NON-WOVEN TEXTILE FABRIC, SUITABLE FOR FORMING A MECHANICAL REINFORCING LAYER IN A COMPOSITE MATERIAL

Abstract

Non-woven textile fabric, suitable for forming a permeable layer in a composite material, said fabric being made from chopped glass fibers, and incorporating means for bonding said glass fibers together, characterized in that it comprises at least two types of glass fibers, namely: - on the one hand, fibers of a first type, derived from chopped rovings, having a sizing of a first type; and on the other hand, fibers of at least one of the following two types, namely - fibers of a second type, derived from direct rovings, having a sizing of a second type, different from the sizing of the first type; - fibers of a third type, free of sizing.

Description

Title of the invention: NON-WOVEN TEXTILE FABRIC, SUITABLE FOR FORMING A MECHANICAL REINFORCEMENT LAYER IN A COMPOSITE MATERIAL Technical field

[0001] The invention relates to the field of technical textiles, and more particularly to textiles used for the manufacture of composite materials, that is to say materials combining one or more textile layers impregnated with a material in the liquid phase during its application, then intended to solidify subsequently. These may be materials of various natures, of a thermosetting or thermoplastic nature, or even of a bituminous or cementitious base.

[0002] More specifically, the invention relates to a mat more specifically based on cut glass fibers, produced by a mixture of different types of fibers, including in particular fibers from recycling.

[0003] The invention also relates to the use of this type of reinforcement for the manufacture of different types of composite materials. Previous techniques

[0004] Generally speaking, textile mats are non-woven fabrics, made up of fibers, most often cut, which are oriented in a quasi-random manner, and combined to give this set of fibers a certain cohesion. The assembly can be done by different processes, of a mechanical nature, for example by needling, sewing or carding, or of a chemical nature, by the incorporation of binders, in the form of powder, hot-melt filaments, or sprayed droplets.

[0005] For mats intended to serve as reinforcement, the use of fibers of high-tenacity materials such as glass is conventional. The mats are manufactured from bundles of filaments, or rovings, which are generally cut to form segments of fibers of a predetermined length. To ensure a quasi-isotropic distribution of the orientation of the fibers, the cutting of the rovings is done at a certain height from the plane on which the mat will be formed, and the fall of the fibers thus cut causes their random orientation when they reach the reference plane. For the manufacture of this type of product, so-called "cut rovings" or "assembled rovings" are used, which were developed by glassmakers exclusively for the production of glass mats and which have the advantage of having very regular geometric and mechanical properties.

[0006] One of the advantages of this type of roving lies in the use of certain types of sizing which cover the individual filaments of the roving. Indeed, for the cutting rovings, the size can be applied to a bundle of filaments gathered into small bundles. After the size has dried, the bundles are grouped together again into a roving. When cutting a cutting roving, the filaments remain gathered according to the initial bundles, which has the advantage of facilitating cutting, and of guaranteeing the isotropy and the relatively low thickness of the mat obtained.

[0007] Traditionally, the manufacture of glass fiber mats therefore requires the use of glass rovings which have been manufactured specifically for this use, in particular with regard to sizing, and hereinafter referred to as “cut rovings”. Description of the invention,

[0008] Furthermore, in the field of technical textiles, and in particular textiles based on glass fibers, a large quantity of waste is produced. This may, for example, be waste generated during the manufacture of textile articles, for example the selvedges of the fabrics, which are cut at the exit of the loom. It may also be scraps generated during the cutting of fabrics, or even mats during the production of shaped pieces, or even second-choice rolls. The rovings used for the manufacture of these articles are different from the cut rovings, as regards the sizes used.Indeed, for rovings used for example for weaving glass fabrics, or for manufacturing fabric based on non-corrugated fibers (NCF), the glass filaments are grouped in a single bundle and the size which covers them is formulated to allow the filaments to move relative to each other, in order to facilitate the spreading of the threads in particular. This type of roving is generally called "direct roving".

[0009] There are also other wastes that are generated when using textile fabrics in the manufacture of composite materials. Thus, when producing shaped composite parts, scraps are generated, in which the textile fabric itself is found combined with a thermosetting or thermoplastic resin. It may also be waste from end-of-life products, including composites.

[0010] One of the objectives of the invention is to enable the recovery of these different wastes by reusing them in the manufacture of reinforcement mats.

