EP0648286B1 - Process and device for manufacturing mineral fiber products - Google Patents

Abstract

When manufacturing mineral fiber products with compressed surface areas made of mineral fiber webs, in which the fibers extend substantially parallel, perpendicular or obliquely to the large surfaces of the mineral fiber web, which contains an uncured binder, it is very important to achieve a high tearing resistance and a strong fiber connection between the compressed surface areas or layers and the remaining part of the mineral fiber web. It is therefore proposed to expose at least one surface area to needling down to a predetermined penetration depth, in order to felt the fibers and at the same time to compress the surface area.

Description

The invention relates to a method for producing mineral fiber products with compacted surface areas from mineral fiber webs, the fibers within the mineral fiber web running essentially parallel or perpendicular or obliquely to the large surfaces of the mineral fiber web, and wherein the mineral fiber web contains an uncured binder.

A method of the aforementioned type and a device for carrying out the method have become known above all through Canadian Patent 1,057,183. To produce a compacted surface area or a surface layer, a partial web is cut off by a horizontal cut running parallel to the large surfaces of the mineral fiber web. This partial web is then lifted from the remaining mineral fiber web and pressed between pressure rollers and thus compressed. This compressed partial web is then returned to the remaining mineral fiber web. This is followed by a common pass through a hardening furnace in which the binder which has not been cured up to that point in the mineral fiber web and also in the partial web is cured. In practice, however, it has been found that the fibers in the lifted partial web are crushed by the high static compressive forces and the partial web is additionally pressed apart, comparable to a bread dough that is rolled out. This creates relatively inhomogeneous, densified zones within the partial web. The teaching conveyed in the Canadian patent specification has also been developed further, namely that a relatively thin partial web has been cut open, pressed together and then subsequently applied in folds to the remaining mineral fiber web using a pendulum device. In all cases, however, it has been shown that no reliable permanent fiber composite could be achieved between the two differently treated layers. The mineral fiber boards ultimately produced as the end product with different bulk densities in the two aforementioned layers always had an inadequate tear resistance in practice. For example, when laying such panels or longer sheets on a flat roof of a building or when attaching to building walls, the compacted surface layers have detached from the underlying undensified mineral fiber web and in some cases even assumed a wave form because the compacted material tried to, if only, again slightly to expand. In principle, nothing would change here if one came up with the idea of placing an adhesive layer between the two partial webs of different bulk densities, apart from the fact that this would incur considerable additional costs and hardening in a hardening furnace would lead to considerable difficulties.

The easiest and most obvious way to create a densified surface area or a surface layer would be not to cut the mineral fiber web into partial webs, but rather to exert pressure directly on the surface. In the case of a mineral fiber web in which the binder has not yet hardened, however, no surface area or surface layer can be compacted because the material escapes compression due to considerable deformations and at most the fibers are crushed in the direct vicinity of the surface.

In contrast, the invention is based on the object of providing a method for producing mineral fiber products with compressed surface areas or layers create through which high tear strength and an intensive fiber composite can be achieved.

The object is achieved according to the invention in that at least one surface area is subjected to needle impact to a predetermined depth of penetration, so that the fibers become matted and at the same time the surface area is compressed.

In this way, there is the essential advantage that a surface area or a surface layer can be compacted to a certain depth in a simple and targeted manner without influencing the remaining part of the mineral fiber web, but at the same time both a high tear-off strength and a high flexural strength of the end product is obtained. The end product is usually sheets that are cut to a predetermined length after the treated mineral fiber web has passed through the hardening furnace.

The stroke frequency of the needles in relation to the normal conveying speed of the mineral fiber web is an important factor both for the degree of compaction and for matting. A change in the strength properties of the end product can therefore be achieved in that the stroke frequency of the needle strokes can be changed and adjusted . With a high stroke frequency, there is the advantage that the mineral fiber layer not hit by the needles is not deformed or even compressed due to the inertia.

It goes without saying that the tightness of the needles, ie the distance between the needles standing next to and / or behind one another, has an important influence on the end product, but the number of needles to be selected and their spacing from one another is unique for a larger product group through tests to be determined. A change in Strength properties of an end product can, however, be achieved in a simple manner in that the stroke and the depth of penetration of the needles can be changed and adjusted.

An advantageous further development of the method is further achieved by continuously moving an endless mineral fiber web, subjecting it to a first mechanical pre-compression, then further compacting and matting in the given surface area by means of needle strokes, and applying a heat treatment to harden the binder under a second compression.

