RU2337187C2 - Compound cloth - Google Patents

Abstract

FIELD: textile; paper.

SUBSTANCE: fabric has upper and lower layers, at that each layer has fibers of mechanical direction and fibres of crosswise direction, interlaced together. Fabric contains pairs of threads which interlace together upper and lower layers. Threads are interlaced such as to be integral part of first layer and make a contribution into its structure. Connecting pairs are not integral part of second layer and do not make a contribution into its structure. On length of weaving repeat at least one of two threads of pair is interlaced with fibres of first layer as its integral part and passing over outside surfaces of two not following to each other fibers in second layer. As a result can be formed binding structure of "duplex knuckle".

EFFECT: improving of received in result compound cloth continuity by means of reduction of length of thread through fabric path.

27 cl, 41 dwg

Description

Field of Invention

This invention relates, in General, to the technology of paper production and relates, in particular, fabrics for use in paper machines.

Description of the prior art

During the papermaking process, the cellulosic pulp web is formed by applying the fibrous pulp, that is, an aqueous dispersion of cellulose fibers, onto a moving forming fabric in the forming section of a paper machine. A large amount of water is removed from the liquid solution through the forming fabric, leaving a cellulosic fibrous web on its surface.

The newly formed cellulosic fibrous web is transferred from the molding section to the pressing section, which comprises a number of pressing zones. The cellulosic fibrous web passes through the press zones supported by the press fabric, or, as is often the case, located between two press fabrics. In the pressing zones, the cellulosic fibrous web is subjected to compressive forces that squeeze water out of it and combine the cellulosic fibers in the web with each other to turn the cellulosic fibrous web into a paper web. Water is absorbed by the fabric or fabrics of the press section and, ideally, does not return to the paper web.

Finally, the paper web is transferred to the drying section, which contains at least one row of rotating drying drums or cylinders, heated from the inside by steam. The newly formed paper web is guided along a serpentine path sequentially around each of the cylinders using a drying cloth that holds the paper web close to the surfaces of the cylinders. Heated cylinders reduce the water content in the paper web to the desired level by evaporation.

All fabrics for molding, pressing and drying in a paper machine are in the form of endless loops and function like conveyor belts. It should also be understood that papermaking is a continuous process that takes place at significant speeds. That is, the fibrous liquid mass is continuously applied to the forming fabric in the forming section, while the newly manufactured paper web is continuously wound on the drums after it leaves the drying section.

Woven materials have many different shapes. For example, they can be woven endless or woven flat and subsequently processed into an endless shape with a seam.

Molding fabrics play a critical role during the paper manufacturing process. One of their functions, as mentioned above, is the molding of the manufactured paper product and its transfer to the pressing section. However, the design of the forming fabric should also solve the problems of water removal and sheet formation. That is, the forming fabrics are designed to allow water to pass through (i.e., control the rate of dehydration) and at the same time prevent fibers and other solid particles from passing through with water. If dehydration occurs too quickly or too slowly, the web quality and machine performance suffer. In order to regulate dehydration, a space for removing water, usually called a void volume, must be provided in the forming fabric.

Modern forming fabrics are produced in a wide variety of varieties, designed to meet the requirements of the paper machines on which they are installed, for manufactured paper grades. Typically, they include carcass fabric woven from monofilament and can be single or multi-layered. The yarns are usually extruded from any of several synthetic polymer resins, such as polyamide and polyester resins, used for this purpose by those of ordinary skill in the art of fabric technology for a paper machine.

The design of the forming fabrics further requires a compromise between the desired pulp support function and the strength of the fabric. A small mesh fabric may provide the desired surface properties of the paper, but it may not have the necessary strength, resulting in a short tissue life. Conversely, large-mesh fabrics provide strength and long life to the detriment of the pulp support function. To minimize the constructive compromise and optimize the support function and strength characteristics, multilayer fabrics have been developed. For example, in fabrics with two and three layers, the forming side is designed to provide support, while the side in contact with the machine is designed to provide strength and durability.

Specialists in the art know that fabrics are created in the weaving process so that the resulting fabric has a weaving pattern — a weaving pattern that repeats in either the warp or machine direction, or in the weft or transverse machine direction.

Multilayer fabrics, such as three-layered fabrics, can come apart during use and cause unacceptable levels of abrasion in the structure. The present invention provides a fabric that mitigates or eliminates such disadvantages.

