CH656093A5 - FLEXIBLE COMPACT COMPOSITE MATERIAL. - Google Patents

Description

The present invention relates to flexible compact composite materials which can in particular be used for the production of interior lining sheaths for damaged pipes, for example.

The materials used, up to now, for damaged inner lining sheaths, for example, are not provided with a reinforcing reinforcement. Thus, for pipes of large diameters, the thickness of the sheath becomes considerable to have the necessary resistance to cracking and possible rupture. In addition, these composite materials generally comprise an outer layer or the like capable of absorbing an adhesive, the outer face of this layer being applied against the inner face of the pipe until the adhesive hardens; the pipe then being provided with a protective sheath. However, the thickness of the sheath necessarily increasing as a function of the section of the pipe to be filled, the thickness of the outer absorbent layer also increases. Consequently, the quantity of adhesive to be supplied to ensure the adhesion of the sheath to the pipe increases not only as a function of the external surface of the sheath (therefore of the cross-section of the pipe), but also, in a disproportionate manner, depending on the thickness of the adhesive absorbing layer of the sheath. Thus the sheath becomes excessively heavy, the pressures for applying the sheath against the pipe become increasingly high, which makes it very difficult to introduce the sheath into the pipe, its application against the inner face of the pipe and maintaining the application pressure until the adhesive hardens. Finally, the cost of the equipment and the filling operation becomes excessive.

The material according to the invention is comparatively light and easy to handle while having considerable mechanical strength.

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The object of the present invention is to overcome these drawbacks. In accordance with the present invention, the flexible compact composite material is characterized in that it comprises at least one assembly comprising at least one first upper part made up of at least one first nonwoven fabric and at least one flexible reinforcement and one second part consisting of at least one second nonwoven fabric disposed on the lower part of said assembly.

According to one embodiment, a flexible reinforcing reinforcement is embedded in at least one part constituted by a nonwoven fabric so that it can follow, without friction between itself and said part, any deformation of said assembly.

According to one embodiment, at least one of the end parts of said assembly is produced in the form of a flexible and waterproof sheet made of a natural or synthetic material.

According to one embodiment, said part of nonwoven fabric is made of natural or synthetic fibers, said reinforcement being arranged substantially at mid-thickness of said part.

According to one embodiment, the warp of said mesh has di-20 mensions greater than those of the weft.

Said material can be used for the production of an inner lining sheath of a pipe, this lining being effected in that said sheath, which is permeable over at least part of its thickness, is coated with a polymerizable resin so that at least the outer face of said sheath is well coated and that the inner face of a pipe is optionally coated, that said sheath is applied against the pipe by means of a pressurized fluid, directly or indirectly by introducing into the sheath an inflatable mold, said mold being constituted by a sheet so or membrane in a material which does not adhere to the sheath under the action of said resin, which one inflates said mold by controlling the temperature for applying the sheath firmly against the inner face of the pipe and that the mold is deflated and removed after at least partial polymerization and at least partial curing of the resin.

The sheath can be made from at least one sheet of a material entirely permeable to said resin so as to be able to take a shape corresponding to the section of the pipe, the ends of the sheet coated with the resin being connected by a joint. with 40 overlap which allows the sliding of one end relative to the other as long as the resin is not yet hard, so that the section of the sheath can enlarge under the action of the pressure exerted directly or indirectly on its internal face until the sheath is firmly and perfectly applied by its external face against the internal face of the pipe.

Such a process can be in accordance with that filed in the form of a patent application, in France on April 18, 1980, under No. 80 08 679 and published under No. 2,480,901.

Other advantages and characteristics will emerge from the following text 50, given by way of example, and from the figures relating thereto.

Figure 1 shows, in section and enlarged, a first embodiment of the composite material.

Figure 2 shows, in section and enlarged, a second embodiment of the composite material.

55 Figure 3 shows, in section, on a small scale, a sheath made with the material shown in Figure 1.

Figure 4 shows, in section, on a small scale, the installation of a sheath made with a material shown in Figure 2 in a pipe.

Figure 5 shows, in section and enlarged, a third embodiment of the composite material.

Figure 6 shows, in perspective and enlarged, an embodiment of a frame.

