EP0741212A1 - Sealing joint for construction element - Google Patents

Abstract

Sealing joint between two panel building elements comprises a seal (9) made from a flexible and compressible polymer with a covering of a material that is non-combustible and/or which retains its integrity at high temps. at least one the surface which seals against an adjacent element.

Description

The invention relates to seals for a building element. These joints are usually intended to fulfill at least one of the following two functions: they can ensure the intrinsic tightness of each of the construction elements, when this is necessary in view of the structure of these. They can also be used to seal the assembly of a plurality of adjacent elements forming a wall.

The invention relates more particularly to seals for insulating wall panels, sometimes called “sandwich” panels, and which consist of generally metallic walls delimiting a cavity filled with a material with high insulating power on the plane. thermal and / or phonic, of the rigid foam polymer type such as polyurethane. Such panels are interesting in that they combine rigidity, lightness and thermal / acoustic performance.

Very schematically, the manufacture of such panels takes place in the following way, although many variants exist: continuous strips of horizontal metal sheet and facing each other, maintained at a given distance from one another, run on a conveyor. A very reactive liquid mixture is injected between these sheets which expands in all directions in the form of a polymer foam. In order to avoid foam overflows, the sheets have lateral flanges, at the joint of which sealing rings have been pressed continuously before the foam has started to expand.

Once the foam is fully expanded, the sheets are cut transversely to obtain panels of the desired length, panels which can then be assembled side by side to form a wall, a partition, a ceiling, ... The joints placed on the sides, which initially served to contain the expansion of the foam inside the cavity defined by the metal sheets, therefore to ensure the tightness of this cavity, again serve to ensure the tightness at the level of the zones jointing between adjacent panels, in particular with respect to humidity, and to avoid the creation of a thermal bridge when these panels are used outdoors, which is the most frequent case.

The seals, to ensure these different functions, have to fulfill certain criteria. Thus, they have to have good flexibility and good compressibility, and this is the reason why they are usually themselves based on polymer foam. They also have to allow a good “hooking”, a good adhesion with respect to the foam of the cavity of the panel with which they are brought into contact, which can prove to be awkward if they offer too much external surface. smooth, which is sometimes the case when they are closed cell foam. To remedy this, two solutions can be envisaged, but each having their drawbacks: the surface of the joint intended to be in contact with the foam of the panel can be made rougher, by abrasion or by resealing the foam of the joint in its thickness, but these methods are complicated and generate dust or waste which must then be managed. You can also make the seal adhesive, using an acrylic type glue for example. However, the presence of certain plasticizers in the joint foam can reduce this adhesive power. In addition, the adhesives are combustible, which can weaken the usually high fire resistance of the panels. Indeed, the strips are capable of considerably delaying the progression of the fire, the only areas of jointing being their "weak point", because the joints can be directly exposed to the flame, and the fire may risk spreading laterally, through them to the foam of the panels.

The object of the invention is to design seals for construction elements which are better, in particular overcoming the drawbacks mentioned above, by improving their fire behavior without degrading their ability to adhere to the elements on which they have to be deposited.

The subject of the invention is a seal based on flexible / compressible polymer, in particular intended to ensure the proper sealing of a building element and / or the sealing between two adjacent building elements, elements of the panel type. of wall. This seal is designed so as to be provided, at least on its surface intended to be brought into contact with said element, with a surface coating of a non-combustible material and / or retaining its integrity at high temperature.

Thus, this surface coating constitutes an effective barrier to the propagation of fire in the panel via the joint, which has two major advantages. By thus improving the fire behavior of the seal, the panels are ignited one after the other significantly by a chimney effect at their weak point, that is to say their jointing areas. Secondly, with regard more particularly to construction elements of the hollow panel type containing an insulating product in the form of polymer foam, this polymer was hitherto chosen in order to be qualified as "hardly flammable" according to standard DIN 4102, which corresponds to the so-called B1 class. Thanks to the seals of the invention, which already considerably delay the contact of the panel foams with the flames, we can afford to substitute these foams classified B1 with foams slightly less efficient in terms of flammability, in particular foams simply qualified as "normally flammable" according to DIN 4102, which corresponds to the so-called B2 class. This substitution, which does not cause any reduction in the fire resistance of this type of panel, on the other hand leads to gains in terms of cost of raw materials quite substantial, the so-called B2 foams being significantly less expensive than the foams. say B1, and the additional cost due to the presence of the additional surface coating of the joint being minimal in comparison.