SUMMARY OF THE INVENTION

In accordance with the invention, there is provided a fabric used to make paper that has a first and second layer, where each layer has a machine direction thread (a direction of movement of the fabric in the machine) and a cross direction machine thread woven together. Many pairs of binder yarns bind together the first and second layer. Binding pairs are intertwined so as to be an integral part of the first layer and contribute to its structure. Binding pairs are not an integral part of the second layer and do not contribute to its structure. At the length of the rapport, at least one of the two binder yarns of the binder pair is interwoven with the yarns of the first layer as an integral part thereof and extends over the outer surfaces of two non-consecutive yarns in the second layer. As a result, a “double bend” binder structure can be formed that improves the integrity of the resulting multilayer fabric, decreasing the path length of the binder yarn through the fabric.

The above and other features and advantages of the present invention will become more apparent from the following detailed description of preferred forms of its implementation.

List of drawings

The following detailed description is given as an example and is not intended to limit the scope of the present invention. It will be more clearly understood in conjunction with the accompanying drawings, in which like elements and details are indicated by like reference numerals.

Figure 1 shows a cross section in the machine direction for part of the first fabric, depicting a binder pair in accordance with this invention.

Figure 2 shows a cross section in the machine direction for another part of the first fabric, showing the threads of the transverse direction (CD).

Figure 3 is a photograph of the side of the first fabric in contact with the machine.

Figure 4 is a photograph of the cross section of the first tissue in the machine direction.

Figure 5 shows a cross section in the transverse direction for part of the first fabric, depicting the lower layer.

Figure 6 shows in cross section the location of the transverse thread of the second fabric in accordance with this invention.

7 is a cross-sectional diagram showing an example of a weaving pattern of the transverse threads of the first fabric.

On Fig shows a cross-sectional diagram for an example of a weaving pattern of the transverse thread of the second fabric.

Fig.9 is a photograph of the side of the second fabric supporting the paper web.

Figure 10 is a photograph of the side of the second fabric in contact with the machine.

11A, 11B and 11C are cross-sectional diagrams of a tissue according to a second embodiment of the present invention.

11D and 11E respectively show views of a paper web supporting and machine-contacting side of a fabric woven in accordance with the disclosed invention.

12A and 12B are cross-sectional diagrams of a tissue according to another embodiment of the present invention.

12C and 12D are views of a paper web supporting and machine contacting fabric side woven in accordance with this invention.

13A and 13B are cross-sectional diagrams of a fabric according to yet another embodiment of the present invention.

13C and 13D are respectively views of a paper web supporting and machine-woven sides of a fabric woven in accordance with this invention.

Figa and 14B are diagrams of a cross section of a fabric according to another form of implementation of the present invention.

FIGS. 14C and 14D, respectively, are views of a paper web supporting and machine contacting fabric side woven in accordance with the present invention.

FIG. 15 is a cross-sectional diagram of a fabric according to another embodiment of the present invention.

Fig. 16 is a view of a fabric weave pattern according to one embodiment of the present invention.

Figa depicts another form of execution of the connecting pair according to this invention.

Figv depicts a binder pair that can be used in fabric with a binder pair of figa.

Figa and 18B depict a pair of couples that can be used in tissue according to this invention.

Fig. 19 depicts yet another embodiment of a binder pair according to this invention.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS

Turning now to FIG. 1, a cross-section is shown of a binder pair that forms part of a multilayer fabric 100 in accordance with one embodiment of the present invention. The fabric 100, which is used mainly in the papermaking process, consists of a plurality of machine direction (MD) yarns (warp yarns) and transverse direction (CD) yarns (weft yarns). Machine direction yarns, such as 1-20, are arranged in two layers, with yarns 1-10 in the lower layer (on the side in contact with the machine) and yarns 11-20 located respectively in the upper layer (layer of the side supporting the paper web, or a layer of the forming side).

