Low-volume-density mineral wool mat comprising thermally bonding fibres

Abstract

The present invention relates to a mineral wool mat (1) comprising at least a plurality of mineral fibres stacked on top of each other and side by side within the mineral wool mat (1), the mineral fibres being rigidly connected to one another by means of thermally bonding fibres, the volume density of the mineral wool mat (1) being less than 40 kg.m-3 and the thickness of the mineral wool mat (1) being greater than 50 mm.

Description

[0001] DESCRIPTION

[0002] Title: Low volume density mineral wool mattress comprising thermally bonding fibers.

[0003] The present invention relates to the field of construction materials, and more particularly to the field of construction materials for buildings formed from a mineral wool mattress, for example of the glass wool type. Such construction materials are notably used to provide thermal and / or acoustic insulation.

[0004] Mineral wool blankets are commonly used as insulation materials for thermal and / or acoustic insulation, for example, during building construction. The insulating properties of mineral wool blankets are achieved, in particular, by the ability of the mineral wool blanket to trap air in a stable and immobile manner within itself.

[0005] Mineral wool mattresses are obtained by passing a mineral fiber mat through an oven, formed on a conveyor device upstream of the oven by a mixture of mineral fibers, virgin or recycled, entangled with each other, and binding elements intended to bind the fibers together during passage through the oven. This mineral fiber mat can be produced by different types of installation, for example by a fiberizing station and projection of liquid binder onto the mineral fibers obtained previously, the torus of mineral fibers thus bonded falling onto a conveyor device guiding the assembly towards the oven. Alternatively, without this being limiting of the invention, the mineral fiber mat formed before the oven can be obtained in a station in which the mineral fibers and binding elements are blown into a box and sucked onto a conveyor device guiding the assembly towards the oven.

[0006] The thermal and / or acoustic insulation performance of mineral wool mats obtained after being placed in an oven, consisting of non-woven fibrous materials, depends in particular on the arrangement of the fibers in the finished product, in order to avoid a conduction bridge being formed from one side of the mat to the other by a group of mineral fibers. This insulation performance thus depends in particular on the thickness and volume density of the mineral fiber mat as well as on the interaction of the mineral fibers with the binder before being placed in the oven.

[0007] These mineral wool mattresses, intended in particular for the construction of buildings, have a thickness of at least 50 mm, so that their structural characteristics are distinguished from mineral wool materials that can be used in other applications, such as in the automotive industry for example. The inventors were able to observe that the mineral wool mattresses of the prior art, used in construction, although efficient, do not have optimal performance. Some of these mineral wool mattresses are obtained by a manufacturing installation using a box within which mineral fibers are blown and then sucked so as to be pressed against a conveyor device taking the carpet of mineral fibers thus formed to an oven.The distribution of mineral fibres on the conveyor device by such installations is not satisfactory and other manufacturing installations forming the mineral fibre mat by mechanical deposition of the mineral fibres on top of each other have been developed.

[0008] The present invention falls within this context and aims to propose a mineral wool mattress in which the thermal and / or acoustic insulation is improved by using a manufacturing installation mechanically depositing the mineral fibers on a conveyor device of the installation.

[0009] Thus, the present invention relates to a mineral wool mattress comprising at least a plurality of mineral fibers superimposed on each other and next to each other within the mineral wool mattress, the mineral fibers being secured to each other by means of thermobonding fibers, the volume density of the mineral wool mattress being less than 40 kg.m' 3 and the thickness of the mineral wool mattress being greater than 50 mm.

[0010] Such a mineral wool mattress is intended for building construction. The production of these panels is carried out by installations which mix the mineral fibers and mechanically deposit them on a conveyor device feeding an oven, so as to obtain an optimal configuration of the mineral fibers within the mineral wool mattress. The inventors were able to determine that this optimal configuration is obtained by the combination of a thickness of at least 50 mm and a volume density of the mineral wool mattress of at most 40 kg.m' 3, and the use of thermobonding fibers. The mineral wool mattress according to the invention is advantageously obtained by a manufacturing installation by mechanical deposition of the mineral fibers on a conveyor device taking the mineral fiber mat to an oven in order to be heated there. The thermobonding fibers actively contribute to limiting the production costs of mineral wool mattresses by limiting maintenance and upkeep interventions.

[0011] According to a characteristic of the invention, the mineral fibers are glass fibers.

[0012] According to a characteristic of the invention, the thickness of the mineral wool mattress is greater than 100 mm.

[0013] According to a characteristic of the invention, the thickness of the mineral wool mattress is greater than 250mm.

