FR2862316A1 - Fibre-based reinforcing material contains homogeneous mixture of glass and thermoplastic filaments - Google Patents

Abstract

Reinforcing material comprises a coherent web (9) containing glass and thermoplastic filaments. A number of web layers can be felted by water jets and stuck to a backing (15) of reinforcing fibres of glass, carbon or thermoplastic. Reinforcing material comprises a coherent web (9) containing glass and thermoplastic filaments. The web has a preferable weight of about 20 g/m2> and comprises about 50-80 wt.% of glass filaments between 10 and 24 Microm in diameter and about 80-20 wt.% of thermoplastic filaments between 10 and 30 Microm in diameter. The filaments are about 30-60 mm long, with the glass filaments at least partially bonded by the thermoplastic ones. A number of web layers can be felted by water jets and stuck to a backing (15) of reinforcing fibres of glass, carbon or thermoplastic.

Description

4410DEP 2862316 1

  The present invention relates to reinforcing products used in the field of composite materials and intended to enter the composition of parts or products to impart improved mechanical properties.

  The invention relates more particularly to reinforcing products intended to constitute planar or shaped structural elements, which can be incorporated in a matrix during the manufacture of a shaped part.

  The invention is based on the use of staple fibers of equal or unequal lengths obtained from glass filaments co-mingled with thermoplastic filaments. EP-A-0 599 695 and EP-A-0 616 055 disclose processes for making such mixed-blend yarns composed of glass filaments and filaments of an organic thermoplastic material. In all the applications described, the composite yarns themselves constitute the essential reinforcement structure, and the mechanical properties obtained are determined by the orientation of the yarns themselves.

  Son-based reinforcement products consisting of a combination of glass filaments and thermoplastic filaments are already known. For example, the document FR 2 797 892 uses such son to form two sheets of perpendicular son which are pressed hot against each other to ensure their bonding and form a plate. The document FR 2 784 931 uses these same son to form a composite tape, the son being placed longitudinally side by side in a sheet and hot pressed to form the ribbon. The document FR 2 779 988 uses these same son by arranging them in the form of sheets that can be incorporated in a mold to be embedded in a matrix during the manufacture of a part by molding.

  A disadvantage is that these structures son plies lack flexibility in implementation, in particular by the fact that it is necessary to arrange the son in the form of plies, which can be relatively easy in the longitudinal direction during production Continuous, but what is then more delicate when one wants to arrange the son in the transverse direction. Also, these applications are limited to the use of glass as a mechanical reinforcing element.

  Furthermore, it is known that the technique of carding glass fibers is not industrially applicable for the realization of a card web of low weight. Indeed, when the fibers to be carded have a diameter greater than 8 or 10 microns, thick sheets are obtained, used mainly as insulating materials. But it is industrially very difficult to obtain a card web having a basis weight as low as 20 to 40 grams per square meter.

  The object of the invention is to design new fiber-based reinforcement structures that can both be manufactured economically by industrial processes, and be implemented in a particularly flexible manner to accommodate the majority of applications.

  The invention seeks to take advantage of the advantageous properties of mixtures of glass filaments and thermoplastic filaments, which can be assembled by simple heating under pressure producing a bonding.

  The invention aims to provide such a mixture of glass filaments and thermoplastic filaments in a form that is economical to produce, and which is especially available in very thin to control the amounts of thermoplastic material and allow compatibility in applications that need to minimize the presence of the thermoplastic material.

  For this, the invention results from the surprising observation that staple fibers of equal or unequal length are cardable and allow the formation of a thin web and a weight of the order of 20 to 40 g / m2, when they are obtained from yarns made of continuous glass filaments co-merged with continuous filaments of thermoplastic material, or are obtained by appropriate homogeneous mixing of pre-cut glass filament sections and pre-cut filament sections of thermoplastic material.

