WO1998003712A1

WO1998003712A1 - A device for producing integrated nonwoven three dimensional fabric

Info

Publication number: WO1998003712A1
Application number: PCT/SE1996/000968
Authority: WO
Inventors: Nandan Khokar; Ejert Peterson
Original assignee: FORSKARPATENT I VäSTSVERIGE AB
Priority date: 1995-01-30
Filing date: 1996-07-23
Publication date: 1998-01-29

Abstract

A device for producing integrated nonwoven 3D fabric comprising essentially three sets of yarns of any fibre type, including brittle fibre type, such that the employed three sets of yarns are incorporated in the produced fabric in a nearly mutual perpendicular orientation. A plate (P) constitutes: (a) two sets of profiled tracks (D and C) existing in a mutually perpendicular configuration and in the same plane on the front face of the plate (P); (b) two sets of binder yarn spool carriers (K and L); (c) two pairs of tracking arrangement, such that each pair being situated at the terminal sides contains between it all the tracks of sets D and C respectively; and (d) orderly arranged openings B extending through the entire thickness of the plate (P) such that the openings are arranged in row-wise and column-wise manner.

Description

TITLE:

A Device for Producing integrated Non oven three dimensional Fabric .

TECHNICAL FIELD:

The present invention relates to a device for producing integrated nonwoven three dimensional fabric comprising essentially three sets of yarns of any fibre type, including brittle fibre type, such that the employed three sets of yarns are incorporated in the produced fabric in a nearly mutual perpendicular orientation by the device.

BACKGROUND:

Fabrics are employed in the production of textile based composite materials. An integrated 3D fabric system is advantageous compared with a multilayered (or plied and stitched fabric. This is because an integrated 3D fabric system is a single fabric system and hence highly resistant to delamination and splitting. The resistance to delamination and splitting comes from the yams which are intentionally incorporated in the fabric-thickness direc- tion along with the yarns in the fabric length and the width directions .

Usually a high-performance fibre material like the carbon, ceramic, glass, polyester etc. is selected as the yarn material depending upon the end-application of the composite material. To realize the utmost of the properties of a high-performance fibre in a composite material application, it becomes important to:

(1) process such a fibre material safely, and

(2) incorporate such a fibre material in the fabric with preferably no crimp (waviness of a fibre) . The first point implies that physical damage to the high-performance fibres during fabric production should be kept to the minimum. Damage to the fibres (which are in the form of yarns or filaments can result from the adverse interaction between the fibres (yarns or filaments) and the elements of the processing machine/s. Through such an adverse interference the high-performance fibres can be broken and thus lower the reliability and performance of the composite material. The second point concerns efficient translation of the tensile properties of the high-performance fibre material. If the filaments or yarns of high-performance fibre material acquires crimp or waviness as a result of fabric constructional characteristics (such as interlacing due to weaving, or interlooping due to knitting, or intertwining due to braiding) then tensile load bearing capacity of that yarn or filament is lowered. This is because with the formation of crimps in the yarn the resultant line of tensile loading gets deviated from the axis of the yarn. Thus, it is important for a fabric intended for composite material application to have the constituent yarns preferably as straight as possible, i.e., preferably without crimp.

The conventional fabric-forming techniques employed for producing integrated 3D fabric systems for composite material application are weaving, knitting and braiding. These techniques inevitably lead to the formation of crimps in the yarns of the fabric . This is because the yarns are made to interlace (weaving), interloop (knit- ting) and intertwine (braiding) to realize structural integrity of the fabric . Apart from these conventional 3D fabric-forming techniques there is the nonwoven technique of fabric manufacture. There are many ways of producing a nonwoven 3D fabric such as needle-punching, fluid jet entanglement, thermal bonding, adhesive bonding etc. In addition to these well-known methods, there is an entire- ly different method which may be supposed to have some resemblance to the weaving technique. However, by this unique nonwoven fabric-forming process the 3D fabric is produced without any interlacement of the employed yarns unlike in the weaving process where interlacement of warp and weft is the main process characteristic. Further, this nonwoven 3D fabric-forming process differs from the conventional weaving process in that it is essentially designed to process three sets of yarns into a nonwoven 3D fabric unlike the weaving process which is essentially designed to process two sets of yarns, the warp and the weft. Consequently, these three sets of yarns are assembled nearly mutually perpendicular to one other in the produced nonwoven 3D fabric .

