NETWORK-LIKE WOVEN 3D FABRIC MATERIAL

Abstract: A network-like woven 3D fabric material (9) comprises select multilayer warp yarns (8) occurring substantially linearly, the remainder multilayer warp yarns (7) occurring in the helical configuration and two orthogonal sets of weft (12c and 12r) and such a network-like fabric construction (9) made possible through a dual-directional shedding operation of the weaving process. Such a fabric may additionally incorporate non-interlacing multi-directionally orientated yarns (n1-n8) across the fabric cross section to improve the fabric's mechanical performance. The produced 3D fabric material, which may be cut into any desired shape without the risk of splitting, may be used wholly or in parts in technical applications.

Description: NETWORK-LIKE WOVEN 3D FABRIC MATERIAL TECHNICAL FIELD This invention relates to a woven 3D fabnc and its method of production In particular, the woven 3D fabnc compπses select multilayer waφ yams occurring substantially linearly, the remainder multilayer warp yams occurring in a helical configuration and two orthogonal sets of weft and such a network-like fabnc construction made possible through a dual-directional shedding operation of the weaving process Such a fabnc. which may additionally incoφorate non-interlacing multi-directionally orientated varns across the fabnc cross-section for improving its mechanical performance, is considered useful in techmcal applications like the manufacture of composite matenals, filters, insulating matenals. separator-cum-holder for certain matenals, electπcal/electronic parts, protection matenal, etc BACKGROUND In the conventional weavmg process the foremost operation of shedding is limited in its design to form a shed m only the fabnc-width direction The employed waφ. which is either in a single or a multiple layer, is separated mto two parts in a 'crossed' manner, m the direction of the fabnc-thickness through the employment of the heald wires which are reciprocated through their frames by means such as cams or dobb\ or jacquard to form a shed m the fabnc-width direction Each of these heald wires are reciprocated either singly or jointly or m suitable groups m only the fabnc-thickness direction to form a shed in the fabnc-width direction A weft inserted into this formed shed enables interconnection between the separated two layers of the waφ The so interconnected waφ and weft results in an interlaced structure which is called the woven fabnc A fabnc when produced using a single layer warp results in a sheet-like woven matenal and is referred to as a woven 2D fabnc as its constituent yarns are supposed to be disposed in one plane Similarly, when a fabnc is produced using a multiple laver waφ. the obtained fabnc which is charactenstically different in construction from the woven 2D fabnc. is referred to as a woven 3D fabnc because its constituting yams are supposed to be disposed in a three mutually peφendicular plane relationship However, in the production of both these types of woven 2D and 3D fabncs the conventional weavmg process, due to its inherent working design, can only bring about interlacement of two orthogonal sets of yarn- the waφ and the weft It cannot bring about interlacement of three orthogonal sets of yams a multiple layer waφ and two orthogonal sets of weft This is an inherent limitation of the existing weaving process The present invention provides a dual- directional shedding method to form sheds in the columnwise and the row-wise directions of a multilayer waφ to enable interlacement of the multilayer waφ and two orthogonal sets of weft in such a way that select yams of the multilayer waφ occur substantially linearly and the remainder yams, which interlace with the two orthogonal sets of weft, occur in a helical configuration and the obtained fabnc has a network-like structure Certain techmcal fabnc applications require complex or unusual shapes besides other specific charactenstics for performance such as a high degree of fabnc integration and proper onentation of the constituent varns For example, at present it is not possible to obtain a suitable fabnc block from which preforms (reinforcement fabnc for composite matenal application) of anv desired shape may be cut obtamed This is because the present fabnc manufacturmg processes of weavmg, kmttmg. braidmg and certam nonwoven methods which are employed to produce preforms cannot deliver a suitable highly integrated fabnc block from which preforms of any desired shape may be cut obtamed With a view to obtain certam regular cross-sectional shaped preforms, suitable fabnc manufacturmg methods working on the principles of weavmg, kmttmg, braidmg and certain nonwoven techniques have been developed Such an approach of producing preforms having certam cross-sectional shapes is referred to as near-net shaping However, through these various techniques preforms of only certam cross-sectional profiles can be produced and preforms of anv desired shape cannot be manufactured The obtaining of preforms of any desired shape can be made practically possible if only a highly integrated fabnc block can be made available so that the required shape can be cut from it without the nsk of its splitting up Also, fabrics for other applications like filters