that two roller conveyor pairs (30, 32) are arranged in the conveying direction (F). Apparatus according to claim 21 or 22, characterized in that each group of rollers (39) consists of two to eight rollers, in particular of four to six rollers arranged one behind the other. Apparatus according to claims 21 to 23, characterized in that at least one of the roller conveyor pairs (30, 32) is provided with means for Tilting the opposing groups of rollers (39) against each other, e.g. tapering of the web in the conveying direction. Apparatus according to claims 21 to 24, characterized in that the diameter of the rollers and the gap between the rollers (39) in the direction of conveyance of the web are such that the web is not ruptured or crimped. Device according to claims 21 to 26, characterized in that the diameter of the rollers is less than 180 mm, preferably 60 to 160 mm and most preferably 80 to 120 mm. Apparatus according to claims 21 to 24, characterized in that at least the first conveyor pair (30) is provided with means for adjusting the conveyor track with respect to the position of the conveyor track extending in the next conveyor pair (32). Apparatus according to claims 21 to 27, characterized in that the conveyor pairs (30, 32) are arranged horizontally. Apparatus according to claims 21 to 28, characterized in that a separating device (41) is arranged between the pairs (31, 33, 35, 37) of the roller conveyors and the curing oven (25) for separating the web into two auxiliary layers (43, 43, 38). 45), wherein the apparatus is provided with at least one pair (53, 54) of conveyors for the thickness and / or longitudinal compression of the at least one auxiliary web of nonwoven, and further provided with conveyors for holding the compressed web and auxiliary layers on the path to the curing oven (25) prevent deformation in the direction of thickness or tear. Apparatus according to claim 29, characterized in that the distribution device (41) and the at least one conveyor (47) are height adjustable for the production of monolayer or multilayer products. Apparatus according to claims 29 and 30, characterized in that the metering device (57) is designed for metering the binder onto the interfaces of the nonwoven layers (43, 45). Apparatus according to claims 21 to 30, characterized in that the means for independently driving the means of transport are between the pressing stage (17) and the curing oven (25) and in the curing oven (25). Apparatus according to one of Claims 21 to 32, characterized in that the pressing unit (19) comprises first conveying means for conveying the web to the splitting device (41) for splitting the web into at least two auxiliary webs (43, 45) of the web and means for compressing the at least one nonwoven web (45) in the thickness direction, the second conveying means (23) for subsequently joining the nonwoven webs (43, 45 ') and feeding into the curing oven (25) for bonding the binder, the first conveying means comprising a longitudinal compression device and comprising at least two pairs of conveyors (31, 33, 35, 37) arranged one after the other in the conveying direction, and the means (49, 50, 51, 59, 61, 63, 65) arranged to prevent tearing of the stretched auxiliary a plurality of nonwoven layers (43, 45) between the compression unit (19) and the curing oven (25). Apparatus according to claim 33, characterized in that the metering device (57) is arranged to apply a binder to the auxiliary layers (43, 45) prior to joining them. Apparatus according to claim 32 or 33, characterized in that the distribution device (41) consists of a band knife or a band saw. An apparatus according to claims 33 and 35, characterized in that it comprises a cleaning device for continuous or intermittent cleaning of the band knife or band saw. Device according to claims 33 to 36, characterized in that at least the distribution device (41) and the subsequent conveyor belt (49) are vertically adjustable in the region of the multiple unit (21). Apparatus according to claims 33 to 37, characterized in that for producing substantially undulating products, the distance of the opposing conveyors from the conveyor pair (31, 33, 35) is adjustable to 0.5 to 0.1 of the conveyor distance of the following pair (33, 33, 35). 35, 37) of the conveyors and the conveying path defined by the two pairs of conveyors is substantially aligned in a row.