  To achieve these and other objects, the invention provides a reinforcing product comprising a coherent web consisting of a mixture of oriented filament sections containing sections of glass filaments; in the mixture, the oriented filament sections contain a homogeneous mixture of sections of glass filaments and sections of thermoplastic filaments. The sections of thermoplastic filaments provide some attachment in the card, and protect the sections of glass filaments against their tendency to break. It is thus possible to card traditional glass fibers irrespective of the diameter of the unitary filaments. Carding gives the veil its coherence, by an ordered entanglement of the sections of filaments which ensures their connection, and preferentially directs the sections of filaments in the direction of movement of the card.

  The haze may advantageously be from about 15 g / m 2 to about 40 g / m 2, preferably about 20 g / m 2.

  In the present description and in the appended claims, the term "co-mixed" is used to designate yarns composed of glass filaments and thermoplastic filaments which are mixed within the yarns, which yarns are generally obtained by assembling the filaments directly during their manufacture, for example, and without limitation, according to the methods described in documents EP-A-0 599 695 or EP-A-0 616 055. The filaments of the two types of material are intimately mixed, preferably homogeneously in the wire.

  From such co-mingled filaments, co-mixed filament sections which have both good properties for carding and a satisfactory composition for subsequent assembly, gluing, and applications requiring a low proportion of thermoplastic material.

  Alternatively, a suitable homogeneous blend of sections of glass filaments and thermoplastic filament lengths can also be prepared by cutting separate filaments of glass and thermoplastic material, and providing sufficient mixing, ie in which is substantially alternating sections of glass filaments and sections of thermoplastic filaments.

  Preferably, in the mixture, the sections of glass filaments are present in a proportion of between approximately 50 and 80% by weight, and the sections of thermoplastic filaments are present in a proportion of between approximately 50 and 20% by weight.

  In the mixture, the sections of glass filaments may have a diameter of between about 10 and 24 microns, and the sections of thermoplastic filaments may have a diameter of between about 10 and 30 microns. These dimensions are compatible with the economic requirements of an industrial production, with a glass filament diameter sufficiently high for economical production, the presence of thermoplastic filaments ensuring the efficiency of the carding operation for the constitution of the veil .

  To ensure carding with traditional cards, it is advantageous that in the mixture, the sections of filaments have a length of between 30 mm and 60 mm.

  The thermoplastic material may be selected from the group consisting of polyester, polyolefins, polyamides, polyacrylonitriles, polyethylene terephthalate, polybutylene terephthalate.

  In the web, the sections of filaments may advantageously be partially bonded to each other by the thermoplastic material. This bonding is provided by a static or dynamic heating after carding.

  According to a first application, the veil can be continuous and monolayer. In this case, the fibers are oriented substantially in the longitudinal direction, providing a reinforcement structure with longitudinal preferential action.

  Alternatively, if a greater thickness is desired, the web may be zigzag-coated, and the adjacent web sections may be adhered to each other by the thermoplastic material. A veil is thus produced, the fibers of which are preferably oriented in oblique directions, constituting a transversely acting reinforcing structure without having to weave or sew transverse fibers.

  The fiber fleece according to the invention finds important applications in the production of composite reinforcing structures.

  A first possibility is to stick the veil by the thermoplastic material on a support based on reinforcing fibers such as glass fibers, carbon fibers, aramid fibers.

  For example, the support may be a sheet of parallel continuous son, oriented longitudinally or optionally oriented transversely.

  In both cases, the web can be glued to one face of the web of continuous son.

  In another example, the successive continuous son of the web are glued alternately on both sides of the web.

  Another possibility consists in adhering the veil to a support in the form of a grid with oriented fibers in at least two directions.

  A thicker product can be produced by providing a stack of sheets of continuous son of glass, carbon or aramid, having a web inserted between each pair of successive layers and sticking to each other said successive layers.

  Alternatively or in addition, it is possible for several layers of sail to be needled by jets of water and possibly glued to a support based on reinforcing fibers such as glass fibers, carbon fibers or aramid fibers. .

  It is also possible to add to the mixture sections of filaments made of another material such as linen, hemp, sisal, jute, wool.

  According to an advantageous embodiment, the mixture may also contain crimped monofilaments of thermoplastic material whose melting temperature is higher than that of the thermoplastic material of the filament sections, constituting a thick and elastic assembly.