of unusual shapes can be similarly cut obtamed from a suitable fabnc block For analogy, this strategy of obtaining any desired shape of three-dimensional fabnc item may be seen as the cutting of different shapes of fabnc items from a suitable sheet of 2D fabnc, for example, during the manufacture of a garment Therefore, as can be inferred now, to cut obtain three- dimensional fabnc items of any desired shape it is essential to first produce a highly integrated fabnc m the form of a block The present invention provides a novel woven 3D fabnc and the method to produce such a fabnc block which can be cut without the nsk of splitting up and which ma> additionally lncoφorate non-interlacing yams m a multi-directional oπentation to impart mechanical performance to the fabnc. so as to be useful in techmcal applications OBJECTIVES OF THE PRESENT INVENTION An objective of this invention is to make available a block of network-like integrated 3D fabnc which additionally incoφorates yams suitably onentated to impart proper mechanical strength to the fabnc so that suitable fabnc items of any desired shape can be cut without the nsk of its splitting up Because certain fabnc items of any desired shape mav be obtamed easily this way. such an approach can be advantageous in techmcal applications such as the manufacture of preforms, i e remforcement fabnc for compsites application, filters etc Another objective of this invention is to provide a dual-directional shedding method to enable interlacement of three orthogonal sets of yam a set of multilayer waφ and two orthogonal sets of weft Such an interlacement of the three orthogonal sets of yam is necessary to provided a high degree of lntegnty to the fabnc to render the fabnc resistant to splitting up in the fabnc-width as well as in the fabnc-thickness directions This way the objective of producmg a network-like interlaced 3D fabnc. which may additionally incoφorate non-interlacing multi-directionally onentated varns. is made possible The integnty of the fabnc is made possible through the formation of multiple row-wise and columnwise sheds in the emploved multiple layer waφ Two orthogonal sets of weft when inserted in the formed row-wise and columnwise sheds produce a network-like interlaced 3D fabnc Because the foremost operation of the weavmg process happens to be the shedding operation, all other subsequent complementing operations of the weaving process, for example picking, beatmg-up etc . will follow suit accordingly As the dual-directional shedding method enables interlacement of two orthogonal sets of weft and a multilayer waφ by way of forming sheds in the columnwise and row-wise directions of the multilaver waφ to produce a highly integrated network-like fabnc stmcture having a high mechanical performance, it will be descnbed in detail The subsequent complementing weavmg operations like picking, beatmg-up. taking-up, letting off etc will not be descnbed as these are not the objectives of this mvention With a view to keep the descnption simple and to the pomt. the simplest mode of carrying out the dual-directional shedding operation will be exemplified and will only pertain to the production of the woven plain weave 3D fabnc according to this mvention The method of producmg numerous other weave patterns through this invention will be apparent to those skilled m the art and therefore it will be only bnefly mentioned as these vanous weave patterns can be produced on similar lmes without deviating from the spint of this mvention BRIEF DESCRIPTION OF THE DRAWINGS The mvention is descnbed m reference to the following illustrations Fig 1 shows the general arrangement of the shedding shafts for carrying out dual-directional shedding Fig 2 shows the disposal arrangement of the active and the passive waxp yams compnsing the Fig 3 shows the location of the shedding shafts in relation to the passive yams of the multilayer waφ indicated m Fig 2 Fig 4a shows the top view of the level position of the shedding shafts and the multilayer waφ pnor to columnwise shed formation Fig 4b shows the top view of the shedding shafts displacing the active waφ yams drawn through its eyes towards the nght side of the passive waφ yams and the formation of the multiple nght side columnwise sheds with the passive waφ yams Fig 4c shows the top view of the shedding shafts displacing the active waφ yams drawn through its eyes towards the left side of the passive waφ yams and the formation of the multiple left side columnwise sheds with the passive waφ yams Fig 5a shows the side view of the level position of the shedding shafts and the multilaver waφ pnor to row-wise shed formation Fig 5b shows the side view of the shedding shafts displacing the active waφ yams drawn through its eyes m the upward direction to form the multiple upper row-wise sheds with the passive waφ yams Fig 5 c shows the side view of the shedding shafts displacing the active waφ yams drawn through its eyes in the downward direction to form the multiple lower row-wise sheds with the passive waφ yams Fig 6a is a three-dimensional representation of the typical yam paths of the active waφ yarns at the edges and the surfaces of the plam weave constmction of the woven 3D fabnc Fig 6b is a three-dimensional representation of the typical varn