[0014] The thickness of the mineral wool mattress to be considered here is the nominal thickness of the mattress, i.e. the thickness that can be observed by the user when using the product for the purpose of insulating a building in particular.

[0015] In accordance with known practices of the prior art, the mineral wool mattress according to the invention is obtained by passing through an oven, configured at a determined cooking temperature, a carpet of mineral fibers, previously constituted, if necessary on a conveyor device directing the carpet of mineral fibers towards the oven, by a mixture of mineral fibers, virgin or recycled, entangled with each other, and binding elements, here thermobinding fibers according to the invention, intended to bind the fibers together during passage through the oven.

[0016] The nominal thickness may in particular be measured after packaging, for example when the product is purchased. For example, the nominal thickness as mentioned above is observed after various successive stages of the industrial manufacturing process during the implementation of the product, these stages possibly including, after the mineral fiber mat has been placed in an oven, the cutting into panels or rolls of appropriate dimensions of the mineral wool mat obtained after the oven has been placed, the compression of these panels or rolls prior to a packaging operation, the packaging and storage before marketing.

[0017] According to a characteristic of the invention, the mineral fiber mat is produced continuously, in a single pass during which the fibers participating in forming the mineral fiber mat passing through the oven are deposited in series on top of each other. In other words, it is not a question here of obtaining a mineral wool mat whose nominal thickness is greater than a given value by superimposing mineral fiber mats produced on installations operating in parallel before the oven, or by superimposing several mineral wool mats on top of each other.

[0018] According to a characteristic of the invention, the surface mass of the mineral wool mattress is greater than 4000 gm' 2. It is understood that obtaining a mineral wool mattress of low density and thickness greater than that known from the prior art implies a surface mass, or grammage, greater than that known. The inventors were able to target a particularly advantageous combination of value ranges, with a density of less than 40 kg.m' 3 , a thickness greater than 50 mm and a surface mass greater than 4000 gm' 2 .

[0019] According to a characteristic of the invention, the volume density of the mineral wool mattress is between 7 kg.m' 3 and 40 kg.m' 3 .

[0020] According to a characteristic of the invention, the volume density of the mineral wool mattress is between 10 kg.m' 3 and 35 kg.m' 3 .

[0021] According to another characteristic of the invention, the volume density of the mineral wool mattress is between 20 kg.m' 3 and 30 kg.m'3 .

[0022] According to a feature of the invention, the mineral fibers are joined together by a dry process. Such a method has the advantage of not dirtying mechanical elements of a manufacturing installation, such as rollers between which the mineral fibers are intended to pass. Indeed, the use of binder in liquid form leads to covering the mechanical elements of the installation with binders which must be removed subsequently, which requires shutting down the manufacturing installation and therefore increasing the production costs of a mineral wool mattress.

[0023] According to a feature of the invention, the mineral wool mattress comprises between 2% and 30% of thermally bonding fibers. Such a proportion ensures that each mineral fiber is bonded with at least one other mineral fiber while retaining the maximum insulating properties of the mineral wool mattress.

[0024] According to a characteristic of the invention, the mineral wool mattress comprises between 3% and 15% of thermally bonding fibers.

[0025] According to a characteristic of the invention, the mineral wool mattress comprises between 4% and 10% of thermally bonding fibers.

[0026] According to a characteristic of the invention, the percentage of mineral fibers present in the mineral wool mat is complementary to the percentage of thermally bonding fibers. In other words, the mineral wool mat is essentially formed of mineral fibers and thermally bonding fibers, the percentage of mineral fibers being of the order of 90% when the percentage of thermally bonding fibers is of the order of 10%. It should be noted that by "essentially formed" or "of the order of", the aim is to provide a margin of the order of 0.1 to 2%, in particular to provide for the presence of a coupling agent in the composition, in addition to the mineral fibers and the thermally bonding fibers.

[0027] According to a characteristic of the invention, the thermobonding fibers comprise a core and a sheath, the core having a melting temperature different from the melting temperature of the sheath.

[0028] According to an optional feature of the invention, the binding element is obtained by melting the thermobonding fibers. It is thus notable that the thermobonding fiber is to be distinguished from the mineral fibers insofar as it participates in forming the binding element associated with these mineral fibers, in particular by melting a part of the sheath of the thermobonding fiber or by partial melting of the thermobonding fiber itself. According to an optional feature of the invention, the distribution of the mineral fibers is homogeneous within the mineral wool mattress.