The material (10) shown in Figure 1 comprises at least one 65 comprising a first layer (1) of a non-woven fabric, such as natural or artificial felt. Preferably, this layer (1) is made of polyester fibers. This layer (1) is followed by at least one flexible and resistant reinforcement (2), for example of

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656093

glass fiber or glass fiber mesh. Several frames (2) can be arranged one on the other, for example, a fabric frame can be combined with a frame having the configuration of a mesh, etc. If the material has only one assembly (1,2), a layer (3) of a non-woven fabric is fixed to the underside of the layer (2) comprising at least one frame. The thickness (ej) of the layer (1) can, in this case, be equal to that (e3) of the layer (3); however, this is not compulsory: the thicknesses (e ^ and (e3) can be chosen so as to allow the most advantageous production of a material (10) for the execution of a sheath (Gj) for example Likewise, the thickness (e2) of the layer comprising at least one reinforcement is chosen as a function of the number of reinforcements used and of the flexibility and the mechanical resistance which it is desired to impart to the material (10) to be used for make a sheath (Gj). The material (10) can comprise several sets: a layer of non-woven fabric - reinforcement layer. The example shown in FIG. 1 comprises two sets: layers (1, 2) and layers (3, 4); however the last layer (5) is preferably made of a non-woven fabric; it is fixed to the lower part of the last layer comprising at least one frame.

The thicknesses of the layers of nonwoven fabric (e /), (e3), (3S) and the thicknesses of the layers - reinforcements (e2), (e4) are chosen so as to confer the best possible qualities for the constitution of a sheath (Gj), for example. Thus we can admit for the material (10), shown as an example in Figure 1, that e! = es, that e3> C], and that e2 = e4. The method of assembling the layers on top of each other is not part of the invention. One can, however, for example, imagine that a compact and resistant material can be obtained by spraying the polyester fibers onto the glass fiber fabric. All the layers (1, 2, 3, 4, 5) are permeable to an adhesive such as a thermosetting resin. This gives a light material (10), easy to handle and resistant. These qualities allow the advantageous use of this material (10) for the production of sheaths (Gj) of internal lining for pipes. A sheet of material (10) is rolled to form a tubular element whose outside diameter (D) is slightly less than the inside diameter of the pipe. The ends (10x, 102) of the sheet produced in the material (10) form a lap joint, which facilitates the determination of the diameter (D) most advantageous for the introduction of the sheath (Gj) in the pipe ( see Fig. 3). Before its introduction into the pipe, the sheath is coated with the adhesive which penetrates all the layers of the material (10). The ends (10d, 102) of the sheet can then slide relative to each other as long as the adhesive remains liquid.

When the sheath (Gj) coated with adhesive is introduced into the pipe, there is also introduced into the sheath a bag or the like having at least the length of the sheath. This bag is made of a sheet of polyethylene, polyvinyl chloride or the like. This sheet cannot therefore adhere to the sheath by the action of the adhesive. The bag is inflated; the temperature is possibly increased. The sheet of polyethylene, polyvinyl chloride or the like is then applied firmly against the underside of the sheath (layer 3 or layer 5) and the sheath (Gj) is applied firmly against the interior face of the pipe. The sheet constituting the airbag being smooth, the adhesive cannot flow on the underside of the sheath (layer 3 or layer 5) and the latter remains smooth and airtight after the adhesive has hardened and after the bag will have been deflated and removed. When applying the sheath against the pipe under pressure, the diameter (D) of the sheath (G!) Increases without the material (10) being subjected to stresses. This is made possible by sliding the ends (10j, 102) of the lap joint relative to each other before the adhesive hardens.

After hardening of the adhesive, the diameter (D) then corresponding substantially to the internal diameter of the pipe, the material (10) impregnated with hard polymerized resin allows the constitution of a sheath (Gj) light, resistant and waterproof and whose the inside is smooth.

The material (11) shown in Figure 2 is similar to that shown in Figure 1 except that it comprises as a lower layer a flexible and waterproof sheet (6) attached to the layer (5) of nonwoven fabric. This sheet (6) can be made of polyethylene, polyvinyl chloride, etc., as is already known from patent application No. 82 00933 of January 21, 1982, publication No. 2520021, in the name of the holder. This material (11) can be used to form sheaths (G2) of interior lining for pipes (C) (see FIG. 4). At least one of the ends of the sheath (G2) is extended in the bottom of the well (P) for access to the ground pipe (S) so as to exceed the end of the pipe (C) . The edges of the end of the sheath (G2) are then pressed against each other and joined by welding, for example. The tightness of the sheath (G2) at one of its ends is thus ensured. The layers (1, 2, 3, 4, 5) of the material (11) constituting the sheath (Gj) are impregnated with an adhesive such as a thermosetting resin. The adhesive cannot penetrate into the layer (6), nor pass through the layer (6). The sheath (G2) being thus prepared and introduced into the line (C), a pressurized and possibly heated fluid acts directly or indirectly on the inner face of the sheath (G2). This is applied firmly by its outer face to the inner face of the pipe (C) until the adhesive hardens. The part of the sheath (G2), the edges of which are welded, which exceeds the end of the pipe (C) is cut flush with the wall (20) of the well (P), for example. 25 The sheath (G2) is in place.

