Method and apparatus for weaving a three-dimensional fabric

Abstract

A method and apparatus for weaving a three-dimensional fabric involves inserting simultaneously a parallel weft yarns into the sheds between multiple warp yarn layers and selectively inserting at least one group of binder yarns between parallel spaced warp yarns. The group of binder yarns are moved relative to the warp yarns between weft insertions. The yarns may be moved between more than two positions relative to the warp yarns during weaving of the fabric so as to insert binder yarns. In one embodiment the binder yarns are moved such that they extend in a direction that is not orthogonal to the warp yarns.

Claims

1. A method for producing a three dimensional woven fabric, the method comprising: providing a plurality of layers of warp yarns under tension, such that there is a top warp yarn layer corresponding to the top of the fabric, a bottom warp yarn layer corresponding to the bottom of the fabric, and at least one warp yarn layer interposed between the top and bottom warp yarn layers, each layer comprising a plurality of parallel spaced yarns, and separating the layers of warp yarns so as to define a shed between each layer; in a weft insertion step, selectively inserting simultaneously a plurality of parallel weft yarns a predetermined distance into the sheds between the warp yarn layers; in a first interweft insertion step, selectively positioning at least one group of binder yarns in a first position between parallel spaced yarns of the warp yarn layers, the first position corresponding to a first warp yarn layer and carrying out a weft insertion step whilst the group of binder yarns is at the first position; and a) in a second interweft insertion step, selectively moving the group of binder yarns relative to the warp yarn layers from the first position to a second position corresponding to a second warp yarn layer; carrying out a weft insertion step whilst the group of binder yarns is at the second position; in a third interweft insertion step, selectively moving the group of binder yarns relative to the warp yarn layers from the second position to a third position corresponding to a third warp yarn layer; and carrying out a weft insertion step whilst the group of binder yarns is at the third position, wherein at least one of the first, second and third position does not correspond to the top warp yarn layer or the bottom warp yarn layer; and/or b) in a single interweft insertion step, selectively moving the group of binder yarns through only some of the warp yarn layers, such that the transit of binder yarns from the top warp yarn layer to the bottom warp yarn layer, or from the bottom warp yarn layer to the top warp yarn layer, does not occur in a single interweft insertion step.

2. A method according to claim 1, wherein the group of binder yarns are moved in such a manner that they extend in the woven fabric progressively through multiple yarn layers, occupying different positions relative to the warp yarn layers between each weft insertion.

3. A method according to claim 1, wherein the group of binder yarns are moved between successive weft insertions such that the binder yarns extend in a direction in the woven fabric that is not orthogonal to the warp yarns.

4. A method according to claim 1, further comprising not moving the group of binder yarns between selected weft insertions such that they extend through the woven fabric in a series of orthogonal steps, without extending across all the layers of the warp yarns between successive insertions of weft yarns, optionally wherein the binder yarns extend in the woven fabric in a first direction that is orthogonal to the warp and weft yarns and, after one or more insertions of the weft yarns, extend in a second direction that is perpendicular to the first direction and parallel to the direction of the warp yarns.

5. A method according to claim 1, wherein there is more than one group of binder yarns, the groups being moved independently.

6. A method according to claim 1, further comprising threading the binder yarns of the at least one group through an eye in a respective heald wire, each heald wire having a plurality of vertically spaced eyes for receipt of yarns from different layers, each heald wire being movable in a direction along its length to move the binder yarns, optionally wherein the group of binder yarns is moveable in unison by a heald frame, the heald wires for the group being supported in the heald frame.

7. A method according to claim 1, further comprising threading the warp yarn through an eye in a respective heald wire, each heald wire having a plurality of vertically spaced eyes for receipt of yarns from different warp yarn layers.

8. A method according to claim 1 wherein at least one group of binder yarns is moved such that the binder yarns pass through substantially all the layers of warp yarn, such that for an integer n of warp yarn layers, the binder yarns move through up to n1 warp yarn layers in a single interweft insertion step.