[0029] Within the mineral wool mattress according to the invention, the homogeneous distribution of the mineral fibers is achieved in particular by orienting each of the mineral fibers substantially in the same direction, and / or in several successive layers. As a result of this orientation of the mineral fibers, the air is trapped within the mineral wool mattress between successive layers of mineral fibers. It is understood that such an orientation greatly limits the formation of thermal bridges. In addition, this distribution of the mineral fibers forms a resistance to the passage of air, which tends to make the air immobile within the mineral wool mattress and thus increase the thermal and / or acoustic insulation properties of the mineral wool mattress.The inventors were able to determine that a homogeneous distribution of mineral fibers within the mineral wool mattress, that is to say a homogeneous density, in particular due to a controlled arrangement of the mineral fibers, would allow for a range of products whose density is less than 40 kg.m'. 3 , to obtain products that go beyond the known performance of a mineral wool mattress for the same given density.

[0030] According to a characteristic of the invention, at least the mineral fibers are distributed homogeneously within the mineral wool mattress, the homogeneous distribution of the mineral fibers being considered in a transverse and / or vertical direction, each of these directions being perpendicular to a main longitudinal elongation direction of the mineral wool mattress.

[0031] According to a characteristic of the invention, the coefficient of variation of the distribution of the mineral fibers within the mineral wool mattress between at least a first lateral zone of the mineral wool mattress and a second lateral zone of the mineral wool mattress is less than 5%, the first lateral zone and the second lateral zone being offset from each other in a transverse direction perpendicular to the main longitudinal elongation direction. It should be noted that these zones more specifically form strips having identical dimensions which can range from 10cm to 30cm depending on the protocols implemented. It should also be noted that the mineral wool mattress can be cut into any number of strips, the width or thickness of which allows the coefficient of variation to be measured between each strip.

[0032] According to a characteristic of the invention, the coefficient of variation of the distribution of mineral fibers within the mineral wool mattress between at least a first lateral zone of the mineral wool mattress and a second lateral zone of the mineral wool mattress is less than 3%.

[0033] According to a characteristic of the invention, the coefficient of variation of the distribution of the mineral fibers within the mineral wool mattress between at least a first vertical zone of the mineral wool mattress and a second vertical zone of the mineral wool mattress is less than 10%, the first vertical zone and the second vertical zone being offset from each other in a vertical direction perpendicular to the transverse direction and to the direction of main longitudinal elongation. It is understood that the coefficient of variation is established between each of the strips of the mineral wool mattress, relative to each other. In other words, the coefficient of variation of a zone is the same for each other zone of the mineral wool mattress.

[0034] According to a characteristic of the invention, the coefficient of variation of the distribution of mineral fibers within the mineral wool mattress between at least a first vertical zone of the mineral wool mattress and a second vertical zone of the mineral wool mattress is less than 5%.

[0035] The invention also relates to a method for producing a mineral wool mat as previously mentioned, the production method implementing at least a first step during which the thermobonding fibers and the mineral fibers are mixed with each other, at least a second step during which the mineral fibers and the thermobonding fibers previously mixed are deposited on a conveyor device by means of a mechanical guide means to form a carpet of mineral fibers, at least a third step during which the carpet of mineral fibers is conveyed by the conveyor device to an oven in which the mineral fibers and the thermobonding fibers are heated to form the mineral wool mat.

[0036] According to a characteristic of the invention, the mineral fiber mat is produced during the second step continuously, in a single pass during which the fibers participating in forming the mineral fiber mat passing through the oven are deposited in series on top of each other.

[0037] Other characteristics, details and advantages of the invention will emerge more clearly on reading the description which follows on the one hand, and examples of embodiment given for informational and non-limiting purposes with reference to the appended schematic drawings on the other hand, in which:

[0038] [Fig.l] represents a graph illustrating the surface mass as a function of their volume density of different mineral wool mattresses of the prior art and the area of ​​interest of the mineral wool mattresses in accordance with the present invention;

[0039] [Fig.2] schematically represents a general view of a mineral wool mattress in accordance with the present invention;

[0040] [Fig.3] represents the mineral wool mattress, as represented by Figure 2, which is schematically divided into a plurality of zones, making it possible to illustrate a characteristic of homogeneous distribution of the fibers within the mattress according to the invention;

[0041] [Fig.4] represents a local view of the mineral fibers and the thermobonding fibers present within the mineral wool mattress represented by figures 1 and 2;

[0042] [Fig.5] represents a manufacturing installation capable of forming a mineral wool mattress in accordance with the invention.