We can also note that it is in fact surprising that a simple surface coating, by definition relatively thin, can increase the fire-fighting performance of the joint, and in fact, that of construction elements using this type of joint.

Preferably, the surface coating is chosen from at least one material belonging to the following group: glass, ceramic, metal, carbon, graphite, aramid. Very advantageously, these materials are in fact used in fibrous form, the fibrous material being woven, or nonwoven, but agglomerated using a binder.

This fibrous material is preferably composed of threads themselves made up of unitary filaments. In particular when they are glass-based and obtained by mechanical drawing under a die, these unitary filaments usually have a diameter of between 5 and 12 micrometers, in particular around 7 to 9 micrometers. They are then assembled in tens, twisted or not, to become yarns of a linear weight advantageously between 10 and 150 tex (1 tex corresponding to 1g / 1000m of yarn), in particular about 22 or 68 tex.

The advantage of a fibrous material lies in particular in the fact that it makes it possible to manufacture a surface coating having a certain surface roughness, greatly facilitating the “attachment” of the joint to the construction element, and, in particular in in the case of an element in the form of an insulating panel with polymer foam, the "hooking" of the joint against the expanding foam. This eliminates the need for adhesive on the surface coating, which is expensive and often poses problems of resistance to high temperature. A fibrous material also has the advantage, in particular in the case of a fabric, of being able to easily conform to any joint surface, whether it is flat, curved or has angles.

Thus, one of the preferred embodiments of the invention for this surface coating is a fabric-based or veil-based coating of glass fibers, which is made of a material which is both very resistant to temperatures of the order of 500 ° C and of a texture offering flexibility and a light surface roughness very favorable to a good adhesion to foam of expanded polymer of the polyurethane type.

More generally, it is advantageous to choose a surface coating with a thickness of between 50 and 250 micrometers, in particular approximately 100 to 200 micrometers, range of thicknesses sufficient to obtain the effect of slowing down of propagation on fire desired.

Likewise, a surface coating of a grammage between 50 g / m ² and 300 g / m ² , preferably around 100 to 200 g / m ² , is preferably chosen, grammage corresponding to a coating sufficiently dense to give it its role as a barrier to the spread of fire.

The seal according to the invention, in addition to the surface coating, is based on a polymer preferably chosen from a flexible foam of at least one of the following polymers: polyvinyl chloride PVC, polyurethane PUR, polyethylene PE, terpolymer of polyethylene and polypropylene EPDM, silicone, polypropylene PP, rubber, styrene-butadiene-nitrile polymer SBN, neoprene, possibly treated polymers, and in particular plasticized to obtain the desired flexibility. The foam texture has the advantage of giving the polymer a high compressibility, which is what is sought when the joint is “wedged” between two construction elements, and must compress more or less in order to adapt to the distance between them, taking into account the manufacturing tolerances of said elements. It is indeed not uncommon for such seals to have a compressibility in their thickness of at least 30% or 50% and more.

The polymer can advantageously be treated in order to improve its resistance to high temperature and to fire, in particular by incorporating into it an flame retardant additive. This additive can in particular be chosen from at least one of the following compounds: antimony oxide Sb ₂ O ₃ , hydrated alumina or aluminum hydroxide, zinc borate, brominated hydrocarbon or chlorinated paraffin. Details on these compounds and their proportion relative to the polymer can be found, for example, in US patent US-4 806 162.

Chosen and suitably treated, the polymer of the seal according to the invention can also itself comply with DIN 4102, in particular belonging to class B1, which reinforces the fire barrier effect of the seal. conferred by its surface coating.

One of the preferred embodiments of the invention relating to this polymer consists in choosing a polyvinyl chloride foam plasticized to which was added one of the additives mentioned above and in particular obtained from plastisols and blowing agents, for example based on nitrogen products such as sulfohydrazides or azo-dicarbonamides. We will have more details, in particular concerning PVC plasticizers and plastisols, by referring to the chapter devoted to PVC in the treaty "Plastics - Chemistry Applications" by Jean BOST - published by "Techniques et Documentation" in 1980. More details on Cellular PVC can also be found in the TITOW Treaty, "PVC Technology", ELSEVIER edition of 1984, chapter 25.

