EP1838910A1

EP1838910A1 - Gauze cloth and method and mechanical loom for producing the same

Info

Publication number: EP1838910A1
Application number: EP05824203A
Authority: EP
Inventors: Adnan Wahhoud
Original assignee: Lindauer Dornier GmbH
Current assignee: Lindauer Dornier GmbH
Priority date: 2004-12-31
Filing date: 2005-12-22
Publication date: 2007-10-03
Anticipated expiration: 2025-12-22
Also published as: ATE446399T1; BRPI0519768A2; JP4584318B2; US7287553B2; DE502005008394D1; RU2347022C1; US20060169347A1; JP2008525658A; WO2006069562A1; EP1838910B1

Abstract

A leno cloth is prepared, which comprises at least ground warp threads 1 , leno warp threads 3 and weft threads 2 , and in which the weft threads 2 and the ground warp threads 1 are arranged essentially interspace free. The weft threads are bound-off by means of the leno warp threads 3 , which comprise a clearly lower titer relative to the ground warp threads 1 , with such a lower tension relative to the ground warp threads, so that the crossings of the leno warp threads 3 with the ground warp threads 1 that are present due to the binding are arranged in a plane parallel to the plane of the maximum thickness of the weft threads. The leno warp threads 3 comprise a higher working-in or take-up into the woven cloth than the ground warp threads 1 . According to a further aspect of the invention, a method for the production of a leno cloth as well as a loom for the carrying out of the method for the production of a leno cloth are described.

Description

description

Leno fabric and method and weaving machine for its production

The invention relates to a leno fabric and a method and a loom for its production.

Drehergewerbe existing base warp, Dreherkettfäden and weft threads are known; as well as methods and looms for their production.

DE 100 04 376 A1 discloses a method for producing a leno base fabric and a loom for carrying it out. This method is realized by means of a loom, in which as shedding devices known per se half heald with lifting healds according to DE 197 508 04 C1 are used in combination with at least two stranded frames. The production of the leno base fabric takes place in that at least two heddle frames are equipped with a plurality of first lifting healds for half heald and the other heald frame is equipped with the same plurality of lifting healds for the half heald. In the production of such Drehergrundgewebes the warp tension plays both the so-called Stehrfadenkette and the Dreherfadenkette an important role. In this known method it is provided that the Sollkettspannung the Stehrfadenkette is about twice as large as the Sollkettspannung the leno thread chain. As a result, a leno fabric is achieved with a relatively high resistance to sliding. However, it has proved to be disadvantageous in this known method or in the weaving machine for carrying out the method that the service life of the half-healds with the lifting healds is not sufficient. Another disadvantage is that the two equipped with the half and lifting heald shank in the usual way require a shedding machine, which is expensive, because the cost of the shedding machine in the weaving machine is relatively independent of the number of heddles.

Furthermore, from DE 101 285 38 A1 a weaving machine for producing a

Leno fabric known in which the drive for the shedding devices, in which the Steherkettfäden and Dreherkettfäden retracted and in which they are guided, derived from the drive of the loom itself. At this known weaving machine are used as shedding means a so-called leno-Nadelriet and a standing-Nadelriet. Each Nadelriet owns a plurality of needles, at the free ends of which at least one eyelet for passing the respective leno warp thread or the respective Steherkettfadens is provided. The needles of each needle reed are separated by flat bars to ensure that each leno warp thread can only skim over one needle of the stirrup when making the leno weave. In this known weaving machine, the leno and the warp warp threads are provided by at least one bottom warp beam and fed to the shed forming means via at least one spreading beam. Therefore, the leno warp yarns and the warp warp yarns have the same warp tension. The variety of patterns in such leno fabrics is limited insofar as qualitative differences between the leno warp yarns and the warp warp yarns, particularly the fineness of the warp yarns or yarns, are largely excluded.

According to a further aspect, the invention relates to a leno fabric with novel functional properties, in particular for use as a floor covering.

For floor coverings velor, loop or smooth textiles are used. For the production of these floor coverings various manufacturing methods are known. So it is known to manufacture velor and loop carpets on complicated and elaborate rod and Doppelteppichwebmaschinen. In the well-known so-called Tuftingteppichen and process for their preparation, a carrier layer z. As a fleece or a fabric in the form of a Pohlschicht introduced, usually by incorporating yarn loops, wherein the surface may be formed as velor or in the form of loops. To solidify the incorporated loops, these are then connected by a binder with the carrier material. This means that several process steps are required to make tufted carpets. One of the reasons why these production methods are so costly is that floor coverings on the upper side and bottom side thereof generally have to have different functional properties. Special requirements are mainly due to the surface structure, the Tread comfort and the robustness of the top. On the underside of the floor coverings, especially those properties are particularly important, which come into play in cooperation with the respective substrate. These include, for example, skid resistance and adhesiveness. In addition, certain requirements are placed on the floor covering as a whole, such. As a certain stiffness and slip resistance and a desired basis weight.

Fabrics, in particular the leno fabrics considered here, which have different properties on their upper surface than on their underside are also referred to as so-called "double-face fabrics." On the one hand, these different properties can relate to physical properties, as with floor coverings, but they can also have aesthetic aspects of patterning and color intensity on the front and / or back of the fabric.

The invention is therefore based on the object to provide a dense leno fabric, which has different functional and / or aesthetic top and bottom sides, which is easy to manufacture and a variety of applications is accessible. Moreover, it is a further object of the invention to provide a method and a loom for realizing such a method for producing the leno fabric according to the invention.

This object is achieved by a leno fabric with the features of claim 1, by a method with the features of claim 15 and by a loom with the features of claim 17. Advantageous developments are defined in the respective dependent claims.