In absence of any interlacement between the employed yarns, the structural integrity of this type of nonwoven 3D fabric results from the unique manner of "binding" (not knotting) the employed three sets of yarns. The structural integrity of the nonwoven 3D fabric is achieved, as shown in Figure 1, by traversing two sets of yarns (X and Y) through the third set of yarns (Z), and between the corresponding opposite outermost yarns of the set Z of the nonwoven 3D fabric. Clearly, such a unique manner of traversing the yarns of the two sets X and Y enables self-binding of the fabric structure. Thus, in such a nonwoven 3D fabric, the incorporated three sets of yarns are assembled nearly mutually perpendicular to one other, i.e., one set of yarn is orientated along the direction of fabric length, another set of yarns is orientated along the direction of fabric width and the last set of yarns is orientated along the direction of fabric thickness .

Further, because of no interlacement etc, of the employed yarns, it becomes possible to have all the constituent yarns of such a nonwoven 3D fabric without crimps as can be seen in Figure 1. Such a fabric therefore becomes particularly suitable for composite material application. It is thus amply clear that such a process and a fabric is entirely different from the weaving process and the woven fabric . For ease in understanding the present invention as different from the weaving process, a list of some new equivalent terms employed to describe the nonwoven 3D fabric-forming process, the nonwoven 3D fabric-forming device and the nonwoven 3D fabric are given in the accompanying annexure. This annexed list is only for the purpose of guidance.

For a method to be particularly capable of processing brittle continuous-fibre materials like ceramic, carbon, glass etc. into a satisfactory 3D fabric, i.e., a fabric having minimum of broken fibres, which is particularly suitable for composite material application, it is most important for the fabric-forming device to treat such brittle fibre types most gently to avoid undue breakage of the fibres. The damage to the brittle fibres during fabric forming process results mainly from the adverse action of the elements of the fabric-forming device. For example, with special reference to the weaving device, the damage to the brittle fibres can arise from the rubbing action of the weft inserting element (shuttle, rapiers etc.) on the warp yarns of brittle fibre material during picking, or the bending of the warp yarns of brittle fibre material by the heald-wire during shedding, or the rubbing and the beating action of the reed on warp and weft yarns of the brittle fibre material during the beating-up operation etc. It is thus clear that to produce a satisfactory fabric comprising of brittle fibre material, the adverse interaction/s between the fabric-forming machine element/s and the brittle fibre material has to be kept to the minimum because the inter- action between the fibre material and the machine element/s cannot be altogether eliminated.

To meet with the requirement of safely processing brittle or any other fibre material, the fibre manufacturers of course provide a suitable finish or protective coating called sizing to enable further processing/s without difficulty. However, because of the characteristics of certain fabric-forming processes, such as weaving and knitting, such a protective coating may not prove to be a sufficient protection, particularly in the case of brittle fibre materials like ceramic, carbon etc. For example, the conventional weaving process will be too severe on the brittle fibres like the ceramic and the carbon to allow satisfactory production of the fabric. Of course there is the possibility of braiding such brittle fibre materials as the braiding process characteristics are such that it will cause less damage to the brittle fibres compared with the weaving process. But there can arise a situation for a given end application of the composite material where a woven fabric construction may be preferable to a braided fabric construction, or it may be difficult to braid a particular size or shape. From these points of view it is sufficiently clear that it will be advantageous to have a device which can safely process all fibre types, including brittle fibre material types, into a satisfactory fabric which is particularly suitable for composite material application.

DISCLOSURE OF THE INVENTION:

The main objective of the present invention is to safely process all fibre types, including brittle fibre materials, into an integrated 3D fabric system which is particularly suitable for composite material application. Thus, the other objective of this invention is to have the constituent yarns of the 3D fabric preferably without crimp .