[0043] It should first be noted that while the figures set out the invention in detail for its implementation, these figures can of course be used to better define the invention, where appropriate. It should also be noted that these figures only set out examples of embodiments of the invention. The characteristics, variants and different embodiments of the invention may be combined with each other, in various combinations, provided that they are not incompatible or mutually exclusive. In particular, variants of the invention may be imagined comprising only a selection of characteristics described below in isolation from the other characteristics described, if this selection of characteristics is sufficient to confer a technical advantage or to differentiate the invention from the state of the art.

[0044] In the figures, elements common to several figures retain the same reference.

[0045] In the following description, we will refer to an orientation depending on the Longitudinal, Vertical and Transverse axes as they are arbitrarily defined by the trihedron L, V, T shown in figures 2 to 5. The choice of names for these axes is not limiting to the orientation that the mineral wool mattress can take.

[0046] As a reminder, the invention relates to a mineral wool mattress 1 whose volume density is less than 40 kg.m-3, whose thickness is greater than 50 mm and which comprises thermobonding fibers. It should be noted that in the present invention and in the description given thereof, a distinction is made between the mineral wool mattress which is the subject of the invention and a mineral fiber mat in that a mineral wool mattress is obtained by passing a mineral fiber mat through an oven. Prior to passing through the oven, said mineral fiber mat is formed by depositing mineral fibers intermixed with thermobonding fibers on top of each other and it is the cooking in the oven of this assembly, and where appropriate various subsequent steps including, for example, compression before conditioning, which form the mineral fiber mat.

[0047] Figure 1 illustrates a graph 7 representing the surface mass, or commonly referred to as the grammage, expressed in gm' 2 (grams per square meter) as a function of the volume density expressed in kg.m' 3 (kilogram per cubic meter) of different mineral wool mattresses as they were able to be tested by the inventors, by different weighing operations. As visible in this graph 7, the first mineral wool mattresses of the prior art 5 whose volume density is less than 40 kg.m' 3 have a surface mass lower than second mineral wool mattresses of the prior art 51 whose volume density is greater than 40 kg.m' 3 The known polymerized mineral wool mattresses shown in Figure 1 all have a surface mass of less than 2000 g. m' 2it being clearly recalled that these are mineral wool mattresses, comprising for example glass wool fibres, and not wood wool for which it is known to have higher surface masses, or grammage. In this context of mineral wool and grammage less than 2000 g. m' 2 , the mineral wool mattresses of the prior art 5, 51 have a surface mass which increases with the increase in their volume density.

[0048] It should be noted that the surface mass of a mineral wool mattress is equal to the product of the volume density and the thickness of the mineral wool mattress. In the various mineral wool mattresses forming the known prior art, the thickness of the first and second mineral wool mattresses of the prior art 5, 51 is less than 200 mm.

[0049] The inventors were able to observe that the first mineral wool mattresses of the prior art 5, having a very low volume density of between 20 kg.m' 3 and 35 kg.m' 3 , have a surface mass between 700 gm' 2 and 1000 gm' 2 . The second mineral wool mattresses of the prior art 51, having a volume density of between 35 kg.m' 3 and 50 kg.m' 3 , have a surface mass between 1000 gm' 2 and 2000 gm' 2 . It is noted that for the mineral wool mattresses of the prior art 5, 51 the increase in the surface mass leads to an increase in the volume density. As a result, the first and second mineral wool mattresses of the prior art 5 and 51 have a low thickness which limits the volume of immobilized air and which thus limits the thermal performance of these mineral wool mattresses.

[0050] In this context, to apply the mineral wool mattress to constructions that we wish to insulate and obtain satisfactory insulating properties, it may be necessary to double the mineral wool mattress, for example by cutting it into panels that are superimposed on each other.

[0051] An area of ​​interest 6 containing surface mass values ​​greater than 4000 gm' 2 and volume density less than 40 kg.m' 3 is also shown in Figure 7. Such mineral wool mattresses have a homogeneous distribution of mineral fibers and a volume density of less than 40 kg.m' 3 , preferably between 7 kg.m' 3 and 40 kg.m' 3 , more preferably between 10 kg.m' 3 and 35 kg.m' 3 , more preferably between 20 kg.m' 3 and 30 kg.m' 3. Furthermore, such mineral wool mattresses have, according to the invention, a thickness greater than 50 mm, preferably greater than 100 mm, preferably greater than 300 mm, more preferably greater than 400 mm.

