SI9200007A - Process and apparatus for manufacturing mineral fiber boards and mineral fiber boards manufactured therefrom - Google Patents

Abstract

In the process for manufacturing mineral fibreboards, in which mineral fibres wetted with a binder are deposited on a conveyor device to form a mineral-fibre layer, in order to feed them to a continuous-flow oven, during conveyance the mineral-fibre layer is precompressed in thickness in front of the continuous-flow oven and subsequently is folded in length as a result of alternate bulging, the mineral fibres of the mineral-fibre layer are felted, and then the mineral-fibre layer is so compressed in thickness that, after hardening, it has a virtually plane surface, the mineral-fibre layer is felted in a controlled manner in particular regions, in that, when a force which can be applied to the mineral fibres is exerted, the vertical component of the force is maximised in the region to be felted. <IMAGE>

Description

The process and preparation for the manufacture of mineral fiber plates as well as the mineral plate produced by this process

The invention relates to a method for the manufacture of mineral fiber boards, wherein the binder-moistened mineral fibers are deposited on a conveyor in order to form a mineral fiber layer in order to feed them into a continuous furnace, in which a layer of mineral minerals is further transported before the continuous furnace. the fibers are pre-compressed by the thickness, and then, by the length of the inclination, with alternating protrusions, the mineral fibers of the mineral fiber layer are rolled, and then the mineral fiber layer is compressed so that it encloses a practically flat surface after curing. The invention further relates to a preparation suitable for carrying out the process. Finally, it refers to the corresponding mineral fiber boards.

In order to increase the strength of mineral fiber boards and, in the present case, the stiffness thereof, a number of measures have been proposed.

Thus, the process for the manufacture of mineral fiber panels is known from CH-C-620 861, in which the mineral fiber panels are precompressed and folded. This is achieved by the fact that many fibers of the layer lie at an angle on the smooth surface of the plates, this orientation occurs when the layer of mineral fibers is compressed even after the thickness of the sheet so that, after hardening of the binder, it comprises essentially a flat surface. This increases the compressive and tensile strength of the finished slab transversely to the plane of the slab.

A comparable process is known from DE-A-38 32 773, wherein the longitudinal compression with the projection of the mineral fiber layer follows in several successively arranged stages until it enters a continuous furnace. It is thus avoided that the protrusion after pre-compression of the mineral fiber layer is carried out relatively suddenly in the inlet region of the furnace continuum. With this improvement, the known process of CH-C620 861 is applicable to a variety of different types of mineral fibers.

Although good values of compressive and tensile strength have been obtained with such a hinge structure, it has the disadvantage that it tends to stretch, so that both tensile strength in the longitudinal direction and flexural strength are only punctual.

These disadvantages are to be overcome by the proposal of EP-A-0 133 083 in such a way as to allow fibers to be received in the inner region of the plate in as many directions as possible without the overall orientation of the fibers in the longitudinal direction of the plate being appreciably altered. Although this process requires considerable costs in realization, the finished product largely lacks the characteristics that distinguish the pleated mineral fiber board.

The process of the aforementioned type as well as the preparation for carrying out the process are finally known from DE-A-16 35 620. Thereafter, a layer of fiber fibers is rolled over the entire thickness of the roller in order to fix the projections.

It is often necessary to produce mineral fiber panels with specified customer-specific strengths, which requires a well-defined mineral fiber density profile, especially perpendicular to the plane of the slab. Such a density profile is known by known methods or methods. preparation cannot be achieved.

Therefore, the invention is based on a technical problem of how to prepare a process by which a mineral fiber board with a density profile can be made, while at the same time achieving, in particular, to maintain at least the flexural strength of the manufactured mineral fiber board compared to the known longitudinally compressed products with continuous interlacing of fibers during forming.

This problem is solved by the process of the above mentioned type with the characteristics given in the characteristic part of claim 1.

It is a further task to develop a preparation for carrying out the process according to the invention. This is the subject of claim 1. Preferred implementation of the process or. preparations are the subject of each sub-claim.

