EP0420750B1 - Composed insulating panel using mineral wool and method of obtaining the same - Google Patents

Abstract

The invention relates to an insulating composite panel consisting of two sheets (1, 2) and an alveolate internal structure (3) of the honey-comb type. The alveoles are filled with mineral-wool flock particles, the ratio of the size of the alveoles to the average diameter of the flock particles lying between 50/1 and 1/1 (unity), and preferably being approximately 10/1. <IMAGE>

Description

The subject of the invention is a composite insulating panel based on mineral wool, in particular glass wool, intended more particularly for insulating the sub-roofs of buildings for residential use. It also relates to a process for obtaining such composite panels, from an insulating felt of mineral wool. Insulating panels known as sub-roofs are known, constituted by rigid prefabricated elements whose length corresponds if possible to the height of roofs which supposes spans of for example more than 5 meters for inclined roofs. These panels are formed of one or two plates, for example of laminated wood or agglomerated particles, separated by a rigid panel of synthetic foam of the polyurethane or expanded polystyrene type. These insulating panels, however, only provide thermal insulation and little or no acoustic insulation and, above all, do not have the most satisfactory fire behavior, in particular with the risk of release of toxic gases during a fire.

It is also known from FR.A.2608964 the production of trough-shaped boxes, made up of wooden panels agglomerated by rafters also serving as dividers defining compartments whose interior is subsequently filled with glass wool flakes produced by a carding operation from a compressed sheet of glass wool. Glass wool provides thermal and acoustic insulation and is also non-combustible. However, such panels are penalized by a high production cost due to the increase in the number of reinforcing interlayer rafters as soon as their length increases.

In another area, that of the realization of modular partitions, it is known from US-A-3 998 023 a double-skin panel having an internal structure of the honeycomb type, the cells of which are filled with an insulating material of the perlite type or the like. However, the depth of the cells is very small (less than 3 inches, 75 mm), as is their size; this implies an extremely fine filling material. In addition, such panels have a complex structure intended to allow assembly by tenons and mortises themselves insulated to avoid the formation of thermal bridges. Furthermore, no indication is given as to the filling method, but this poses many problems as soon as the material used does not have a low coefficient of friction and the cells are deep.

It is also known from patent application FR-A-2 066 112 a method of filling a honeycomb structure consisting in suspending mineral fibers in a stream of fluid which is directed in parallel collimation columns placed in the alignment of the cells, in order to give the fibers an orientation parallel to said columns, this prevents the fibers from draping the upper part of the walls of the cells.

It is known from patent application FR-A-2 550 313 a honeycomb structure filled with a finely divided insulation material, in particular a micro-porous material, a gel, a powder, material packed in the cells by vibration. The structure can be produced in a waterproof cardboard using a continuous layer of glue which is polymerized.

US Pat. No. 4,153,084 describes a method of obtaining a composite panel filled with cellulosic fibers, comprising a step of shredding a compact mass of these fibers, using articulated rotary flails, and the US patent. -4,271,876 describes a method of obtaining a composite panel using the same type of fibers involving a step of scanning the panels after filling using brushes mounted on an axis perpendicular to the axis of scrolling of the panel, brushes associated with scrapers to complete the filling of the cells with the fibrous material.

The object of the present invention is to provide a composite panel possibly insulating over long lengths, fire resistant and of relatively low production cost. In addition, the composite panel according to the invention must be able to be used in particular as a sub-roofing panel for the insulation of inclined roofs of buildings for residential use.

This object is achieved according to the invention by a composite panel whose internal structure is a honeycomb type honeycomb structure filled with mineral wool flakes, for example obtained by grinding a felt -or waste from the production of a felt - mineral wool. The ratio between the size of the cells and the average diameter of the flakes is close to 10 to 1. Preferably the depth of the cells is greater than 100 mm, the density of the insulator being advantageously between 30 and 40 kg / m³. The honeycomb structure is advantageously made from a material that is both economical and fire-resistant, such as kraft paper cardboard impregnated with a salt and / or a phenolic resin.

The filled honeycomb structure is sandwiched between two wooden plates, laminate or agglomerated wood particles, the agglomerated plates being preferred because of their lower cost. These plates are preferably coated with a continuous layer of adhesive, for example polyurethane, which serves both as a bonding agent for the honeycomb structure and as a barrier layer impermeable to water vapor and liquid water, this in order to '' prevent the vapor which is present in the relatively warmer atmosphere of the attic from condensing at the rear of the composite panel, roof side and damaging it.