[0052] The mineral wool mattresses are formed from a homogeneous distribution of mineral fibers capable of limiting the formation of thermal bridges within the mineral wool mattress and thus capable of offering better resistance to the passage of air than the first and second mineral wool mattresses of the prior art 5 and 51. These mineral wool mattresses can be obtained by different manufacturing processes, with at least one passage in an oven of a set of mineral fibers and thermobonding fibers forming a carpet of mineral fibers, the cooking of the carpet of mineral fibers resulting in a mineral wool mattress in accordance with the invention, with a homogeneous volume density and less than 40 kg.m' 3. Such mineral wool mattresses also have a thickness which is advantageously greater than 50 mm. One of these manufacturing processes will be described in more detail in connection with Figure 5.

[0053] It is notable that the mineral wool mat according to the invention is obtained without an additional step during which the thickness of the mineral wool mat is doubled by superimposing it on itself at the oven inlet. In other words, the mineral wool mats according to the present invention are obtained during a linear manufacturing process during which mineral fibers are deposited one on top of the other to form a mineral fiber mat whose thickness is sufficient so that once passed through the oven, the mineral fiber mat becomes a mineral wool mat whose thickness is greater than a given value, in particular greater than 50 mm, preferably greater than 100 mm and more preferably greater than 250 mm, with a grammage, or surface mass, greater than 4000 gm 2 .

[0054] Figure 2 illustrates a mineral wool mattress 1 according to the present invention. This mineral wool mattress 1 extends in a longitudinal main elongation direction, that is to say a direction substantially parallel to the axis L. Furthermore, this mineral wool mattress 1 has a thickness greater than 50 mm, and more precisely, in the embodiment shown, of approximately 400 mm. It should be noted that this thickness of the mineral wool mattress 1 is measured in a vertical direction, perpendicular to the axis L and parallel to the axis V.

[0055] The mineral wool mat 1 is formed from an entanglement of mineral fibers 2 which, in the embodiment shown, are glass fibers bonded to each other by means of a binding element formed by thermally bonding fibers. More precisely, these mineral fibers 2 are superimposed on each other and next to each other within the mineral wool mat 1 with an orientation substantially parallel to the main longitudinal elongation direction of the mineral wool mat 1. It should be noted that the binding element for securing the mineral fibers 2 to each other will be described in more detail in the description to come in connection with FIG. 4.

[0056] As can be seen in Figure 2, the mineral fibers 2 are arranged substantially longitudinally within the mineral wool mat 1, that is to say in a direction parallel to the main elongation direction of the mineral wool mat 1. It should be noted that this longitudinal orientation of the mineral fibers 2 within the mineral fiber mat, and within the mineral wool mat 1 after passage in an oven, represents an embodiment of the invention and that, without departing from the context of the invention, the mineral fibers 2 may, in an alternative embodiment, be oriented differently and in particular in different directions provided that the distribution of the mineral fibers is homogeneous in each zone of the mineral wool mat, as will be described in more detail in connection with Figure 3, and that the volume density of this same mineral wool mat is less than 40 kg.m' 3 .

[0057] As mentioned previously, this mineral wool mattress, whose volume density is less than 40 kg.m' 3 and whose distribution of mineral fibers 2 is homogeneous can in particular be obtained by an installation for manufacturing a mineral wool mattress, which will be described more precisely in connection with figure 5. In addition, this manufacturing installation also makes it possible to ensure the longitudinal distribution of the mineral fibers 2 in a homogeneous manner within the mineral wool mattress 1, and in particular to limit the formation of agglomerates of mineral fibers 2 within the mineral wool mattress 1.

[0058] It should be noted that the mineral fibers 2 are distributed homogeneously within the mineral wool mattress 1 in the thickness of the mineral wool mattress 1, that is to say in a direction parallel to the axis V, and in a transverse direction perpendicular to the main longitudinal elongation direction of the mineral wool mattress 1 and perpendicular to the axis V.

[0059] Figure 3 represents the mineral wool mattress 1 illustrated by Figure 2, and more particularly the homogeneous distribution of the mineral fibers 2 within the mineral wool mattress 1.

[0060] As seen in Figure 3, the mineral wool mattress 1 comprises a first lateral zone 11, a second lateral zone 12 and a third lateral zone 13.

[0061] These lateral zones 11 to 13 have similar dimensions and extend longitudinally and vertically from one longitudinal end of the mineral wool mattress 1 to an opposite longitudinal end. Furthermore, each lateral zone 11, 12, 13 is offset relative to an adjacent lateral zone 11, 12, 13 in the transverse direction parallel to the axis T and perpendicular to the main longitudinal elongation direction of the mineral wool mattress 1.