The leno fabric according to the invention has at least base warp threads, leno warp threads and weft threads, wherein the weft threads on the

Base warp threads are arranged substantially free of space. The term gap-free should be understood to mean that the weft threads are arranged so close to each other that they touch each other at least slightly, so that the side of the leno fabric, which is formed by the weft threads, is essentially formed by its structure or color. The weft threads are bound by means of the leno warp yarns which have a much lower titer than the ground warp yarns, being set at such a lower tension than the warp yarns that the interlacing of the leno warp yarns with the ground warp yarns, which are present by the binding, are arranged in a plane which is different from the plane which runs through the maximum thickness of the weft threads and in the longitudinal direction. This means that the crossings either face the base warp threads or are arranged on the upper side formed by the weft threads, but not between the weft threads. The leno warp yarns have a higher incorporation into the fabric than the base warp yarns. This means that the weft threads remain essentially without twisting in their longitudinal extent, while the leno warp threads due to their significantly lower warp tension loop around the weft threads to their setting with the base warp threads in the sense of greater incorporation.

If the leno warp yarns are arranged between the base warp yarns and the weft yarns, ie below the maximum weft yarn thickness, the crossovers are essentially covered by the weft yarns touching each other, so that they are essentially not visible on the upper side of the leno fabric formed by the weft yarns. Due to the tension-related laying of the crossings on the underside of the weft threads and thus in the direction of the ground warp threads, a so-called double-face property of the leno fabric can be achieved with a corresponding color or structural coordination of ground warp threads and leno warp threads. Therefore, on the side of the base warp yarns, the color or structure of the base warp yarns and the leno warp yarns dominates, whereas on the opposite side of the leno fabric, i. on the top, the color or structure of the weft threads dominates.

For fabric formation, the leno warp yarns are thus provided by a first warp beam and the base warp yarns by a second warp beam, wherein the leno warp yarns are fed into first shed forming means and the ground warp yarns are fed into second shed forming means. Both types of warp threads are brought together in the binding point of the leno fabric to be produced. As a result of that the warp yarns and the leno warp yarns of warp beams each having its own electromotive drive, that is, electromotive warp let-off, are provided, the tension of both the ground warp yarns and the leno warp yarns can be individually adjusted and controlled. This makes it possible, depending on the set tension, to arrange the interlacings of the leno warp threads with the base warp threads, which arise as a result of the binding, either below a plane extending through the maximum thickness of the weft threads or above this plane. Thus, it is possible, for example, to produce a characteristic leno fabric in that the ground warp threads consist of substantially coarser warp material than the leno warp threads, wherein the tension of the ground warp threads can well be several times the tension of the leno warp threads.

Preferably, in the leno fabric according to the invention, the weft threads are arranged and bound so close together that the fabric has a sliding structure. Sliding-resistant structure is understood to mean a very dense tissue, which otherwise can be achieved at best with plain weave. A major advantage of such a leno fabric consists, above all, in the fact that the structure or pattern or color of at least one side of the leno fabric is determined by the weft yarns, which can easily be inserted as required into the respective shed at the respective location, whereas a conventional fabric, the different shape or pattern over the base warp threads is achieved, for different colors, a relatively large effort in terms of winding different yarns or different colors on the warp beams. Thus, the leno fabric according to the invention has a very high flexibility in patterning and structure compared to conventional leno fabrics.

Since the tension of the leno warp yarns is significantly lower compared to the ground warp yarns, the ground warp yarns are incorporated only so weakly that they are substantially rectilinear and bonded by means of the heavily incorporated leno warp yarns. The weft threads cover the leno warp threads and thus also the ground warp threads almost completely. As a result, the color, structure or the surface of the leno fabric on the one hand by the Weft threads and on the other side determined by the Grundkettfäden and the leno warp threads, so that so that a so-called double-face fabric can be generated.

Preferably, the leno fabric is formed so that on the top of the base warp yarns alternately at least one coarse and especially soft weft and at least one thin and in particular stiff weft are arranged such that the coarse weft yarns substantially cover the thin weft yarns and a substantially closed, by In particular, color and structure of the coarse weft threads define defined surface. The coarse weft threads and the thin weft threads may be arranged alternately; However, it is also possible that in each case two coarse weft threads are followed by a thin weft threads or vice versa or other combinations of coarse weft threads and thin weft threads are realized. The order of the arrangement of coarse weft threads and thin stiff weft threads contributes significantly, in addition to the stiffness in the warp direction generated by the base warp yarns, also to the stiffness of the fabric in the weft direction. The voluminous coarse tail yarns cover the finer, stiff weft threads towards the surface, thereby forming the already mentioned dense, substantially closed surface. They thus ensure that the surface properties, in particular of a floor covering, do not change despite increased rigidity of the entire fabric.

The weft threads and the ground warp threads are looped around by the leno warp threads, that is to say the leno warp threads run both horizontally and vertically in several planes and bind the weft threads and the ground warp threads together to form a firm fabric. By means of a suitable material selection of the individual threads or yarns, the desired different functional properties are achieved at the upper side or at the lower side of the fabric. For example, when heavy-duty coarse weft threads are used, the top of the fabric becomes rugged and abrasion-resistant

Surface formed. Especially with floor coverings are called

Basic warp such materials used that a non-slip, rigid

Underlayer of the tissue arises. Characterized in that the base warp threads of the fabric according to the invention are arranged on the underside of the fabric and extend substantially straight in a plane, they form a support plane for the weft threads when they are arranged correspondingly tight.

A significant advantage of the leno fabric according to the invention is that can be easily realized by appropriate selection of materials, the respective structure, the physical properties and aesthetic designs with the fabric according to the invention for any applications on the use of appropriate weft threads. Different functional properties on the respective sides of the fabric are particularly advantageous for awning fabrics, for example. The functional properties include in particular volume, topography of the surface, failure, color and tread comfort and surface resistance, as well as the patterning.