The invention also relates to a process for obtaining a composite panel according to the invention which essentially comprises a phase of grinding a mineral wool felt and a phase of filling the honeycomb structure during which the panel scrolls under the device for supplying the filling material, the grinding being obtained by means of rotary flails and being continued according to the invention until the flakes thus formed fall through a grid whose passage meshes have a dimension between 1/20 and 1 times the size of the cells and preferably of the order of 1/10; the filling phase comprising a sweep by means of sets of brushes mounted slightly inclined around an axis perpendicular to the direction of travel of the panel.

As indicated above, the flakes are obtained by grinding a mineral wool felt. It can be a continuous felt produced for this purpose or possibly non-continuous production waste. For this, we pass for example a mineral wool felt, previously compressed between two rollers, in front of articulated flails carried by a rotating shaft, the flakes produced escaping from the threshing chamber through an opening closed by a grid whose passage meshes have a dimension between 0.05 and 1 times the size of the cells of the honeycomb structure and preferably of the order of 0.1. After this grid, the flakes are preferably used directly to fill the honeycomb structure which is preferably conveyed at a speed for example between 0.20 and 20 meters per minute. This first removal is completed by at least one of the following measures: suction, sweeping, vibration. For a suction, the honeycomb structure must be arranged on a porous bottom preferably constituted by a fiberglass veil left in place during the bonding of the surface plates. Preferably, however, the alveo5 laire structure is directly glued to a surface plate conveyed by a vibrator and / or scrolling under one or more sets brushes rotating around one or more axes perpendicular to the longitudinal axis of the panels and slightly inclined relative to the transverse axis of the panels so that the brushes "scan" the panels transversely and thus favor the filling of the cells by flakes. If several sets of brushes are used, it is preferably made so that the bristles of the downstream sets penetrate deeper into the cells than those of the first sets to come into contact with the flakes; the penetration height can advantageously be between 1 and 10 mm. Furthermore, all the parts in contact with the flakes, in particular the walls of the threshing chamber, the grid and the bristles of the brush, are preferably made of plastic material, for example Plexiglass R for rigid parts, this in order to '' prevent the glass wool crushed by the plagues from sticking to these elements by the effect of attracting electrostatic charges.

• figure 1 : un panneau composite selon l'invention
• figure 2 : une vue schématique d'une ligne de production d'un panneau composite selon la revendication 1.

Other details and advantageous characteristics of the invention are described below with reference to the appended drawings which represent:

• Figure 1 : a composite panel according to the invention
• Figure 2 : a schematic view of a production line of a composite panel according to claim 1.

A composite panel according to the invention and such as that shown diagrammatically in FIG. 1 should preferably be able to have a length L corresponding to the dimensions of the inclined sections of a sloping roof, and not require too many fixing points during its implementation. Such qualities therefore assume a range of 5 to 6 meters or more which cannot be obtained with a simple panel of compressed mineral wool bound by a formo-phenolic resin for example. It is also not desirable to reinforce the panels with spacers of the chevron type because, in addition to the inherent cost thereof, their installation may require, for example, an economically impractical grooving operation. The solution according to the invention consists in the use of a spacer structure of the honeycomb type which we know to be allows a particularly high mechanical resistance. Advantageously, a relatively inexpensive prefabricated structure can be used, for example made of a cardboard having undergone chemical treatment to improve its fire resistance by impregnation with a phenolic resin and / or an appropriate saline solution. This spacer structure 3 is glued between two wooden plates, plywood, chipboard, at least one of these two plates can be replaced possibly by a plasterboard, fiber cement or equivalent. The height of this structure is preferably greater than 100 mm and more preferably 130 mm, this in order to provide a sufficient filling volume for quality insulation. The size of the cells is preferably between 20 and 50 mm and is advantageously of the order of 40 mm.

The insulating material for filling the cells is preferably constituted by flakes whose average diameter is close to 1/10 times the size of the cells. For flakes between glass wool a ratio of 1 to 10 is a good compromise which makes it possible to satisfy both the requirements in terms of insulation - which supposes "light" flakes trapping a good amount of air and the filling requirements so that the flakes penetrate well into the cells.

Advantageously, these flakes are obtained by grinding a glass wool felt possibly containing a resin. It is possible, for example, to use the production scrap from installations for producing insulation felts whose density is between 90 and 100 kg / m³ or even felts specially prepared for the invention. The milling technique used is related to the technique more commonly used for the production of blown wool, but by interposing a grid between the milling chamber and the outlet so as to allow only flakes smaller than a given size to pass through. .

The grid meshes preferably have a length of between 1/20 and 1 times the size of the cells and advantageously the meshes of the grid have a length of between 1/10 to 1/3 of the size of the cells.