[0062] The mineral wool mat 1 also comprises a first vertical zone 14, a second vertical zone 15 and a third vertical zone 16. These vertical zones 14 to 16 have similar dimensions and extend longitudinally and transversely from one transverse end of the mineral wool mat 1 to an opposite transverse end. Furthermore, each vertical zone 14, 15, 16 is offset from an adjacent vertical zone 14, 15, 16 in the vertical direction perpendicular to the longitudinal main elongation direction of the mineral wool mat 1 and to the transverse direction.

[0063] It should be noted that this division into several lateral zones and several vertical zones is arbitrary and that a different number of lateral or vertical zones could be considered. This number of three lateral zones and three vertical zones illustrates the arbitrary division made during the calculations and subsequently during the tests set up by the inventors to ensure the veracity of the calculations and the homogeneous distribution of the fibers within the produced mattresses. Each mineral wool mattress can thus, as an illustrative and non-limiting example, be divided into two to six zones of 10 cm to 30 cm.

[0064] The mineral fiber mat is such that the distribution of the fibers from one lateral zone 11-13 to the other has a coefficient of variation of less than 5%, preferably less than 3%. In other words, the homogeneity of the mineral fibers 2 is such that the quantity of fibers present in one of the lateral zones is substantially equal to the quantity of fibers present in another of the lateral zones, with a variation in quantity of less than 5%, preferably less than 3%. For this homogeneity of lateral distribution, as for the homogeneity of vertical distribution which will be discussed below, the coefficient of variation is calculated by weighing and measuring the thickness of each of the zones concerned according to the cutting considered, lateral or vertical, in accordance, for example, with standard EN 1602. An average density and a standard deviation are deduced therefrom, by considering the difference between the average density and the density of each zone.The coefficient of variation is obtained by dividing the standard deviation by the mean density.

[0065] Similarly, the inventors were able to determine by calculation, and verify by the tests implemented that the mineral fiber mat has, from one vertical zone 14-16 to another, a homogeneous distribution of the fibers with a coefficient of variation of less than 10%, and preferably less than 5%. In other words, the homogeneity of the glass fibers 2 is such that the quantity of mineral fibers present in one of the vertical zones is substantially equal to the quantity of fibers present in another of the vertical zones, with a variation in quantity of less than 10%. Such homogeneity of distribution of the mineral fibers within the zones 11 to 16 allows the mineral wool mattress 1 to have similar thermal and / or acoustic insulation properties from one zone to another, which reinforces the effectiveness of the insulation.

[0066] Figure 4 illustrates a local view of the mineral wool mattress 1. More specifically, this view of the mineral wool mattress 1 illustrates the mineral fibers 2 joined together by a dry process. The use of dry binding elements as a means of joining the mineral fibers 2 together helps to ensure the homogeneity of the mineral fibers 2 within the mineral wool mattress 1. This use of dry binding elements also helps to obtain a thickness and a grammage in accordance with those recommended for the mineral wool mattress according to the invention.

[0067] Unlike a wet sizing technique, with liquid binder sprayed by appropriate spray nozzles, the dry process facilitates maintenance of the manufacturing facility and limits its damage. Indeed, the liquid binder sprayed onto the mineral fibers is deposited on the rollers of the manufacturing facility. Such a binder deposit must be removed to ensure optimal operation of the manufacturing facility during the next operation. However, roller maintenance requires a production line shutdown, increasing the manufacturing costs of mineral wool mattresses. Furthermore, this dry process does not form mineral fiber agglomerates 2, as can be the case when several mineral fibers are trapped in a liquid binder.

[0068] As can be seen in Figure 4, the mineral fibers 2 are joined together by binding elements which, according to the invention, are thermobonding fibers 3. These thermobonding fibers 3 are deposited concomitantly with the mineral fibers 2 to form the mineral wool mat 1 with a content of thermobonding fibers 3 in the mineral wool mat 1 of between 2% and 30%, preferably between 3% and 15%, more preferably between 4% and 10%.

[0069] In the example illustrated, the thermobonding fibers 3 are oriented in the same direction of elongation as the mineral fibers 2. In other words, the thermobonding fibers 3 and the mineral fibers 2 are each oriented in a direction of elongation parallel to the main longitudinal direction of elongation of the mineral wool mattress 1.

[0070] Furthermore, the thermobonding fibers 3 are formed of a core 31 and a sheath 32. The core 31 forms a rigid part of the thermobonding fibers 3 providing the mineral wool mattress 1 with mechanical strength, while the sheath 32 ensures the bonding of the mineral fibers 2 with each other. For this purpose, the core 31 and the sheath 32 have different melting temperatures, and more precisely the sheath 32 has a lower melting temperature than the core 31.