The said objectives are achieved by means of the device according to the present invention which is characterized by a plate constituting: (a) two sets of profiled tracks and existing in a mutually perpendicular configuration and in the same plane on the front face of the plate, and the length of each track of the two profiled track sets extending linearly between its respective pair of track- ing arrangements, (b) two sets of binder yarn spool carriers, each set containing multiple binder yarn spool carriers and each such binder yarn spool carrier having a matching profile at one side of it to fit slidingly into the profiled tracks so that each of the binder yarn spool carriers can be traversed in its respective track without the possibility of it coming off the track, and hence the binder yarn spool carriers forming an integral component of the plate, (c) two pairs of tracking arrangement, such that each pair being situated at the terminal sides con- tains between it all the profiled tracks of sets respectively, to shift the binder yarn spool carriers of the sets from its just traversed path to the adjacent path, such that through the employment of a pair of oppositely located tracking arrangement, the binder yarn spool carriers can be made to traverse in a closed loop circuit, without leaving the plate, about the corresponding row and column of the axial yarns which pass through the orderly arranged openings in the plate, and hence the tracking arrangement by virtue of restricting the binder yarn spool carriers from coming out of the plate forming an integral component of the plate, and (d) orderly arranged openings extending through the entire thickness of the plate such that the openings are arranged in row-wise and columnwise manner, into each of which is fixed a guide tube to allow the axial yarns to pass through the plate and each such opening which contains a guide tube, which would be eventually occupied with a yarn during fabric forming operation, is completely surrounded by the profiled tracks of the sets.

By means of the device according to the present invention, all kinds of fibres, including brittle fibre material types, can be safely processed into an integrated nonwoven 3D fabric, and furthermore, the device according to the present invention incorporates the constituent yarns of the nonwoven 3D fabric without crimps. Thus, such a fabric will be highly suitable for composite material application.

According to an embodiment the device is further charac- terized by the capability of bringing about the integration of the fabric under production directly, i.e. through traversing the binder-yarn carriers of the sets in a closed-loop path about the corresponding rows and columns of the axial yarns through the employment of the tracking means.

According to a further embodiment the device is further characerized by the capability of traversing the binder yarns carriers of each of the two sets either collec- tively, or in suitable small groups, or individually, depending upon the complexity of the cross section profile of the fabric under production.

According to a further embodiment the device is further characterized by the capability of traversing the binder yarn carriers of each of the two sets in sequences in accordance with the cross-section profile of the fabric under production to bring about the integration of the fabric directly. According to a further embodiment the device is further characterized by the total number of tracks in each of the directions, that is the vertical and the horizontal directions, being one more than the number of the corre- sponding rows and columns formed by the guide tubes such that every tube will be surrounded by the tracks.

According to an embodiment the device is further characterized by each of the guide tubes capable of (a) accomodating various shapes, sizes and materials of

'axial yarns' such as metallic and non-metallic foils and tapes, optical filaments, cords and ropes, organic and inorganic filaments/yarns, electricity and heat conducting filaments, metallic drawn-wires etc., (b) providing reliable protection to yarn material passing through it from the traversing binder yarn carriers, (c) forming uniformly shaped and clear passage both in the horizontal and the vertical directions for the unhindered traverse of the binder yarn carriers through the yarns of the set, by way of extending out at the front side of the plate in length equal but not lesser than the length of the binder-yarn carrier projecting out of its track, and (d) supporting the downwardly inclining horizontal set of binding yarn carriers to aid it to traverse smoothly.

According to an embodiment the device is further characterized by the total effective number of binder yarn carriers operable in each of the sets for producing fabric of a given cross-section profile corresponds to the total number of rows and columns of the guide tubes occupied by 'yarn' material of the set.

According to a further embodiment the device is further characeterized by the axial distance between any two adjacent tubes in a row being such that each of the binder-yarn carriers of the horizontal set is supported by at least one tube at all times during its traverse.

According to a further embodiment the device is further characterized by the axial distance between any two columnwise adjacent tubes being such that each of the binder-yarn carriers of the set can be traversed unobstructedly .