The filaments of RA and PB of the transverse direction together constitute a pair of binder filaments, which are depicted in the structure 30 of the plot of the binder pair according to one embodiment of the invention. The function of the binder yarns PA, PB is to bond the upper layer (L1) of the warp yarns to the lower layer (L2) of the warp yarns to form a multilayer fabric 100. In this embodiment, the bonding is achieved by the binder yarn PA, which extends along the path in the transverse direction and is interwoven with several warp threads in the upper layer L1, then goes into the lower layer L2, interwoven with several warp threads in the lower layer and subsequently goes back to the upper layer to repeat the same or obny weave pattern. Similarly, the tie thread PB, which can run parallel to and adjacent to the tie thread PA or weave with the thread PA, binds the warp threads of the upper and lower layers in a similar manner, preferably complementary to the thread PA. That is, by arranging appropriately the intersection of the binder filaments PA and PB, it is possible to obtain a substantially uniform surface of the upper side of the layer, which is preferred for use as the layer of the side supporting the paper web. As a result, a pair of binder yarns 30 forms part of the structure of the upper layer L1, moreover, the binder pair can be considered as a “built-in” type binder pair, which is an integral part of the upper layer, since it contributes to its structure. The binder pair, however, can be considered as not being an integral part of the lower layer, since it does not contribute to the structure of the lower layer. (It should be noted here that in other forms of the invention, pairs of binder yarns, such as PA, PB, can be laid in the machine direction to bond, instead of the transverse direction).

In the part of the fabric depicted in FIG. 1, two rapports are shown, the first containing a part of the threads PA and PB, which bind 20 main threads 1-20. The second rapport connects the threads of the machine direction from 1 'to 20'. Each weave pattern can be considered as spanning ten “columns” of warp yarns, with two layers in each column and two transverse binder yarns RA, PB, together forming at least part of the “row” of the weft yarn system in both layers. Further, the binder yarns PA and PB can pass in the transverse direction so close to each other that when viewed from above on the fabric 100, the binder yarns PA and PB essentially overlap each other, that is, they are almost aligned vertically. Note that the terms "columns" and "rows" are used here for convenience of explanation, and are not intended to limit the invention to machine-made and transverse threads, which are necessarily orthogonal; for example, yarns of machine direction may be inclined relative to each other. The warp yarns may be substantially uniform across the cross section and the gap in the upper and lower layers, as shown yarns 1-20, although it is possible to use warp yarns of different cross sections and shapes (e.g., cylindrical, elliptical, non-circular or rectangular cross-section) in upper and lower layers. In the transverse direction, the weft yarns can be arranged with different weave patterns in consecutive rows, and different weave patterns can be formed so that every N rows are repeated, as will be discussed below. Cross threads can have the same with the main threads or other profiles and diameters, and can also consist of the same or different material.

A distinctive feature of the pair of 30 binder yarns is the formation of double bend structures such as DK1 or DK2. That is, the double bend DK2 is formed when the thread PA forms loops (kinks) around the outer surfaces of two non-successive warp threads, 7 and 9, when passing to the thread 15 located above on one side and thread 11 'located above on the other . A double bend DK1 is formed in a similar manner between threads 2-4. Note that the double bends DK1 and DK2 shown are formed so that two non-successive strands around which they are formed in the form of loops (for example, strands 7 and 9), have only one strand in the layer in contact with the machine (for example, thread 8), on the outer (lower) surface of which the binder thread does not pass. It is contemplated, however, that in other embodiments of the bonding elements of the present invention, more than one strand of a layer in contact with the machine may exist between the “bends” of the double-bend structure.

In any case, the double-bend structure improves the integrity of the resulting multilayer fabric, reducing the length of the binder yarn through the fabric. That is, this structure gives short “inner floorings” for binder yarns. Compared to traditional designs, between the layers, better contact is achieved, which provides less contact between the thread and the thread and, therefore, less internal wear. Another effect is that the bonding element becomes more symmetrical and therefore counteracts twisting, which could otherwise be a problem. The double bend is also fixed in place in the second layer due to increased contact with numerous threads of the machine direction. This differs from traditional binder yarns, which have some freedom of sliding along a single thread of machine direction. In addition, a double bend improves the strength of the fabric seam.

The material of the binder element is often medium to high shrinkage material, while the back wefts (for example, wefts W1 in the L2 layer, which will be described later) typically have low shrinkage. In known tissues, this combination leads to significant twisting. In order to balance the materials, in the embodiments of the present invention, lower material may be used to give greater shrinkage. However, in this case, the external wear resistance on the rear side is adversely affected (less smooth warp / weft difference). To compensate for the losses, an alternative weaving pattern of the back side with long (for example, 10-jaw) flooring can be used.

