Classifications

• • D—TEXTILES; PAPER
  • D03—WEAVING
  • D03D—WOVEN FABRICS; METHODS OF WEAVING; LOOMS
  • D03D37/00—Circular looms
• • D—TEXTILES; PAPER
  • D03—WEAVING
  • D03D—WOVEN FABRICS; METHODS OF WEAVING; LOOMS
  • D03D13/00—Woven fabrics characterised by the special disposition of the warp or weft threads, e.g. with curved weft threads, with discontinuous warp threads, with diagonal warp or weft
  • D03D13/002—With diagonal warps or wefts
• • D—TEXTILES; PAPER
  • D10—INDEXING SCHEME ASSOCIATED WITH SUBLASSES OF SECTION D, RELATING TO TEXTILES
  • D10B—INDEXING SCHEME ASSOCIATED WITH SUBLASSES OF SECTION D, RELATING TO TEXTILES
  • D10B2505/00—Industrial
  • D10B2505/02—Reinforcing materials; Prepregs

Definitions

• the invention relates to the field of technical textiles, and more specifically to textile reinforcements used as reinforcing elements.
• the invention also relates to a machine for manufacturing this type of fabric.
• An object of the invention is to reduce this angle, or even to cancel it, so that the reinforcement optimally increases the resistance of the element to be reinforced.
• Multi-axial textiles are also known, produced on wefting machines, and comprising sets of threads arranged with orientations that are not perpendicular to each other. These sets of wires are then joined to each other by sewing.
• These textiles have drawbacks, in particular for reinforcement applications.
• sub-assemblies of threads are assembled according to the stitching pitch, which harms the homogeneity of the textile.
• the seam groups the threads together by compacting them in sub-assemblies, which reduces the wettability of the textile, which is known to be a particularly important factor in making coated reinforcements.
• the invention therefore relates to a textile fabric, which is capable of being integrated into a reinforcing reinforcement.
• This fabric is formed from the association by heat bonding or the like of at least two layers of superimposed threads, to form a structure comparable to a grid.
• this fabric is characterized in that it comprises in our weft very strong yarns in comparison with the warp yarns.
• very high titer it is meant that most of the surface mass of the fabric, that is to say at least 80%, is constituted by the web of weft threads.
• these weft threads therefore have a non-perpendicular inclination relative to the warp threads.
• the weft threads are not strictly perpendicular to the main direction of the fabric, so that during the winding of the fabric on a piece to be reinforced, these weft threads are found parallel to the main direction of the part to be reinforced, thus compensating for the effect of the winding pitch.
• weft threads are chosen from the families of high tenacity threads, such as glass threads, aramid fibers and carbon fibers.
• weft threads are flattened and contiguous, to form a continuous surface, while the warp threads are on the contrary spaced and regularly distributed, so as to disturb the arrangement of the weft threads as much as possible.
• the warp threads can be coated with a th material . ermofusiblei allowing their attachment to the weft son, and therefore the blocking of the structure.
• the angle formed by the weft threads and the warp threads can be variable depending on the application and the winding pitch. In practice, it is generally between 60 and 89 °, and preferably close to 80 °.
• the fabric can take different forms.
• it can be in the form of a tubular structure, in which the weft threads form helices, when the tubular structure is formed into a cylinder.
• This cylinder can be flattened so as to have layers whose weft threads are oriented on either side of the perpendicular to the warp threads.
• This cylinder can also be cut along one of its generatrices, so that the fabric is then in the form of a flat ribbon.
• the invention also relates to a machine for producing this type of fabric.
• This machine includes:
• a cylinder receiving on the generatrices of its external face the warp threads coming from these supply means,
• heating means for heat sealing or the like of the weft threads on the warp threads • heating means for heat sealing or the like of the weft threads on the warp threads.
• this machine makes it possible to continuously deposit the weft threads, and to generate the inclination of the weft threads relative to the warp threads by the continuous advance of these warp threads along the cylinder.
• the heating means making it possible to heat-bond the weft threads and the warp threads can be formed by a portion of the cylinder, on which the warp and weft threads come into contact.
• the machine may also include means for adjusting the driving speed of the warp threads, as well as the deposition speed of the weft threads, so as to adjust the angulation of the weft threads relative to perpendicular to the warp threads.
• the fabric thus produced at the fall of this machine can either be kept in tubular form, to be integrated into a reinforcement, or even be open on a generator, to then form ribbons in which all the weft threads have a unique orientation. .
• This tape can then be used to wrap different types of mechanical parts, having a section either cylindrical, or even a variable section, such as conical or frustoconical.
• FIG. 1 is a top view of a fabric according to the invention.
• FIG. 2 is a sectional view in the weft direction of FIG. 1.
• FIG. 3 is a top view of a cylindrical piece reinforced by a ribbon based on the fabric illustrated in FIG. 1.
• Figure 4 is a general summary perspective view of a machine for making the fabric according to the invention.
• the invention relates to a textile fabric which can be used inside a reinforcing reinforcement.
• An example of such a fabric is illustrated in Figure 1.
• Such a fabric (1) is assimilated, from a point of view of the structure, with a grid, and it comprises in the warp direction (C) two layers of wires
• the web of warp threads (2) is produced from threads of low strength, in comparison with that of the weft threads (4).
• the fabric comprises two plies of warp threads, one located above (2) and the other below (3) of the weft thread ply (4), but the The invention also covers the variants in which a single ply is used in the chain.
• These two layers are associated by heat-bonding phenomena, for example by using warp threads which are previously coated by annular extrusion, and which, when subjected to a heat source, see their coating pass into a melting state. . It may also be a question of wires produced solely from hot-melt materials.