This type of foam is indeed advantageous in terms of compressibility, it has an adequate density of around 100 kg / m ³ and the manufacturing process is well controlled.

More generally, the density of the joint is preferably chosen to be around 80 to 150 kg / m ³ . If it is a foam, it may be closed cell. In case the cells are at least partially open, it is better to plan to impregnate it with a moisture repellant.

The seal according to the invention can have extremely varied shapes. Usually, it is in the form of a continuous ribbon, the section of which has been calibrated, a section which may in particular have the shape of a quadrilateral such as a square, rectangle, trapezoid, parallelogram. But its section can also be chosen round or oval.

There are different manufacturing methods for obtaining the desired shape of seal, and in particular the shape of the polymer which constitutes it mainly. This polymer, preferably based on foam, can thus be obtained directly at the desired size by an extrusion technique. The surface coating is then associated with it once the extrusion is completed, in particular by using a device of the conforming type. It may also be necessary to use an adhesive to facilitate bonding between the foam and its coating.

The polymer, when it is particularly foam-based, can also be produced in the form of a continuous sheet, by passing through an oven at suitable pressure and temperature, on a support which is preferably constituted by the surface coating. itself resting on a conveyor. The ply, once the expansion of the foam is complete, can then be cut to obtain the desired size, and in particular width joint. With this type of process, the manufacture of the foam and the association with the surface coating are carried out in a single step, the foam "hanging" on the coating without the need for adhesive.

The joint according to the invention can be provided with a first surface coating based on fibrous material on its surface intended to adhere to the panel - in order to facilitate the attachment of this joint - and with a second surface coating on at least one part of the rest of its outer surface, second coating which may be in the form of a continuous film, in particular metallic. Indeed, this second coating is not intended to have to adhere to a foam of an insulating panel, it can therefore have a very smooth surface without disadvantage.

It is therefore possible to choose to cover the entire outer surface of the joint with one or more surface coatings according to the invention: this guarantees an optimum effect of slowing down the propagation of fire by the joint.

As mentioned above, the use of gaskets according to the invention is particularly recommended for sealing construction panels comprising essentially metallic walls delimiting a cavity comprising a thermal and / or sound insulation material of the foam type. rigid polymer, in particular to improve fire resistance. The seals of the invention are preferably placed on at least part of the "joint" area of the walls of such a panel, sometimes called a "sandwich" panel.

• figure 1 : un assemblage de panneaux isolants jointoyés selon l'invention,
• figure 2a - 2b : une étape de fabrication de panneau isolant avec pose du joint selon l'invention,
• figure 3 : une coupe selon un plan horizontal de la zone de jointoiement entre deux panneaux assemblés selon la figure 1.

The details and advantageous characteristics of the invention emerge from an embodiment detailed below, which is non-limiting and illustrated with the aid of the appended figures which represent:

• FIG. 1 : an assembly of grouted insulating panels according to the invention,
• FIG. 2a - 2b: a step of manufacturing an insulating panel with fitting of the joint according to the invention,
• Figure 3: a section along a horizontal plane of the jointing area between two panels assembled according to Figure 1.

The panels 1 shown very schematically in Figure 1 are arranged in a vertical plane to form an exterior wall of the building. Each panel has the shape approximately of a parallelepiped with a thickness of approximately 60 to 100 mm, a width of approximately 2 to 3 m and a length which can range in particular from 3 to 16 meters and more. They are assembled along a vertical plane to form a building wall (and mechanically fixed using a metal frame not shown). Each panel 2, 3 is made up of flat or profiled sheet metal walls, in particular of steel and 0.6 to 0.9 mm thick, delimiting a cavity 4 filled with rigid polyurethane foam 5 classified B1 or B2 in terms fire resistance according to DIN 4102.

Figures 2a and 2b detail, still very schematically, the manufacture of such panels 1, each of the opposite lateral edges of which is identified by the letter A and the letter B respectively: sheet metal sheets 2, 3 arranged one on the other and kept at a distance d pass on a conveyor, with, at the level of the joint zones 6 between the two strips, a free space. The reaction liquid based on polyurethane precursors and suitable expansion agents is injected, continuously, between the two strips 2, 3. Always continuously, and while the expansion of the foam has just started, rollers presseurs7 come, on side A, to press the seal 8, 9 according to the invention which, to do this, is unwound gradually. The seal 8, 9 is then placed so that its surface coating 8 is against the joint area 6 and the free space that it defines. The pressure of the pressure rollers 7 is maintained over a length sufficient for the foam 5 of the panel 1 to adhere to the surface covering 8, and thus fixes the seal 8, 9 in position.