9. A method according to claim 1 wherein at least one group of binder yarns is moved such that the binder yarns pass through only a selected number of successive layers of warp yarn in a single interweft insertion step.

10. A method according to claim 1, further comprising selectively moving at least one warp yarn layer relative to the other warp yarn layers, when the warp yarn layers are separated, optionally further comprising selectively moving at least one warp yarn layer outwards of the other warp yarn layers so that they are removed from the woven fabric.

11. A loom for weaving a three-dimensional fabric comprising: a shedding assembly comprising at least one support for providing a plurality of separated layers of warp yarns under tension, such that there is a top warp yarn layer corresponding to the top of the fabric, a bottom warp yarn layer corresponding to the bottom of the fabric, and at least one warp yarn layer interposed between the top and bottom warp yarn layer, each layer comprising a plurality of parallel spaced yarns, the separated the layers of warp yarns defining a shed between each layer; a weft picking mechanism for, in a weft insertion step, selectively inserting simultaneously a plurality of parallel weft yarns a predetermined distance into the sheds between the warp yarn layers; a binder yarn positioning mechanism for, in a first interweft insertion step, selectively positioning at least one group of binder yarns in a first position between parallel spaced yarns of the warp yarn layers, the first position corresponding to a first warp yarn layer, and carrying out a second weft insertion step whilst the group of binder yarns is at the first position; the binder yarn positioning mechanism being operable to a) in a second interweft insertion step, prior to a third weft insertion step, selectively move the group of binder yarns relative to the warp yarn layers from the first position to a second position corresponding to a second warp yarn layer; and in a third interweft insertion step, prior to a fourth weft insertion step, selectively move the group of binder yarns relative to the warp yarn layer from the second position to a third position corresponding to a third warp yarn layer, wherein at least one of the first, second and third position does not correspond to the top warp yarn layer or the bottom warp yarn layer; and/or b) in a single interweft insertion step, selectively move the group of binder yarns through only some warp yarn layers such that the transit of binder yarns from the top warp yarn layer to the bottom warp yarn layer, or from the bottom warp yarn layer to the top warp yarn layer, does not occur in a single interweft insertion step.

12. A loom according to claim 11, wherein the binder yarn positioning mechanism comprises a plurality of heald wires having heald eyes for receipt of a respective binder yarn, the heald wires being selectively movable between said more than two positions, and/or wherein the shedding assembly has at least two groups of supports, each for supporting at least one warp yarn layer, optionally wherein the supports are selectively moveable relative to one another, wherein the supports are optionally heald frames, each having at least one heald wire with at least one eye for supporting a warp yarn.

13. A loom according to claim 11, wherein the shedding assembly comprises a plurality of heald wires having vertically spaced heald eyes for receipt of warp yarns, such that the warp yarns are held apart to define sheds between them, optionally wherein there are at least two groups of heald wires in the shedding assembly, a first group for a first group of warp yarn layers and a second group for a second group of warp yarn layers, at least one of the first and second groups being movable relative to the other.

14. A component made from a composite material comprising a substrate in the form of three-dimensional woven fabric produced according to a method of claim 1, the substrate being impregnated with a polymer.

15. A loom according to claim 11, wherein the shedding assembly comprises at least one elongate yarn guide for providing a plurality of separated yarns under tension, the elongate yarn guide comprising first and a second end portions joined by an elongate central body portion, the elongate body portion comprising a plurality of apertures spaced along its longitudinal axis, each aperture being configured to receive at least one yarn under tension, optionally wherein the at least one elongate yarn guide is a heald wire comprising a plurality of apertures spaced along the longitudinal axis of the wire, each aperture configured to receive at least one yarn under tension.