[0011] For this purpose, the Applicant has designed a specific textile fabric. Conventionally, this non-woven fabric, which is suitable for forming a permeable layer in a composite material, is made from chopped glass fibers, and incorporates means ensuring the bonding of these fibers.

[0012] According to the invention, this fabric comprises at least two distinct types of glass fibers, namely: - on the one hand, fibers of a first type, from cut rovings, which have a first type of sizing, and on the other hand at least one of the following two types of fibers, namely: - fibers of a second type, from direct rovings, which have a size of a second type, different from the size of the first type, - fibers of a third type, free from size.

[0013] In other words, the invention therefore consists of producing the mats by combining several types of glass fibers of different origins. A portion of these fibers comes from rovings dedicated to the manufacture of mats, in other words first-hand fibers, or “virgin” fibers.

[0014] Another part of the fibers can come from recycling and more precisely from fibers from production edges, from fabric recycling, but also from hardened composite materials, or from textiles pre-impregnated with resin and recycled. Composite materials can come from machining waste, or from end-of-life products.

[0015] The sizing used for direct rovings does not allow the grouping of fibers in the form of bundles, unlike the sizing used for fibers from cut rovings. Surprisingly, the coexistence of these two sizes in the mat of the invention is not prohibitive for the manufacture and cohesion of the mat.

[0016] Similarly, the fibers from the recycling of composite materials had to undergo steps to remove the thermosetting or thermoplastic resin that impregnates the fibers. This removal, by thermal or chemical means, also has the effect of removing the sizing that covers the glass fibers. Also surprisingly, the cutting of these recycled fibers to the desired length for the mat, as well as the incorporation into the mat itself, is done without any major negative effect that might have been expected with the absence of sizing on these fibers.

[0017] In one embodiment, the fabric comprises at least three types of glass fibers, namely: - fibers of a first type, from cut rovings, having a sizing of a first type;

[0018] - fibers of a second type, from direct rovings, having a size of a second type, different from the sizing of the first type; - fibers of a third type, free from sizing

[0019] In practice, the means ensuring the bonding of the fibers together can be of different natures. It can for example be a binder, formed by a powder, or by fibers at least partially fusible on the surface, which after softening or even fusion can stick the different fibers with which they are in contact, or even sprayed droplets of glue. The bonding can also be obtained by a mechanical action on the glass fibers themselves, by needling in particular, so that the fractions of these glass fibers pass through all or part of the thickness of the fabric to mechanically ensure the cohesion of the mat by phenomena of friction. It is also possible to hold the fibers together by sewing operations.

[0020] In practice, in a specific embodiment, the average length of the fibers of the first type may be greater than the average of the fibers of the second and / or third type. In other words, the fibers from cut rovings are longer than the fibers from recycling, which have generally suffered breakages during the recycling steps allowing them to be extracted from their original fabrics or mats, and to be cut to the desired length.

[0021] In practice, it is generally found that the standard deviation in length of the fibers of the first type is less than the standard deviation in length of the fibers of the second and / or third type. In other words, the fibers from cut rovings are very regular in length, these depending only on the settings of the cutting tool. Conversely, the fibers from recycling are of very different lengths, depending on the dimensions of the portions of articles from which they are recycled, as well as on the sequence of the different operations making it possible to cut and / or fray the textile waste to be recycled.

[0022] In practice, the fibers of the first type, that is to say from cut rovings, have an average length of between 25 and 100 millimeters, whereas the fibers of the second type, for example from weaving scraps, have an average length of between 15 and 50 millimeters, whereas the fibers of the third type, from the recycling of composite articles, have an average length of between 15 and 50 millimeters.

[0023] Depending on the desired applications, in terms of mechanical properties, and resin of the composite material in which the mat is integrated, different configurations are possible with regard to the proportion of the different types of glass fiber within the mat.

[0024] Thus, in a first case, the proportion by weight of the glass fibers is: - for the fibers of the first type, between 25 and 50%; - for fibres of the second type and / or the third type, each between 25 and 50%;

[0025] This distribution configuration is more particularly intended for mats used for example as a support for a bituminous coating, or as a reinforcing layer in a sliding board.

[0026] In another case, the proportion by weight of the glass fibers may be: - for the fibers of the first type, between 50 and 80%, - for fibers of the second and / or third type each between 5 and 50%.

[0027] This type of reinforcement is for example intended for applications of reinforcement of composite material with thermosetting matrix.