Finally, the invention provides a mineral fiber board made according to the disclosed process.

According to the process according to the invention, the mineral fiber layer is targeted at the roller, thereby maximizing the vertical force component at the force exerted on the mineral fibers from the outside in the rolled area. Matter. the extent to which the maximum value for the vertical component of the given force is reached. it follows the orientation of the mineral fibers in the area, which means the rolling of the mineral fibers with one another. The rolled area, on the one hand, prevents the longitudinally compressed structure from spreading as it is already known, so that the flexural strength of the known mineral fiber plates can be maintained, and the tensile strength in the longitudinal direction does not suffer any damage.

Furthermore, any desired density profile can be created in advance by specifying the appropriate area. By doing so, with continuous or stepping, respectively. stepwise density transitions can make as good adjustments as possible to the strength specifications of the products. Crude densities of the order of 80 to 220 kg / m ³ can be obtained in the rolled areas, while the crude densities in the non-rolled areas of the mineral fiber slab lie in the range of 30 to 150 kg / m ³ .

Maximizing the vertical force component can be e.g. is achieved by introducing at least one needle or pin into the mineral fiber layer, minimizing the relative velocity between the needle or pin and the mineral fibers in the area to be rolled. In this case, the adhesive forces of the binder support the transfer of force between the needle or the needle. jamming and mineral fibers especially large.

Device for making mineral fiber plates, in particular for carrying out the process according to claim 1 or claim 2, comprising a conveyor device for transporting mineral fiber layers and a pre-press for pre-compressing the thickness of mineral fiber layers, a device for longitudinally compressing mineral fiber layers with alternating projections, longitudinally compressing a roller conveyor in series and a continuous furnace, further comprising a conveyor belt device, the roller assembly being arranged directly in front of the transfer belt device and the continuous furnace directly behind it.

Further, a device is provided for the rolling device to maximize the vertical component of the force transmitted from the rolling device to the mineral fibers of the mineral fiber layers.

The device for the vertical component can be realized e.g. with a needle board machine with oscillatingly moving needles which, with this oscillatory motion, penetrates differently into the areas to be rolled correspondingly, layers of mineral fibers, with the needle speed moving essentially a sine function with a minimum speed at turning points of oscillatory motion.

It is particularly advantageous if the needles are provided with at least sections with at least one beard projecting from the circumferential surface of the needle, or alternatively or. also, in combination with at least one backward notched notch. Generally, a series of such beards or notches are arranged, spaced apart from each other in the longitudinal direction of the needle. These beards, respectively. protrusions. formed between adjacent notches capture the fibers in the motion of the needle board, so that the desired transfer of force follows in a particularly simple manner. This action is advantageous in combination with the sinusoidal movement of the needles themselves.

Further, needles of various lengths can be provided, which are again equipped with beards or. notches. This results in the fact that in certain areas only longer spaced apart needles are spaced apart from each other, while in others the whole is now closely adjacent to the needles, resulting in varying degrees of rolling.

It may also be that the needle may not be fitted with beards or. notches along their entire length, but e.g. only in the area of their lower end section. A needle board machine can only be designed as a one-sided layer of mineral fiber machine operating. For most applications, however, it is advantageous if the needle-board machine comprises two needles positioned opposite each other, each side provided with a series of needles facing the mineral fiber layer.

The vertical component of the force device may also be designed with at least one rotating metal brush whose rotational speed can be controlled individually. This is where brush pins work much like beards on needle boards. In this design, the device is preferably used when the surface area of the mineral fiber layer is to be affected, the length of the brush pins or needles being substantially corresponding to the thickness of the surface layer to be rolled, the mineral fiber layers, the narrowest spacing of the cylinders about the thickness of the mineral fiber board being manufactured. Here, too, by selecting the parameters of the device, it can be determined to what extent the rolling should be followed, without further adjusting to the desired thickness of the final product layer.