paths of the active waφ yams m the intenors of the plain weave constmction of the woven 3D fabnc Fig 7 is a two-dimensional representation of the front view of the fabnc constmction shown in Fig 6 Fig 8a is a two-dimensional representation of the top view of the fabnc constmction shown m Fig 6a Fig 8b is a two-dimensional representation of the side view of the fabnc constmction shown m Fig 6a Fig 9a is a two-dimensional representation of the top view of the fabnc constmction shown in Fig 6b Fig 9b is a two-dimensional representation of the side view of the fabnc constmction shown m Fig 6b Fig 10a is a two-dimensional representation of the axial view of a modified fabnc constmction showing the path of the active waφ yams obtainable according to a specific sheddmg order Fig 10b is a two-dimensional representation of the axial view of a modified fabnc constmction showing the path of the active waφ yams obtainable according to a specific sheddmg order Fig 10c is a two-dimensional representation of the axial view of a modified fabnc constmction showing the path of the active waφ yams obtainable according to combined specific sheddmg orders indicated in Figs 10a and 10b Fig 11 is the front view of the fabnc constmction incoφorating additional non-mterlacmg yams m the fabnc-width, -thickness and the two diagonal directions Fig 12a is a two dimensional representation of the front view of a useful fabnc constmction producible m which the exteπor part is only interlaced to function as a woven covering for the non-mterlacmg yams which occur internally withoutnterlacement Fig 12b is a two dimensional representation of the front view of a useful fabnc constmction producible in which specifically disposed yams of the multilayer waφ are interlaced to form a sandwich or a core type of fabnc constmction DESCRIPTION OF THE PREFERRED EMBODIMENTS The method of producmg the woven 3D fabnc using two orthogonal sets of weft and a multilayer waφ will now be descnbed in reference to the above stated drawings The working principle of the dual- directional sheddmg method will be descnbed first and then the particular way of constructing useful fabncs accordmg to this invention will be descnbed The method to be descnbed now follows a completely new plan for effectmg sheddmg compared with the conventional sheddmg methods In Fig 1 is shown the essential features of the novel dual- directional sheddmg arrangement (1) for effectmg shed formation in the fabnc-width and -thickness directions Each of the cylmdncal heald shafts (2) carry a set of fixed flat healds (3) as indicated Each heald has two openings the front one is the heald-eye (4) and the rear one is a heald-guide (5) Such an assembly compnsmg the cylmdncal heald shaft (2) and the flat healds (3) is suitably supported m supports (s), as indicated in Fig 1, in a manner that each of these assemblies can be reciprocated m two directions (l) along and (n) about the shaft axis, that is linearly and angularly respectively The disposal arrangement of the employed multilayered waφ (6) is indicated m Fig 2 Such a disposal is required to achieve a uniform integration at the fabnc ' s surfaces (excluding end surfaces) and for the balanced distπbution of the yams the fabnc The pecuhanty of this arrangement is that it compnses active (7) and passive (8) waφ yams such that each passive waφ end (8) is 'sunounded' by active warp ends (7) for achieving uniform fabnc integration Such a multilayer waφ disposal arrangement (6) may be descnbed as compnsmg alternate rows or columns of active (7) and passive (8) waφ ends Thus, the active-waφ yam rows will be designated by 'a', 'c', 'e' etc. and the passive-waφ yam rows by 'b', 'd', etc as indicated m Fig 2 The occumng alternate columns of the active (7) and passive (8) waφ yams will be designated by 'A'. 'C, 'E' etc and 'B', 'D' 'F' etc respectivelv as indicated in Fig 2 Each of the active waφ ends (7) of a given row (or column) is drawn through the corresponding flat heald's (3) guide (5) and the eye (4) The passive waφ yams (8) of a given row (or column) are drawn through the open space occurring between corresponding two adjacent heald shafts (2) Thus, the multilayer waφ varns (6) and the heald shafts (2) will occur as indicated Fig 3 The above descnbed disposal arrangement of the multilayer waφ (6) and the sheddmg shafts (2) shown m Fig 3 defines the level position of the system From this level position, each of the active waφ ends (7) passing through a conesponding heald eye (4) can be displaced m the fabnc-width and -thickness directions by moving the heald shaft (2) along its axis and turning it about its axis respectively In relation to the passive waφ ends (8), which do not pass through the heald eyes (4), and hence are stationary, the displaceable active waφ ends (7) readily form multiple columnwise (10) and row-wise (11) sheds upon their displacement m the required direction from the level position as shown m Figs 4 and 5 The linear and the angular displacements of the heald shafts (2) from its level position to form the row-wise (11) and the columnwise (10) sheds can conespond to the distance between two adjacent active (7) (or passive (8)) waφ yams m the given direction of movement and may be refened to as the sheddmg displacement pitch In the