[0028] In a third case, the proportion by weight of the glass fibers may be: - for the fibers of the first type, between 5 and 20%,

[0029] - for fibers of the second and third type, each between 30 and 55%.

[0030] This configuration is particularly intended for applications in the manufacturing of composite materials, such as for example sliding boards.

[0031] In practice, the fibers of the at least partially fusible thermoplastic materials ensuring the bonding of the glass fibers may be made of a material chosen from the group comprising polyesters, co-polyesters, co-polyolefins and copolyamides, taken alone or in a mixture with one or more materials chosen from the group comprising polyolefins, polyesters and polyamides.

[0032] In a particular embodiment, the majority of the fibers of the first type are gathered in a first fraction of the thickness of the fabric, the fibers of the second and / or third types being gathered in a different fraction of the thickness of the fabric. In other words, the fibers from cut rovings form a sub-layer distinct from the sub-layer grouping the fibers from recycling. These two sub-layers can be assembled by mechanical action, such as sewing or needling, or by gluing, for example thanks to the binder ensuring the cohesion of the fibers between them. This structure can for example be obtained by depositing fibers from cut rovings on and / or under a fibrous sheet composed essentially of recycled fibers, from direct roving and / or from recycling of composite parts.This stacking of different fibers within the same product makes it possible to achieve mats of lower thickness than the previous cases, and also greater mechanical properties.

[0033] In a particular embodiment, it is possible to use the fabric described above to form a complex further comprising an additional layer consisting of a woven fabric, a unidirectional yarn web, a mat, a fabric based on non-crimped fibers (NCF), or a mat of polypropylene fibers for example. It is also possible to produce complexes stacking several fabrics described above.

[0034] In other words, it is possible to use the characteristic mat in association with reinforcing layers having a priori higher mechanical properties, because these are structures having continuous threads in the case of fabrics and NCFs, or because it is a mat made essentially or even exclusively from cut rovings.

[0035] Of course, this association can be adapted according to the applications, using an alternation of as many mats including recycled fibers and layers additional based on fabrics, NCF or mats with high mechanical properties.

[0036] In some cases, the complex may comprise a first layer formed by a mat composed essentially, or even exclusively, of the first type of fibers, namely fibers from cut rovings. The second layer is also a mat, composed of a mixture of fibers of the first type, from cut rovings, and one or more types of recycled fibers, i.e. either fibers from recycling a non-impregnated textile, i.e. from direct rovings, or fibers from recycling impregnated textiles. In other words, the complex is obtained by assembling pre-existing layers, which are joined together by sewing, gluing or other mechanical and / or chemical action.

[0037] Generally speaking, the mats or complexes according to the invention can advantageously be used for the manufacture of composite materials including a thermosetting resin, or a bituminous base and, more generally, with any low-viscosity matrix, such as that used in resin transfer molding (RTM), pultrusion, infusion, or even impregnation and manual positioning (or HLU for Hand Lay-Up) processes, as opposed to thermocompression processes which use high-viscosity matrices. Examples of achievements

[0038] As already mentioned, the invention relates to a mat or a complex integrating this mat, made from three different types of glass fibers.

[0039] The various examples described below were produced from fibers of the three types, according to different varieties according to the following definitions:

[0040] For the first type, i.e. cutting rovings, two varieties were used.

[0041] The first variety (TlVI) corresponds to fibers from cut rovings marketed by the company OWENS CORNING with a count of 2400 tex. These rovings have a size of the commercial reference P244, and are cut to lengths of approximately 50 mm.

[0042] The second variety (T1V2) corresponds to fibers from cut rovings marketed by the company SISECAM CAM ELYAF with a count of 2400 tex. These rovings have a size of the commercial reference KCR10, and are cut to lengths of approximately 50 mm.

[0043] For the second type, that is to say fibres from textile waste, coming almost exclusively from direct rovings, tests were carried out with different varieties.

[0044] A first variety (T2V1) is formed from a mixture of substantially equal weight of three categories of fibers. A first category (T2V1C1) is formed from scraps of selvedges recovered from the loom, from yarns from the companies 3B and OWENS CORNING with a count of 200 to 4800 tex, and having a size bearing the reference 111 A. This first category has an average fiber length of between 30 and 40 millimeters, obtained without additional cutting. The second category (T2V1C2) is formed from offcuts of selvedges from multi-axial fabrics, based on 600 tex fibers, having a size bearing the reference 111A from the company OWENS CORNING. This second category has an average length of around 25 mm, with a high disparity in length because the waste is initially 200 mm and then cut by guillotine to a target of 25 mm. The third category (T2V1C3) is composed of fibers obtained from the offcuts of a complex marketed under the reference G-PLY by the Applicant.This complex comprises several layers of fabric based on yarns with counts of 600 and 1200 tex, combined with a veil of glass fibres of 30 g / m2, by sewing with a polyester binding thread. The glass fibres of this third category also contain a sizing of the commercial reference 111A from the company 3B. The length of these fibres of this third fraction is of the order of 25 millimetres.