The bonding elements used in the present invention may comprise “interior floorings” which are of short or minimal length. The term "internal flooring", as used here, refers to the interval that the thread passes between the upper and lower main threads of the multilayer fabric during the transition between the upper and lower layers of the multilayer fabric. By using a short inner deck for each bonding element, the reliability of the resulting multilayer fabric can be improved. In the embodiment of FIG. 1, for example, a binder yarn PA weaves the warp yarns 11 through 15, passing over yarn 11, under yarn 12, above yarn 13, under yarn 14 and above yarn 15. The RA yarn then passes from the top layer L1 to the lower layer L2, passing between the two layers the interval (in the transverse direction) corresponding to one main thread, plus a short interval on both sides. Thus, the inner flooring F1 of the binder yarn PA can be considered as the interval that the thread passes only between one upper and lower thread of the machine direction (which are in the same column in this embodiment), as between threads 6 and 16, plus short spacing between threads on either side of these warp threads.

The binder yarn PB in the embodiment of FIG. 1 has an internal flooring, that is, an overlap F2 longer than the internal flooring F1 of the yarn PA. That is, the binder yarn PB weaves the main yarns 1-4, then passes from the lower layer L2 to the upper layer L1, passing from under the yarn 4 into the inner region between the yarns 5, 15 and then between the yarns 6, 16 before reaching the area above the yarn 17 The PB thread then weaves the yarns from 17 to 20. Therefore, the inner deck F2 of the PB yarns represents the spacing in the transverse direction in the inner region between the yarns 5 and 15 and then between the yarns 6 and 16, plus short spacing between the yarns on both sides. Thus, the inner deck F2 has a length corresponding to the two main threads (plus a short spacing between the threads on both sides).

The structure 30 of a pair of binder yarns with the above-described internal flooring design gives uniformity to the upper surface of the layer L1 (usually a supporting surface for supporting the paper web). That is, the PA thread weaves the warp yarns of the upper layer 11-15 so that the interleaved yarns 11, 13 and 15 are below the binder yarn PA and then the PB thread interweaves the yarns 17-20 of the upper layer so that the interleaved yarns 17 and 19 are lower than the PB . As a result, the interleaved yarns 11, 13, 15, 17 and 19 are located below the yarns of the binder pair, whereby on the upper surface a stitch pattern is obtained essentially of the type of continuous plain weaving. A pair of 30 binder yarns can be considered as an integral part of the surface of the upper layer L1, since it contributes to its structure. However, a pair of 30 binder yarns is not considered an integral part of the surface of the lower layer L2, since it does not contribute to its structure, as will become apparent below.

Figure 2 is a cross-sectional view showing weft (transverse) yarns W1 and W2 of fabric 100. These yarns together are included in a weave rapport 50, interwoven with warp yarns 1-20. The weft thread W2 weaves only the upper threads 11-20, while the weft thread W1 weaves only the lower threads 1-10. As can be seen in the photograph of FIG. 3, which shows the view of the (lower) side of the fabric 100 in contact with the machine, the weft threads W1 and W2 may extend between the pairs 30 of binder threads. In the illustrated embodiment, the weft yarns W1 of the lower layer are thicker than the weft yarns W2 of the upper layer. (In FIG. 3, only the threads W1 of the side in contact with the machine are clearly visible).

Using the partial circuit 50 shown in FIG. 2, the thread W1 is laid along a path that extends over the machine direction 1, below the machine direction 2-5, over the machine direction 6 and below the machine direction 7-10. Thus, the thread W1 passes over the threads (or "around the loop") of single warp threads, such as threads 1 and 6, every five threads. The weave can be changed so that the thread W1 passes over each N-th main thread, where N is more or less than five. Also, the thread W1 can pass over several successive main threads, and not over one main thread, as shown. It should be noted that the cross-sectional area, profile (e.g., circular, elliptical, non-circular, rectangular) and the material used for the W1 yarn may be the same as used for the transverse binder yarns described previously, or be different from them.

The threads shown in figures 1 and 2 can be combined into a composite fabric, which has a ratio of weft threads 2: 1. A full fabric sample containing these weave yarns is discussed below with reference to FIG.

4 is a cross-sectional photograph of an example of fabric 100 and depicts a typical relationship between weft threads W1, W2, connecting threads PA, PB, and warp threads 1-20. In this embodiment, the weft thread W1 is significantly thicker than other weft threads. As a result, the thickness of the lower layer L2 is greater than that of the upper layer L1, so that in the papermaking process, the lower layer L2 is abrasion resistant on the side in contact with the machine. It is also obvious that due to the interweaving of the strands W1 and the binder strands PA, PB, the warp yarns 1-10 are no longer aligned, as previously shown in FIG. On the other hand, the warp yarns 11-20 of the upper layer L1 remain precisely aligned, whereby a substantially uniform surface of the upper layer is achieved.