BRIEF DESCRIIPTION OF DRAWINGS: The present invention will now be described in detail in one embodiment with reference to the accompanying drawings. In Figure 1 a perspective view of the integrated nonwoven 3D fabric produceable by means of the device according to the present invention is shown. In actual production all the constituent yarns of the indicated 3D fabric will of course be closely packed to have sufficiently high level of fibre volume-fraction. Figure 2 shows a general perspective view of the complete device for the manufacture of the nonwoven 3D fabric . Figures 3 and 4 schematically shows the traverse sequence of the two sets of binder-yarn carriers that are employed in this device and which form an integral part of the present device as shown in Figure 2. Figure 5 shows the end view of a tube-holding plate which constitutes the main part of the device according to the present invention.

Figure 6 shows a cross-sectional view of the tube-holding plate along the lines VI-VI in Figure 5. Figure 7 shows the end view of the tube holding plate together with a binder-yarn carrier .

DESCRIPTION OF THE PREFERRED EMBODIMENT: From Figure 1 it is clear that this integrated nonwoven 3D fabric consists of three sets of yarns X, Y and Z which are mutually perpendicular to one other. Accordingly, the employed three sets of yarns are: (1) the set of principal reinforcement yarns (axial) Z, (2) the set of binder yarns (horizontal) X, and (3) the set of binder yarns (vertical) Y. In reference to Figures 2 and 6. each yarn-end of the set of the axial yarns Z, the supply source of which is located in the creel J, can be drawn through a tube G which is fixed in each of the openings B on the plate P. The binder-yarn carriers K lays the set of horizontal yarns X and the binder-yarn carriers L lays the set of vertical yarns Y in the production of the integrated nonwoven 3D fabric shown in Figure 1.

To produce an integrated nonwoven 3D fabric of the above-described structure, a device according to the embodiment of Figure 2 is preferably employed. The device consists of a frame A which supports the tube-holding plate P and clamp H for holding the produced fabric F. The clamp H forms a part of the fabric take-up system and is suitably mounted to aid advancement of the produced fabric regularly. The tube-holding plate P has a plural- ity of openings B which are arranged to form rows and columns. Into each of these openings is fixed a tube G as indicated in Figure 6. Consequently, the tubes G form rows and columns on the plate P. As already mentioned, each yarn-end of the set of axial yarns Z can be drawn out through each of these tubes G as shown in Figure 6. However, it is not necessary to occupy all rows and columns of tubes G with yarn-ends of the set Z . Depending on the number of yarn-ends of the set Z that may be required for a given fabric construction specification, some of the tubes G can be left unoccupied.

All the yarn-ends of the set Z which have been drawn out through the tubes G are jointly held in the clamp H. As can be understood from Figure 2. the yarns of set Z from the tubes G converge at cloth-fell. Further, the plate P has in-built horizontal and vertical tracks D and C respectively on one side of the tube-holding plate P. The tracks D and C run at either sides of every row and column of the tubes G. The length of the tracks D and C extends beyond the outer-most (top-most and bottom-most) rows and (leftmost and right-most) columns of the tubes G. Thus, each track of the two sets of tracks D and C runs between two adjacent rows and columns, and also at each of the exterior side of the outer-most rows and columns of the tubes G as shown in Figures 2 and 6. This way, there is a total of one more track in the horizontal and the vertical directions D and C respectively than the total number of rows and columns formed by the tubes G. The tracks D and C, which in the example as shown are T shaped slots as indicated in Figure 6, function as guide-ways for the binder-yarn carriers K and L. Every binder-yarn carrier of the sets K and L has a matching profile to fit slidingly into the T-shape slotted tracks D and C. The binder-yarn carrier has a provision to contain a spool of the binder yarn. An exhausted spool in a binder-yarn carrier can be replaced with a full spool without the need to take off the corresponding binder-yarn carrier from in-built tracks on the plate P. This way all the binder-yarn carriers form an integral part of the tube holding plate P. Furthermore, the total number of binder-yarn carriers in each to the sets K and L is equal to the corresponding total number of rows and columns formed by the tubes G.

Further, an arrangement for accomplishing structural integrity of the produced 3D fabric is provided within the plate P at each end of the horizontal and the vertical tracks D and C. There are thus four such arrangements located; two for the horizontal track-ends of the tracks D and two for the vertical track-ends of the tracks C. This arrangement collectively shifts all the binder-yarn carriers of a given set K or L, at the termination of their traverse, from the tracks in which have arrived to the corresponding adjacent track. Through such a "tracking" arrangement it becomes possible to traverse the binder-yarn carriers of set K and L in a close circuit as indicated in Figures 3 and 4.