  It is also possible to add to the composite structure thus formed at least one nonwoven web of glass, of polyester, which can be glued to the coherent web of fibers.

  According to another aspect, the invention provides a method for producing the coherent web reinforcement product consisting of a mixture of oriented filament sections containing sections of glass filaments; the process comprises the steps of: a) preparing a homogeneous mixture of sections of glass filaments and thermoplastic filament lengths of length appropriate for a carding operation, the sections of glass filaments being homogeneously mixed with sections of thermoplastic filaments, b) treating this mixture of filament sections in a card to produce a coherent web of oriented filament sections.

  The homogeneous mixture of sections of filaments can advantageously be obtained by cutting wires consisting of glass filaments co-mixed with thermoplastic filaments.

  Alternatively, blending may result from cutting glass filaments and thermoplastic filaments which are then blended until proper homogeneity is achieved.

  In that the card longitudinally orients the sections of glass filaments, a veil with a longitudinal preferential reinforcing action is produced.

  According to another possibility, the method may comprise an additional step c) according to which, at the exit of the card, the veil passes into a lapper which folds it into a zigzag. This produces a web having transverse reinforcing properties, which are a function of the angle at which the sail sections are folded.

  Then, according to a step d), one can optionally apply the veil on a support based on fibers.

  And there is provided a subsequent step e) gluing, during which: the constituents of the reinforcing product are heated to a temperature sufficient to give the thermoplastic material properties of glue or binder, the constituents are pressed against each other the others, 44I0DEP 2862316 6 - the assembly is cooled, and the pressure is released to release the reinforcing product.

  Other objects, features and advantages of the present invention will emerge from the following description of particular embodiments, made with reference to the appended figures, in which: FIG. 1 is a diagrammatic perspective view illustrating a sail structure according to a first embodiment of the present invention; - Figure 2 illustrates in perspective a sail structure according to a second embodiment of the present invention; Io - Figure 3 is a cross section of a sail reinforcement structure and longitudinal fiber web according to the invention; - Figure 4 is a cross section of another structure of reinforcing sail and longitudinal fibers according to the invention; - Figure 5 is a cross section of another structure of reinforcing sail, longitudinal fibers and additional layer according to the invention; - Figure 6 schematically illustrates the cross section of a glass filament composite yarn and thermoplastic filaments that can be used according to the invention; FIG. 7 is a schematic view of a reinforcement product manufacturing facility according to one embodiment of the invention; FIG. 8 is a schematic perspective view partially illustrating the reinforcement product manufacturing facility of FIG. 7; FIG. 9 is a perspective view partially illustrating the installation of reinforcement products of FIG. 7, according to another embodiment; - Figure 10 schematically illustrates, in cross section, another reinforcement structure according to the invention to stack of several sheets of continuous son glued to each other by webs; - Figure 11 illustrates schematically in cross section, a thick web according to the invention, based on glass fibers and plastic fibers including crimped monofilaments of thermoplastic material with higher melting temperature; and FIG. 12 illustrates in cross-section a reinforcement product according to another embodiment, comprising several layers of sail needle-punched by water jets and glued to a support.

  Referring first to Figure 7, which schematically illustrates a reinforcement product manufacturing facility according to one embodiment of the invention.

  44I0DEP 2862316 7 This installation comprises first a supply of wire 1, containing a wire 2 formed of glass filaments co-mixed with filaments of a thermoplastic material. A possible structure of such a composite yarn is shown in cross-section in FIG. 6, in which the glass filaments 3 shown in dark and the thermoplastic filaments 4 shown in the clear are distinguished. It can be seen that the distribution of the glass filaments 3 and the thermoplastic filaments 4 is relatively homogeneous in the cross section of the wire 2.

  In FIG. 7, the yarn store 1 is, for example, a bobbin from which the yarn 2 is unwound to bring it to a cutting device 5 which delivers the yarn in sections of appropriate length so that the fibers can then be carded. The cutting length may advantageously be between about 30 mm and about 60 mm, although different lengths may be chosen depending on the structure of the card which is then used.