[0045] A second variety (T2V2) is formed from a mixture of substantially equal weight of two categories of fiber. A first category (T2V2C1) is formed from selvedge scraps recovered at the exit of the loom, from yarns from the company OWENS CORNING with a count of 200 to 2400 tex, and having a size bearing the reference SE1200. This first category has an average fiber length of between 20 and 40 millimeters. The second category (T2V2C2) is composed of fibers obtained from scraps of a complex marketed under the reference G-PLY by the Applicant. This complex comprises several layers of fabric based on yarns with counts of around 200 tex, associated with a veil of glass fibers of 30 g / m2, by sewing with a polyester binding thread. The glass fibers in this second category also include a sizing of the commercial reference SE1200 from the company OWENS CORNING.The length of these fibers of this third fraction is of the order of 25 millimeters.

[0046] A third variety (T2V3) is formed from selvedge scraps recovered from the loom, from CPIC company yarns with a count of 200 to 2400 tex depending on the type of recycled fabric, and having a size bearing the reference 469L. This third variety of fibers has an average fiber length of between 20 and 40 millimeters, and are used without additional cutting.

[0047] A fourth variety (T2V4) is formed from a mixture of substantially equal weights of three categories of fibers. A first category (T2V4C1) is formed from selvedge scraps recovered from the weaving loom, from PPG yarns with a count of 200 to 2400 tex, and having a size bearing the reference 2002. This first category has an average fiber length of between 20 and 40 millimeters, obtained without additional cutting. The second category (T2V4C2) is formed from offcuts of multi-axial fabric selvedges, based on 600 tex fibers, having a sizing bearing the reference 2002 from the company PPG. This second category has an average length of around 25 mm, cut in a single operation. The third category (T2V4C3) is composed of fibers obtained from the offcuts of a complex marketed under the reference G-PLY by the Applicant. This complex comprises several layers of fabric based on yarns with counts of 600 and 1200 tex, combined with a veil of glass fibers of 30 g / m2, by sewing with a polyester binding thread. The glass fibers of this third category also have a sizing of the commercial reference 2002 from the company PPG.The length of these fibers of this third fraction is of the order of 25 millimeters, obtained in two successive cuts.

[0048] The fibers of the third type (T3V1) come from the recycling of composite materials. After a step of destruction of the composite resin (by pyrolysis for example), the textile fraction obtained comprises a stack of mats and NCF, initially sewn, and fabrics. These fibers are free of sizing, which has been destroyed by pyrolysis. The length of these fibers is around 25 mm, obtained in two successive cuts. Example No. 1:

[0049] The first example concerns a mat which has a weight of 50 g / m2, and which includes by weight 15% of fibers forming a binder, consisting of a mixture of polyester and copolyethylene fibers of a low count.

[0050] The rest of the mat is therefore composed of 85% glass fibers. The three types of fibers are represented with the same proportion.

[0051] The fibers of the first type correspond to the first variety (T1V1) mentioned above.

[0052] The fibers of the second type correspond to variety No. 1 (T2V1) mentioned above. The fibers of the third type are of the variety (T3V1) mentioned above.

[0053] The mat according to this example has particular aptitudes for being used for the manufacture of composite materials, as a resin support layer, or adhesion promoting layer, or even as a support layer in association with a grid for a bituminous coating. Example #2:

[0054] A second example was made to form a mat which has a surface mass of 50 g / m2.

[0055] This mat comprises a weight of 50% of copolyethylene and polyester fibers forming the binder intended to hold the glass fibers.

[0056] The glass fibers therefore represent 50% by weight. The distribution of the glass fibers is balanced between the fibers of the first, second and third type.

[0057] The fibers of the first type correspond to variety No. 1 (T1V1) and the fibers of the second and third types are identical to the fibers of example No. 1.