Description

LIST OF FIGURES

(1) Specific embodiments of the present invention will now be described, by way of example only, with reference to the accompanying drawings in which:

(2) FIG. 1 is a perspective view of a weaving loom embodying one aspect of the present invention;

(3) FIG. 1a is a close-up view of the shedding assembly area of the weaving loom of FIG. 1;

(4) FIG. 2 is a side view of the weaving loom of FIG. 1;

(5) FIG. 3 is a front view of the weaving loom of FIG. 1;

(6) FIG. 3a is a schematic representation of part of a heald frame of the weaving loom of FIGS. 1 to 3;

(7) FIGS. 4a-4g are diagrammatic cross-sectioned views of woven fabrics that may be produced on the loom of FIGS. 1 to 3;

(8) FIGS. 5a to 5c are schematic side views of a loom in accordance with the present invention, illustrating how binder yarns are moved between weft insertions to achieve an angle interlocked weave;

(9) FIGS. 6a to 6c are schematic side views of a loom embodying the present invention, illustrating how binder yarns are moved in order to create layer-to-layer weaves;

(10) FIGS. 7a to 7c are schematic side views of a loom embodying the present invention, illustrating how warp stuffer yarns are moved out of the weaving area in order to create ply drops;

(11) FIGS. 8a-8c are schematic side views of a loom embodying the present invention, illustrating the removal of warp stuffer yarns from a middle of the weave to create a weave having two separately bound sections; and

(12) FIGS. 9a-9c are schematic side views of a loom embodying the present invention, illustrating the movement warp stuffer layers to produce a slit or pocket.

(13) FIGS. 10a and 10b are perspective views of exemplary components produced according to a method of the present invention.

(14) FIG. 11 provides a perspective view of an exemplary component formed as an inverted T shape prepared according to a method of the present invention.

DETAILED DESCRIPTION OF FIGURES

(15) FIGS. 1 to 3a of the drawings illustrate the shedding assembly 1 of a loom L that operates to weave a plurality of layers of warp yarns 2, orthogonal weft yarns 3 and at least one additional yarn 4 that may be mutually orthogonal to the warp and weft yarns or may be woven in such a manner that it is off-axis, that is, it extends generally in a direction that is not perpendicular or parallel to either of the warp or weft yarns. The additional yarn typically serves as a binder yarn for binding together the layers of warp and weft.

(16) The loom comprises a framework that provides a supporting structure for the operating parts of the loom. Such framework is not significant to the invention and is therefore not described in detail.

(17) The yarns 2, 3, 4 are supplied under tension from a conventional creel (not shown) to the shedding assembly 1 from where the woven fabric 5 is directed to a take-up area T. The warp yarns 2 are arranged in multiple layers, each layer comprising a horizontal array of parallel yarns and being spaced from the adjacent layer to define a shed 6 (best seen in the side view of FIG. 2) into which a weft yarn 3 may be inserted. The warp yarns 2 pass through a first heald frame 10 that comprises a plurality of parallel heald wires 11, each having eyes 12 for receipt of respective yarns (the eyes are hidden in FIGS. 1 to 3 but an example of part of one heald wire 11 with three heald eyes 12 is shown in FIG. 3a). One warp yarn 2 from each layer passes through each eye 12 in the heald wire 11. The eyes 12 serve to shed the warp yarns 2 so as to allow insertion of the weft yarns 3.

(18) The weft yarns 3 are arranged in a vertical array and are picked simultaneously between the warp yarns 2 in the perpendicular direction. The weft yarns 3 are inserted from one side by a suitable picking mechanism. In this particular embodiment the picking mechanism comprises a rapier 13, which is of known construction in the industry and is not therefore described any further.

(19) As is convention in a loom of this kind the weft yarns 3 are beat-up by a reed 14 that is ordinarily disposed at a location between the first heald frame 10 and the rapier 13 but is movable along the weave direction to push the newly inserted weft yarn securely against the fell of the fabric 5. The first heald frame 10 generally remains in a fixed location as the position of the warp yarns 2 does not vary. However, in some embodiments it may be movable, as will be described below.