  The cut fibers 6, or sections of filaments, coming out of the cutting device 5 are collected in a fiber reserve 7, which then feeds them appropriately into a card 8.

  Can be used a card 8 such as those traditionally used in the textile industry, comprising a rotating cylinder equipped with teeth or needles which rotate in front of workers to drive the sections of filaments by painting them, thus producing a veil 9 continuous and thin in which the sections of filaments 9a are preferably oriented in the longitudinal direction 10 of the web 9.

  Referring to Figure 1, which illustrates in perspective on a larger scale the structure of the web 9, formed of sections of filaments 9a carded preferably oriented in the longitudinal direction.

  In the embodiment of Figure 7, the web 9 is then treated by a lapper 11 which performs a cross-folding. At the exit of the lapper 11, a lapped sail 12 is collected, the structure of which is more clearly illustrated in FIG. 2: by successive folds crossed in a zigzag fashion, a continuous strip is produced which runs in the longitudinal direction 13, formed of a succession of sail section such as adjacent sections 12a and 12b, which are oriented transversely obliquely with respect to the longitudinal direction 13. Thus, the section 12a makes with the longitudinal direction 13 an angle A, while the section 12b makes with the same longitudinal direction 13 an angle B. The angles A and B may be equal and opposite, and are less than 90 and greater than 45. Depending on the angle chosen, it performs a more or less complete overlap successive sections 4470DEP 2862316 8 12a and 12b on each other, which adjusts to some extent the thickness of the web 12 thus obtained.

  In the embodiment illustrated in FIG. 7, the fleece veil 12 is then treated by an assembly device 14 which glues together the coated veil 12 with a support 15 based on reinforcing fibers such as glass fibers, fibers of carbon, aramid fibers. There is illustrated a support 15 consisting of a web of parallel fiber locks. For example, glass roving wicks of 160 Tex to 4800 Tex, or glass yarns of 34 Tex to 544 Tex can be advantageously used.

  The assembly device 14 provides heating of the constituents at a temperature sufficient to give the thermoplastic material of the fiber web glue or binder properties, which presses the components against each other. The temperature is advantageously chosen only slightly lower than the melting temperature of the thermoplastic material in question. For example, for polyethylene, one will choose about 190 C - 200 C.

  The constituents can then be allowed to cool in the ambient air.

  Preferably, downstream of the assembly device, a cooling device 16 is provided which cold presses the constituents between two or more rollers to cool them and to set the thermoplastic material.

  At the outlet of the assembly device 14 or the cooling device 16, the reinforcing product 17 is collected, either in a continuous strip which can be packaged in coils, or in cut plates.

  An example of an assembly device 14 is illustrated schematically in FIG. 8. In this case, the assembly device 14 processes a lapped web 12 coming out of the lapper 11. The assembly device 14 comprises in particular two pressing means 14a and 14b in opposition to each other, between which is passed both the coated web 12 and a support 15 from a support reserve 18. In the embodiment illustrated, the support 15 is a sheet of fiber locks parallel, which may be carbon, aramid or other. Alternatively, the support 15 may be a grid of fibers oriented in at least two directions, preformed and conditioned in the support reserve 18. The pressing means 14a and 14b provide both the plating of the coated web 12 and the support 15. one over the other, and maintaining a satisfactory pressure. They can also be heated to ensure the heating of the assembly to a temperature ensuring sufficient softening or a temporary melting of the thermoplastic material contained in the composite fibers constituting the fleece lined 12. Alternatively, the heating may be provided by hot sources such as infrared radiation sources upstream of the rollers, and the rollers 14a and 14b can squeeze the constituents without heating them.

  At the outlet of the assembly device 14, by the effect of the sufficient melting or softening of the thermoplastic material, then by the effect of the cooling which freezes the thermoplastic material, the coated veil 12 is glued to the support 15, the composite fibers of the web 12 are partially glued to each other, and adjacent sections such as sections 12a and 12b of the web 12 are also glued to each other.