[0071] Thus, when a mineral fiber mat is passed through an oven to obtain a mineral wool mattress according to the invention, the sheath 32 can bathe the adjacent mineral fibers 2 and then resolidify while cooling at the outlet of the oven so as to secure these mineral fibers with each other. It should be noted that the melting temperature of the core 31 is provided so that, despite the passage through the oven of a mineral fiber mat consisting of the mixture of mineral fibers and binders, the core 31 retains its rigid property helping to ensure mechanical strength to the mineral wool mattress 1 after the oven.

[0072] Figure 5 represents a part of a manufacturing installation 4 for a mineral fiber mat 10 capable of forming a mineral wool mattress 1 in accordance with the invention. It should be noted that the manufacturing installation 4, as it will be described in connection with Figure 5, represents an embodiment which is not exclusive of the form that the manufacturing installation can take, since it makes it possible to obtain a mineral wool mattress 1 in accordance with the invention, namely mineral fibers 2 secured to each other by thermobonding fibers 3 with a thickness of the mineral wool mattress greater than 50 mm and a volume density less than 40 kg.m' 3This manufacturing installation 4 comprises a distribution station 8 upstream of which, considering the direction of circulation of the mineral fibers 2, there is a feed device, not shown here, for a conveyor belt 42. Within the feed device, the mineral fibers 2 and the thermobonding fibers 3 are mixed in such a way that the mineral fiber belt 10 comprises between 2% and 30% of thermobonding fibers 3 and between 70% and 98% of mineral fibers 2.

[0073] The conveyor belt 42 is configured to move at a running speed, which can be modified by an appropriate control instruction. The conveyor belt 42 has a fiber distribution end which is arranged above the distribution station 8 mentioned above.

[0074] The distribution station 8 comprises at least one roller train 81 equipped with rollers 811 and a conveyor device 82 on which the mineral fiber carpet 10 is capable of forming, as the mineral fibers 2 and the thermobonding fibers 3 are deposited on the conveyor device 82. The roller train 81 is arranged on the path of the mineral fibers 2 between the conveyor belt 42 and the conveyor device 82.

[0075] The roller train 81 is formed of a plurality of rollers 811 arranged in parallel to each other and capable of pivoting about axes of rotation 800 parallel to each other. These rollers 811 are configured to allow, on the one hand, separation of the mineral fibers 2 and avoid the deposition of agglomerated mineral fibers 2 on the conveyor device 82 and, on the other hand, to achieve a substantially longitudinal orientation of these mineral fibers 2, perpendicular to the axis of rotation 800 of the rollers, within the belt of mineral fibers 10.

[0076] In this roller train, there is a proximal roller, arranged at a first end of the roller train closest to the conveyor belt 42 and its fiber distribution end, a distal roller arranged at the opposite end of the roller train and a plurality of central rollers arranged successively between the proximal roller and the distal roller. The distribution station 8 comprises mechanical guide means 19 for guiding the mineral fibers arriving at the fiber distribution end towards the roller train and more particularly towards the proximal roller.These mechanical guide means 19 can take different forms including a flexible conduit, a rigid container forming a funnel, or a guide ramp as illustrated in FIG. 5, these mechanical guide means 19 consisting of guiding, in particular towards the proximal roller and the immediately neighboring rollers, the mineral fibers falling by gravity into an environment where they are neither blown nor sucked.

[0077] In this context, the distribution station 8 is configured to separate the mineral fibers 2 from each other so that the mineral fibers 2 which would not have been completely separated in the feed device, in particular by the arrangement of the rollers 811 in a roller train 81 within which the rollers 811, which rotate in the same direction of rotation, participate in directing a portion of the mineral fibers 2 between two neighboring rollers 811 towards the conveyor device 82 and another portion of the mineral fibers 2 towards the neighboring roller 811 to advance along the roller train 81 and be discharged further onto the conveyor device 82.

[0078] The distribution station 8 helps to ensure the homogeneity, transversely and vertically, of the mineral fibers 2 within the mineral fiber belt 10. This homogeneity, in particular transversely, is enabled by spreading means, not visible in FIG. 5, provided at the end of the conveyor belt 42 closest to the distribution station 8. These spreading means enable the mineral fibers 2 and the thermobonding fibers 3 to be spread over the entire transverse dimension of the rollers 811 of the roller train 81, this transverse dimension being parallel to the transverse direction of the mineral fiber belt 10.