Each set of binder-yarn carriers K and L are traversed alternately across the corresponding track D or C and preferably simultaneously for higher fabric production efficiency. The simultaneous traverse of the binder-yarn carriers of a given set K or L is also dependent on the shape of the cross-section of the fabric being produced. The binder-yarn carrier driving means can be rods or bands etc. operated from the track-end sides of the tube holding plate P. Although all the binder yarn carriers of a given set K or I, are simultaneously traversed, each of the binder-yarn carriers of the given sets K and L traverses in accordance with the sequence schematically indicated in Figures 3 and 4. The sequence of binder-yarn carrier traverse is definite as it has a bearing on accomplishing directly the structural integrity of the fabric .

To commence the process, one set of binder-yarn carriers, say the horizontal set K, are traversed, say, from right end to the left end of the tracks D. It is necessary at this point of the process that the top-most binder-yarn carrier traverses in the track above the top-most row of the tubes G. As a result, the binder yarn from this top-most binder-yarn carrier will be laid open on the outer side of the top-most row of the yams Z. Every other binder yarn of this set X will be laid between corresponding two adjacent rows of the yarns of set Z.

Next, the vertical set of binder-yarn carriers L is traversed. With a view to directly achieve the structural integrity of the fabric, it is necessary to start the traverse of this set of binder-yarn carriers L from the top end of the track C. and with the left-most binder-ya carrier traversing in the left-most track C. As a result, the binder yarn from this left-most binder yarn carrier will be laid open on the outer side of the left-most column of the yarns Z . Every other binder yarn of this set Y will be laid between corresponding two adjacent columns of the yarns of set Z .

Next, the horizontal set of binder-yarn carriers K is traversed from the left side to the right side of the track D. However, this time these binder-yarn carriers of the set K are not made to traverse in the same track in which they had come. In this return traverse each binder-yarn carrier of the set k is made to traverse in a track immediately below the corresponding previously traversed track. This shifting of the binder yarn carriers of set K to the corresponding adjacent horizontal track D is achieved through the tracking arrangement which is located on that side. In doing so, the left-most yarn of the vertical set Y which is on the outside of the left-most column of yarns of set Z gets bound into the set of binder yarns X which are now folding back. This way complete and direct selfbinding of the left side of the produced 3D fabric is accomplished. In this return traverse, the bottom-most binder-yarn carrier therefore traverses in the bottom-most track D. As a result, the yarn from this bottom-most binder-yarn carrier will be laid open on the outer side of the bottom-most row of the yarns of set Z . Every other binder yarn of this set X will be laid between corresponding two adjacent rows of the yarns of set Z.

Next, the vertical set of binder-yarn carriers L is traversed from the bottom end to the top end of the tracks C. However, this time these binder-yarn carriers of the set L do not traverse the same path in which they had come In this return traverse, each binder-yarn carrier of the set L is made to traverse in a track immedi- ately right of the corresponding previously traversed track. This shifting of the binder yarn carriers of set L to the corresponding adjacent vertical track C is achieved through the tracking arrangement which is located on that side. In doing so, the bottom-most yarn of the horizontal set of binder yarns X which is on the outside of the bottom-most row of yarns of set Z gets bound Into the set of binder yarns Y which are now folding back. This way complete and direct self-binding of the bottom side of the produced 3D fabric is accomplish- ed. In this return traverse, the right most binder-yarn carrier therefore traverses in the right-most track C. As a result, the yarn from this right-most binder-yarn carrier will be laid open on the outer side of the right-most column of the yarns of set Z. Every other binder yarn of this set Y will be laid between corresponding two adjacent columns of the yarns of set Z.