  FIG. 3 illustrates, in cross-section, the structure of the reinforcement product obtainable using such an assembly device 14 and a monolayer support 15, in an application in which the assembly device 14 processes a web 9 which was not coated. The web 9, forming the upper layer, is distinguished and the support 15 forming the lower layer is distinguished and constituted by a sheet of longitudinal fibers such as the fiber 15d.

  FIG. 9 illustrates a variant of the assembly device 14, in an installation in which the assembly device 14 directly processes a web 9 coming out of the card 8.

  In this variant, the support 15 is formed of two partial supports, namely a lower support 15a coming from a lower support reserve 18a, and an upper support 15b coming from a higher support reserve 18b. The lower support 15a is pressed under the lower face of the web 9, while the upper support 15b is pressed onto the upper face of the web 9, the assembly being compressed by the pressing means 14a and 14b. At the output, a reinforcing product is obtained as illustrated in the cross-section in FIG. 4, in which the web 9, which takes on a wavy shape, is distinguished, the fibers of the lower support 15 a lying under the underside of the veil 9 , the fibers of the upper support 15b being on the upper face of the web 9. In the case of supports 15a and 15b in the form of webs of continuous son, the successive fiber locks, when considering the reinforcing product in section transverse, are glued alternately on both sides of the veil 9.

  Naturally, this provision also applies to a napped veil 12.

  In all cases, the pressing means 14a and 14b which provide the compression and heating of the materials can be associated, downstream, with cooling means which ensure a rapid setting of the thermoplastic material.

  For clarity, in Figures 8 and 9, the pressing means 14a and 14b have been schematically illustrated by rollers. In reality, it will be possible advantageously to use pressure pads, for example as described in US Pat. No. 4,997,507. Two opposite pressure pads can provide upstream heating and compression in the assembly device 14, two other pressure pads opposite providing downstream cooling with pressure maintenance in the cooling device 16.

  In the embodiment illustrated in FIG. 5, the reinforcement product structure illustrated in FIG. 3 is found, with a carded web 9 and a lower reinforcement 15, with, in addition, at least one nonwoven glass veil 19, polyester glued to the carded veil 9.

  Referring again to the installation illustrated in FIG. 7, it will be understood that this installation can be simplified in the case where it is desired to produce reinforcing products as illustrated in FIGS. 3, 4 or 5. Indeed, in this case, we do not use a lapper 11.

  Also, the installation of FIG. 7 as illustrated uses cut fibers 6 coming solely from the yarn store 1 containing a composite yarn 2 comprising co-mixed filaments of glass and thermoplastic material.

  Alternatively, the yarn store 1 can separately dispense continuous glass filaments and continuous filaments of thermoplastic material, which the cutter 5 intersects. The sections of filaments are mixed in the cutting device 5 and / or the fiber reserve 7 to produce a homogeneous mixture in which the glass and the thermoplastic material are found in generally constant proportions.

  In addition, sections of filaments of different types, for example sections of filaments of flax, hemp, sisal, jute and wool, can also be added to the fiber reserve 7 by mixing them together. These fibers are then found in the veil 9.

  The thermoplastic material used will be chosen according to the envisaged uses of the reinforcement product. For example, thermoplastic materials compatible with other materials in which the reinforcing product is to be incorporated will be used. Depending on the uses, the thermoplastic material may be selected from the group comprising polyester, polyolefins including polypropylene, polyamides, polyacrylonitriles, polyethylene terephthalate, polybutylene terephthalate. Polyethylene or polypropylene may be of interest because of their low melting temperature.

  The support 15 based on reinforcing fibers may consist of glass fibers, carbon fibers, aramid fibers. It may be advantageous to use layers of strands of parallel fibers.

  In the yarn 2 used to make the web 9 by carding, it will advantageously be provided that the glass filaments will have a diameter of between 10 and 24 μm, the thermoplastic filaments having a diameter of between 10 and 30 μm, the glass filaments being present in a proportion of between 50 and 80% by weight, and the thermoplastic filaments being present in a proportion of between 50 and 20% by weight approximately.