On the B side, two variants are possible: either we do the same operation as on the A side, by applying the same type of seal 8, 9, or, as shown, we have crimped, in the joint area, a metallic film 10 aluminum type.

The sides A and B have profiled edges so as to define a female part (side A), and a male part (side B), which will allow to easily assemble the panels later by fitting them one inside the other.

Once the foam 5 is fully expanded, cutting tools (not shown) cut the strips transversely to their axis of travel on the conveyor in order to obtain the finished panels at the desired length.

Let us return in more detail to the structure and manufacture of the seal: the seal 8.9 used is here of rectangular section, (width 45 mm - thickness 6 mm) and is provided on one of its faces with a fabric 8 of glass 100 micrometers thick, with glass wires of linear weight 22 tex made up of the assembly of unitary filaments of 7 micrometers in diameter and a grammage of 107 g / m ² . Good results are also obtained with slightly thicker fabrics, for example around 180 micrometers and / or slightly denser, for example from 200 to 210 g / m ² obtained in particular from slightly linear yarns. higher, for example about 70 tex or more. This joint is based on plasticized PVC foam 9, and it has a compressibility rate in its thickness of at least 50%. Containing fire-fighting additives, this foam 9 is classified B1 according to DIN 4102.

The seal was manufactured in the following way: on the glass fabric 8 having the predefined characteristics and deposited on a conveyor, a reaction liquid is poured based on plastisols and ad hoc expansion agents, then the assembly is passed through an oven at adequate pressure and temperatures, the plasticized PVC foam 9 then gradually expands onto the glass fabric 8 while strongly adhering to it. This foam also contains fire-fighting additives, comprising antimony trioxide at approximately 1.25% by weight, zinc borate at approximately 1.25%, and chlorinated paraffin at 4% by weight relative to the weight of PVC, paraffin being chosen in particular from the range of products sold under the name of CERECLOR by the company "Imperial Chemical Industries PLC". Once cooled, the sheet of foam obtained is cut by cutting tools of the circular saw type arranged in a row above it, in the direction of its axis of travel on the conveyor, in order to obtain a plurality of ribbons. rectangular section desired, ribbons then wound before use as previously described. This manufacturing method is very advantageous in terms of yield and manufacturing cost. However, techniques of the extrusion type of the joint directly to the desired size are also of interest, insofar as they can make it possible to obtain seals 8, 9 with more elaborate sections, in particular circular sections.

Figure 3 shows in section the jointing area between two panels 1 as assembled in Figure 1: the joint 8, 9 is compressed by at least 30% in its thickness, the sides B of the first panel coming to fit together in side A of the second panel, with a certain "flapping" in fact inevitable, given the manufacturing tolerances of this type of panel. In fact, in the event of a fire, the seals 8, 9 are directly exposed to the flames, hence the importance of improving their fire behavior to prevent the fire from spreading from the foam 5 of a panel 1 to the foam of an adjacent panel via the joints 8, 9, the only “weak points” of these structures since the sheet metal strips 2, 3 of the panels 1 are moreover very effective in delaying the progression of the fire.

Surprisingly, the glass fabric 8 of the seals 8, 9 according to the invention has proved to be excellent for slowing the progression of fire, and its texture has proved to be very advantageous since it also improves the foam adhesion 5 of the panel 1 / joint foam 9, without requiring treatment of joint foam and / or addition of adhesive.

The fact that the joint foam itself is treated with fire-fighting additives reinforces the very good fire resistance of the joints according to the invention. Many variations are possible: thus, it is possible to use a material other than glass as a non-combustible or low-combustible material; it is also possible to modulate the thickness and grammage of the surface coating, and cause this coating to cover several of the faces of the joint instead of just one, in particular the lateral faces of the joint, or even all of its external surface.

The dimensions of the joint can also vary considerably according to the needs, with, in the case of joints of rectangular section, thicknesses of for example 3 to 20 mm and widths adapting to the dimensions of the panels to be joined, for example from 10 to 100 mm.

