Method for producing cold cut textile webs

Abstract

In order to produce a plurality of fabric strips (22) from a fabric (20) during the manufacturing process thereof, a method is proposed which utilizes the steps of: inserting weft threads (24) into the open warp thread shed, laying of a plurality of cover threads (30, 34) in a zigzag shape by a plurality of feed needles (32, 36), cutting the fabric (20) in the drawing-off direction into a plurality of woven strips (22), and pulling off the warp threads (60) that are located between the cutting-side laying points of the cover threads and the cutting device. This method can be implemented in a particularly advantageous manner if, in addition to the cover thread (30, 34) introduced in zigzag manner, a further cover thread (70) is introduced at each fabric edge (26) by a further feed needle in such manner that it is connected to the zigzag thread whereby the zigzag thread is prevented from fraying.

Claims

1. A method for producing a plurality of woven fabric strips by means of a weaving loom, wherein the weaving loom comprises at least a weft thread insertion device, a reed or an equivalent means, a plurality of laying devices for additional cover threads and at least a cold cutting tool for cutting of the woven material into woven fabric strips, comprising the steps of inserting weft threads into an open warp thread shed, laying a plurality of cover threads by means of a plurality of feed needles, cold cutting of the woven fabric in take-off direction into a plurality of woven fabric strips, whereby the cold cutting avoids partially or completely melting through threads of the woven fabric strips, characterized in that the cover threads are laid in a zigzag manner and are introduced into the warp thread shed from above through the feed needles in such manner that said cover threads are overstitched by the weft thread insertion device and thereby are bound into the woven fabric by means of the weft threads.

2. The method according to claim 1, characterized in that weft thread tails are formed by the cold cutting step or after the cold cutting step.

3. The method according to claim 2, characterized in that the weft thread tails are formed in such manner that in a further step the woven warp threads that are located between the cutting-side laying points of said cover threads and the cutting device are pulled off.

4. The method according to claim 2, characterized in that the weft thread tails are formed in such manner that the warp threads that are located between the cutting-side laying points of said cover threads and the cutting edge are permanently maintained in the low shed during the weaving process and the pulling off takes place downwards between the reed and the cutting device.

5. The method according to claim 2, characterized in that the weft thread tails are formed in such manner that the warp threads that are located between cutting-side laying points of said cover threads and cutting edge are pulled off upwards or downwards already before the shed.

6. The method according to claim 2, characterized in that the weft thread tails are formed in such manner that the cover threads are inserted under such high tension that the warp threads being bound by said cover threads are drawn together in weft direction in a region whereby a cutting path is formed and no excess warp threads need to be pulled off.

7. The method according to claim 1, characterized in that a distance between cutting-side laying points of said cover threads and the cutting tool is at least 0.2 mm.

8. The method according to claim 1, characterized in that the weft threads to be cut cold are not meltable.

9. The method according to claim 1, characterized in that the woven fabric is fixed in a region of a cutting point by heating.

10. The method according to claim 1, characterized in that at least of the cover threads, weft threads or warp threads located at a cutting-side laying point is thermally meltable.

11. The method according to claim 1, characterized in that the cover thread is fused with the weft threads, the underside of the woven fabric, by means of a heating element.

12. The method according to claim 1, characterized in that at least one of the woven fabric's threads is provided with a hot-melt adhesive coating and that the zigzag structure is hot-adhered by means of a heating element, at temperatures below a melting point of the threads used in the fabric structure.

13. The method according to claim 1, characterized in that in addition to the cover thread introduced in zigzag manner, a further cover thread is introduced at each fabric edge by means of a further feed needle in such manner that said further cover thread is connected to the zigzag thread whereby the zigzag thread is prevented from fraying.

14. The method according to claim 13, characterized in that prior to cutting, the woven fabric is fixed in a region of a cutting point by heating, the additional cover thread being thermally meltable.

15. The method according to claim 13, characterized in that the additional cover thread is fused with the weft threads and/or to the cover threads, on the underside of the woven fabric, by means of a heating element.

16. The method according to claim 13, characterized in that the additional cover thread (70) is provided with a hot-melt adhesive coating and the zigzag structure is hot-adhered by means of a heating element, at temperatures below the melting point of the threads used in the fabric structure.

