METHOD OF FABRICATING A TEXTILE STRUCTURE OF VARYING THICKNESS

Abstract

A method of fabricating a textile structure of varying thickness, the method including weaving a fiber texture in the form of a strip and winding the fiber texture under tension onto a mandrel, the fiber texture including a greater-thickness portion presenting greater thickness. During winding of the fiber texture on the mandrel, an interleaving element is interposed between adjacent turns of the fiber texture on the mandrel, the interleaving element extending in the width direction of the fiber texture over a portion of the texture that lies outside the greater-thickness portion. The interleaving element presents, over the portion of the texture situated outside the greater-thickness portion, a thickness that corresponds at least to the difference between the thickness of the greater-thickness portion and the thickness of the portion of the texture situated outside the greater-thickness portion.

Claims

1. A method of fabricating a textile structure of varying thickness, the method comprising using a loom to weave a fiber texture in the form of a strip extending lengthwise along a longitudinal axis and widthwise along an axis perpendicular to the longitudinal axis, and winding the fiber texture under tension at the outlet from the loom onto a mandrel, the fiber texture including a greater-thickness portion presenting greater thickness, wherein, during winding of the fiber texture on the mandrel, an interleaving element is interposed between adjacent turns of the fiber texture on the mandrel, the interleaving element extending in the width direction of the fiber texture over a portion of the texture that lies outside said greater-thickness portion and, over the portion of the texture situated outside the greater-thickness portion, wherein the interleaving element presents a thickness that corresponds at least approximately to a difference between a thickness of said greater-thickness portion and a thickness of the portion of the texture situated outside said greater-thickness portion, and wherein the interleaving element is made of a material that is deformable.

2. The method according to claim 1, wherein the deformable material is constituted by an elastomer.

3. A textile structure of varying thickness comprising a fiber texture wound on a mandrel and including a greater-thickness portion presenting greater thickness, wherein an interleaving element is interposed between adjacent turns of the fiber texture on the mandrel, the interleaving element extending in a width direction of the fiber texture over a portion of the texture that lies outside said greater-thickness portion and, over the portion of the texture situated outside the greater-thickness portion, wherein the interleaving element presents a thickness that corresponds at least to a difference between a thickness of said greater-thickness portion and a thickness of the portion of the texture situated outside said greater-thickness portion, and wherein the interleaving element is made of a material that is deformable and waterproof.

4. The textile structure according to claim 3, wherein the deformable and waterproof material is constituted by an elastomer.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0009] Other characteristics and benefits of the invention appear from the following description of particular implementations of the invention given as non-limiting examples, with reference to the accompanying drawings, in which:

[0010] FIG. 1 is a diagrammatic perspective view showing a fiber texture of varying thickness being wound onto a storage mandrel in the prior art;

[0011] FIG. 2 is a diagrammatic section view showing the textile structure obtained after winding the FIG. 1 fiber texture;

[0012] FIG. 3 is a diagrammatic perspective view of a loom showing the weaving of a fiber texture of varying thickness;

[0013] FIG. 4 is a diagrammatic perspective view showing the fiber texture leaving the FIG. 3 loom and being wound onto a storage mandrel in accordance with an implementation of the method of the invention; and

[0014] FIG. 5 is a diagrammatic section view showing a textile structure obtained after winding the fiber texture in the manner shown in FIG. 4.

DETAILED DESCRIPTION

[0015] The invention applies in general to fabricating textile structures obtained from woven fiber textures having at least one portion of greater thickness, which fiber textures are made by three-dimensional weaving between a plurality of layers of warp yarns or strands and a plurality of layers of weft yarns or strands, and they are then wound onto a mandrel at the outlet from a loom.