Claims (20)

Flexible / compressible polymer-based seal (8, 9), in particular intended to ensure the proper sealing of a construction element and / or the seal between two adjacent construction elements, elements of the type wall panels (1), characterized in that said seal (8, 9) is provided, at least on its surface intended to be brought into contact with said element, with a surface coating (8) made of a non-combustible material and / or keeping its integrity at high temperature. Joint (8, 9) according to claim 1, characterized in that the surface coating (8) is chosen from at least one of the following materials: glass, ceramic, metal, carbon, graphite, aramid. Joint (8, 9) according to one of the preceding claims, characterized in that the surface covering (8) uses a fibrous material, woven or nonwoven. Joint (8, 9) according to one of the preceding claims, characterized in that the surface coating (8) is based on fabric or veil of glass fibers. Joint (8, 9) according to claim 3 or 4, characterized in that the fibrous material is based on threads, in particular with a linear weight of between 10 and 150 tex, themselves made up of unitary filaments, in particular of a diameter between 5 and 12 micrometers. Joint (8, 9) according to one of the preceding claims, characterized in that the surface coating (8) has a thickness between 50 and 250 micrometers. Joint (8, 9) according to one of the preceding claims, characterized in that the surface coating (8) has a basis weight between 50 g / m ² and 300 g / m ² . Joint (8, 9) according to one of the preceding claims, characterized in that the flexible / compressible polymer (9) of said joint is based on foam of at least one of the following polymers: polyvinyl chloride PVC, polyurethane PUR, polyethylene PE, terpolymer of polyethylene and polypropylene EPDM, silicone, polypropylene PP, rubber, styrene-butadiene-nitrile polymer SBN, neoprene, in particular plasticized. Joint (8, 9) according to one of the preceding claims, characterized in that the flexible / compressible polymer (9) of the joint comprises at least one flame retardant additive, in particular chosen from the following group: antimony oxide Sb ₂ O ₃ , hydrated alumina or aluminum hydroxide, zinc borate, brominated hydrocarbon, chlorinated paraffin. Joint (8, 9) according to one of the preceding claims, characterized in that the flexible / compressible polymer (9) of said joint is based on plasticized polyvinyl chloride foam, in particular obtained from plastisols and agents of expansion based on nitrogen products such as sulfohydrazides or azo-di-carbonamides. Joint (8, 9) according to one of claims 8 to 10, characterized in that the flexible / compressible polymer (9) of said joint has a density of approximately 80 to 150 kg / m ³ . joint (8, 9) according to one of claims 8 to 11, characterized in that the flexible / compressible polymer (9) of said joint is based on foam with closed cells, or with cells at least partially open in which case the foam is impregnated with a moisture repellant. Joint (8, 9) according to one of claims 8 to 12, characterized in that it is in the form of a strip of quadrilateral section, of the parallelogram, square, rectangle, trapezoid, or oval, or round type. . Joint (8, 9) according to one of claims 8 to 13, characterized in that the polymer (9) is based on foam and is obtained directly at the desired size by an extrusion technique. Joint (8, 9) according to claim 14, characterized in that the surface coating (8) is associated with the polymer (9) once extruded, in particular using an adhesive and a device of the conforming type. Joint (8, 9) according to one of claims 8 to 13, characterized in that the foam-based polymer (9) is produced in the form of a continuous sheet, by passing through an oven at suitable pressure and temperature, preferably on a support made up of the surface coating itself, a sheet then cut to obtain the desired size seal. Joint (8, 9) according to one of the preceding claims, characterized in that it is provided with a first surface coating (8) based on material fibrous on its surface intended to be in contact with the panel and a second surface coating in the form of a continuous film, in particular metallic, on at least part of the rest of its external surface. Joint (8, 9) according to one of the preceding claims, characterized in that one or more surface coatings (8) cover the entire external surface of said joint. Use of the joint (8, 9) according to one of the preceding claims for sealing construction panels (1) comprising essentially metallic walls (2, 3) delimiting a cavity (4) containing a thermal insulation material and / or sound of the rigid polymer foam type (5), in particular to improve fire resistance. Construction panel (1) comprising essentially metallic walls (2, 3) delimiting a cavity (4) containing a thermal and / or sound insulation material of the rigid polymer foam type (5), and provided on at least one of its sides, in particular on at least part of the joint zone (6) of its walls (2,3), a joint (8, 9) according to one of claims 1 to 18.

Images