17. The method according to claim 14, characterized in that the additional cover thread is fused with the weft threads and/or to the cover threads, on the underside of the woven fabric, by means of a heating element.

18. The method according to claim 14, characterized in that the additional cover thread is provided with a hot-melt adhesive coating and the zigzag structure is hot-adhered by means of a heating element, at temperatures below the melting point of the threads used in the fabric structure.

19. The method according to claim 15, characterized in that the additional cover thread is provided with a hot-melt adhesive coating and the zigzag structure is hot-adhered by means of a heating element, at temperatures below the melting point of the threads used in the fabric structure.

20. The method according to claim 2, characterized in that the weft threads to be cut cold are not meltable.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) Examples of the weaving loom will henceforth be described in more detail by reference to the drawings, which show:

(2) FIG. 1 the weaving process, with the insertion of the weft thread and the zigzag threads in the first position;

(3) FIG. 2 the weaving process, with the insertion of the weft thread and the zigzag threads in the second position;

(4) FIG. 3 the cutting process, with the pulling-off of the loose warp threads;

(5) FIG. 4 the cutting process in a first alternative embodiment, in which the warp threads between the cutting device and the fabric edge remain in the low shed during the entire weaving process and are pulled off downwards independently of the cutting process;

(6) FIG. 5 the cutting process in a second alternative embodiment, in which the warp threads between the cutting device and the fabric edge are pulled off upwards already before the shed;

(7) FIG. 6 the situation of the zigzag thread, which is already held in place by the weft thread tails;

(8) FIG. 7 the situation of the zigzag thread, which is fixed by an additional cover thread independent of the weft thread tails, and

(9) FIG. 8 an embodiment in which the cover threads are inserted under high tension.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS OF THE INVENTION

(10) FIGS. 1 to 5 show a first, simple embodiment of the invention. As shown in FIG. 1, the weft thread 24 is inserted weft by weft into the open respective warp thread shed 28 by means of a weft thread guide 40, whereby in the embodiment example the weft thread guide 40not shown in FIG. 1transfers to a transfer gripper and thus produces the base woven fabric 20by means of beating through the reed 10. According to the invention, the zigzag shaped cover threads or effect threads 30, 34 are inserted by means of a plurality of feed needles or reed hooks 34, 36. For this purpose, one of the known methods and devices, respectively, is used. The insertion of such cover threads or effect threads 30, 34 is already described in its principles in CH 490541 A. However, in the embodiment of the invention, the cover threads or effect threads 30, 32 are introduced into the shed or warp thread shed 28 from above by means of feed needles or reed hooks 32, 36 in such manner that they are overstitched by the weft thread insertion device 40 and thereby are bound into the woven fabric 20. This binding of the zigzag threads into the woven fabric by means of binding the corner points of the zigzag pattern into the woven fabric prevents a later fraying from the outset. The feed needles 32, 36 are arranged between the reed beat-up and the reed 10. The reed 10 is closed at the top as usual. Alternatively, the zigzag laying can also be carried out as described in WO 2011/095262 A1, according to which the feed needles are not arranged between the reed beat-up and the reed 10, but between the reed 10 and the shed forming device, and the reed 10 has upwardly open reed teeth. In the exemplary embodiment for laying a zigzag arrangement, the two feed needles 32 and 36 shown here, which form only an illustrative section of the overall device, together with a further feed needle, not shown here, are synchronously guided back and forth in and against the weft insertion direction, as shown in FIGS. 2 and 3.

(11) FIG. 3 additionally shows the cutting tool. By means of the cold cutting tool 50, which in the present embodiment is but a simple cutting knife, the woven material 20 is cut in the region of the fabric take-off into a plurality of woven fabric tapes 22, noting that in FIG. 3 only the cutting interface between two of these woven fabric tapes 22 is shown. In the exemplary embodiment, the cutting process is carried out centrally between the two end points of the zigzag arrangement facing the cutting knife 50. In the exemplary embodiment, the respectively exposed four warp threads 60 are then pulled off laterally at an angle, so that the remaining weft thread regions form weft thread tails 25which are approximately 1 mm long in the embodiment examplewhich, on the one hand, already prevent the additional cover threads 30, 34 from fraying, since they are held in tension, and which, on the other hand, form a velvet-like finish to the respective woven fabric strips 22.