[0016] As shown in FIG. 3, a fiber texture 100 is made in conventional manner by weaving using a Jacquard type loom 10 having arranged thereon a bundle of warp yarns or strands 20 in a plurality of layers, the warp yarns being interlinked by weft yarns or strands 30. The fiber texture is made by three-dimensional weaving. The term three-dimensional or 3D weaving is used herein to mean a weaving technique whereby at least some of the weft yarns interlink warp yarns occupying a plurality of layers of warp yarns, or vice versa. An example of three-dimensional weaving is weaving with a so-called interlock weave. The term interlock is used herein of weaving to designate a weave in which each layer of warp yarns interlink a plurality of layers of weft yarns with all of the yarns in a given weft column presenting the same movement in the weave plane.

[0017] As shown in FIGS. 3 and 4, the fiber texture 100 is in the form of a strip that extends lengthwise in a direction X corresponding to the travel direction of the warp yarns or strands 20 and widthwise or transversely in a direction Y corresponding to the direction of the weft yarns or strands 30.

[0018] As shown in FIG. 4, the fiber texture 100 has a greater-thickness portion 101 of thickness that is different from that of a portion 102 of the texture that lies outside the portion 101. The greater-thickness portion 101 is obtained by using warp yarns or strands in this portion that are of greater size or weight than those in the portion 102. On leaving the loom 10, the fiber texture 100 is wound on a storage mandrel 50. The fiber texture 100 is wound onto the mandrel 50 under tension. For this purpose, the end 103 of the fiber texture is fastened to the mandrel 50, which is itself coupled to a rotary drive system (not shown in FIG. 4). Such winding under tension makes it possible firstly to apply low takeup tension on the warp yarns or strands for weaving, and secondly to apply high winding tension as is, needed for debulking the preform. The tension exerted by the mandrel 50 on the fiber texture 100 is, in an embodiment, constant throughout its weaving.

[0019] In accordance with an embodiment of the invention, and as shown in FIG. 4, an interleaving element, in this example a layer of elastomer 60 such as neoprene, for example, is placed on the fiber texture 100 from the beginning of winding the texture portion 102 that lies outside the portion 101. The elastomer layer 60 is in the form of a strip of width 60 that extends in the Y direction corresponding to the axis of the mandrel 50 and that corresponds to the width 102 over which the portion 102 extends. The length of the elastomer layer that extends in the direction X is determined as a function of the length of the fiber texture 100 that is to be wound onto the mandrel 50. The elastomer layer 60 presents a thickness e60 that corresponds to the difference between the thickness e101 of the greater-thickness portion 101 and the thickness e102 of the portion 102 of the texture that lies outside the portion 101, so as to fill in the thickness variation between the portions 101 and 102 during winding of the fiber texture.

[0020] FIG. 5 shows a textile structure 160 that results from winding a plurality of turns (six turns in the example shown) of the fiber texture 100 on the mandrel 50 with the elastomer layer 60 being interposed between adjacent turns of the texture 100 as described above. It can be seen that by interposing the elastomer layer 60, the warp yarns or strands of a same layer and present in each turn of the winding of the fiber texture 100 are all approximately at the radial distance from the rotational axis 50a of the mandrel 50. More precisely, a warp yarn or strand 30a situated in the greater-thickness portion 101 is located in each winding turn at the same level as a warp yarn or strand 30b situated in the portion 102 of the texture lying outside the portion 101. Consequently, the ratio L30a/L30b of the length L30a of the warp yarns or strands 30a situated in the greater-thickness portion 101 over the length L30b of the warp yarns or strands 30b situated in the portion 102 remains approximately constant throughout the weaving and the winding of the fiber texture 100.

[0021] The use of an elastomer layer as an interleaving element is beneficial in that it is easily deformable around the radius of the mandrel while presenting good resistance to compression in the thickness direction. The elastomer layer is easily manufactured to have a variety of shapes so as to match the shape and/or the varying thickness of the fiber texture.

[0022] The interleaving element used in the method of the invention for compensating the thickness difference in the fiber texture while it is being wound on the storage mandrel may be made using elements other than a layer of elastomer. In general manner, any element presenting at least the following properties can be used:

[0023] capacity for deforming to match the radius of the storage mandrel;

[0024] poorly or completely incompressible under the tensions applied in weaving; and

[0025] no risk of damaging fibers of the texture.