If a plate-shaped end product is to be obtained, it is expedient that the needle shocks for compaction and felting are distributed uniformly over the entire surface area.

In practice, there are numerous applications for a plate-shaped mineral fiber product in which both sides or the two large surfaces are to be compacted and, if appropriate, also have hard layers, e.g. B. for free-standing building partitions or for external wall heat and sound insulation, if in the latter case one side of the panel is to be attached to the building wall and a plaster is to be applied to the outside. In order to achieve such products, it is advantageous that the needle-push treatment is carried out on both surface areas of the mineral fiber web running parallel to one another.

The production of board material can be increased while the conveying speed remains the same in that the mineral fiber web is cut in a cutting plane parallel to the large surfaces after the binder has hardened, so that two mineral fiber boards are produced with a layer compacted on one side.

There is a great need for mineral fiber products that are used on curved surfaces, e.g. B. need to be attached to pipes. It is then advisable to design the method in such a way that the needle strokes are carried out in rows in the longitudinal and / or transverse direction of the mineral fiber web, so that the finished product plates can be bent or bent polygonally. In this way, a product is obtained which, in addition to flexibility or kinkability, also has a high compressive strength in zones.

A matting between the compressed surface layer and the non-compressed mineral fiber layer can be further promoted and the tear resistance increased by treating with different types of needles or needle shapes. In this context, it is advantageous that the surface area is compacted and felted by means of short needles, and that part of the fibers are pushed out of the outer, compressed surface area into the inner, uncompressed area of the mineral fiber web by means of longer needles.

Without having to carry out time-consuming redesigns on the manufacturing machine, numerous variants in the end product can be achieved by determining the thickness of the compacted layer in the surface area by choosing the depth of penetration of the needles, the stroke frequency and the shape of the needle, such that, on the one hand, small depths of penetration , high stroke frequencies and needles with a large effective cross section result in thin, highly compressed layers and, on the other hand, large penetration depths, low stroke frequency and needles with a small cross section result in thick, less compressed layers.

If a plate-shaped end product is desired which has the hardest and most pressure-resistant surface layer, this can be achieved in a simple manner by that additional additives are introduced through hollow needles for additional reinforcement of the surface area. These additives can act as small stamps after curing. However, they can also be injected in such a way that they penetrate into the area between the adjacent fibers and thus bring about an even greater cohesion within the compacted surface layer. However, the additives can also be introduced into the uncompressed mineral fiber layer, so that in addition to the matting in the area between the compressed and the uncompressed layer, numerous additional anchors are achieved. With these products as well as with all other products which can be produced by the process according to the invention, the advantage is maintained that good vapor diffusion capability is provided.

For a plate material that is to be provided with a plaster, paint or other coating, it is advantageous that a thin fleece made of a fiber material, preferably glass fibers, is placed on the surface of the mineral fiber web and then the needle-pushing process is carried out, so that part of the nonwoven fibers is embedded in the mineral fiber web.

An alternative to this results from the fact that a fabric is placed on the surface of the mineral fiber web and then the needle-pushing process is carried out, so that part of the fabric is embedded in the mineral fiber web. The thin fleece or the fabric can also consist of a different fiber material than mineral fibers, such. B. made of plastic fibers, textile fibers or metal fibers.

• Figur 1 eine Prinzipdarstellung des Förderweges einer Mineralfaserbahn mit Fördervorrichtungen und einer Verdichtungs- und Verfilzungsmaschine,
• Figur 2 ein Ausführungsbeispiel einer Nadel,
• Figur 3 ein anderes Ausführungsbeispiel einer Nadel und
• Figur 4 eine Seitenansicht auf einen Ausschnitt einer beidseitig verdichteten und verfilzten Mineralfaserbahn in vergrößerter Darstellung und
• Figur 5 eine Prinzipdarstellung gemäß Figur 1, jedoch mit beiderseitigen Verdichtungs- und Verfilzungsmaschinen.

In the drawing, exemplary embodiments of the device according to the invention are shown in the diagram, namely:

• FIG. 1 shows a schematic diagram of the conveying path of a mineral fiber web with conveying devices and a compacting and felting machine,
• FIG. 2 shows an embodiment of a needle,
• Figure 3 shows another embodiment of a needle and
• Figure 4 is a side view of a detail of a mineral fiber web compressed and matted on both sides in an enlarged view and
• FIG. 5 shows a basic illustration according to FIG. 1, but with compression and felting machines on both sides.