formation of these multiple sheds (10) and (11), the displacement of the active waφ ends (7) of a given row or column may thus be refened to as a unit sheddmg displacement pitch However m real praαice this displacement can be mcreased up to a maximum of 1 5 tunes the sheddmg displacement pitch to form a conespondingly greater shed for practical advantage in weft insertion In its simplest mode, all the shafts (2) are moved simultaneously, either linearly or angularly, and m the same direction to form conesponding directional movement's multiple sheds as shown m Figs 4 and 5 respectively By picking a weft (12) m each of these formed sheds (10) and (11), interlacement within the individual columns and the rows of the multilayer waφ (6) with the conesponding wefts (12c and 12r) is achieved Such an alternate row-wise and columnwise sheddmg and conesponding picking thus leads to the production of the plain weave woven 3D fabnc of this method The typical yam paths at the edges and the surfaces of the fabnc (9), and in the intenors of fabnc (9) are respectively indicated m Figs 6a and 6b The simplest working of this dual-directional sheddmg system (1) is outlmed below m reference to Figs 4 and 5 In Fig 4 is illustrated the formation of the columnwise sheds (10) Fig 4(a) indicates the level position of the system In Figs 4 (b) and (c) are shown the directions of the linear movement of a heald shaft (2) along its axis The former and the latter figures respectively show the displacement of the active waφ ends (7). from their level positions, in the fabnc-width direction to form the nght side and the left side columnwise sheds (10) with the stationary passive waφ yams (8) Fig 5 shows the formation of the row-wise sheds (11) Fig 5(a) indicates the level position of the system In Figs 5 (b) and (c) are illustrated the directions of the angular movement of a heald shaft (2) about its axis The former and the latter figures respectively show the displacement of the active waφ ends (7). from their level positions, in the fabnc-thickness direction to form the upper and lower row-wise sheds (11) with the stationary passive waφ yarns (8) As can be infened from the Figs 4 (b) and (c) and 5 (b) and (c). the optimum displacement of the shafts can be up to 1 5 times the sheddmg displacement pitch in practice to obtain relatively larger sheds for convenience in weft insertion The shafts mav be displaced up to the extent that an active waφ yam (7) does not cross two passive waφ yams (8) It is to be noted that m reference to the stationary passive waφ yams (8). the nght and the left side columnwise sheds, and the upper and the lower row-wise sheds are not formed simultaneously but m a specific order The sheddmg shafts (2) revert to their level position every time subsequent to a particular shed formation and picking operation For example, m the constmction of the plain weave woven 3D fabnc (9) obtainable through this method, and mdicated m Fig 6. the order of sheddmg and pickmg mdicated below is followed, starting from the level position of the system The movements of the sheddmg shafts descnbed below are viewed from the rear of the sheddmg means in the direction of the fabnc-fell 1) Upward angular movement of the sheddmg shafts (2), formation of the row-wise upper sheds (11), followed by pick insertion in the formed sheds (i e m the fabnc-width direction) 2) Reverting sheddmg shafts (2) to the level position of the system 3) Rightward linear movement of the shafts (2). formation of the columnwise nght side sheds (10), followed by pick insertion m the formed sheds (I e in the fabnc-thickness direction) 4) Reverting shafts (2) to the level position of the system 5) Downward angular movement of the shafts (2), formation of the row-wise lower sheds (11), followed by pick insertion m the formed sheds (l e in the fabnc-width direction) 6) Reverting shafts (2) to the level position of the system 7) Leftward linear movement of the shafts (2), formation of the columnwise left side sheds(lθ), followed by pick insertion m the formed sheds (l e in the fabnc-thickness direction) 8) Reverting shafts (2) to the level position of the system The above indicated sheddmg order, together with the necessary complementing operations of the weavmg process like pickmg. beatmg-up. taking-up etc at appropnate moments constitute one complete working cycle of the process Fig 7 shows the front view of the plain weave woven 3D fabnc constmction (9) obtainable through the above stated sheddmg order It is to be noted that the two sets of weft (12c and 12r), which may be inserted in their respective sheds by employing means like shuttles, rapiers etc and may be picked m as either a smgle yam or haiφin-like folded yam, uniquely interlace with the active waφ yams (7) and get connected to the passive waφ yams (8) Because of their interlacement with the active waφ yams (7) the two sets of weft (12c and 12r) will occur m an undulating manner and not straight as mdicated m Figs 6 and 7 These two sets of weft (12c and 12r) are shown straight for only easy representation However, the incidence of its crimp can be reduced, for example, by feeding the active waφ yams (7) under suitable tension and at a suitable rate In Figs 8a and 8b are shown the top and the side views respectively of the fabnc (9) to mdicate the typical paths of the active waφ yams (7) at the fabnc's edges and surfaces The senes of letters A-B-C-D. P-Q-R-S etc respectively indicate the individual active waφ yam (7) paths at the edges and surfaces of the fabnc constmction shown m Figs 6a and 7 In Figs 9a and 9b are shown the top and the side views respectively of the fabnc (9) to mdicate the typical path of the active waφ yam (7) m the mtenor of the fabnc constmction shown in Fig 6b The senes of numbers 111-112-113-114 indicates the mdividual active aφ yam (7) path m the mtenor of the fabnc constmction shown m Figs 6b and 7 An important feature of the fabnc constmction (9) to be noted m Figs 6. 