Figure 5 shows, in section, an embodiment of the material according to the invention, and Figure 6 shows, in perspective, on a larger scale, an embodiment of a reinforcing reinforcement of the material con-30 form to the invention.

The material (M) shown in Figure 5 has a thickness equal to (e) and has a first layer (100) which may be constituted by a flexible and waterproof sheet of a natural or synthetic material, such as rubber, butyl, polychloride vinyl, polyethylene 35, etc. The thickness of the layer (100) is equal to (e20).

In the case of an inner pipe lining sheath, this sheet (100) constitutes the inner layer of the composite material; its free underside is therefore preferably smooth in order to reduce, as much as possible, the friction between the fluid flowing in the conduit and the lining. A second layer (110) having a thickness (e10) is fixed on the first layer (100). This second layer (110) consists of a natural or synthetic felt provided with a flexible frame (120) disposed substantially at mid-thickness (elO / 2) of this layer. The felt is made up of cotton fibers, for example, or preferably polyester fibers which are, for example, flocked or applied under hot pressure (by calendering for example) on the upper face of the sheet ( or layer) (100), the reinforcement (120) being put in place prior to flocking or hot calendering, for example. The method of manufacturing the material (M) not forming part of the invention is not described. This felt is intended to absorb and retain an adhesive during the pressure application of the lining sheath against the inner face of the layer; the adhesive can be applied on the layer (110), on the inner face of the pipe or on both (layer and 55 pipe). The frame (120) is preferably, but not exclusively, constituted by a glass fiber grid, for example. The grid shown in Figure 6 has chains (122) and wefts (121) arranged perpendicular to each other. The chains (122) can have dimensions larger than those of the 60 frames (121), for example. According to one embodiment of the sheath, the chains (122) are arranged in the direction of the longitudinal axis of the sheath. But it is also possible to drown the reinforcement (120) in the layer (110) so that, during the manufacture of the material (M), the wefts (121) are arranged in the direction of the longitudinal axis of 65 the sheath formed in said material (M). According to another embodiment, the chains (122) and wefts (121) of the frame (120) can be arranged diagonally with respect to the longitudinal axis of the sheath.

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As already mentioned above, the reinforcement (120) gives increased resistance to the whole of the material (M) whose total thickness (e) will only vary in comparatively small proportions as a function of the increase in diameter ( or section) of the pipe to be provided with an inner lining sheath formed in said material (M). Also, the amount of adhesive will only increase by a comparatively small amount, since the thickness (e10) of the layer (110) will only increase slightly. The total weight of the lining sheath comprising the adhesive always remains comparatively low; consequently, the pressure necessary to apply the sheath against the inner face of the pipe increases only slightly as a function of the diameters (or of the section) of the pipe. There is therefore an energy saving compared to known filling methods; the consumption of adhesive is lower than in known methods; and the quantity of material (M) is in4

lower than that necessary in processes practiced until now. Also, the equipment to create the pressure to apply the sheath against the pipe and to apply the adhesive may be lighter than that used on existing construction sites. There is therefore a gain in energy, in the quantity of materials, and a reduction in the cost of the process.

Many improvements and modifications can be made without departing from the scope of the invention. The reinforcement may, for example, have a configuration different from that of a grid, the thickness of the absorbent layer may be very small and the flexible and waterproof sheet may be produced in the form of a thin membrane. It is also within the framework of the invention to use the material according to the invention for the production of sheaths having square, octagonal, oval, etc. sections, to be applied against pipes having the same sections.

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1 sheet of drawings

Claims (9)

656,093 CLAIMS 1. flexible compact composite material, characterized in that it comprises at least one assembly comprising at least a first upper part constituted by at least one first nonwoven fabric and at least one flexible reinforcement, and a second part constituted by at least one second nonwoven fabric disposed on the lower part of said assembly. 2. Material according to claim 1, characterized in that said first nonwoven fabric is the same as said second nonwoven fabric. 3. Material according to claim 1 or claim 2, characterized in that the non-woven fabrics are made of natural or synthetic fibers. 4. Material according to one of the preceding claims, characterized in that the frame is made of a flexible and resistant material. 5. Material according to claim 4, characterized in that the reinforcement is made in the form of a woven fabric or a mesh. 6. Material according to one of the preceding claims, characterized in that it comprises a flexible sheet made of a natural or synthetic material, fixed to the underside of the second nonwoven fabric. 7. Material according to one of claims 1 to 6, characterized in that the flexible reinforcement (120) of reinforcement is embedded in at least one part (110) constituted by a nonwoven fabric so that it can follow, without friction between itself and said part (110), any deformation of said assembly (100, 110, 120). 8. Material according to claim 7, characterized in that said frame (120) is arranged at mid-thickness of said part (110). 9. Material according to claim 5, characterized in that the chain of said mesh has dimensions greater than those of the frame.