(20) One or more additional heald frames 15 are located in parallel to the first heald frame 10 and are designed to support the insertion of one or more additional binder yarns 4. The binder yarns 4 extend between the warp yarns 2 and in the same general direction. Each of the additional heald frames 15 is supported so that it is movable in the vertical direction, perpendicular to both the warp and weft yarns 2, 3. The movement of the frame is effected by a servo-controlled actuator such as a stepper motor (not shown) so that it may be located in one of many vertical positions. The control of the actuator may be such that the frames 15 are moved between a discrete number of positions, the number being greater than two. In one exemplary embodiment the number corresponds to the number of warp layers. In an alternative embodiment the number corresponds to the number of warp layers plus or minus one or two. In a further alternative the control may have such a fine resolution such that the frame may effectively occupy any chosen position.

(21) Each of the additional heald frames 15 supports a group of parallel heald wires 16 spaced apart along the frame 15 and extending in the vertical direction. Each of the wires 16 has one or more eyes 17 through each of which a binder yarn 4 may be threaded (see FIG. 3a). The additional frames 15 are positioned relative to the first heald frame 10 such that the respective groups of heald wires 16 are laterally offset so as to allow the binder yarns 4 pass in the spaces between the warp yarns 2.

(22) In operation the heald frames 15 are selectively moved relative to the warp heald frame 10 so that the binder yarns 4 are moved (via the heald wires 16 and eyes 17) relative to the warp yarns 2 and weft yarns 3. The binder yarns 4 are thus progressively moved through successive layers of the warp yarns 2 in the woven fabric 5.

(23) FIGS. 4a to 4g show cross-sectioned views of different weaves that may be performed using the loom of FIGS. 1 to 3. In FIG. 4a a conventional orthogonal weave comprises warp yarns 2, orthogonal weft yarns 3 (extending in a direction perpendicular to the plane of the paper) and two binder yarns 4a, 4b that extend in a vertical direction orthogonal to both the warp and weft yarn directions. The binder yarns 4a, 4b extend across all the warp yarn layers 2.

(24) FIG. 4b shows a modified orthogonal weave in which three sets of binder yarns 4a, 4b, and 4c extend step-wise through the fabric. Each binder yarn 4a, 4b, 4c has sections that extend vertically past two adjacent weft yarns 2 in a single weft insertion and horizontal sections that extend over two successive weft insertions 3 in a direction that extends parallel to the warp yarn 2. Each binder yarn 4a, 4b, 4c may extend up and down the fabrics in the orientation shown in the figure.

(25) FIG. 4c illustrates an angle interlocked weave in which the binder yarns 4a, 4b pass in a direction that is off-axis. The binder yarns 4a, 4b and pass progressively through all the layers, one layer at a time between weft insertions.

(26) FIG. 4d illustrates a weave in which the binder yarns 4a, 4b, 4c pass between one or two layers of warp stuffer yarns but not across the full thickness of the fabric 5, so as to provide layer-to-layer binding. Again, the binder yarns pass is a direction that is off-axis. It will be appreciated that the respective heald frames 15 may be moved so that the binder yarns 5 are shedded so as to pass through any number of layers. In the particular embodiment shown, the binder yarns pass between two layers of warp yarns 2 only. It will be appreciated that in other embodiments they may pass progressively between more warp yarn layers.

(27) FIG. 4e is a variation of the weave shown in FIG. 4d and shows only two sets of binder yarns 4a, 4b; one binder yarn, 4a, passing in alternate directions between weft insertions 3 through a single yarn layer 2, the other passing progressively through two yarn layers 2 and then reversing its direction back through the same two layers.

(28) FIG. 4f shows an angle interlocked weave corresponding to that of FIG. 4c in which there are only two sets of binder yarns 4a, 4b.

(29) FIG. 4g illustrates an angle interlocked weave without warp stuffers.

(30) FIGS. 5 to 9 are schematic diagrams intended to illustrate the movement of heald frames and therefore binder and/or warp yarns between weft insertions. The heald frames are represented schematically with only part of a single heald wire being depicted for each frame. As a consequence their movement is best understood by reference to the positions of the heald frame eyes. It will be appreciated that the warp and binder yarns extend rearward of their respective heald frames, but this is omitted for the sake of clarity and ease of understanding.