  In the support 15, the fiber locks may be longitudinal, or may be oriented transversely or obliquely, depending on the desired mechanical properties of the reinforcing product.

  Circular pieces in the form of a disc can also be produced by depositing on the veil a disc-shaped support consisting for example of wicks of spirally wound threads.

  The same technology can be used to produce parts having other contours, for example rectangular, triangular, polygonal, flat surface or left contours. In the embodiment illustrated in FIG. 10, the product of

  reinforcement according to the invention comprises a stack of several plies of continuous son 15a, 15b, 15c and 15d, each of which may be glass, carbon or aramids. These materials may be identical or different for each sheet, depending on the overall properties sought for the reinforcing product.

  A web 9a, 9b or 9c is inserted between each pair of successive webs, respectively 15a and 15b, 15b and 15c, 15c and 15d. The sails 9a, 9b and 9c stick to each other the successive layers.

  In the embodiment illustrated in FIG. 11, in order to produce the fleece according to the invention, the starting point is a mixture which, in addition to the sections of glass filaments and the sections of thermoplastic filaments, also contains monofilaments crimped from thermoplastic material whose melting temperature is higher than that of the thermoplastic material of the filament sections. Thus, in the web 9 thus formed, there are, for example, sections of filaments 3 of glass fibers co-mingled with the thermoplastic filament sections 4, with, in addition, the crimped monofilaments 20 made of thermoplastic material having a higher melting temperature. .

  For example, the thermoplastic filament stretches 4 may be made of polyethylene, while the thermoplastic crimped monofilaments may be made of polypropylene having previously received a texturizing treatment, for example by stuffing, giving them a permanent crimp. After forming the haze, the heat treatments melt the polyethylene forming the thermoplastic filament sections 4 to ensure the bonding, but the temperature remains below the melting temperature of polypropylene monobrins, which do not melt and retain their elastic properties conferred by texturing. The assembly thus retains an elasticity given by the crimped monofilaments made of thermoplastic material with a high melting temperature, and can be calendered to fix the thickness thereof. This produces a thick and elastic material, without having to resort to a sewing knitting procedure.

  In the embodiment of FIG. 12, several layers of sail 9a, 9b and 9c are provided which are needled by water jets and possibly bonded to a support 15 based on reinforcing fibers such as glass fibers, carbon fibers, aramid fibers. Needling by water jet consists in pushing sail fibers in the direction of the thickness, and is shown diagrammatically in the figure the filament sections 21, 22 and 23, for example, which connect two successive layers of sail 9a, 9b or 9c.

  This produces a thick web, which can be used for example as a sealing reinforcement.

  An example of reinforcing product is the following: a sheet of continuous glass yarn 720 glm2, composed of six son centimeter of a wick (roving) of 1200 Tex, laminated on a cardboard veil of 40 g / m2 ( two layers), whose filament sections are oriented mainly obliquely after passing through a lapper, which allows, with a mixture by weight of 75% of glass and 25% of thermoplastic material, to obtain a component reinforcement transverse (weft), the final weight being 760 g / m2. Such a reinforcing product can be used in the manufacture of skis.

  The presence of sewing knitting yarns, which are present in the present reinforcements of non-directional roving sheets and glass sheets, is avoided. These sewing knitting yarns constitute surface irregularities which remain apparent after manufacture of the ski, and adversely affect the appearance of the product.

  The present invention is not limited to the embodiments which have been explicitly described, but it includes the various variants and generalizations thereof within the scope of the claims below.