In contrast, the base warp threads disposed on the underside of the fabric essentially perform the function of the stiffness of the fabric and the desired properties, such as in the case of a floor covering, the properties of the fabric in connection with the substrate on which the floor covering is to be laid. Since the base warp threads on the underside of the floor covering run almost in a straight line and also form a certain area with appropriate density, these may consist entirely or partly of metallic fibers, whereby a conductivity is achieved, which is used for detection tasks such as in particular the monitoring of rooms and / or the discharge of electrostatic charges can be used.

The leno warp yarn is used as a binder yarn and forms the tie between the weft yarns forming the surface and the ground warp yarns. Thus, in a single operation and with relatively little effort in the production of a dense and non-slip leno fabric is produced that can be used excellently as a floor covering in particular.

Another advantage of the leno fabric according to the invention is, inter alia, that an article change can be easily realized because only the Weft yarns and / or the weft density can be changed quickly and easily. For example, up to 16 colors pic-pic for the weft insertion can be presented to a rapier loom in the weft. According to a preferred embodiment of the invention, with the variation of the fineness of the weft yarn in the range of 20,000 dtex (0.5 Nm) to 500 dtex (20 Nm), for example of natural and synthetic fibers, the thickness of the fabric is changed and adapted to the particular application. Likewise, it can easily be achieved by a special selection of a particular shooting game or by using such a weft yarn that step-like contours arise on the top of the fabric, without changing the contour of the bottom. Because the shape of the bottom is determined exclusively by the basic warp threads. This is desirable, for example, in textile floor coverings to achieve certain aesthetic effects. In the leno fabric according to the invention, the weft density can be adjusted so that the fibers of the weft yarns can be more or less densified, depending on the desired performance property. The characteristic of the binding threads with the correspondingly adjustable thread tension during weaving influences the robustness of the floor covering due to the constriction which occurs between weft threads and base warp threads. The wrapping of the weft threads and the base warp threads with the binding threads by 180 degrees in each case results in a very robust fabric with an extremely high sliding strength. Additional consolidation on the underside of the fabric, as is necessary, for example, in tufted carpets, is therefore no longer necessary with the leno fabrics according to the invention.

Depending on the required robustness and abrasion resistance, the leno warp threads acting as binding threads can be made from natural or synthetic fibers with finenesses between 22 and 5000 dtex.

For example, in a gamma unit, the leno warp yarns of e.g. 22 dtex polyester and the base warp yarns of e.g. Polyester with 1,100 dtex and the

Weft threads of e.g. Polyester of any yarn count a fabric in

Dreherbindung obtained in which the base warp threads on one side of the

Tissue visually dominant emerge, while on the other side of the

Fabric the weft threads visually dominant emerge. This results in particular because the leno warp yarns due to their fineness of 22 dtex with the naked eye in the tissue are not or barely perceptible. This is an example of the above-described double-face property of the fabric.

According to one embodiment of the invention, at least two base warp threads are tied together by means of the leno threads. The two ground threads form a group of ground warp threads, wherein at least two weft threads can be tied together by means of the leno threads. But it is also possible that, for example, the individual weft threads or groups of weft threads are bound with at least two leno warp threads.

In order to be able to form step-like structures on the surface of the leno fabric, the weft yarns are preferably varied in groups with respect to their titer, the number of weft yarns depending on their thickness and their size on the surface of the fabric to achieve a step-like structure.

These characteristics of the leno fabric are thus produced by incorporating groups of ground warp yarns into the shed warp shed forming means and, accordingly, reversely groups of leno warp yarns into the shed bottom warp shedding means. When using the above-mentioned yarn counts for the warp and the weft, the entire fabric surface or fabric sections can be designed so that they are visually dominant or, vis-à-vis other fabric sections, the base warp threads are visually dominant, depending on the variation of the weft threads. In this way, e.g. Leno fabrics are made with longitudinal stripes. The particularly dense fabric with non-slip structure offers the possibility, for example, with multi-colored weft material and einfarbigem warp material to produce a fabric in which the colors of the weft threads clearly on only one side of the fabric, while on the other fabric side, the fabric underside, the basic warp threads clearly can be seen and thus the colors of the weft threads are either optically blurry or only indistinct or only weak.

Tissues with these properties could previously only be produced by material-consuming atlas or twill weaves. By an appropriate selection the Garnfeinheiten for the weft threads and the warp threads and with a suitable setting or selection of the tension of the leno warp yarns and the Grundkettfäden is achieved in a leno fabric according to the invention, the already described double-face property even with very thin and light leno fabrics. Preferably, each tear resistant type of yarn is usable as the base warp. The main advantages of the leno fabric according to the invention in terms of high thread density and high incorporation of Dreherkettfäden offers the opportunity to produce high quality home textiles as well as technical fabrics.

Preferably, the weft threads have a denier of 500 dtex to 20,000 dtex and the base warp threads are stiff. The base warp yarns are preferably formed at least partially from metallic material or are metallized and preferably have a titer of 500 dtex to 2000 dtex, wherein the leno warp yarns preferably have a titer of 15 to 5000 dtex. To make the leno warp optically withdraw behind the weft threads, but still to achieve a reliable setting, the leno warp yarns have a yarn count of 1/30 to 1/60, in particular 1/50 of the ground warp threads. Preferably, the yarn count of polyester leno warp yarns is in the range of 15 to 30 dtex and that of the base warp yarns is on the order of 1100 dtex.

Since a variety of materials can be used as weft threads, it is provided in a preferred embodiment of the invention to use so-called fancy threads as weft threads. With these effect yarns special surface structures and effects are achieved.

According to a second aspect of the invention, there is provided a method of making a leno fabric as described above. In the process, leno warp yarns as the first warp yarn and base warp yarns as the second warp yarn of respective warp beams are fed to the fabric. The leno warp yarns bind at least one weft yarn, in each case, onto the ground warp yarns together with the ground warp yarns, the leno warp yarns being set to a warp tension which is opposite to the warp yarns Base warp yarns is significantly lower, and wherein the leno warp threads are incorporated into the fabric stronger.