In the embodiment of a device according to the invention according to FIG. 1, a mineral fiber web 1 is continuously fed in the direction of arrow 22 between endless conveyor belts 2 and 3 with a certain thickness. The mineral fiber web comes from a known, unsigned collecting chamber in which the mineral fibers produced are deposited into a layer on an air-permeable conveyor belt after the addition of a binder. The mineral fiber web is then initially held in a relatively loose state between the two conveyor belts 2, 3, which are guided around deflection rollers 4 and 5. There is then a certain somewhat exaggerated pre-compression of the mineral fiber web between pressure rollers 6, 7 to 8, 9 or between appropriately arranged and guided conveyor belts. Since the binder within the mineral fiber web has not yet hardened and the mineral fibers run essentially parallel to the large surfaces of the web due to the previous manufacturing process, the mineral fiber web can be mechanically pre-compacted very homogeneously in this first conveying section until a pre-compacted mineral fiber web 10 of a given one Thickness arises.

The mineral fiber web 10 pre-compressed in this way then passes into a compression and felting device, which is shown in simplified form in FIG. It has a plurality of needles 13 which are connected in groups or together with a lifting device which carries out a high-frequency lifting movement in the direction of arrow 15. Such a lifting device is arranged on at least one surface side, either on the upper or lower side, of the mineral fiber web 10, 17 and is provided with a lifting drive (not shown). In this embodiment, the needles 13 are attached to a plate-like carrier 11. This plate-like carrier is connected to the lifting device and the drive, in such a way that the needles penetrate periodically into the surface area of the mineral fiber web 10, 17 up to a predetermined penetration depth and compress it in the preselected surface area and simultaneously matt it.

The stroke of the lifting device is advantageously adjustable and adjustable to a certain height, and the stroke frequency can be regulated via the drive. It is also advantageous if the impact forces of the needles 13 can be regulated. By limiting the impact forces, the compression needles can be prevented from deforming within the mineral fiber web when unwanted wool inclusions occur, so that the risk of the needles breaking off is reduced. In practice, these previously explained settings and controls can be accomplished in a simple manner in that the lifting device can be actuated pneumatically or hydraulically.

The needles 13, in particular the compression needles used for compression, have a chisel-like widened head 27 or 30 which, according to FIGS. 2 and 3, are molded onto the end of the needle shaft 26 or 29. The needle head 27 has a cutting edge 28 at the lower end, which when striking force them into a loop shape on the fibers and thus result in a matting with the neighboring fibers. In the embodiment of the needle according to FIG. 3, a needle tip 31 which projects downward is provided on the chisel head 30. Instead, several needle tips can be arranged. The needle tips expediently have small lateral hooks 32 and 33, which lead to further deformation and matting of mineral fibers, particularly in the boundary region between the compressed surface region on the one hand and the non-compressed region of the mineral fiber web. Another constructive design serves the same goal of felting and connection between the two aforementioned layers, according to which at least two different needle groups, namely a group of short front needles and a group of longer post needles, are provided. In order to achieve the effect of good felting, the needles or plungers have a larger diameter and, as shown in FIGS. 2 and 3, other shapes than are known from the textile industry, for example in the case of multi-needle sewing machines. The arrangement of the compression needles should suffice for a tangle stitch arrangement, so that the outer surface areas or layers are pre-compressed as uniformly and evenly as possible in a punctiform manner and according to the stroke frequency to be set. It is important to concentrate the impact stress from the needles on a small area in relation to the surface of the entire mineral fiber web, so that the impact forces compress the outer zones explained and due to the force distribution at point loads, the layers below are only subjected to minor stresses. By an appropriate choice of compaction needles, e.g. B. with a short front needle, the fibers are forced from the outer compressed layers into the underlying undensified fiber layers, so that additional connections are formed which continue to have a favorable influence on the bending and tearing behavior of the finished product. The compression needles themselves are advantageously made of light and abrasion-resistant material. The aim is to reduce the mass of the needles and the components to be moved as much as possible, so that correspondingly higher stroke frequencies are possible. This is particularly important at high line speeds in the production of mineral fiber webs.