(31) FIGS. 5a-5c show an embodiment of the loom in which the first heald frame 10 for the warp yarns 2 is disposed at the front of other heald frames 15a, 15b, immediately behind the weft picking mechanism. The warp yarns 2 of each layer pass through an eye 12 in each heald wire 11, the eyes 12 of each layer being horizontally aligned.

(32) There are eight layers in all and therefore the warp yarns 2 pass through eight vertically spaced eyes 12 in each heald wire 11. The first heald frame 10 remains fixed in this embodiment.

(33) The weft yarns 3 are shown inserted into the sheds between the warp yarns 2, immediately adjacent to the first heald frame 10, prior to being beaten into the woven fabric by the reed (not shown). Behind the first heald frame 10 (i.e. in the direction away from the fell) there is a plurality of further heald frames 15a, b for the binder yarns 4. In this particular embodiment only two further heald frames are shown for ease of understanding. It will be understood that additional heald frames may be provided. A second heald frame 15a, for example, has multiple heald wires 16a (only one shown in the figure as the others are hidden behind) arranged across its width, each heald wire 16a having three vertically spaced eyes 17a for supporting a group of three binder yarns 4 as they are moved through the warp layers 2 in an off-axis direction. It can be seen in the woven fabric 5 that the binder yarns 4a progress through the fabric layers gradually by virtue of incremental movement of the second heald frame 15a in a vertical direction, each incremental movement occurring between weft insertions. Similarly a second group of three binder yarns 4b progresses in the opposite direction, their movement being controlled by the movement of heald frame 15b, which is immediately behind heald frame 15a. Heald frame 15b has heald eyes 17b supported by heald wires 16b. The incremental movement of the heald frames 15a, 15b, and therefore the binder yarns, can be seen by comparing the positions of the heald frame eyes in each of FIGS. 5a-5c.

(34) FIGS. 5a, 5b and 5c show, in a chronological sequence, the weaving process. Between each of the temporal snapshots represented by the figures, the weft yarns 3 shown in the sheds between the warp yarns 2 are beaten up by the reed (not shown) into the woven fabric shown on the right. A comparison of FIGS. 5a and 5b shows that heald frame 15a has moved vertically down one increment from the position shown in FIG. 5a to that shown in FIG. 5b. This causes corresponding movement of the heald eyes 17a and displaces the binder yarns 4a downwards relative to the weft yarns 3 and warp layers 2. For example, in FIG. 5a the uppermost binder yarn 4a is shown outboard of the uppermost weft yarn 3 but in FIG. 5b it has moved inboard of the uppermost weft yarn. Similarly heald frame 15b moves up by one increment. In FIG. 5c both heald frames 15a, 15b have moved a further step inwardly of the shedding assembly. It can be seen from an inspection of the woven fabric on the right that the binder yarns 4a, 4b progressively extend at an angle to the warp layers 2 so as to provide an angle interlocked weave. It will be understood that the number of binder yarn groups may be increased by using more heald frames 15. Only two moving heald frames 15a, 15b are shown here for clarity and in order to demonstrate the principle.

(35) In FIGS. 6a, 6b and 6c, the first heald frame 10 for the warp yarns 2 remains fixed and each of the second and third frames 15, 15b reciprocates in the vertical direction, between weft insertions, such that it alternates between two positions. Thus, in FIG. 6c, the heald frames 10, 15a, 15b all occupy the same positions as they did in FIG. 6a. This produces layer-to-layer binding. Although only two binder yarns in each group are shown it will be understood that this number may be varied depending on the application. Moreover, the second and third heald frames 15a, 15b may be moved sequentially to further positions such that the binder yarns 4a, 4b each extend progressively through more than one warp layer 2 and fewer than all the layers (as depicted in FIG. 5). As in FIG. 5, the number of heald frames may be increased to provide additional binder yarn groups.