7, 8 and 9 is the occunence of the active waφ yams m a 'helical' configuration Though not following a circular path, the active waφ yams occur m a 'tnangular helix' at the fabnc's edges and surfaces (mdicated by different senes of letters. A-B-C-D, P-Q-R-S etc m Fig 7) and m a 'square helix' m the mtenors (mdicated by different senes of numbers, 101-102-103-104, 131-132-133-134 etc m Fig 7) Further, both these helices are not formed about any of the passive waφ yarns Also, the fabnc has a network-like constmction There may be introduced minor alterations m the above framework of operations For example, the above mdicated order of sheddmg operations may be altered to produce a modified network-like fabnc constmction (9m) shown in Fig 10 In reference to the sheddmg order indicated above, if the order given below is earned out, then modified network-like fabnc constructions (9m) may be obtamed and will conespond with those mdicated m Fig 10 m which the general path of the active waφ yam m the mtenor of the fabnc is only shown and conesponds as follows a) Sheddmg order 1, 2, 5, 6, 3, 4, 7, 8 and repeat b) Sheddmg order 1. 2, 5, 6, 7, 8, 3. 4 and repeat c) Sheddmg order 1. 2, 5, 6, 3, 4, 7, 8, 1, 2, 5, 6. 7, 8, 3, 4 and repeat These obtamed modified network-like fabnc constructions (9m) shown m Fig 10 will differ from the one mdicated in Figs 6, 7, 8 and 9 in which the typical paths of the active waφ yams (7) m accordance with the initially mentioned sheddmg order are mdicated The difference m the fabnc constmction (9m) due to the change of the sheddmg order will be that the wefts of a given set will occur successively and not alternately as shown in the figures, and also the active waφ yams (7) will additionalh occur m the fabnc-width and -thickness directions in addition to the diagonal directions as represented m Fig 10 This is because the wefts (12c and 12r) will be picked successively m the 'forward and backward' directions of the respective side (row-wise or columnwise direction) Nevertheless, the active waφ yams (7) in all these constructions (9) and (9m) may be considered to occur in a helical configuration for the puφose of easy understanding From the foregomg descnption of the dual-directional sheddmg method, the following points will be apparent to those skilled m the art a) All the columnwise (or the row-wise) sheds can be formed simultaneously for mcreased production efficiency and not successively one columnwise (or row-wise) waφ layer after the other b) Multiple wefts of a set may be picked simultaneously employing means like shuttles, rapiers etc and each of the wefts may be inserted as either a smgle yam or a haiφm-like folded yam c) The active waφ yams (7) may be made to occur m the fabnc-length direction either m ahe cal configuration or additionally m the fabnc-width and - thickness directions by controllmghe sheddmg order d) The helical progression of all the active waφ yams (7) provides unique network-like fabnc integration throughout the fabnc by interlacing with the two sets of weft and interconnecting these two sets of weft to the passive waφ yams e) The helical progression of the active waφ yams (7) provides unique discrete placement of the active waφ yams (7) m either the 'diagonal " directions or additionally in the fabnc-width and -thickness directions f) The optimum sheddmg displacement pitch of the sheddmg shaft (2) m the fabnc-thickness and the - width directions is 1 5 since a greater displacement will cause interference with the pick insertion and unnecessary concentration of the active waφ yams (7) at the fabnc's surfaces and thus lead to uneven fabnc surface and unbalanced fabnc constmction g) Different weave patterns can be created by displacmg mdependently and selectively in the fabnc- width and -thickness directions the required shafts (2) which bear the healds (3) which are suitably threaded h) It is possible to cany out sheddmg mvolvmg only the active waφ ends (7) by displacmg mdependently pairs of the shafts (2) m opposite directions, and the healds (3) of which are suitably threaded l) Tubular fabncs of either square or rectangle cross-section and solid profiled fabncs like L. T, C etc can be directly produced by disposmg the multilayer waφ in accordance with the cross-sectional profile to be produced and suitably effectmg the sheddmg and the pickmg operations in a suitable discrete manner, for example by employing more than one set of pickmg means m each of the two directions It will now be apparent to those skilled in the art that the mechamcal performance of the fabnc can be unproved, if