Furthermore, surface treatment has proved particularly advantageous if the rolling device comprises at least one brush roller and a needle plate machine. Although the brush would have the advantage of continuous processing of the mineral fibers, the intensity of the needles is too low here, so that good results would require multiple plates or multiple times. down the brush. To avoid this, needle-board machines have been added to bring about better needling, although with more sophisticated propulsion, increased machine costs have to be met.

The invention is further concretized on the basis of the embodiment shown in the accompanying drawings, in which FIG. 1 is an apparatus for making mineral fiber panels, in particular for carrying out the process of the invention, wherein a pair of metal brushes is inserted as a rolling device, FIG. 2 is a further embodiment of a device for carrying out the process according to the invention, in which the final step includes both a pair of metal brushes and a needle board machine; FIG. 3 is a schematic view of a first embodiment of a needle board machine; FIG. 4 is a schematic view of another embodiment of a needle board machine; FIG. 5 is a schematic view of a third embodiment of a needle board machine, and FIG. 6 is a schematic cross-sectional view of mineral fiber panels manufactured according to the process of the invention.

In FIG. 1 presents an apparatus 1 for the manufacture of mineral fiber plates, in which the mineral fibers are conveyed to the press 4 by a conveyor device 2, in which the mineral fibers are assembled and compressed into a layer 3 of mineral fibers. The pre-press 4 consists of two opposite to one another the fluid cylinders 26 and 27 with a diameter larger than the diameter of the compression cylinders used in the longitudinal compression device 5.

A layer 3 of mineral fibers protruding from the press 4 is supplied to this longitudinal compression device 5, with compression elements, e.g. the aforementioned rollers being evil conveyor belts driven at a continuous circumferential speed in the direction of the continuous furnace 7. This results in a slow protrusion of the mineral fiber layer, leading to folding of the layer, whereby the folds are formed substantially transversely to the transport direction of the mineral fiber layer 3.

Apparatus 5 for longitudinal compression is connected in series by a rolling device 8 consisting of two opposite to each other metal and metal brushes 28,29. These metal brushes 28,29 extend like rollers over the entire width of the layer 3 of mineral fibers. A series of pins or needles are applied to the roll surface, the length of the pins or needles being substantially equal to the thickness of the layer of surface area to be rolled by the 3 mineral fiber layers. The narrowest spacing of the outer roller surfaces corresponds approximately to the thickness of the mineral fiber board. The pins or needles tear the fibers preferably from the protuberances of the mineral fiber layers and roll the fibers of the adjacent protrusions. This not only attaches to the interconnection of the protuberances, but also creates a pre-glossed surface of the mineral fiber layers.

With the help of the displacement strip 6, which is connected in series to the rolling device 8, the surface of the mineral fiber layer 3 is further smoothed and this layer 3 leads to a continuous furnace 7.

In order to carry out the process according to the invention with this preparation, the binder-moistened mineral fibers are deposited on the transport device 2. These fibers are fed to the press 4, where they are directed substantially to the transport direction. In this way, a layer of 3 mineral fibers is formed, the thickness of which is determined by the distance between the cylinders 26, 27 of the press 4. This extruded layer of 3 mineral fibers is fed to a device 5 for longitudinal compression, by means of which a layer of mineral fibers is folded. In the roller assembly 8 connected in series, the surface areas of the mineral fiber layer are freely pierced to a pre-selected depth so that the adjacent projections of the mineral fiber layer are interconnected with fibers which are substantially isotropically oriented in the area. The homogenized surface areas, namely, the lower and upper sides of the mineral fiber layer, are surface-smoothed with the conveyor belt device 6 from two opposite to one another 24, 25 and thus lead to a continuous furnace 7, thus preparing the mineral fiber layer according to the invention solidifies into a solid plate.