(36) In FIGS. 7a to 7c the outermost warp yarns 2a in the weave are threaded through separate heald frames 10a, 10b to the other warp yarns 2. These additional heald frames are disposed between the first heald frame 10 for shedding the warp yarns 2 and subsequent heald frames 15a, 15b, 15c, 15d that control the position of the binder yarns 4. The outermost layers of warp yarns 2a, 2b are threaded through eyes 20a, 20b in heald wires 21a, 21b of respective heald frames 10a, 10b. As shown in FIG. 7b, vertical movement of the second heald frame 10a through a predetermined distance in an upwards direction serves to move the upper layer 2a of warp stuffer yarns out of the weaving area, and thus out of the fabric 5, in order to create ply drop (in which the number of layers in reduced). Similarly downwards vertical movement of the third heald frame 10b through a predetermined distance (as also shown in FIG. 7b) serves to move the lower layer 2b of warp stuffer yarns out of the weaving area and create a further ply drop. The connecting floats (unwoven parts of the warp yarns 2a, 2b) may be removed. The plies can be reintroduced if required by moving the second and third heald frames 10a, 10b back to the positions shown in FIG. 7a. This arrangement may be used in combination with one or more additional heald frames 15a etc. for binder yarns. In this exemplary embodiment four such additional heald frames 15a to 15d are illustrated and control the positions of four groups of binder yarns 4a, 4b, 4c, 4d (for a large part of their length binder yarns 4b and 4d are hidden behind yarns 4a and 4c).

(37) A comparison of FIGS. 7a and 7b shows that heald frames 15a and 15c have moved upwards and heald frames 15b and 15d downwards. This movement serves to move the binder yarns through all of the warp yarn layers (by virtue of being threaded through respective eyes in heald wires). It will be understood that other forms of binding weaves (such as, for example, angle interlocking) may be used.

(38) In FIG. 7a it can be seen that the binder yarns 4a-4d have passed vertically through all the warp layers 2. After the outermost warp yarns 2a, 2b have been removed from the weave as shown in FIG. 2, the binder yarns 4a-4d may serve to bind the warp yarns 2 in upper and lower sections as can be seen in FIG. 7c, which illustrates the position after eight further weft insertions.

(39) FIGS. 8a to 8c illustrate a similar principle to that shown in FIGS. 7a to 7c only in this instance warp stuffer yarns 2c, 2d from the middle layers are moved outside of the weave by moving respective heald frames 10c, 10d in opposite vertical directions (see FIG. 8b). This may provide for a stronger fabric as the outermost warp layers 2 are continuous. As in the embodiment of FIGS. 7a to 7c the fabric is reduced in thickness and the binder yarns 4a-4d may bind the remaining warp yarns in upper and lower sections. FIG. 8c illustrates the position after eight further weft insertions, the positions of the second and third heald frames 10c, 10d remaining unchanged from the positions shown in FIG. 8b.

(40) In the embodiment of FIGS. 9a to 9c, the warp yarns 2 are shed by three separate heald frames 10, 10e and 10f. A first of the frames 10 supports an upper three warp yarn layers 2 and a lower three warp yarn layers 2. The second frame 10e supports a one of the middle warp yarn layers 2e in heald eyes 17e whereas the third frame 10f supports another middle warp yarn layer 2f in heald eyes 17f. In FIG. 9a the frames 10, 10e, 10f are shown in a first position which is equivalent to all the warp yarns 2 being supported by a single frame as in the embodiments of FIGS. 1 to 6. In FIG. 9b the two frames 10e, 10f have swapped vertical locations so that the middle warp stuffer yarns 2e, 2f swap positions. This technique may be used to create a pocket or slit 30 in the woven fabric 5, as illustrated in FIG. 9c. The frame positions may move back to their original positions after a predetermined number of weft insertions.

(41) The number of heald frames supporting the warp yarn layers 2 may vary depending on the number of such layers that require movement. In one example, the warp yarn layers are separated into two groups of upper and lower layers, each group being supported in separate frames. At a predetermined point in the weaving process those frames swap positions such that upper and lower also swap positions in the woven fabric.