required, by the inclusion of non-interlacmg 'sniffer' yams m the fabnc-width. -thickness and the two diagonal directions across the fabnc cross-section An example of one such constmction is outlmed below In reference to the sheddmg and pickmg order mentioned earlier, the insertion of non-mterlacmg yarns (nl-n8) may be mcluded m the fabnc according to the steps mdicated below and illustrated in Fig 11 1) Upward angular movement of the sheddmg shafts, formation of the row-wise upper sheds, followed by pick insertion (12r) m the formed sheds 2) Reverting sheddmg shafts to the level position of the system 3) Insertion of the set of non-interlacmg yam (nl) between given two rows of the passive waφ yams (8) 4) Insertion of the set of diagonal non-interlacmg yam (n2) between given two diagonally occurring layers of the passive waφ yams (8) 5) Rightward linear movement of the shafts, formation of the nght side columnwise sheds, followed by pick insertion (12c) m the formed sheds 6) Reverting shafts to the level position of the system 7) Insertion of the set of non-mterlacmg yam (n3) between given two columns of the passive waφ yams (8) 8) Insertion of the set of diagonal non-mterlacmg yam (n4) between given two diagonally occumng layers of the passive waφ yams (8) 9) Downward angular movement of the shafts, formation of the lower row-wise sheds, followed by pick insertion (12r) m the formed sheds 10) Reverting shafts to the level position of the system 11) Insertion of the set of non-mterlacmg yam (n5) between given two rows of the passive waφ yarns(8) 12) Insertion of the set of diagonal non-mterlacmg yam (n6) between given two diagonally occurring layers of the passive waφ yarns (8) 13) Leftward lmear movement of the shafts, formation of the left sidecolumnwise sheds, followed by pick insertion (12c) m the formed sheds 14) Reverting shafts to the level position of the system 15) Insertion of the set of non-interlacmg yam (n7) between given two columns of the passive waφ yarns (8) 16) Insertion of the set of diagonal non-mterlacmg yam (n8) between given two diagonally occurring layers of the passive waφ yarns (8) Further, this method is not limited to the production of a block of either fabnc constmction (9) or (9m) or (9n) having either a square or a rectangle cross-section By disposmg the multilayer waφ m accordance with the desired shape of cross-section, including tubular types with square or rectangle cross-section, and following suitable discrete sequence of operations descnbed above, network-like fabnc constructions either (9) or (9m) or (9n) of the conesponding cross-sectional profile can also be produced It may be mentioned here that depending on the complexity of the cross-sectional profile bemg produced, more than one set of weft inserting means for each of the two directions can be employed Such different sets of the weft inserting means of a given direction (I e row-wise or columnwise) may be operated either simultaneously or discretely to achieve the required weft insertion for the profile under production This method of fabnc production is therefore not limited to the production of a fabnc of a particular cross-sectional profile Further, because of the unique networklike interlacement, there is no need to carry out any separate bmdmg operation at the exteπor surfaces of the fabnc to achieve the fabnc integnty This elimmation of the bmdmg process is apparently advantageous in simplifying and quickenmg the fabnc production Further, this method of producmg network-like interlaced 3D fabnc blocks and other cross-sectional profiles eliminates to the need to develop methods for producmg certam cross-sectional shapes as from the produced block of the network-like fabnc obtainable through this method, any desired shape of preform, filter etc matenal can be easily cut obtamed without the nsk of its splitting up Further, it is possible to produce another useful fabnc matenal by carrying out sheddmg mvolvmg only the waφ yams occumng at the extenors of the disposed multilayer waφ (6) by suitably displacmg the shafts (2), the healds (3) of which have been conespondingly threaded as descnbed earlier In reference to Fig 12a, the top and the bottom woven surfaces can be produced by movmg angularly the top and the bottom shafts (2), and hence displacmg the healds (3), to displace the active waφ yarns (7) to form row-wise sheds with the passive waφ yams (8) and inserting the wefts (12r) into these extenor top and bottom row-wise sheds Similarly, the left and the nght side woven surfaces can be produced by movmg linearly the shafts (2), and hence displacmg the healds (3). to displace the active warp yams (7) to form columnwise sheds with the passive waφ yams (8) and inserting wefts (12c) mto these extenor left and nght columnwise sheds Thus such operations will produce an interlaced extenor surface which will function as a woven covering for the internally occumng non-mterlacmg multilayer varns (6n) of the fabnc matenal (9e) as shown in Fig 12a Further, it is also possible to produce a core or a sandwich type of fabnc matenal (9s) shown in Fig 12b by interlacing the suitably disposed multilayer waφ yams Here again, by displacmg independenth the heald shafts (2), the healds (3) of which have been conespondmgly threaded, the