Preferably, the leno warp yarns are fed individually or in groups into a first shed forming device and the ground warp yarns individually or in groups into a second shed forming device. By controlling or adjusting or adjusting the tension of the leno warp threads in relation to the ground warp threads, it is achieved that the crossing point during setting moves, depending on the stress ratio, into a plane which is different from the plane defined by the maximum thickness of the weft threads in their longitudinal direction runs. This means that the crossings are either below or above this level related to the maximum thickness of the weft threads. If the crossings are below the said plane, they may be completely covered by these with the appropriate thickness of the weft threads. However, it is also possible that the crossings are arranged above the weft threads, resulting in a completely different surface structure and thus a completely different appearance of the surface. In this case, the surface structure is defined by the weft threads or by the weft threads and the crossings formed by the leno warp threads.

According to yet another aspect of the invention, there is provided a weaving machine for carrying out the method of manufacturing a fabric as described above. The weaving machine according to the invention comprises a leno warp warp beam having a first drive and a ground warp warp beam having a second drive. A Schwenkriet to guide the Dreherkettfäden to form a first shed and a Steherriet to guide the Grundkettfäden to form a second shed are provided, wherein the Schwenkriet are drivingly connected to a sley and the Steherriet via a transmission with a drive shaft. Furthermore, a weft thread insertion device is provided, by means of which the weft threads can be introduced into a shed which can be formed from the leno warp threads and the base warp threads. Sensors for detecting the warp tension and the leno warp yarns as well as the ground warp yarns are provided. These sensors provide signals (actual values) to a device for control and adjustment and in turn provides appropriate signals to the drives of the warp beams, on the basis of which the warp tension is adjusted so that the tension of the leno warp threads is substantially lower than the tension of the ground warp threads, whereby the incorporation of the leno warp threads in the fabric therefore higher, in particular considerably higher than that the basic warp is.

By means of the adjustment and control of the tension of the leno warp yarns as well as of the ground warp yarns, depending on the leno fabric to be produced by the weaving machine according to the invention, in which plane - based on the plane passing through the maximum diameter in the longitudinal axis of the weft yarn - interlacing between leno warp yarn and ground warp yarn is obtained are located. This influences the extent to which or even the leno warp threads on the upper side of the fabric, which is essentially formed by the weft threads, are visible, regardless of whether the leno warp threads are already so thin that they are already visible to the naked eye Thus, the crossings migrate downwards or upwards from the middle of the tissue, and it is to be understood here that the crossings are located below an imaginary plane which extends in the direction of the weft longitudinal axis through its maximum diameter region parallel to the weft axis By up-wandering it is understood that the crossings are arranged above this plane.

Preferably, the batten carries a reed, by means of which the weft thread inserted into the shed can be hit at the binding point of the fabric in a manner known per se.

Preferably, in the weaving machine, a winding device for removing and winding the finished fabric is provided, wherein the winding device may have an independent drive, by means of which the peel or winding speed of the finished fabric, and thus the warp tension can be influenced.

In the weaving machine according to the invention, the first warp thread share consisting of a multiplicity of leno warp threads is preferably inserted into the first one Drawn shedding device, subsequently passed through a second shedding device and then through the reed, wherein the respective warp threads are brought together in the so-called binding point of the fabric to be produced with a second Kettfadenschar.

The second of a plurality of ground warp yarns existing warp thread is passed through the first shed forming device, subsequently fed into a second shed forming device and then passed through the reed and merged in the binding point with the first Kettfadenschar.

So that possibly occurring warp thread breaks can be signaled, the first and second warp thread groups pass through a warp stop motion which is arranged between the shed forming devices and the spreading boards. Both in the Dreherkettfadenschar and in the Grundkettfadenschar voltage sensors are provided for separate detection and for separately influencing or controlling the warp tension, which deliver the measured actual voltage to the weaving machine control by means of a signal transmission. The stresses are now adjusted so that the base warp yarns are subjected to a higher tension than the leno warp yarns. For this purpose, the finished after the binding point tissue is almost completely wrapped by a rotationally driven tissue take-up roller and then guided via suitable guide rollers to a rotary driven cloth beam and wound up by this. The rotationally driven fabric draw-in roller, like the first and the second warp beam, is operatively connected to a separate electromotive drive, which is likewise connected to the loom control in order to transmit corresponding signals. Thus, the actual warp tension is detected in the respective Kettfadenschar means of the voltage sensors and transmitted as an electrical signal to the loom control. In the weaving machine control, the deviation of a predetermined desired warp tension is determined on the basis of a desired-actual-value comparison. When determined deviations from the desired warp tension of the relevant electromotive drive of the respective warp beam is driven in the sense of increasing and lowering the warp tension. The aforesaid first and second shedding devices are so-called Nadelriete which, as well as they moving drives, among others

DE 101 28 538 A1. The basic structure described therein and its mode of operation are hereby incorporated by reference. Likewise known are devices for introducing the weft thread into a shed formed from the leno warp threads and the ground warp threads. These devices are mechanically driven devices such as e.g. belt or rod-guided weft grippers or pneumatic or hydraulic devices such. air escaping from nozzles or escaping water.

Further advantages and embodiments of the invention will now be explained in detail by means of embodiments with reference to the accompanying drawings.