The compaction and felting can be carried out either on the top or bottom of the mineral fiber web or, as FIG. 5 and in particular FIG. 4 illustrate on an enlarged scale, on both sides. The mineral fiber web 17 compressed on both sides then has two compressed and matted surface areas 34 and 35 and an intermediate non-compacted and non-matted middle layer 17 and 37, however, a good connection between the layers is ensured. If, according to the practical application of the end product plates, only a one-sided compacted and matted layer is desired, a slicing device (not shown) for cutting a mineral fiber web 17 or 21 matted and compacted on both sides can be provided in two partial webs in accordance with the separating cut 36 (FIG. 4).

As FIGS. 1 and 5 also illustrate, the compressed mineral fiber web 17 emerging from the needling or felting machine is fed via conveyor rollers 18, 19 or corresponding endless conveyor belts to a hardening furnace 20, in which the mineral fiber web 21, for example, between another endless belt (not shown) can receive slight post-compaction, especially to smooth the surfaces. The previously uncured binder is then finally cured in the hardening furnace 20. The mineral fiber web emerges from the hardening furnace in the direction of arrow 23 and can be separated into suitable plate pieces and processed into the end product. or the separation cut 36 described according to FIG. 4 can cause the separation into plate parts.

FIGS. 1 and 5 show yet another embodiment of the device according to the invention, namely that a further plate 24 and 25 is provided on one side (FIG. 1) or on both sides (FIG. 5) between the plate-like needle carriers 11 and 12 on the one hand and the mineral fiber web 10, 17 on the other hand in which the needles 13, 14 are guided. These plates 24 and 25 can also be connected to the lifting device. They can bring about a certain additional surface compaction, but above all these plates can be used to push fibers that may have been torn out of the surface back into the surface.

The lifting devices arranged on both sides according to FIG. 5 are advantageously operated in the direction of arrows 15 and 16 with the same lifting frequency and in push-pull mode, ie. H. if the upper lifting device moves downwards, the lower lifting device is moved upwards at the same time and vice versa during the back stroke. Since the device according to FIG. 5 is essentially symmetrical or a mirror image of the horizontal central plane, the same reference numerals have been used for identical or equivalent parts.

A further embodiment of the invention is achieved in that the needles are designed as hollow needles and are connected to a feed device for additives, preferably liquid additives. In particular with higher conveying speeds of the mineral fiber web, it is advantageous that the needles for adaptation to the conveying speed of the mineral fiber web are each cyclically movable, preferably pivotable, on the lifting device during the puncture. In this way, the needles are protected, friction and the associated Avoiding heating and practically completely eliminating the risk of a break. These movements of the needles during the puncture into the mineral fiber web in their conveying direction and the back movements of the needles after exiting the mineral fiber web into the original position can be achieved by simple mechanical gear arrangements, such as, for. B. by means of eccentrics.

In terms of material, mineral fibers or mineral fiber material have always been spoken of in general above. However, it should be particularly emphasized here that both the method and the device are particularly suitable for the production of rock wool products. Furthermore, not only material webs with a fiber course parallel to the large surfaces can be processed, but also lamellar webs or plates in which the fibers run perpendicular or at a different angle to the large surfaces.

Claims (27)