[0058] The mat according to this example has particular aptitudes for being used in applications similar to those of example no. 1. Example #3:

[0059] This example is formed from a mat which has a surface mass of 116 g / m2.

[0060] This mat comprises a weight of 31% of copolyethylene and polyester fibers forming the binder intended to hold the glass fibers.

[0061] The glass fibers therefore represent 69% by weight. The distribution of the glass fibers is balanced between the fibers of the first and second types.

[0062] The fibers of the first type correspond to the fibers of the first variety (T1V1), and the fibers of the second type are identical to the fibers of example no. 1. The mat does not contain fibers of the third type.

[0063] The mat according to this example has particular aptitudes for being used in applications similar to those of example no. 1. Example #4:

[0064] This example concerns a mat which has a weight of 150 g / m2, and which includes by weight 12% of fibers forming a binder, consisting of a mixture of polyester and copolyethylene fibers of a low count.

[0065] The rest of the mat is therefore composed of 88% glass fibers.

[0066] The fibers of the first type correspond to the second variety (T1V2) mentioned above, and represent 17% of the weight of glass.

[0067] The fibers of the second type correspond to a mixture of substantially equal weights of varieties No. 1 (T2V1), No. 2 (T2V2), No. 3 (T2V3) and No. 4 (T2V4) mentioned above, representing 50% of the weight in glass. The fibers of the third type are of the variety (T3V1) mentioned above and represent 33% of the weight in glass.

[0068] The mast according to this example has particular aptitudes for being used for the manufacture of composite materials in the field of nautical construction. Example No. 5#:

[0069] This example of mat was produced with a weight of around 300 g / m2.

[0070] The binder, composed of polyester and copolyethylene fibers, represents 2% of the weight of the mat.

[0071] The rest of the mat is composed of glass fibers according to the three types already mentioned.

[0072] The fibers of the first type, from the first variety (T1V1) mentioned above, represent approximately two thirds of the total weight of the glass fibers in the mat.

[0073] The fibers of the second type, from the first variety (T2V1) mentioned above and from the third type, each have approximately 17% of the weight of the fiberglass mat.

[0074] Such a mat is particularly suitable for producing stacks with textile structures to form additional thicknesses, used in the manufacture of composite materials. Example #6:

[0075] This example of mat was produced with a weight of around 300 g / m2.

[0076] The binder, composed of polyester and copolyethylene fibers, represents 3% of the weight of the mat.

[0077] The rest of the mat is composed of glass fibers according to the three types already mentioned.

[0078] The fibers of the first type, from the second variety (T1V2) mentioned above, represent 17% of the total weight of the glass fibers in the mat.

[0079] The fibers of the second type correspond to a mixture of substantially equal weights of varieties No. 1 (T2V1), No. 2 (T2V2), No. 3 (T2V3) and No. 4 (T2V4) mentioned above, representing 50% of the weight in glass. The fibers of the third type are of the variety (T3V1) mentioned above and represent 33% of the weight in glass.

[0080] Such a mat is particularly suitable for producing stacks with textile structures to form additional thicknesses, used in the manufacture of composite materials. Example #7:

[0081] This example corresponds to a complex combining two layers, and has a surface mass of the order of 300 g / m2, of which 1% corresponds to the weight of the binder.

[0082] The complex comprises two layers of equal weight. A first layer, which therefore represents 50% of the total weight of glass fibers in the complex, is itself produced by combining the glass fibers of the second variety of the first type (T1V2) at a rate of 58%, of a mixture of substantially equal weights of varieties No. 1 (T2V1), No. 2 (T2V2), No. 3 (T2V3) and No. 4 (T2V4) of the second type, at a rate of 25%, and third type (T3V1), at a rate of 17%.

[0083] The second layer corresponds to a mat made solely from fibers of the first type, from the first variety (TlVI).

[0084] The masts of the two layers are joined by sewing. Example #8#:

[0085] This example corresponds to a complex combining three layers, and having a surface mass of the order of 600 g / m2, of which 1% represents the weight of the binder.

[0086] The complex comprises two outer layers and a central layer. The two outer layers are mats made from fibers of the first type, of the first variety (T1V1). Each of the outer layers represents approximately 25% by weight of the complex.

[0087] The central layer, which therefore represents 50% of the total weight of glass fibers in the complex, is itself produced by combining the glass fibers of the second variety of the first type (T1V2), and a mixture of substantially equal weights of varieties No. 1 (T2V1), No. 2 (T2V2), No. 3 (T2V3) and No. 4 (T2V4) of the second type. Within the central layer, the fibers of the first type represent 58% by weight of the layer. The fibers of the second type together represent 42% of the weight of glass fibers in the mass of the central layer.