In the drawings show:

Figure 1 a) a fabric in conventional plain weave with a slip resistance of 100%;

Figure 1 b) fabric in conventional leno weave with increased slip resistance by 70%;

FIG. 2 shows a diagram for comparing the weft density in comparison to the fineness of the weft yarn;

Figure 3 is a comparison of incorporation in conventional dense canvas fabric and dense leno fabric;

FIG. 4 shows a leno fabric according to the invention with alternately arranged different weft thread materials;

Figure 5a) is a schematic representation of a leno fabric in a sectional view;

FIG. 5b) the schematic representation according to FIG. 5a) in plan view; Figure 6a) is a schematic representation of the leno fabric according to the invention according to Figure 4 in a sectional view;

Figure 6b) is a schematic representation of the leno fabric according to the invention according to Figure 6a) in plan view;

Figure 7a) is a schematic representation of another embodiment of the leno fabric according to the invention in a sectional view with tightly arranged weft threads;

FIG. 7b) a schematic representation of the leno fabric according to the invention according to FIG. 7a) in plan view with high weft density and high

Incorporation of the leno warp threads;

8 shows a further embodiment of the leno fabric according to the invention in a schematic representation of the plan view with groupwise setting of the weft threads in the ground warp direction and in the weft direction;

Figure 9 is a schematic representation of a loom for performing the method as a side view;

Figure 10 is a schematic representation of the weaving machine for performing the method in side view with Nadelriet as shedding device for the base warp threads; and

Figure 11 is a schematic representation of the weaving machine for performing the method in side view with Nadelriet as shedding device for leno warp threads.

In FIG. 1, the sliding resistance of a traditional one is the comparison

Plain weave contrasted with a conventional leno weave. figure

1a) shows a traditional plain weave with warp threads 1 and weft threads 2, wherein in the side sectional view, the forces are shown, which along the Weft threads around a warp result. Assuming a sliding resistance of 100% in the conventional plain weave according to FIG. 1a), according to FIG. 1 b), the slip resistance of a conventional leno weave is about 170%. In plan view, the base warp threads 1 and the weft threads 2 and the leno warp threads 3 are shown. It can be seen that due to the angle of wrap of the weft threads and the leno warp yarns result in more acute angle between the forces acting on a base warp forces. The latter is shown in the side sectional view. With FQ, the thread tensile forces in the tissue and with α or Ci ₁ or α _2, the angle between the respective forces are shown.

Thus it turns out that textile fabrics with leno weave are much more resistant to shifting than fabrics with weaves such as canvas, twill and satin. Characteristic of the slip resistance of fabrics are the frictional forces that come about through the crossing of the threads together. The slip resistance of a fabric made with canvas L1 / 1 (see Figure 1a)) is a function of the number of crossings within a bond unit, the thread tension in the fabric F _G , the coefficient of friction μ between the threads and the wrap angle α at the thread intersection.

FIG. 1 b) now shows that the slip resistance of a leno fabric is greater due to the higher number of thread crossings within a binding unit and due to the larger wrap angles at the thread crossings.

Assuming the same yarn density, the same yarn tension and the same coefficient of friction, it follows that the slip resistance of a leno fabric is higher by a factor of 1.7 than that of a linen fabric. The leno fabric according to the invention makes use of this circumstance particularly. In the transition from plain weave to leno weave, the use of materials can be reduced by up to 30% and the productivity of the weaving machine increased by 40%. The slip resistance itself can also be increased again compared to conventional leno fabrics. FIG. 2 shows a comparison of the weft density of conventional leno cloth with leno cloth produced by the method according to the invention, based on the fineness of the weft yarn. For the leno fabric according to the invention also the name Easy Leno ^® 2T is used. From Figure 2 it can be seen that with the leno fabric according to the invention over conventional leno fabric a significantly higher weft density can be achieved. This is partly because the weft threads are arranged almost straight on the base warp threads and the leno warp threads in addition to their significantly lower fineness also have a much higher incorporation, so that due to the rectilinear arrangement of the weft threads they can be arranged closer to the base warp threads. This results in an extremely dense leno fabric, which also has due to the dense packing of weft threads next to each other also improved aesthetic or color or structural properties. In the classical leno fabric, the warp threads cross diagonally. This crossing takes in particular in the warp direction a relatively large volume and thus limits the maximum adjustable weft density. Therefore, conventional leno fabrics have been used only for light, latticed, or transparent fabrics.

The leno fabric according to the invention or the process for its production works positively in forming the leno weave by positive locking. From a technological point of view, this means that the warp tension is varied to a far greater extent than previously known.

In the leno fabric according to the invention, the warp threads are subdivided into two systems, the leno fabric according to the invention being produced by setting different warp tensions. The crossing of the warp threads is no longer - as in the conventional leno fabric - diagonal, and it is produced a leno fabric with a new look, which is significantly influenced by the significantly higher weft density. In addition, it is possible to reproducibly produce a so-called stretch-stop effect by using an elastane yarn for one of the two warp systems. Especially at the

Production of functional textiles, this effect is very beneficial. In particular, with the substitution of the binding threads by finer threads compared to the weft threads used completely novel tissue structures can be produced. In Figure 2 it is clear that with the inventive Leno fabric a much higher weft density can be achieved. The weft threads can be beaten so close to each other that a density of 100% is achieved. The leno fabric thus produced shows on top of a so-called "fake linen weave".

Due to the fact that the weft threads in the leno fabric according to the invention, in contrast to the canvas fabrics is straight, the tissue penetration and the use of massive Breithaltesystemen can be avoided. In addition, the so-called color effects in the fabric can be introduced via the weft threads. For example, in awning fabrics simplifies the preparation in the weaving preparation considerably. This also applies to the twisting, sharpening and sizing to a considerable extent. Because it is weaving technically easier to vary the color or type of yarn on the weft than to produce warp beams, which have wound up the pattern or strip-related color differences on itself. In particular, in the awning weaving a strong increase in flexibility is achieved by the leno fabric according to the invention.

While in a plain weave a maximum color brilliance of about 80% can be achieved with the leno fabric according to the invention a

Color brilliance of about 95% achieved. The color effects of the weft threads are more pronounced, and the fabric surface is given a fine character.

In addition, such a fine surface structure is ideally suited to get a better grip on water and dirt repellency. Such fine surface structures also offer advantages in the application of a fabric thus produced with respect to a base fabric for digital printing, as

Dekatiertuch and for Rauhdecken.