[0079] It should also be noted that the manufacturing installation 4 is configured to form mineral wool mattresses 1 to the desired thickness at the outlet of the oven, at least greater than 50 mm, in particular by varying the thickness of the mineral fiber mat at the outlet of the distribution station 8. For example, increasing the thickness of the mineral fiber mat 10 and therefore increasing the thickness of the mineral wool mattress 1 is possible by accentuating the inclination of the roller train 81, which facilitates the successive deposition of mineral fibers 2 and thermobonding fibers 3 on top of each other over a larger dimension.

[0080] The conveyor device 82 takes the mineral fiber mat 10 composed of the mineral fibers 2 and the thermobonding fibers 3 to an oven, not shown here, and inside which these mineral fibers 2 and these thermobonding fibers 3 are heated to crosslink the sheath 32 of the thermobonding fibers 3. In other words, within the oven, the mineral fibers 2 and the thermobonding fibers 3 are heated so that the mineral fibers 2 become integral with each other. At least the passage through the oven, and if necessary a subsequent compression and cutting before packaging, transforms the mineral fiber mat 10, within which the mineral fibers are integral with each other by means of the thermobonding fibers and according to a determined density and thickness, into a mineral wool mattress according to the invention.

[0081] It appears from the preceding description that the invention indeed achieves the aim it set itself by proposing a mineral wool mattress in which the thermal and / or acoustic insulation is improved by joining the mineral fibres to each other by means of thermo-bonding fibres, for a range of products whose volume density is less than 40 kg. 3 and the thickness greater than 50 mm, allowing the mineral wool mattress to have better insulating properties by improving resistance to the passage of air and limiting the formation of thermal bridges.

[0082] The invention as just described cannot, however, be limited to the means and configurations exclusively described and illustrated, and also applies to all equivalent means or configurations and to any combination of such means or configurations.

Claims

CLAIMS 1. Mineral wool mattress (1) comprising at least a plurality of mineral fibers (2) superimposed on each other and next to each other within the mineral wool mattress (1), the mineral fibers (2) being secured to each other by a binding element formed by means of thermally bonding fibers (3), the volume density of the mineral wool mattress (1) being less than 40 kg.m' 3 and the thickness of the mineral wool mattress (1) being greater than 50 mm.

2. Mineral wool mattress (1) according to the preceding claim, characterized in that the mineral fibers (2) are glass fibers.

3. Mineral wool mattress (1) according to any one of the preceding claims, characterized in that the volume density of the mineral wool mattress (1) is between 7 and 40 kg.m' 3 .

4. Mineral wool mattress (1) according to any one of the preceding claims, characterized in that the thickness of the mineral wool mattress (1) is greater than 100 mm.

5. Mineral wool mattress (1) according to any one of the preceding claims, characterized in that the mineral fibers (2) are joined to each other by a dry process.

6. Mineral wool mattress (1) according to any one of the preceding claims, characterized in that the mineral wool mattress (1) comprises between 2% and 30% of thermally bonding fibers (3).

7. Mineral wool mattress (1) according to any one of the preceding claims, characterized in that the thermally bonding fibers (3) comprise a core (31) and a sheath (32), the core (31) having a melting temperature different from the melting temperature of the sheath (32).

8. Mineral wool mattress (1) according to the preceding claim, characterized in that the binding element is obtained by the fusion of the thermobinding fibers.

9. Mineral wool mattress (1) according to the preceding claim, characterized in that at least the mineral fibers are distributed homogeneously within the mineral wool mattress, the homogeneous distribution of the mineral fibers being considered in a transverse and / or vertical direction, each of these directions being perpendicular to a direction of main longitudinal elongation of the mineral wool mattress.

10. Method for producing a mineral wool mattress (1) according to any one of the preceding claims, the production method implementing: - at least a first step during which the thermobonding fibers (3) and the mineral fibers (2) are mixed with each other, - at least a second step during which the mineral fibers (2) and the thermobonding fibers (3) previously mixed are deposited on a conveyor device (82) by means of a mechanical guide means (19) to form a carpet of mineral fibers (10), - at least a third step during which the mineral fiber mat (10) is conveyed by the conveyor device (82) to an oven in which the mineral fibers (2) and the thermobonding fibers (3) are heated to form the mineral wool mat (1).

11. Method for producing a mineral wool mattress (1) according to the preceding claim, in which the mineral fiber mat (10) is produced during the second step continuously, in a single pass during which the fibers participating in forming the mineral fiber mat (10) passing through the oven are deposited in series on top of each other.

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