44I0DEP 2862316 13

Claims (18)

  Reinforcing product comprising a coherent web (9) consisting of a mixture of oriented filament sections containing sections of glass filaments (3), characterized in that said sections of oriented filaments contain a homogeneous mixture of sections of filament fibers. glass and sections of thermoplastic filaments (4).   Reinforcing product according to claim 1, characterized in that the web (9) has a weight of about 15 g / m 2 to about 40 g / m 2, preferably about 20 g / m 2.   Reinforcing product according to one of claims 1 or 2, characterized in that, in the mixture, the sections of glass filaments (3) are present in a proportion of between approximately 50 and 80% by weight, and the sections of thermoplastic filaments (4) are present in a proportion of between 50 and 20% by weight approximately.   Reinforcing product according to one of Claims 1 to 3, characterized in that in the mixture the sections of glass filaments (3) have a diameter of approximately 10 to 24 μm, and the sections of filaments of thermoplastic material (4) have a diameter of between 10 and 30 pm approximately.   Reinforcing product according to one of Claims 1 to 4, characterized in that in the mixture the filament sections (3, 4) have a length of about 30 mm to 60 mm.   6 reinforcement product according to any one of claims 1 to 5, characterized in that the thermoplastic material is selected from the group comprising polyester, polyolefins, polyamides, polyacrylonitriles, polyethylene terephthalate, polybutylene terephthalate.   Reinforcing product according to one of Claims 1 to 6, characterized in that, in the web (9), the filament sections are partially bonded to one another by the thermoplastic material.   8 reinforcing product according to any one of claims 1 to 7, characterized in that the web (9) is continuous and monolayer.   9 reinforcement product according to any one of claims 1 to 7, characterized in that the web (12) is zigzag-coated, and the adjacent sections (12a, 12b) of sail are glued to each other by the thermoplastic material .     Reinforcing product according to one of Claims 1 to 9, characterized in that the web (9, 12) is adhered by the thermoplastic 4410DEP 2862316 14 to a support (15) based on reinforcing fibers such as fibers of glass, carbon fibers, aramid fibers.   Reinforcement product according to Claim 10, characterized in that the support (15) is a sheet of parallel continuous threads.   Reinforcing product according to Claim 11, characterized in that the web (9, 12) is adhered to one face of the web (15) of continuous filaments.   13 Reinforcing product according to claim 11, characterized in that the successive continuous son (15a, 15b) are glued alternately on either side of the web (9, 12).   Reinforcing product according to claim 10, characterized in that the support (15) is a grid with oriented fibers in at least two directions.     Reinforcing product according to any one of claims 1 to 14, characterized in that the mixture further contains sections of filaments of another material such as linen, hemp, sisal, jute, wool.   Reinforcing product according to any one of Claims 1 to 14, characterized in that the mixture also contains crimped monofilaments of thermoplastic material whose melting temperature is higher than that of the thermoplastic material of the filament sections constituting a thick and elastic set.   17 Reinforcing product according to any one of claims 1 to 16, characterized in that it further comprises at least one web (19) nonwoven glass, polyester, bonded to the coherent web (9, 12).   Reinforcing product according to any one of claims 1 to 9, characterized in that it comprises a stack of sheets of continuous son (15a 15d) of glass, carbon or aramid, having a web (9a 9c) inserted between each pair of successive layers and sticking to each other said successive layers (15a 15d).   19 - reinforcing product according to any one of claims 1 to 9, characterized in that several layers of sail are needled by jets of water and optionally glued to a support (15) based on reinforcing fibers such as fibers of glass, carbon fibers, aramid fibers.     A process for producing a coherent web reinforcing product (9, 12) consisting of a mixture of oriented filament sections containing sections of glass filaments, comprising the steps of: a) preparing a homogeneous mixture of sections of glass filaments glass and lengths of thermoplastic filaments, of suitable length for a carding operation, the sections of glass filaments being homogeneously mixed with filaments of thermoplastic material, b) treating this mixture of filament sections in a card (8) for producing a coherent web of oriented filament sections.   Production method according to claim 20, characterized in that: c) at the card outlet (8), the web (9) passes through a lapper (11) which folds it in a zigzag fashion.   Production method according to one of claims 20 or 21, characterized in that it comprises the step of: d) the web (9, 12) is applied to a support (15) based on fibers.   Production method according to any one of Claims 20 to 22, characterized in that it comprises a subsequent step e) of bonding during which: the constituents of the reinforcing product are heated to a temperature sufficient to give to the thermoplastic material glue or binder properties, the components are pressed against each other, the whole is cooled, and the pressure is released to release the reinforcing product.