In Figure 3, the incorporation of a dense canvas fabric is compared with that of a dense leno fabric. It can be seen that the leno fabric according to the invention on the weaving machine no

Incorporation ability. This means that the warp density can be kept precisely constant over the entire fabric width. This is particularly advantageous in the production of technical textiles for composites and semi-finished products. In the production of coating fabrics can be realized with the inventive leno fabric using, for example, PES filament yarns of fineness 1,100 dtex lattice constructions with four threads per centimeter and tightly knit fabric with a very fine surface texture of up to 22 threads per centimeter. A further field of application is the production of ballistic fabric using aramid filament yarns, wherein a wide variety of degrees of density can be produced according to the use of different yarn counts. In order to achieve the high tensile strength and low elasticity of the aramid filament yarn, the molecular chains are orientated approximately 100% in the tensile direction by the preparation. Since the weft threads can be deposited almost in a straight line onto the base warp threads, the leno weave according to the invention makes it possible to orient the aramid filament threads 100% in the loading direction as well. This allows the properties of the expensive aramid yarns to be utilized up to 100% in the fabric. Due to the fact that the weft threads of the fabric in the leno fabric according to the invention rest on one side on the warp threads and are delimited by the base warp threads on the lower fabric side, weft threads of different fineness produce relief-like fabric surface structures. The use of elastane yarns in the base chain thereby decisively supports the deformability of the leno fabric. Such properties play an important role especially in car upholstery to achieve the desired requirements there such as deformability and relief structures for air circulation and seating comfort.

Figure 3 shows that when a fabric has 50% weft and 50% warp yarns, the weft-insertion incorporation is maximal. It is about 25% and requires to spread the fabric on the loom Stabbreithalter. To reduce the jump in weaving, one reduces the proportion of weft threads and increases the proportion of warp threads accordingly. Thus, the web weaves less on the weaving machine, and only two pinwheels in the edge or auxiliary edge region are sufficient for spreading.

However, if a strip-like, different dense fabric to be produced, so will be with plain weave, twill weave and satin weave training change continuously in the weft direction on the weaving machine. However, this leads to wrinkles in the tissue, which is always disadvantageous in principle.

In contrast, the leno fabric according to the invention has, independent of the thread density, no incorporation ability in the weft direction. For all density settings, wide-cylinder cylinders with two needle wheels, which are used in the edge or auxiliary edge area, are sufficient for fabric guidance, as a result of which, in principle, no wrinkles due to weft density changes occur.

FIG. 4 shows a further exemplary embodiment according to the invention. In this leno fabric relatively thick, bulky weft yarns 2 are arranged on relatively thin, stiff base warp yarns 1. Between each weft thread 2, a thin stiff weft thread is arranged in each case. The weft threads are each connected by Dreherkettfäden 3 with the Grundkettfäden 1. The fact that the thick weft threads are relatively bulky, the thin weft threads are almost covered by the thick bulky weft threads. Since the leno warp yarns have a significantly lower thread thickness than the thick bulky weft yarns, the upper side of the fabric is essentially dominated only by the color or structure of the weft yarns 2. The thin stiff weft threads 2b, together with the base warp threads 1, serve for the stiffness of the leno fabric on its underside. Such a construction is particularly advantageous for floor coverings. Because with it, a desired solidified soft surface structure can be optimally produced. The stability of such velor-like fabric surfaces is comparable to hand knitting. An additional consolidation at the bottom will no longer be necessary, because the thin stiff weft threads 2b bring this additional strength in connection with the base warp threads 1. This makes it possible to design lightweight, environmentally friendly floor coverings.

FIG. 5a) shows a side sectional view and FIG. 5b) shows a corresponding plan view of a leno fabric. The base warp threads 1 run in

The direction of the fabric is rectilinear, and the weft threads 2 arranged at right angles thereto also run in a straight line. In between, the leno warp threads 3 wrap around the base warp threads 1 and the weft threads 2 in an alternating sequence

Figures are not to scale, ie above all the fineness of the leno warp threads 3 or binding threads can still be considerably smaller than quantitatively in FIG. 5 shown. The thinner the leno warp yarns 3 are, the more likely it is that the weft yarns can be arranged lying against each other without gaps, whereby they form a dense, substantially closed surface.

Also, the distances between the individual warp yarns 1 may be significantly lower or substantially disappear completely, whereby a dense fabric underside is formed, which is a bearing surface. In this case, the individual weft threads 2 can be arranged so close to one another that they form a completely dense layer on the upper side of the fabric, as a result of which only the properties of the weft threads 2 determine the surface properties of the finished fabric.

This applies analogously to the base warp threads 1. With correspondingly thin thread strengths of the leno warp threads 3 or binding threads, the base warp threads 1 are arranged so close to one another that they form a dense layer on the underside 5 of the fabric. Thus, by selecting the fineness and the material of the base warp threads 1, the properties of the underside 5 of the floor covering can be advantageously influenced.

FIG. 6 a) shows a sectional view of the leno fabric according to the invention shown in FIG. In Figure 6b) a corresponding plan view is shown. Also, this representation is not to scale, so that with respect to the thread thicknesses and the size of the interstices, the statements or description in conjunction with Figure 5 apply equally. The spaces shown in Figure 6 are shown only for better understanding. For in the leno fabric according to the invention, the weft threads can be arranged so close to each other that these spaces do not exist. At least when using coarse and bulky weft threads 2a, the arrangement is such that they are close to each other. In contrast to a leno fabric according to FIG. 5, in a leno fabric according to FIG. 6 different weft thread types are used in alternating sequence on the base warp threads 1. In this case, a coarse weft 2a is always followed by a thin weft 2b. The thin weft 2b may differ in addition to the fineness and shape in the material of the coarse weft 2a. For a textile floor covering consists of the thin weft 2b for example from a very stiff material and thereby causes a high stiffness of the leno fabric in the weft direction. Thus, on the other hand, the stiff material of the thin weft yarns 2b does not adversely affect the comfort of the textile floor covering, the coarse weft yarns 2a are made of a soft material and are so closely interwoven with the thin weft yarns 2b that they completely cover the thin weft yarns 2b. As a result, the stiff thin weft threads 2b on the upper side 4 of the fabric are not visible and also not noticeable.