(42) In the example shown in FIGS. 9a to 9c, the binder yarns 4a-4d are initially in the position shown in FIG. 9a in which yarns 4b are hidden behind yarns 4a for most of their length and similarly yarns 4b are hidden behind yarns 4c. In FIG. 9b it can be seen that heald frame 15a has moved upwards, taking with it binder yarns 4a (in heald eyes 17a) such that the yarns 4a are towards the middle of the weave. Similarly heald frame 15b has moved downwards so as to move the binder yarns 4a (via heald eyes 17b) towards the middle of the woven fabric. From this position onwards the two frames 15a, 15b continue to alternate between the positions shown in FIGS. 9a and 9b so as to bind the warp yarns 2 in upper and lower sections, as can be seen in FIG. 9c. Heald frames 15c, 15d and binder yarns 4c, 4d operate in the same fashion but move greater distances so that binder yarns 4c, 4d extend through all the warp layers 2 between weft insertions so as to ensure the two sections are bound together.

(43) FIGS. 10a and 10b show exemplary components of the invention prepared according to a method of the invention, each having a length, a width, and a thickness. In FIG. 10a, the warp yarns 2 extend along the length of the fabric, the weft yarns 3 extend across the width of the fabric and the binder yarns 4 extend progressively through the warp yarn layers across the thickness of the fabric in a direction that is not orthogonal to the warp yarns. In the component of FIG. 10b, the warp yarns 2 extend along the length of the fabric, the weft yarns 3 extend across the thickness of the fabric and the binder yarns 4 extend progressively through the warp yarn layers across the width of the fabric in a direction that is not orthogonal to the warp yarns.

(44) FIG. 11 shows an exemplary inverted T shape component prepared according to a method of the invention. The binder yarns 4 in the horizontal bottom portion (i.e. the flange portion) extend progressively through the warp yarn layers across the thickness of the fabric as in FIG. 10a, whereas the binder yarns 4a in the vertical raised portion (i.e. the web portion) extend progressively through the warp yarn layers 2 across the width of the web portion of the fabric as in FIG. 10b.

(45) As in all previous embodiments it will be appreciated that the number of heald frames for the binder yarns may vary, depending on the number of binder yarn groups required.

(46) The fibres used in the methods described above may be, for example, of any suitable kind including, for example, carbon, glass, aramid, Kevlar or a mixture thereof. They may be mixed with conventional textile fibres.

(47) The methods describe above enable the production of three-dimensional fabrics with, optionally, off-axis (non-orthogonal) fibres using a relatively simple and compact loom with reduced distortion or damage to the fibres. It also allows the production of significantly thicker fabrics than has hitherto been possible. A variety of weave styles are possible as discussed above.

(48) Using the above described methods it is possible to produce pre-pregs (pre-impregnated woven structures) that are very close to the desired final shape of the composite component. Such woven fabric structures may be impregnated by any known process such as, for example, resin transfer moulding.

(49) It will be appreciated that numerous modifications to the above described design may be made without departing from the scope of the invention as defined in the appended claims. For example, rather than being supported in movable heald frames in a Dobby-type loom as described above, the heald wires may be arranged into groups, the wires of each group being movable together in unison under the control of, for example, a computer controlled servoactuator, as if connected together by a supporting frame or other structure. This arrangement may be provided on, for example, a Jacquard type loom.

(50) The described and illustrated embodiments are to be considered as illustrative and not restrictive in character, it being understood that only the preferred embodiments have been shown and described and that all changes and modifications that come within the scope of the inventions as defined in the claims are desired to be protected. It should be understood that while the use of words such as preferable, preferably, preferred or more preferred in the description suggest that a feature so described may be desirable, it may nevertheless not be necessary and embodiments lacking such a feature may be contemplated as within the scope of the invention as defined in the appended claims. In relation to the claims, it is intended that when words such as a, an, at least one, or at least one portion are used to preface a feature there is no intention to limit the claim to only one such feature unless specifically stated to the contrary in the claim. When the language at least a portion and/or a portion is used the item can include a portion and/or the entire item unless specifically stated to the contrary.