An exemplary embodiment will now be described with reference to FIG. 2. The installation shown here schematically comprises from the bottom up a loading assembly 4, a grinding assembly 5 and a filling assembly 6. The loading assembly 4 is essentially constituted by a felt conveyor belt 7, a guide roller 8 and two compression rollers 9 and 10 which compress the felt and force it to penetrate into the grinding assembly 5, the walls of which for example made of glass or material plastic are not shown here. The grinding means are constituted by articulated flails 11 rotatably mounted around a shaft 12. The flakes then formed must pass through a grid 13 whose mesh is 10 mm in the case of example then arrive at the lower level or level filling 6. This filling level 6 comprises a conveyor 14 on which pass panels 15 consisting of a plate 16 for example made of chipboard and a honeycomb structure 17 whose cells are for example 130 mm high and 40 mm large. The structure, made of fireproof cardboard, is glued to the plate 16 which is therefore made impermeable to water vapor.

When falling, the flakes form a more or less regular layer above the honeycomb structure, but only a few fall immediately to the bottom of the cells. This actual filling operation is carried out by means of sets of brushes 18, 19 in the form of discs. Each set here comprises brushes with axes perpendicular to the direction of advance of the conveyor 14, but whose plane is inclined so that their bristles sweep a certain width. These bristles are preferably flexible bristles of plastic material of the nylon type.

Preferably the brushes of the set 19, positioned further downstream of the line, are such that their bristles penetrate into the honeycomb structure a little deeper than those of the brushes of the set 18. The respective penetration depths can be for example 1 and 10 mm. Optionally one or two additional sets can be used. Under these conditions, the cells can be completely filled with a density of insulating material of, for example, between 30 and 40 kg / m³.

After this filling operation, another plate is glued to the top of the honeycomb structure to permanently trap the mineral wool flakes.

The fire resistance of composite panels according to the invention has been verified as follows: a model is made having the dimensions 4300 mm x 1600 mm by abutting two composite panels according to the invention of 4300 mm x 800 mm, the central joint being constituted by a flexible self-adhesive plastic material. The model is exposed to a fire and its fire resistance is measured using the loss of flame resistance and the loss of fire resistance as a criterion. We finally obtain a fire resistance of 45 minutes, a more than satisfactory duration. Furthermore, the composite panels according to the invention provide sound and sound insulation of quality.

Claims (11)

1. Composite roof insulating panel for dwellings, consisting of two sheets (1, 2) and a interior cellular structure of the honeycomb type (3, 17), characterised in that the cells are filled with mineral wool flakes, the ratio between the size of the cells and the average diameter of the flakes being approximately 10/1.
2. Composite insulating panel according to Claim 1, characterised in that the depth of the cells is greater than 100 mm.
3. Composite insulating panel according to either of the preceding claims, characterised in that the lateral dimension of the cells is between 20 and 50 mm, and is preferably of the order of 40 mm.
4. Composite insulating panel according to any one of the preceding claims, characterised in that the density of the insulating filler material is less than 40 kg/m³ and preferably less than 30 kg/m³.
5. Composite insulating panel according to any one of the preceding claims, characterised in that the honeycomb structure (3, 17) is made of a fire-resistant cardboard.
6. Composite insulating panel according to any one of the preceding claims, characterised in that the plates (1, 2) are covered with a continuous layer of adhesive, forming, after polymerisation, a layer that is impervious to water vapour and to water in the liquid state.
7. Method of producing a composite panel according to any one of Claims 1 to 6, comprising a stage of grinding a mineral wool felt and a stage of filling the cellular structure (3, 17) during which stage the panel (15) passes under the device supplying the filler material, characterised in that grinding is performed by means of articulated rotating flail devices (11), and is continued until the flakes thus formed fall through a grille (13), the meshes of which have a size of between 1/20 and 1 times the size of the cells of the honeycomb structure (3), and preferably of the order of 1/10; and in that the filling stage comprises a sweeping process by means of sets of brushes (18, 19) mounted so as to be slightly inclined about an axis perpendicular to the direction of travel of the panel.
8. Method of producing a composite panel according to Claim 7, characterised in that the depth to which the bristles of the brushes (18, 19) penetrate the cellular structure (3, 17) is between 1 and 10 mm.
9. Method of producing a composite panel according to Claim 7 or Claim 8, characterised in that a plurality of sets of brushes (18, 19) are used, the bristles of the downstream sets of brushes penetrating more deeply into the cellular structure (3, 17) than those of the first set in order to come into contact with the mineral wool flakes.
10. Method of producing a composite panel according to any one of Claims 7 to 9, characterised in that the filling stage comprises a suction of the flakes.
11. Method of producing a composite panel according to any one of Claim 7 to 10, characterised in that the filling stage comprises a passage over a vibrating belt.

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