FIG. 7 shows a dense leno weave in which the weft threads are arranged as close together as the thickness of the leno warp threads permits both in the sectional view according to FIG. 7a) and in the plan view according to FIG. 7b). If the leno warp yarns 3 are chosen to be very thin, the weft yarns 2 can be arranged close together. With appropriate thickness of the leno warp threads, however, these can contribute to the fact that gaps are filled, which also creates a dense leno fabric.

In Figure 8, a similarly generated leno fabric is as shown in Figure 7, wherein the direction of setting the leno threads varies in groups, so that over the direction of setting the Dreherkettfäden 3 with the weft threads and / or the Grundkettfäden also strip-like patterns can be generated.

The weaving machine 6 shown schematically in FIG. 9 has a first warp beam 7a with leno warp threads 3 and a second warp beam 7b

Base warp threads 1 on. The first warp beam 7a has an electromotive

Kettablass 8a, while the second warp beam 7b an electromotive

Kettablass 7b has. Both warp let-off motors 7a, 7b are above respective ones

Control lines 9a and 9b signal-transmitting connected to a loom control 10. While the leno warp yarns 3 over a paraxially parallel to the first warp beam 7a arranged coating tree 11 in the direction of

Shedding means 12 run, the base warp threads 1 are arranged on another parallel to the second warp beam 7b arranged bowing tree 13 in

Directed to the shedding device 12 out. The shedding device 12, as described in DE 101 28 538 A1, has a first Nadelriet 12a, in the needles the Dreherkettfäden 3 are retracted, and a second Nadelriet 12b, in whose needles the Grundkettfäden 1 are retracted.

Subsequently, the leno warp yarns and the ground warp yarns 3, 1 pass through a reed 14 which is mounted on a sley 15. Finally, the

Leno warp yarns and the ground warp yarns 3, 1 in a bonding point 16a of the

Leno fabric 16 merged and form together with a weft thread, not shown here, the weave 14 abuts the binding point 16a and which set the Dreherkettfäden and Grundkettfäden, the finished leno fabric 16th

The finished leno fabric 16 is successively fed via a stationary fabric table 17, a guide roller 18 and a provided with a separate electric motor drive 19 Einziehwalze 20, from which it by a nip between the Einziehwalze 20 and a pressure roller 21 via a further guide roller 22 to a Beam 23 passes on which it is wound up. The rollers described are rotatably mounted in a machine frame, not shown here, which also carries the fabric table 17.

In the area between the coating boards 11, 13 and the shed forming devices 12, the leno warp yarns and the ground warp yarns 3, 1 pass through a warp stop motion 24, the lamellae 24a of which open on the warp yarns 3, 1 can detect a warp yarn breakage. Between the corresponding coating tree 11, 13 and the warp stop 24 is in the leno thread chain and the basic thread chain 3, 1 each have a warp tension sensor 25, 26 are arranged. Both warp tension sensors 25, 26 are each signal-connected via a corresponding signal line 25a and 26a to the loom control 10. The drawing-in roller 20 also has a separate electromotive drive 19, which is likewise signal-transmitting connected via signal lines 19a and 19b to the loom control 10. Due to the fact that the Einziehwalze 20 as well as the warp beams 7a and 7b have their own drives and these drives, the speed of the respective trees or roller is controllable, the tension of the Dreherkettfäden as well as the Grundkettfäden on the present system for controlling Control of the warp tension can be adjusted. This is done via appropriate target / actual value Comparisons which maintain or set the predetermined desired warp tension in the leno thread chain and in the ground thread chain 3, 1 or adapted to the respective conditions.

The basic structure and mode of operation of the shedding devices including their drives are described in DE 101 28 538 A1 and are hereby incorporated by reference. In contrast to FIG. 9, FIG. 10 illustrates a possibility which, with a vertical offset of the weaving plane 27 according to FIG. 9, permits the use of only one needle reed in the shed forming devices 12. FIG. 10 shows this vertical offset of the shed forming devices 12, the reed 14 with the sley 15 and the fabric table 17 from the original weaving plane 27 into the weaving plane 27a. In this case, it is sufficient if only a Stehernadelriet 12 b is provided for the formation of a lower compartment for the basic warp threads 1. It is also sufficient if for the lifting of the leno warp yarns 3 to form a top compartment the Drehernadelriet 12a is a conventional lamellae, because the movement of the leno warp yarns 3 from the upper shed in the lower shed with the upper Rietbund 12a 'of the Lamellenrietes 24a can be effected. The return of the Dreherkettfäden 3 from the lower compartment in the upper compartment is in contrast effected due to the prevailing in the Dreherkettfäden 3 warp tension.

FIG. 11 shows the vertical offset of the shed forming device 12, the reed 14 with the sley 15 and the fabric table 17 from the original weaving plane 27 into the weaving plane 27b. The warp stopper 24 is in the direction of the shed forming means 12, a leno warp threads and the base warp yarns 3, 1 holding approximately in the arrangement plane of the warp stop 24 24 hold-down device 28 is provided. Because of this, it is sufficient if only one rotary needle bar 12a is provided for forming a top compartment for the leno warp threads 3. It is also sufficient if for the lowering of the leno warp yarns 3 to form a lower shelf the Steherriet 12b is a conventional lamellae, because the basic warp yarns 1 can be supported after the shed change of Dreherkettfäden 3 in the lower Rietbund 12b 'of Steherrietes 12b to form a top shelf. It is added that the ones shown schematically in FIGS. 9, 10 and 11

Weaving machines have a main drive shaft, which is operatively connected to an electric motor drive 29 and of which the drive for the reed 14, the needle or lamella reed 12a and the needle or

Lamella reed 12b is derived with the interposition of appropriate gear.