At the completion of the described one cycle of operations, the two sets of binder-yarn carriers K and L are back at their original starting positions. The subsequent new cycle of binder-yarn traverse starts all over again from these original positions exactly as before and positioning of the inserted binder yarn at cloth fell and fabric take-up is likewise regularly performed. In this fresh cycle of operations, the two sets of binder-yarn carriers K and L traverse alternately in exactly the same sequence and in the same tracks in which they had formerly traversed at the beginning of the cycle as all the binder-yarn carriers of the two sets K and L are shifted to the corresponding adjacent tracks by the tracking arrangement. As a result, the right-most yarn of the vertical set of binder yarns Y which is on the outside of the right-most column of yarns of set Z gets bound into the set of binder yarns X which are now folding back. This way complete and direct selfbinding of the right side of the produced 3D fabric is accomplished. Likewise, the top-most yarn of the horizontal set of binder yarns X which is on the outside of the top-most row of yarns of set Z gets bound into the set of binder yarns Y which are now folding back. This way complete and direct self-binding of the top side of the produced 3D fabric is accomplished .

In the described sequence of binder-yarn traverses, the other operations like the positioning of the laid binder yarns to the cloth fell and the fabric take-up are regularly performed at proper moments to facilitate normal production of the fabric. However, to prevent damage to the fibre material, the binder yams that have been inserted between the rows and the columns of the yarn-ends of set Z are not beaten-up by a reed to the cloth-fell as is done on a weaving machine. In the present device, a pin is employed to position collectively all the inserted binder yarns of a given set to the cloth-fell. As the outer-most rows and columns of the yarn-ends of the set Z form four exterior sides, there is located one operable pin at each exterior side. After a given set of binder-yarn carriers has fully emerged out of the outer-most row or column of the tubes G and entered into the tracking arrangement, the inserted binder yams and the outer-most row or column of the yarn-ends of the set Z of that side for an angular space. The pin located at the corresponding exterior side of the set of yarns Z is operated to enter into the formed angular space and move towards the cloth-fell. As the pin moves outside of the yarn-ends of the set Z there is no rubbing action between the two. The forward moving pin thus positions the just inserted binder yarns at the cloth-fell. After reaching the cloth-fell position, the pin is maintained there to hold back the positioned binder yarns until the subsequent binder yarns of the other set have been similarly positioned and held back.

The newly positioned binder yarn thus locks-in the previously inserted binder yarns of the other set at the previous cloth-fell position. The pin which was holding back the previously inserted binder yarns can now be withdrawn out of the angular space. However, each pin always moves to the same fixed position at the cloth-fell which is set prior to the commencement of the process in accordance with the size of the cross-section of the fabric to be produced. As a result of this the fabric produced has uniform cross sectional size along is entire length.

As will now be apparent from the above description of the nonwoven 3D fabric-forming process, the two sets of binder-yarn carriers K and L are alternately traversed in a closed circuit as indicated In Figures 3 and 4. Each binder yarn from the two sets of binder yarn carriers K and L is laid straight between the corresponding opposite surfaces of the 3D fabric. Consequently, there is no crimp formation on any of the three sets of yarns. As every binder-yarn carrier traverses in a closed circuit form, each of the binder yarn encircles the corresponding row or column of yarn-ends of the set Z in a loop form. Clearly, by way of such laying of binder yarns in a loop form, and in conjunction with the described ordered sequence of traverse of the two sets of binder-yarn carriers K and L, the structural integrity of the fabric is directly accomplished.

Further, as can be observed from the description of the process, the yarns of the set Z are not subjected to any kind of displacement in the entire cycle of operations like in the weaving process where the warp yarns are subjected to the shedding operation to enable interlacement of the warp and the weft yarns. Clearly, this process of fabric formation is totally different from the weaving process .

From the above-described nonwoven 3D fabric-forming process features and Figure 2 it is clear that the yarns of the set Z are maintained convergingly at all times . Thus, the shape of any two adjacent passages formed by the rows and columns of the yarn-ends of set Z will not be identical. As a result of the non-uniform shapes of the passages, the yarns of the set Z will hinder the traverse of the binder-yarn carriers which are made of uniform shape and size. This is because the converging angle of each yarn-end of set Z will tend to be different from that formed by the adjacent yarn-end of set Z. Apparently there exists the possibility of having inter- ference between these yarns of set Z and the traversing binder-yarn carriers K and L all the time. Thus the risk of damaging the yarns of set Z is present during the traverse of the binder-yarn carriers K and L. The risk of damaging the yarns of set Z is further increased when the binder-yarn carriers, particularly of the horizontal set K, inclines downwardly due to gravity from its support point which is at one end in the T-shaped track D.