• the association of the two plies can also implement, in an additional or unique manner, bonding phenomena by the use of hot-melt powder applied to the warp and / or weft threads by electrostatic phenomena.
• the weft threads (4) have an orientation which is not exactly perpendicular to the direction of the warp threads (2), but which forms an angle ⁇ , as illustrated in FIG. 1.
• This angle ⁇ which therefore differs by 90 °, is determined as a function of the geometry of the part to be wrapped, the step of ehrubanning on this part, as well as the width of the ribbon.
• the plies of warp threads (2,3) may prove useful for the plies of warp threads (2,3) to have variable densities, with a maximum situated at the median level of the ribbon.
• a denser zone of warp yarns is therefore formed at the central level of the ribbon, to facilitate the traction of the ribbon when it is placed on the part to be reinforced.
• This effect can also be increased by using a chain of different wires between the central zone and the peripheral zone.
• a fabric has been produced according to FIG. 1 comprising a ply of weft threads, with a surface mass of 400 g / m 2 , made from weft threads (4), of a count of 1200 tex, and comprising 3.33 threads / cm.
• the threads In a chain, the threads
• the central zone can be glass strands of a title of the order of 70 tex, coated with a material based on copolyamide.
• the density of these warp threads is of the order of one thread per centimeter.
• the warp threads (2) can be coated polyester threads, with a titer close to 40 tex, with a density of the order of 2 threads / cm.
• the weft threads (4) form an angle ⁇ of approximately 80 ° with the warp threads (2,3).
• This fabric (1) can, when it is in the form of a ribbon, be wrapped on a piece (10) as illustrated in FIG. 3, so that the weft threads (4) are all parallel to the main direction (11) forming the axis of the part (10).
• the invention also relates to a machine for making this type of fabric, as illustrated in FIG. 4.
• a machine (20) comprises a cylinder associated with means for supplying warp threads, and means for depositing the weft threads.
• the cylinder (21) comprises, in its upper part, two sets (22, 23) of coils (24, 25) of warp threads.
• a first assembly (22) is located outside the cylinder, while the second assembly (23) is located above the interior volume of the cylinder (21).
• These different assemblies (22, 23) comprise different coils distributed circularly, possibly in several rings, as is the case for the interior assembly (23).
• These two assemblies (22,23) supply the cylinder (21) with warp threads, so that these warp threads are deposited on the vertical generatrices of the cylinder (21).
• the machine (20) also comprises, in the upper part, a turntable (27), receiving different bobbins of weft threads (28).
• This tray is equipped with lower part of a set of rods allowing the routing of the weft threads to the upper part (30) of the cylinder (21).
• the weft threads (4) are therefore deposited along the circumferences of the cylinder (21).
• the fabric obtained is pulled down by winding means, so that the warp threads move along the generators. In doing so, the weft threads (4) adopt a helix geometry on the tubular fabric moving on the cylinder.
• the machine comprises, at the median level (33) of the cylinder, a heating zone.
• This heating zone (33) makes it possible to bring the hot-melt coating of the warp threads to the melting temperature.
• the temperature of the heating zone as well as its length is chosen according to the running speed and the materials of the warp threads.
• the cylinder (21) also comprises, in the lower part (36), a cooling zone, allowing the fixing of the weft threads on the warp threads.
• the lower end of the cylinder (21) may have a slightly conical shape, with a narrowing diameter, to allow the escape of the fabric relative to the cylinder.
• the fabric is then conveyed to return means formed by a call cylinder and winding means not shown.
• the tubular fabric obtained by falling from the cylinder is cut to be then opened and wound flat. It is also possible to provide for making several ribbons from the same tubular fabric.
• the tubular fabric can also be returned without having been opened, so as to form a double-layer fabric in which the weft threads are oriented on either side of the perpendicular to the threads. chain, from one layer to another. It is also possible to provide heating for the assembly in order to assemble the two layers. It follows from the above that the textile fabric according to the invention has the important advantage of making it possible to orient the weft yarns of high resistance in the main direction of the object on which the fabric is wound, in a goal to optimize the additional resistance conferred by rarrnature. To obtain a product of constant thickness, it is then possible to eliminate the selvedges by cutting in particular.
• this fabric can also be obtained from high performance threads, and in particular based on aramid or carbon fibers.
• This fabric can also be combined with a veil or a nonwoven having a certain thickness, which can for example play the role of resin reserve when the ribbon is used in impregnation.
• This fabric can be used to form many types of reinforcements, in particular in combination with thermosetting resins, or even by integrating weft threads pre-impregnated with thermoplastic matrices, such as those sold for example by the company VETROTEX, under the Mark
• This reinforcing fabric can in particular be used to wrap many types of mechanical parts requiring high longitudinal strength.

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• Engineering & Computer Science (AREA)
• Textile Engineering (AREA)
• Woven Fabrics (AREA)

Applications Claiming Priority (3)

Publications (1)

Family

ID=32320093

Family Applications (1)

Country Status (4)

Cited By (1)

Families Citing this family (5)

Family Cites Families (5)

• 2002
  • 2002-12-09 FR FR0215510A patent/FR2848227B1/fr not_active Expired - Fee Related
• 2003
  • 2003-12-09 WO PCT/FR2003/003636 patent/WO2004063444A1/fr not_active Application Discontinuation
  • 2003-12-09 EP EP03815095A patent/EP1583857A1/de not_active Withdrawn
  • 2003-12-09 AU AU2003296789A patent/AU2003296789A1/en not_active Abandoned

Non-Patent Citations (1)

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