The drive connection between the drive motor 29 and the reed shaft 30 is indicated symbolically by the double arrow 31. It is understood that the

Drive 29 via signal lines 29a, 29b is connected to the weaving machine control 10 signal transmitting.

Claims

claims

1. leno fabric which has at least base warp yarns (1), leno warp yarns (3) and weft yarns (2) and in which the weft yarns on the base warp yarns (1) are substantially free of voids and by means of the leno warp yarns (3) having one opposite the base warp yarns (1) have significantly lower titers, with a lower tension compared to the base warp threads (1), that the interlacing of the leno warp threads (3) with the base warp threads (1) in one to the plane of the maximum thickness of the

Weft threads (2) are arranged parallel plane and that the leno warp threads (3) have a higher incorporation into the fabric than the base warp threads (1).

2. leno fabric according to claim 1, wherein the weft threads (2) are arranged and tied so close together that the fabric forms a sliding structure.

3. leno fabric according to claim 1 or 2, wherein the Grundkettfäden (1) are incorporated only so weak that they are tied in a substantially straight line by means of the strong incorporation Dreherkettfäden (3) and almost completely covered by the weft threads (2).

4. leno fabric according to one of claims 1 to 3, wherein the weft threads (2), in particular with their color and structure, the surface of the base warp threads (1) facing away from the fabric.

5. leno fabric according to one of claims 1 to 4, wherein on the upper side of the base warp yarns (1) alternately at least one coarse and especially soft weft yarn (2a) and at least one thin and in particular stiff weft yarn (2b) are arranged such that the coarse Weft threads (2a) substantially cover the thin weft threads (2b) and form a substantially closed surface (4) defined by, in particular, the color and structure of the coarse weft threads.

6. leno fabric according to one of claims 1 to 5, wherein at least two base warp threads (1) are tied together by means of the leno threads (3).

7. leno fabric according to one of claims 1 to 6, wherein at least two weft threads (2) are tied together by leno threads (3).

8. leno fabric according to one of claims 1 to 7, wherein the weft threads (2) by means of at least two leno warp threads (3) are set.

A leno fabric according to any one of claims 1 to 8, wherein the weft yarns (2) vary in group in terms of their titer so that step-like structures are formed on the surface (4) of the fabric.

A leno fabric according to any one of claims 1 to 9, wherein the weft yarns (2) have a denier of 500 dtex to 20,000 dtex, the base warp yarns (1) are stiff, in particular at least partially composed of metallic material or metallised, and a denier of 500 dtex to 2000 dtex and the leno warp threads (3) have a titer of 15 to 5,000 dtex.

11. leno fabric according to one of claims 1 to 10, wherein the Dreherkettfäden (3) have a yarn count of 1/30 to 1/60, in particular 1/50, of the Grundkettfäden (1).

A leno fabric according to claim 11, wherein the leno warp yarns (3) have a yarn count of polyester of 15 to 30 dtex and the base warp yarns (1) have a yarn count of polyester of 1,100 dtex.

A leno fabric according to any one of claims 1 to 12, wherein the ground warp yarns (1) have such a denier and are densely arranged such that the resulting warp yarn (1) has a denier

Fabric bottom / fabric backside (5) has a first structure, and the weft yarns (2) have a denier such that the fabric top / fabric front side (4) formed thereby has a second structure, wherein the first and the second structure form the fabric as a double-face fabric.

14. leno fabric according to one of ^' claims 1 to 13, in which as weft threads (2) fancy yarns are used.

A process for producing a leno fabric having the features of any of claims 1 to 14, wherein leno warp yarns (3) are fed as first warp yarn and base warp yarns as second warp yarns of respective warp beams (7a, 7b) to the fabric, the leno warp yarns (3 ) at least one in each case on the base warp threads (1) weft thread (2) set together with the base warp threads (1) and wherein the leno warp threads (3) are incorporated with a relation to the base warp threads (1) significantly lower warp tension stronger than the latter in the tissue.

16. The method of claim 15, wherein the Dreherkettfäden (3) individually or in groups in a first shedding device and the base warp yarns individually or in groups are fed into a second shed forming device.

17 loom (1) for performing the method according to claims 15 or 16 for the production of a fabric according to claims 1 to 14, which

a) a leno warp warp beam (7a) with a first drive (8a) and a base warp warp beam (7b) with a second drive (8b), b) a Schwenkriet (12a) for guiding the leno warp yarns (3) to form a first Webfaches and a Steherriet (12b) for guiding the Grundkettfäden (1) to form a second

Shed, wherein c) the Schwenkriet (12 a) with a sley (15) and the Steherriet (12 b) are drive-connected via a transmission with a drive shaft, d) a weft insertion device, by means of which the weft threads can be introduced into a shed which can be formed from the leno warp threads (3) and the base warp threads (1), e) sensors (25, 26) for detecting the warp tensions of the leno warp threads (3) and the base warp threads (1 and f) means for adjusting and adjusting the warp tensions such that the leno warp tension is substantially lower than the warp tension and incorporation into the fabric (16) higher than that of the base warp yarns (1).

18. Loom according to claim 17, wherein the sensors (25, 26) with the first drive (8a) and the second drive (8b) via a weaving machine control (10) are connected signal transmitting.

19. Loom according to claim 17 or 18, wherein the warp tension of the leno warp threads (3) is adjustable so that a crossing of the leno warp threads (3) with the ground warp threads (1) from the fabric center moves down or up.

20. Weaving machine according to one of claims 17 to 19, wherein the sley

(15) carries a reed (14), by means of which the inserted into the shed weft yarn to the binding point (16a) of the fabric (16) can be stopped.

A loom according to any one of claims 17 to 20, wherein a take-up means for pulling and winding the finished fabric

(16) is provided.