Evidently to produce an integrated nonwoven 3D fabric successfully and more particularly of a brittle fibre material, a practical solution to the above-described problems is required. More specifically, means for the following are required: (1) a means for forming a uniform and clear passage between the rows and columns of the yarns of set Z for the unhindered traverse of the binder-yarn carriers K and L, (2) means for providing a reliable protection to the yarns of the set Z from the traversing binder-yarn carriers K and L, and (3) means for supporting the downwardly inclining binder-yarn carriers, particularly of the horizontal set K, during its traverse. The present invention according to Claim 1 uniquely overcomes these and other problems with the inclusion of the "tube-holding plate" P in the present device. According to the present invention the "tube holding plate" P is characterized by: (1) having tubes G fixed in rows and columns formation in accordance with Figures 5 and 6, (2) having in-built tracks D and C on one side of the plate P in accordance with Figures 2 and 6, (3) having two sets of binder-yam carriers K and L assigned to tracks D and C respectively such that the two sets of binder-yarn carriers K and L constitute an integral part of the plate P during their traverse in accordance with Figures 2, 6 and 7, and (4) having a "tracking" arrangement for accomplishing directly the structural integration of the produced nonwoven 3D fabric.

Description of the Invention

Each of the tubes G extend out perpendicularly from the front and the rear side of the plate P as indicated in Figure 6. The length of extension of each tube G from the front side of the plate P is not less than the length of the binder-yarn carrier which is extending out of the tracks D and C as indicated in Figure 6. Further the ends of each of the tube have smooth edges so as not cause damage to the yarns passing through it. The length of extension of each tube G from the rear side of the plate P can be according to the requirements for which each tube G may be additionally used for secondary purposes to be described soon. It is now known that each yarn-end of the set Z passes through a corresponding tube G from the creel J to the cloth-fell of the fabric. Therefore, the secondary purposes for which each tube G can be addi- tionally utilized are many. For example, the rear length of tube G can be utilized for injecting air under pressure, in a direction opposite to the direction in which the yarn-end of set Z advances for the purpose of tensio- ning the yarn-end of set Z; or injecting polymer, resin, and other suitable formulations for the purpose of coating the yarn-ends of set Z during the fabric-forming process to produce modified products; or heating the yarn-end of set Z during f bric-forming process for processing convenience, product modification etc., etc.

Coming back to the primary utility and function of tube G according to the present invention, the disposal of the tubes G in the plate P in the described manner uniquely overcomes the various processing problems discussed earlier. Thus, the fixing of the tubes G In plate P in rows and columns arrangement while allowing continuous passage to the yarn ends of the set Z in rows and columns arrangement at the same time: (1) provides reliable protection to the yams of the set Z from the traversing binder-yarn carriers (2) forms uniformly shaped and clear passage both in the horizontal and the vertical directions for the unhindered traverse of the binder yarn carriers through the yarns of the set Z (3) supports the downwardly inclining horizontal set of binder-yarn carriers K and thereby prevent interference between the binder-yarn carriers and the yarns of the set Z.

Apparently with the above-described arrangement, the binder-yarn carriers K and L when traversed In the corresponding tracks D and C cannot under any circumstances interfere with the yarns of the set Z as the extending tubes G aid in forming uniformly shaped clear passage as indicated in Figure 6. Further, the tubes G reliably protects the yarns of the set Z from the traversing binder-yarn carriers of sets K and L. Additionally, the tube G supports particularly the binder-yarn carriers of horizontal set K from inclining downwards and thus prevent interference with the yarn-ends of the set Z . The inclusion of the tubes G in the plate P in the described manner thus allows all fibre types, including brittle fibre types, to be safely processed into an integrated nonwoven 3D fabric .