5 is a cross-sectional view for a portion of fabric 100 depicting a lower layer L2. As can be seen in the drawing, machine-made yarns of fabric 100, such as yarn 1, do not extend continuously in a horizontal plane. Instead, they periodically fall down, as at points A and B, due to weaving of the lower layer with weft threads W1. In the machine direction, it can be seen that intermittent weft threads W1 can be inserted in the spaces between the connecting threads, such as PA.

Turning now to FIG. 6, an alternative arrangement / weaving of 60 weft threads is shown, which can be used instead of the weft arrangement 50 shown in FIG. 2 and described above. That is, the yarns shown in FIGS. 1 and 6 can be combined to form an alternative form of multilayer fabric. (An example of a complete fabric containing these threads is depicted in FIG. 8, which is discussed below). The weft yarn arrangement 60 is distinguished by the addition of a third weft yarn W3, which extends adjacent to the yarn W2 and interweaves the warp yarns 11-20 of the upper layer. The weft thread W3 runs complementary to the threads W2 around the warp threads 11-20. For example, thread W2 passes under thread 12, over thread 13, etc., while thread W3 passes over thread 12, under thread 13, and so on. Although the weft thread W3 is depicted for clarity in dashed lines, it is understood that this thread may be similar or identical in composition and size to the weft thread W2. In the cross section of FIG. 6, pairs of binder yarns 30 are not shown for clarity; however, in a typical case, one arrangement of 60 weft threads is used in combination with one binder pair 30 to realize a ratio of weft threads of 3: 1. That is, three patterns of weaving yarns in the upper layer are used for each weft yarn W1 in the lower layer, with three patterns of weaving yarn in the upper layer containing yarn W2, yarn W3 and yarn PA, PB of the binder pair 30. This arrangement with the ratio of weft yarn 3: 1 will be further described below in connection with FIGS.

Turning now to FIG. 7, an illustrative embodiment of a majority of a multilayer fabric 100 is shown. These drawings illustrate an example of execution, row after row, of a weave weft pattern shown in sections in FIG. 7 and in a bottom view in FIG. 3. Figure 3 shows the weave patterns of weft yarns in six rows from R1 to R5, and they are visible in the cross-sectional diagram of Fig. 7 for rows from R1 to R5 (where, for clarity of illustration, the cross-sections of warp threads are replaced by their actual designations 11, 12 and etc.).

In the example of the weft yarn sequence of FIG. 7, each row, such as R1, is assumed to contain four transverse yarns, i.e., W1, W2, PA and PB. R1 row contains yarns W1 and W2, designated as weave pattern 50 ₁ , as well as binder threads PA, PB, designated as weave pattern 30 ₁ , etc. Each of these 40 threads in the sequence of FIG. 7 is also indicated by thread numbers Y1-Y40. In this example, these 40 yarns Y1-Y40 can constitute a machine-generated weave pattern. Thus, the rows from R1 to R10 are sequentially deployed in the machine direction and can be followed by another set of the same rows from R1 to R10, etc. Typically, the weft yarn W1 of the layer of the side in contact with the machine is thicker than the weft yarn W2 of the layer of the side supporting the paper web, and the binder yarns PA, PB, so that there are two weaving patterns of the side supporting the paper web, that is, the weaving pattern of the yarn W2 and a weaving pattern of the binder pair 30, are used for each thread W1 of the side in contact with the machine.

In consecutive rows of R1, R2, etc. the weaving patterns of the threads W1 of the side in contact with the machine are shifted in the transverse direction. Thus, for example, in Figure 50 _{1 of} row R1, thread W1 forms loops over main threads 1 and 6, but in figure 50 _{2 of} row R2, thread W1 forms loops over main threads 3 and 8, etc. Thus, all the threads of the lower layer are intertwined. Similarly, the patterns of weaving the binder threads are shifted from row to row: each rapport 30 ₁ -30 ₁₀ can be represented as different parts of two combined rapport 30 of weaving Fig.1. For example, the rapport 30 ₁ is the same as the rapport 30 between the sheds 1-20 in FIG. 1; while the rapport 30 ₂ is the same as the rapport 30 between the yaws 9, 19 and 9 ′, 19 ′ in FIG. Thus, since the patterns of weaving the binder yarns are shifted from row to row, complete bonding of the upper and lower layers is achieved.