A further embodiment of the present invention is shown in FIG. 2. The device shown in FIG. 1 differs in the design of the rolling device, while the other elements of the preparation in design and function are the same as those shown in FIG. 1. A wrinkled layer of mineral fibers which has been sown by means of a longitudinal compression device is now guided to a rolling device 8 consisting of opposite needleboards 30, 31 which can be raised above the layer by means of a suitable gearbox. 3 mineral fibers respectively. lower it. These needle boards 30, 31 comprise, in their layer 3 of mineral fibers, an inverted arrangement of needles, whereby, according to their design, the density distribution determined by the respective roll rate can be formed, even within the mineral fiber layer.

In FIG. 3 is a schematic representation of the first embodiment of a needle board 30 with a series of 3 needle-oriented mineral fiber strings 3, of which only four are represented in the present case. In this case, the stroke of the needle board 30 is illustrated by the presentation of four positions. Each needle 32 is provided with beards 33 projecting from the circumferential surface of the needle, wherein the beards 33 are optionally spaced at approximately a constant distance from each other on the needle. The needle board 30 is driven such that the vertical velocity of the needles follows a substantially sinusoidal function, which is superseded by the oscillatory change in penetration. The maximum stroke of the needle board 30 may be, for example, 60 mm. The upper turning point of the stroke is positioned so that the needle board 30 is pulled out of the layer 3 of mineral fibers, while in each of the lower points, it penetrates fully or only half into the layer 3 of mineral fibers, so that either the entire beard 33 or only about half of the beards 33 in the lower region of the needles 32. The sinusoidal velocity course of penetrating and withdrawing the needles 32 causes the fibers to engage with the beards 33 only in certain areas. With a high vertical velocity in the central area, beards 33 cannot be stretched out by the excess adhesion forces compensated for by the beard 33. When approaching the lower turning point, however, the needle speed is reduced to zero, so that here the beards 33 grab the fibers and turn the vertical direction. In FIG. 3 selected arrangements of beards 33 and pins 32 and oscillations of penetration depth change, e.g. between the first depth at the boundary between the central region B and the surface spaced C and the second depth at the boundary between the surface area A and area B, in combination with the sinusoidal course of the needle speed 32, the surface area closer to the roller becomes stronger and the region B connected thereto. weaker, e.g. only half as strong as zone A. If more than one defined penetration depth varies with the oscillato, a corresponding multiple of the rolling roll rate can be achieved.

In order to design the step effect of rolling in another, especially simple, manner, arrangement of needles 32 with beards 33 according to FIG. 4. Approximately half of the total number of needles 32, 34 are truncated so as to limit their action to the surface area A of layer 3 of the mineral fibers. The other half of the needles 34 has an effect in both zone A and its connecting region B. Zone A rolls again strongly and zone B weakens, producing a distinct gradation. Multiple lengths of rolling can also be achieved here by using several different needle lengths.

A third embodiment of the needle board is shown in FIG. 5, wherein the needle board 30 carries a set of needles 35, each of which is provided with beards 33 only in its lower end section. beards 33 have effect, again in combination with sinusoidal movement velocity, in only one of the surfaces spaced by the recumbent region B, while the surface closer area A remains virtually completely unaffected. As explained above, in area A, the velocity of the needles 35 is too high to be stranded. Depending on the purpose of use, only one needle board 30 is selected, and the needle boards on either side of the mineral fiber layer 3, as shown in FIG. 2, or also a combination of differently designed iglanig boards, optionally in combination with metal brushes 28, 29, also according to FIG. 2.

The needle boards 30, 31, as shown in FIG. 2, connected in series with each other opposite the rotating metal brushes 28, 29, corresponding to those already described in connection with FIG. 1. From the needle boards 30, 31 and the metal brushes 28, 29 the rolling roller assembly is re-connected in series to the conveyor belt assembly 6, which consists of two opposite to each other conveyor belts 24,25, which smooths the surfaces of the mineral layers 3. fibers.