Claims

CLAIMS :

1- A device for producing integrated nonwoven 3D fabric comprising essentially three sets of yarns of any fibre type, including brittle fibre type, such that the employed three sets of yarns are incorporated in the produced fabric in a nearly mutual perpendicular orientation by the device CHARACTERIZED BY a plate P constituting: (a) two sets of profiled tracks D and C existing in a mutually perpendicular configuration and in the same plane on the front face of the plate P, and the length of each track of the two profiled track sets D and C extending linearly between its respective pair of tracking arrangements, (b) two sets of binder yarn spool carriers K and L, each set containing multiple binder yarn spool carriers and each such binder yarn spool carrier having a matching profile at one side of it to fit slidingly into the profiled tracks D and C so that each of the binder yarn spool carriers can be traversed in its respective track without the possibility of it coming off the track, and hence the binder yarn spool carriers fomming an integral component of the plate P, (c) two pairs of tracking arrangement, such that each pair being situated at the terminal sides contains between it all the pro- filed tracks of sets D and C respectively, to shift the binder yarn spool carriers of the sets K and L from its just traversed path to the adjacent path, such that through the employment of a pair of oppositely located tracking arrangement, the binder yarn spool carriers can be made to traverse in a closed loop circuit, without leaving the plate P, about the corresponding row and column of the axial yarns Z which pass through the orderly arranged openings in the plate P, and hence the tracking arrangement by virtue of restricting the binder yarn spool carriers from coming out of the plate P forming an integral component of the plate P, and (d) orderly arranged openings B extending through the entire thick- ness of the plate P such that the openings are arranged in row-wise and columnwise manner, into each of which is fixed a guide tube G to allow the axial yarns Z to pass through the plate P and each such opening which contains a guide tube G, which would be eventually occupied with a yarn during fabric forming operation, is completely surrounded by the profiled tracks of the sets D and C.

2. The device according to claim 1 further charac- terized by the capability of bringing about the integration of the fabric under production directly, i.e. through traversing the binder-yarn carriers of the sets K and L in a closed-loop path about the corresponding rows and columns of the axial yarns Z through the employment of the tracking means.

3. The device according to claim 1 further characterized by the capability of traversing the binder yarns carriers of each of the two sets K and L either collec- tively, or in suitable small groups, or individually, depending upon the complexity of the cross section profile of the fabric under production.

4. The device according to claims 1, 2 and 3 fur- ther characterized by the capability of traversing the binder yarn carriers of each of the two sets K and L in sequences in accordance with the cross-section profile of the fabric under production to bring about the integration of the fabric directly.

5. The device according to claim 1 further characterized by the total number of tracks in each of the directions, that is the vertical and the horizontal directions, being one more than the number of the corre- sponding rows and columns formed by the guide tubes G such that every tube G will be surrounded by the tracks D and C .

6. The device according to claim 1 further characterized by each of the guide tubes G capable of (a) accomodating various shapes, sizes and materials of

'axial yarns' such as metallic and non-metallic foils and tapes, optical filaments, cords and ropes, organic and inorganic filaments/yarns , electricity and heat conducting filaments, metallic drawn-wires etc., (b) providing reliable protection to yarn material passing through it from the traversing binder yarn carriers, (c) forming uniformly shaped and clear passage both in the horizontal and the vertical directions for the unhindered traverse of the binder yarn carriers through the yarns of the set Z, by way of extending out at the front side of the plate P in length equal but not lesser than the length of the binder-yarn carrier projecting out of its track, and (d) supporting the downwardly inclining horizontal set of binding yarn carriers K to aid it to traverse smoothly.

7. The device according to claim 1 and 6 further characterized by the total effective number of binder yarn carriers operable in each of the sets K and L for producing fabric of a given cross-section profile corre- sponds to the total number of rows and columns of the guide tubes G occupied by 'yarn' material of the set Z.

8. The device according to claim 1 and 6 further characterized by the axial distance between any two adjacent tubes (G) in a row being such that each of the binder-yarn carriers of the horizontal set (K) is supported by at least one tube (G) at all times during its traverse .

9. The device according to claim 1 and 6 further characterized by the axial distance between any two columnwise adjacent tubes (G) being such that each of the binder-yarn carriers of the set L can be traversed unobstructedly.