row-wise and the columnwise sheds can be respectively formed by movmg these shafts (2) angularly and linearly as descnbed earlier Inserting wefts (12r) and (12c) into the formed row-wise and columnwise sheds respectively, the interlaced fabnc stmcture (9s), generally refeπed to as sandwich or core type fabnc structure, shown in Fig 12b is obtamed Further, it is also possible to produce multiple woven 2D fabnc sheets employing the descnbed sheddmg means Such multiple sheets can be produced by disposmg the multilayer waφ as descnbed before and movmg the shafts (2) either angularly or linearly to form conespondmgly either the rowwise or the columnwise sheds and inserting conespondmgly either wefts (12r) or (12c) mto the formed sheds of the given direction Thus, by forming row-wise sheds and effectmg conesponding pickmg, the multiple sheets of woven 2D fabnc will be produced in the honzontal form Similarly, by forming columnwise sheds and effecting conesponding pickmg, the multiple sheets of woven 2D fabnc will be produced in the vertical form m reference to the anangement shown m Fig 3 Needless to mention, in all the above descnbed methods of fabnc production, the other complementmg operations of the weavmg process like the beatmg-up, taking-up etc will be earned out at the appropπate moments of the weavmg cycle to produce a satisfactory fabnc of the required specification It will be now apparent to those skilled in the art that it is possible to alter or modify the vanous details of this invention without departing from the spiπt of the mvention Therefore, the foregoing descnption is for the puφose of illustrating the basic idea of this invention and it does not limit the claims which are listed below

Claims: CLAIMS 1 A network-like woven 3D fabnc matenal charactenzed by the occurs m accordance with the cross-sectional profile of the fabnc and two orthogonal sets of weft such that select yams of the multilayer waφ occur substantially linearly, the remainder of the multilayer waφ yams occur m a helix-like configuration such that these remainder waφ yams occur an interlacing manner with the two orthogonal sets of weft and link the two sets of weft to the substantially linearly occumng waφ yams m a manner that the remainder waφ yams do not occur m the helix-like configuration about any of the substantially linearly occumng waφ yams compnsmg the fabnc matenal which may additionally incoφorate non-mterlacmg multi- directionally onentated strings m a) the fabnc-width direction, b) the fabnc-thickness direction, c) one or both the diagonal directions of the fabnc cross-section, d) a combmation of any of the above listed directions, to improve the mechanical performance of the fabnc matenal which may be used wholly or in parts in techmcal applications, including but not limiting to composites, and such a fabnc being of either solid or tubular type and possessmg a cross-sectional shape and capable of retaining its structure when cut into a desired form 2 The woven matenal according to claim 1 compnsmg a) one or more fibrous matenal from a selection of carbon fibre, synthetic fibres, natural fibres including from the sea, inorganic fibres, glass fibre, metallic fibres, b) a combmation of any nα -fibrous matenal and any fibrous matenal mdicated in claim 2a, c) all or any of the stnng matenals listed in claim 2a impregnated with a chemical formulation 3 The woven matenal accordmg to claim 1 produced through the weavmg method incoφorating the operation of sheddmg in two mutually peφendicular directions to form row-wise and columnwise sheds m the multilayer waφ disposed accordmg to the cross-sectional profile of the fabnc to be produced through the employment of a sheddmg means charactensed by the constitution of a) one or more shafts each of which is capable of bemg reciprocated linearly along its longitudinal axis and also angularly about its longitudinal axis, b) each of the shafts accordmg to claim 3a bearing a set of means along its length direction such that the length direction of each of these means is onentated peφendicular to the length direction of the shaft accordmg to claim 3 a, c) the means according to claim 3 b intended for supporting the aφ strings threaded through it in accordance with the cross-sectional profile of the fabnc to be produced 4 The dual-directional shedding means accordmg to claim 3 compnsmg one or more sets of sheddmg shaft assemblies ananged in the following manner a) with the longitudinal axis of the shafts occurring in one or more parallel planes. b) with the longitudinal axis of the shafts occumng m a peφendicular onentation to the axis of the disposed strings of the multilayer waφ, c) in a manner to provide space between given two shafts to draw strings of waφ through, d) in a manner that each of the waφ stnngs drawn through the space between given two shafts accordmg to claim 4c . occurs sunounded by the waφ ends which are threaded through the means in accordance with claim 3 c The dual-directional sheddmg shaft assemblies according to claims 3 and 4 capable of bemg reciprocated either linearly or angularly a) as a whole set. or b) m select groups, or c) individually, or d) a combination of clauns 5b and 5c The dual-directional shedding shaft assemblies according to claims 3. 