In FIG. 6a shows a cutout of a mineral fiber panel 3 made according to the method of the invention in which the surface area 36, 37 is machined. In the central area 38, a wrinkled structure is formed in the central region 38, while in the surface areas 36, 37 this orientation fibers raised so that a substantially homogeneous, isotropic fiber layer is formed there, in FIG. 6b shows a cutout of a mineral fiber board made using the needle board of FIG. 5. Here, the central region39 is homogenized, while the surface regions closer to it show their non-intact fold structure.

For all uses, the needle board frequency, i.e. frequency for sine function, dialing from 5 to 25 Hz.

Claims (13)

PATENT APPLICATIONS A method for making mineral fiber boards in which - the binder-moistened mineral fibers are deposited on the conveyor (2) to form a layer (3) of mineral fibers to be fed into a continuous furnace (7) - transport in front of the continuous furnace (7) a layer (3) of pre-compressed mineral fibers, followed by the length of the inclination with alternating projections, - the mineral fibers of the mineral fiber layer (3) roll, and - thereafter, the mineral fibers layer (3) thereafter. compresses the thickness so that, after curing, it comprises a practically flat surface, characterized in that the layer (3) of mineral fibers is targeted by a roller over an area, thereby, for a force exerted on the mineral fibers, in the area to be rolled, the vertical component thereof force maximizes. Method according to claim 1, characterized in that the vertical component of the force is maximized, thereby introducing at least one needle (32, 34, 35) or pin into the mineral fiber layer (3), with roller, minimizes the relative speed between the needle or pin and the mineral trains. Preparation for the manufacture of mineral fiber boards, in particular for carrying out the process according to any one of the preceding claims, s / z - conveyor (2) for the transport of layers (3) of mineral fibers, - press (4) for pressing the thickness of the layer (3) mineral fibers. - a device (5) for longitudinal compression of a layer (3) of mineral fibers with alternating projections, - a rolling device (8) connected in series to a device (5) for longitudinal compression, and - a continuous furnace (7), characterized in that - comprises a conveyor belt device (6), the rolling device (6) being disposed directly in front of the transfer belt device (6) and the continuous furnace (7) directly behind the transfer belt device (6), and - the rolling device (8) comprises a device that maximizes the vertical component of the force transferred from the rolling device (8) to the mineral fibers of the mineral fiber layer (3). Device according to Claim 3, characterized in that the rolling device (8) is a needle board machine (30, 31) with oscillatingly moving needles (32, 34, 35) whose movement speed substantially corresponds to a sine function with a minimum speed at the pivot points of oscillatory motion. Device according to claim 4, characterized in that the needles (32, 34, 35) are provided at least in part with at least one beard (33) projecting from the circumferential surface of the needle. Device according to claim 4 or 5, characterized in that the needles have different lengths. Device according to one of Claims 4 to 6, characterized in that - the needle board machine comprises two needle boards (30,31) facing each other opposite to one another, - it is on the side facing the mineral fiber layer (3) , each provided with a set of needles (32, 34.35). Device according to claim 3, characterized in that the rolling device (8) comprises at least one rotating metal brush (28, 29), the rotational speed of which can be optionally controlled. Device according to claim 8, characterized in. yes - it comprises rotating metal brushes (28, 29) opposite each other, in each case consisting of a cylinder having a series of pins or needles, - the length of the pins or needles being substantially corresponding to the thickness of the surface area layer (36, 37) by the roller, layers (3) of mineral fibers, - the narrowest spacing of the cylinders corresponds to approximately the thickness of the mineral fiber board to be fabricated. Device according to one of Claims 3 to 9, characterized in that the rolling device (8) comprises at least one brush roller (28, 29) as well as one needle board machine (30,31). Mineral fiber board, especially made according to the method of claim 1 or 2, characterized in that, with respect to at least one surface (36, 37), the surface closer to the fibers is rolled. Mineral fiber board, especially made according to the method of claim 1 or 2, characterized in that the degree of rolling in the direction of at least one surface (36, 37) is gradual or continuous. A mineral fiber board, especially made according to the method of claim 1 or 2, characterized in that it is rolled in the central region (39), while the surface areas closer to the fiber are not rolled with respect to at least one surface.