[0088] The mat forming the central layer comprises a binder composed of polyester / co-polyethylene, which allows the fibers of the central layer to be bound together. All three of these layers are bound together by sewing Example No. 9#:

[0089] This example corresponds to a complex combining three layers, and having a surface mass of the order of 600 g / m2, of which 1% represents the weight of the binder.

[0090] The complex comprises two outer layers and a central layer. The two outer layers are mats made from fibers of the first type, of the second variety (T1V2). Each of the outer layers represents approximately 25% by weight of the complex.

[0091] The central layer, which therefore represents 50% of the total weight of glass fibers in the complex, is itself produced by combining the glass fibers of the second variety of the first type (T1V2), at a level of 58%, a mixture of substantially equal weights of varieties No. 1 (T2V1), No. 2 (T2V2), No. 3 (T2V3) and No. 4 (T2V4) of the second type at a level of 25% and of the third type (T3V1) at a level of 17%.

[0092] The mat forming the central layer comprises a binder composed of polyester / co-polyethylene, which makes it possible to bind the fibers of the central layer together. All three of these layers are bound by sewing. Example #10#:

[0093] This example corresponds to a complex combining two layers, and has a surface mass of the order of 600 g / m2, of which 1% corresponds to the weight of the binder.

[0094] The complex comprises two layers of equal weight. A first layer, which therefore represents 50% of the total weight of glass fibers in the complex, is itself produced by combining the glass fibers of the second variety of the first type (T1V2) at a rate of 58%, a mixture of substantially equal weights of varieties No. 1 (T2V1), No. 2 (T2V2), No. 3 (T2V3) and No. 4 (T2V4) of the second type, up to 25%, and third type (T3V1), up to 17%.

[0095] The second layer is a mat made from only fibers of the first type, from the first variety (TlVI).

[0096] The masts of the two layers are joined by sewing. Example No. ll#:

[0097] This example corresponds to a complex combining two layers, and has a surface mass of the order of 600 g / m2, of which 1% corresponds to the weight of the binder.

[0098] The complex comprises two layers of equal weight. A first layer, which therefore represents 50% of the total weight of glass fibers in the complex, is itself produced by combining the glass fibers of the second variety of the first type (T1V2) at a rate of 58%, with a mixture of substantially equal weights of varieties No. 1 (T2V1), No. 2 (T2V2), No. 3 (T2V3) and No. 4 (T2V4) of the second type, at a rate of 42%.

[0099] The second layer is a mat made solely from fibers of the first type, from the first variety (TlVI).

[0100] The masts of the two layers are joined by sewing. Example #12#:

[0101] This example corresponds to a complex combining two layers, and has a surface mass of the order of 716 g / m2, of which 5% corresponds to the weight of the binder.

[0102] The complex comprises two layers. A first layer, which represents approximately 15% of the total weight of glass fibers in the complex, is itself produced by combining the glass fibers of the second variety of the first type (T1V2) at a rate of 50%, and with a mixture of substantially equal weights of varieties No. 1 (T2V1), No. 2 (T2V2), No. 3 (T2V3) and No. 4 (T2V4) of the second type, at a rate of 50%.

[0103] The second layer is made of unidirectional yarns of direct rovings, oriented at 0 degrees, forming a layer of 600g / m2.

[0104] The two layers are joined by sewing. Example #13#:

[0105] This example corresponds to a complex combining two layers, and having a surface mass of the order of 772 g / m2, of which 1.2% corresponds to the weight of the binder.

[0106] The complex comprises two layers. A first layer corresponds to the product of example 6, which represents approximately 38% of the total weight of glass fibers in the complex

[0107] The second layer is a complex marketed by the Applicant under the reference G-PLY BT472, having a weight of 472 g / m2.

[0108] The two layers are joined by sewing. Example #14#:

[0109] This example corresponds to the complex of example no. 9, associated by sewing with a layer of non-woven sold by the Applicant under the reference ROVICORE PP D3, of 180 g / m2.

[0110] The two layers are joined by sewing. Example #15#:

[0111] This example corresponds to the assembly of two complexes of example no. 7, between which is inserted a draining layer of non-woven fabric marketed by the Applicant under the reference ROVICORE PP D3. The assembly is constructed in such a way that the central draining layer is in contact with the layers of the complex of example no. 6 which include fibers of the second type and that the external layers of the complex are made up of fibers of the first type, from the first variety (T1V1).