(12) In a first alternative embodimentas shown in FIG. 4the superfluous warp threads between the cutting device and the fabric edge 26 are pulled off downwards independently of the cutting device 50, thus forming the weft tails 25. In the present embodiment, this is made possible by the fact that these warp threads remain in the low shed during the entire weaving process and therefore never pass above the weft threads. All other steps of the processin particular the steps relating to the cover threadsare carried out in exactly the same way as in the first embodiment.

(13) In a second alternative embodimentas shown in FIG. 5the superfluous warp threads between the cutting line and the fabric edge 26 are already drawn off upwards before the reedalso independently of the cutting device 50, that means, they are not bound in at all. As a result, the weft thread tails are formed in this exemplary embodiment. All other steps of the processin particular the steps relating to the cover threadsare carried out in exactly the same way as in the first embodiment.

(14) In a preferred embodiment of the present inventionas shown in FIG. 8the cover threads 30, 34 are inserted under such high tension that the warp threads being bound by them are drawn together in a region 80 in weft direction in such a strong manner that a cutting path 82 is formed and no excess warp threads need to be pulled off. Due to the resulting cutting path, the cutting device 50 is thus so far away from the nearest warp threads so that these cannot be damaged. Also in this embodiment, the weft thread tails 25 are formed by drawing the warp threads together.

(15) In one embodiment of the method of the present invention, for at least one of the threads used, that means the cover thread, the weft thread or the warp thread, a thermally fixable thread is used in the region of the fabric edge and is thermally fixed, for example, by being slightly melted on its surface and thereby being mechanically fixed with the other threads.

(16) In an extended embodiment of the invention, the cover thread 30, 32 is fused with the weft threads on the underside of the woven fabric by means of a heating element. In this process, fusible cover thread and weft threads and possibly warp threads, are used and connected by fusing to form an even more secure fabric edge. Thereby, it should be emphasized that, in contrast to the prior art, in which the separation is carried out by hot cutting, the threads themselves are not damaged, but just only partially melted on their surface. Therefore,with careful handlingthis also does not result in the described disadvantages of hot cutting.

(17) In an extended embodiment of the invention, for at least one of the threads being used, a hot-melt adhesive is employed, and the zigzag structure is hot-adhered at the point of the fabric edge by means of a heating element at temperatures below the melting point of the threadsprovided that fusible threads are used, which is not necessary in this exemplary embodiment.

(18) In FIGS. 6 and 7, a further securing of the fabric edge 26 of the woven fabric strips 22 is illustrated, namely in FIG. 6 without such securing and in FIG. 7 with such securing. As shown in FIG. 6, the fabric edge 26 is secured to the extent that the cover thread 30, 34 is under tension on its side facing the cutting edge to such an extent that it does not extend over the corresponding weft thread tail 25. Without additional securing measures, such as, for example, the aforementioned melting or hot-adhering, it is however, possible, in the event of careless handling of the woven fabric tape 22, in particular through improper manipulation, that individual ends of the zigzag thread are brought over the weft thread tail 25 and thus the fabric edge 26 is damaged. This can be preventedeither in addition to the above-described measures of melting or hot-adhering, but also as a stand-alone measureby means of a further cover thread 70, which is introduced with a further feed needle. In this embodiment, this additional cover thread 70 has the effect that the respective zigzag thread 30 or 34 is bounded and thus secured with respect to the weft thread 24 or with respect to the weft thread tail 25. Thereby, the additional cover thread 70 lies in warp thread direction substantially between the last remaining warp thread and the first loose warp thread 60 and thus forms the end of the fabric edge 26. However, the additional cover thread can in turn also adopt a zigzag arrangement and does not necessarily form the end of the fabric edge. Its essential function, however, is that it additionally secures (knots) the binding points between the cover thread 30, 34 and the weft thread 24 in order to prevent the zigzag thread 30, 34 from slipping off.

LIST OF REFERENCE NUMERALS

(19) 10 reed 20 woven fabric 22 woven fabric strips 24 weft thread 25 weft thread tail 26 fabric edges 28 warp thread shed 30 first cover thread 32 first feed needle 34 second cover thread 36 second feed needle 40 weft thread guide 50 cold cutting tool 60 loose warp threads after the cutting process 70 additional cover thread for attaching the zigzag thread 80 region of drawn or compressed warp threads 82 cutting path