4 and 5 capable of bemg reciprocated either linearly or angularly a) m the same direction at the same tune, or b) m the opposite directions at the same time, or c) m a discrete manner The sheddmg shaft assembly according to claims 3, 4, 5 and 6 capable of bemg employed to produce multiple woven 2D sheets in accordance with claim 2 AMENDED CLAIMS [received by the International Bureau on 03 July 1998 (03.07.98); original claims 1-7 replaced by amended claims 1-12 (3 pages)] 1. A network-like woven 3D fabric material characterised by the constitution of multilayer warp comprising yarns (7,8) which occur in accordance with the cross-sectional profile of the fabric and two orthogonal sets of weft (12c, 12r) such that yarns (8) of the multilayer warp occur substantially linearly, the remainder of the multilayer warp yarns (7) occur in a helix-like configuration such that these remainder warp yarns (7) occur in an interlacing manner with the two orthogonal sets of weft (12c, 12r) and link the two sets of wefts (12c, 12r) to the substantially linearly occurring warp yarns (8) in a manner that the remainder warp yarns (7) do not occur in the helix-like configuration about any of the substantially linearly occurring warp yarns (8) comprising the fabric material (9,9m). 2. A woven material according to claim 1 comprising additionally non-interlacing yarns (nl-n.8) incorporated in the directions defined by the fabric's width or thickness or one or both diagonal directions of the fabric's (9n) axial cross- section. 3. A fabric material according to anoyone of the claims above comprising one or more fibrous material chosen from carbon, synthetic fibres, natural fibres including from the sea, inorganic fibres, glass fibre and metallic fibres. 4. A fabric material according to claim 3 wherein the woven fabric material comprises a combination of fibrous and non- fibrous material. 5. A fabric material according to claim 3 or 4 wherein all or any of the yarn materials is impregnated with a chemical formulation. 6. A device for producing woven material, preferably 3D fabric, with a weaving method incorporating the operation of shedding in two mutually perpendicular directions to form rowwise and columnwise sheds in the multilayer warp disposed according to the cross-sectional profile of the fabric to be produced through the employment of shedding means (1) characterised by the constitution of: a) one or more shafts (2) each of which is capable of being reciprocated linearly along its longitudinal axis and also angularly about its longitudinal axis, b) each of the shafts (2) bearing a set of means (3) along the shaft's (2) length direction such that the length direction of each of these means (3) is orientated perpendicular to the length direction of said shaft (2) , c) said means (3) intended for supporting the warp strings (7) threaded through its entry port (5) and exit port (4) in accordance with the cross-sectional profile of the fabric to be produced. 7. A device according to claim 6 characterised in that the dual-directional shedding means (1) comprises one or more sets of shedding shaft assemblies (2,3) arranged in the following manner: a) with the longitudinal axis of the shafts (2) occurring in one or more parallel planes, b) with the longitudinal axis of the shafts (2) occurring in a perpendicular orientation to the axis of the disposed strings of the multilayer warp (7,8), c) in a manner to provide space between given two shafts (2) to draw strings of warp (8) through, d) in a manner that each of the warp strings (8) drawn through the space between given two shafts (2) , occurs surrounded by the warp ends (7) which are threaded through said means (3) . 8. A device according to claims 6 and 7, characterised by the dual-directional shedding shaft assemblies (2,3) capable of being reciprocated either linearly or angularly: a) collectively as a whole set, or b) in select groups, or c) individually, or d) a combination of b) and c) . 9. A device according to one of claims 6-8 characterised by the dual-directional shedding shaft assemblies (2,3) capable of being reciprocated either linearly or angularly: a) in the same direction at the same rime, or b) in the opposite directions at the same time, or c) in a discrete manner. 10. A device according to any of claims 6-9 charaterised by the dual-directional shedding means (1) capable of being employed to produce a material (9e) in which the exterior warp yarns (7,8) of the multiple layer warp are involved for interlacement with wefts (12c, 12r) and such an outer interlaced assembly serves to function as a woven covering for the elements (6n) which occur internally. 11. A device according to any one of claims 6-9 characterised by the dual-directional shedding means (1) capable of being employed to produce a material (9s) in which suitably disposed warp yarns (7,8) of the multiple layer warp are involved for interlacement with wefts (12c, 12r) to result in a sandwich or core structure (9s) . 12. A device according to any of the claims 6-9 capable of being employed to produce multiple woven 2D fabric sheets simultaneously.

Inventors: KHOKAR NANDAN, KHOKAR, NANDAN
Applicants: BITEAM AB, KHOKAR NANDAN, KHOKAR, NANDAN
Application year: 1997
Main classification: D03D25
IPC codes: D03D25, D03D41