[0112] The three layers are joined by sewing. Example #16#:

[0113] This example corresponds to the complex of example no. 1, associated by sewing with a complex marketed by the Applicant under the reference G-PLY TL25 600 / 298, having a weight of 898 g / m2. Example #17#:

[0114] This example corresponds to the assembly by sewing of the complex of example no. 7, and a 3-lie 1 twill weave fabric of 1500g / m2 made up of 0 degree warp yarns from direct roving of 2400tex count and weft yarns from direct roving 2400tex. The assembly is constructed in such a way that the fabric is in contact with the layer of the complex of example no. 7 which includes fibers of the second type and that the external layer of the complex of example 7 is made up of fibers of the first type, from the first variety (TlVI).

Claims

Claims

1. Non-woven textile fabric, suitable for forming a permeable layer in a composite material, said fabric being made from chopped glass fibers, and incorporating means for bonding said glass fibers together, characterized in that it comprises at least two types of glass fibers, namely: - on the one hand, fibers of a first type, from chopped rovings, having a sizing of a first type; and on the other hand, fibers of at least one of the following two types, namely - fibers of a second type, from direct rovings, having a sizing of a second type, different from the sizing of the first type; - fibers of a third type, free of sizing.

2. Fabric according to claim 1, characterized in that it comprises at least three types of glass fibers, namely: - fibers of a first type, from cut rovings, having a sizing of a first type; - fibers of a second type, from direct rovings, having a sizing of a second type, different from the sizing of the first type; - fibers of a third type, free from sizing

3. Fabric according to claim 1 or 2 characterized in that the majority of the fibers of the first type are gathered in a first fraction of the thickness of the fabric, the fibers of the second and / or third types being gathered in a different fraction of the thickness of the fabric.

4. Fabric according to claim 1, characterized in that the means ensuring the bonding of the glass fibers together comprise a binder formed by a powder or fibers at least partially fusible on the surface or sprayed droplets of glue.

5. Fabric according to claim 1 characterized in that the means ensuring the bonding of the glass fibers together are formed by fractions of said glass fibers passing through all or part of the thickness of said fabric.

6. Fabric according to claim 1 characterized in that the average length of the fibers of the first type Xi is greater than the average length (X2X3) of the fibers of the second and / or third type.

7. Fabric according to claim 1, characterized in that the standard deviation (Oi) of length of the fibers of the first type is less than the standard deviation (o2 o3) of length of the fibers of the second and / or third type.

8. Fabric according to claim 1 characterized in that the fibers of the first type have an average length Xi of between 25 and 100 millimeters.

9. Fabric according to claim 1 characterized in that the fibers of the second type have an average length X2 of between 15 and 50 millimeters.

10. Fabric according to claim 1 characterized in that the fibers of the third type have an average length X3 of between 15 and 50 millimeters.

11. Fabric according to claim 1, characterized in that the proportion by weight of the glass fibers is: - for the fibers of the first type, between 25% and 50%, - for the fibers of the second and / or third type, each between 25% and 50%,

12. Fabric according to claim 1, characterized in that the proportion by weight of the glass fibers is: - for the fibers of the first type, between 50% and 80%, - for the fibers of the second and / or third type, between 5% and 50%.

13. Fabric according to claim 1, characterized in that the proportion by weight of the glass fibers is: - for the fibers of the first type, between 5% and 20%, - for the fibers of the second and / or third type, between 30% and 55%,

14. Fabric according to claim 4, characterized in that the at least partially fusible fibers ensuring the bonding of the glass fibers are made of a material chosen from the group comprising copolyesters, copolyolefins and copolyamides, taken alone or in a mixture with one or more materials chosen from the group comprising polyolefins, polyesters and polyamides.

15. Complex comprising a fabric according to one of the preceding claims, characterized in that it also comprises at least one additional layer consisting of a woven fabric, a mat, a fabric based on non-corrugated fibers (NCF), a unidirectional sheet of yarns, or a fabric according to one of the preceding claims.

16. Use of the fabric or complex according to one of claims 1 to 15, for the manufacture of a composite material including a thermosetting resin.

17. Use of the fabric or complex according to one of claims 1 to 15 for the manufacture of bituminous-based or cement-based composite material.