1. Method for producing mineral fiber products having compacted surface portions of mineral fiber webs, the fibers within the mineral fiber web extending substantially parallel or vertically or diagonally to the large surfaces of the mineral fiber web and said web containing a non-cured bonding agent, characterized in that at least one surface portion is subject to needle impacts up to a predetermined penetration depth so that the fibers felt and at the same time the surface portion is compacted.
2. Method according to claim 1, characterized in that the frequency of stroke of the needle impacts is variable and adjustable.
3. Method according to claim 1 or 2, characterized in that the stroke and the penetration depth of the needles are variable and adjustable.
4. Method according to any one of the preceding claims, characterized in that an endless mineral fiber web is moved continuously, is subject to a first mechanical pre-compaction, then is compacted and felted further by means of needle impacts within the given surface portion and, during a second compacting operation, is advanced to thermal treatment for curing the boding agent.
5. Method according to any one of the preceding claims, characterized in that the needle impacts for the compaction and felting are uniformly distributed within the entire surface portion.
6. Method according to any one of the preceding claims, characterized in that the treatment by needle impacts takes place on both of the mutually parallel surface portions of the mineral fiber web.
7. Method according to claim 6, characterized in that the mineral fiber web, after curing of the bonding agent, is cut open in a cutting plane parallel to the large surfaces so as to produce two mineral fiber slabs having a unilaterally compacted layer.
8. Method according to any one of the claims 1 to 4, characterized in that the needle impacts are effected by rows in the longitudinal and/or transverse directions of the mineral fiber web so that the finished product slabs are flexible or can be polygonally buckled.
9. Method according to any one of the preceding claims, characterized in that the treatment is effected using different types or shapes of needles.
10. Method according to claim 9, characterized in that a compaction and felting of the surface portion is effected by means of short preliminary needles and that by means of subsequent needles of greater length part of the fibers from the outer compacted surface portion are pushed into the inner non-compacted portion of the mineral fiber web.
11. Method according to any one of the preceding claims, characterized in that the thickness of the compacted layer in the surface portion is determined by selecting the penetration depth of the needles, by the frequency of stroke and by the needle shape so that small penetration depths, high frequencies of stroke and needles having a large effective cross section, on one hand, result in thin and highly compacted layers, while great penetration depths, low frequencies of stroke and needles having a small cross section, on the other hand, result in less compacted layers.
12. Method according to any one of the preceding claims, characterized in that additional additives are charged by means of hollow needles for additional reinforcement of the surface portion.
13. Method according to any one of the preceding claims, characterized in that a thin fleece of a fiber material, particularly glass fibers, is laid onto the surface of the mineral fiber web and thereafter the needle impacting operation is carried out so that part of the fibers of the fleece are embedded in the mineral fiber web.
14. Method according to any one of the claims 1 to 12, characterized in that a tissue is laid onto the surface of the mineral fiber web and thereafter the needle impacting operation is carried out so that part of the tissue is embedded in the mineral fiber web.
15. Apparatus for carrying out the method according to any one of the preceding claims, wherein a plurality of needles (13,14) are connected in groups or in common to a lifting means (15,16) which is arranged at least on one surface side of the mineral fiber web (10,17) and is equipped with a driving means, characterized in that the needles penetrate into the mineral fiber web (10,17) in a clocked manner and up to a predetermined penetration depth, thereby felting and simultaneously compacting said web in the surface portion.
16. Apparatus according to claim 15, characterized in that the stroke of the lifting means (15,16) is adjustable and variable and that the frequency of stroke can be regulated via the driving means.
17. Apparatus according to claim 15 or 16, characterized in that the impact forces of the needles (13,14) can be regulated.
18. Apparatus according to any one of the claims 15 to 17, characterized in that the needles (13,14) and particularly those serving for the pre-compaction have a head (27,30) which is enlarged similar to a chisel.
19. Apparatus according to claim 19, characterized in that at least one protruding pinpoint (31) is provided on the chisel head (27,30).
20. Apparatus according to any one of the claims 15 to 19, characterized in that the needles (13,14;26,29) are formed as hollow needles and are connected to supplying means for additives, preferably liquid additives.
21. Apparatus according to any one of the claims 15 to 20, characterized in that the needles are fixed to a plate-like carrier (11,12) which is connected to the lifting means and to the driving means.
22. Apparatus according to claim 21, characterized in that between the plate-like carrier (11,12) and the mineral fiber web (10,17) a further plate (24,25) is provided in which the needles (13,14) are guided and which is also connected to the lifting means.
23. Apparatus according to any one of the claims 15 to 22, characterized in that at least two different needle groups are provided, one group of short preliminary needles and one group of longer subsequent needles.
24. Apparatus according to any one of the claims 15 to 23, characterized by transport rollers (6,7,8,9) or belts (2,3) on both sides of the endless mineral fiber web (1,10,17) for the pre-compaction thereof, by unilateral or bilateral lifting means with a plurality of needles (13,14) for the felting and compacting by layers of the respective surface portions (34,35) of the mineral fiber web (17) and by further transport rollers (18,19) or belts for the advancement to a hardening furnace (20).
25. Apparatus according to any one of the claims 15 to 24, characterized by cutting means for cutting open a bilaterally felted and compacted mineral fiber web (21) into two partial webs.
26. Apparatus according to any one of the claims 15 to 25, characterized in that the needles (13,14), for the adaptation to the transporting speed of the mineral fiber web (10,17) during the puncture, are supported on the lifting means to be respectively movable and preferably pivotable in a clocked manner in the transport direction.
27. Apparatus according to any one of the claims 15 to 26, characterized in that the lifting means is pneumatically or hydraulically operable.

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