Turning now to FIG. 8, an alternative sequence of weft threads is shown. This sequence differs from the sequence in FIG. 7 in that the weft arrangement 50 is replaced by the arrangement 60 shown in FIG. 6, resulting in the aforementioned weft ratio 3: 1. In particular, we used three patterns of weaving the weft of the upper (supporting the paper web) layer, i.e., patterns of weaving the weft threads W2, W3 and figure 30 of weaving the paired binder threads for each weft thread W1 of the lower layer (side layer in contact with the machine). Thus, each of the rows from R1 to R10 is considered as containing five threads, while each repeat in the machine direction contains only 50 threads, from Y1 to Y50.

Figures 9 and 10 are photographs of the side supporting the paper web and the side in contact with the machine, respectively, for real fabric, designated as 100a, which contains the sequence of weaving patterns shown in Fig. 8. The top view shows that each row, such as R1, contains three adjacent weaving patterns of the upper layer, which are formed from the threads W2, W3 and the connecting elements PA, PB with a pattern of 30 ₁ . As seen from the side in contact with the machine, each row, such as R1, contains one weft thread W1 of the lower layer. Thus, each row R1 contains one weaving arrangement 60 _i and one paired tie member 30 _i .

In yet another embodiment of the present invention, double transverse parallel (DCP) type binder pairs can be used in rows or in places inserted in the gaps of any of the binder weave patterns and weft weave patterns discussed above. Such binder pairs of double transverse parallel type are disclosed in US patent application 10/334166 under the name DOUBLE CROSS PARALLEL BINDER FABRIC, the contents of this application are incorporated herein by reference to the appropriate source. In a binder pair of a double transverse parallel type, two binder yarns extend over at least one common (same) yarn on the outer surface of a layer, such as a side layer supporting the paper web, within the weave repeat.

Embodiments of the invention, which will be described below, include binder pairs of double transverse parallel type. In particular, the forms of the invention described below relate to a fabric, such as a three-ply fabric, which can be used in the papermaking process. Such a three-layer fabric may contain a first (upper) layer and a second (lower) layer, each of the first and second layers having a system of machine direction (MD) threads and cross direction (CD) threads interwoven with them.

The first layer may be a layer of the side supporting the paper web or the front side onto which the pulp / paper pulp is applied during the papermaking process, and the second layer may be a layer of the side in contact with the machine or the back side. The first and second layers can be bonded together using a variety of stitching or binder yarns. Such crosslinking threads may be several threads of transverse and / or machine direction. For example, several pairs of transverse threads can be used, with two threads of each pair being adjacent to each other and working in parallel. A pair of such transverse threads may be an integral or non-integral part of the weaving pattern of one or both of the first and second layers and may also hold the two layers together.

FIG. 11A shows a portion or pattern of weaving of the binder pair 88. Namely, FIG. 11A shows a cross section of a portion of fabric 100 ′ that contains a first layer L14 (side supporting the paper web) and a second layer L16 (side in contact with the machine) and has a plurality of machine direction threads 21-38 in the layer L14 of the side supporting the paper web, a plurality of machine direction threads 41-58 in the layer L16 of the side in contact with the machine, and a number of tie pairs 88, each of which has transverse threads 90 and 92, woven with thread direction. As shown in this drawing, the transverse thread 90 extends over the machine direction threads 21, 24, 28 and 32, under the machine direction threads 22, 26, 31, 34 and 38 of the machine layer of the side L14 supporting the paper web, and passes under the machine direction thread 56 layer L16 of the side in contact with the machine. The transverse thread 92 passes over the threads of the machine direction 21, 32 and 36 and under the threads 22, 24, 28, 31, 34 and 38 of the machine direction of the layer L14 of the side supporting the paper web, passes over the threads of the machine direction 42, 44, 48 and 51 and under the thread 46 of the machine direction of the layer L16 of the side in contact with the machine.

A plurality of binder pairs 88 can be woven into fabric 100 ′ as shown in FIG. 11D (view of the side of the fabric supporting the paper web) and FIG. 11E (view of the side of the fabric in contact with the machine). Additionally, a certain number of transverse pairs 66 can also be interlaced in fabric 100 'and located therein between adjacent connecting pairs 88. Each of the transverse pairs can have transverse threads 62 and 64, which can be intertwined with machine threads of the layer L14 of the side in contact with paper web, and layer 1-16 of the side in contact with the machine, as shown in figs. Further, a certain number of pairs 70, each of which contains transverse threads 72 and 74, can also be interwoven with machine-made threads of the layer L14 of the side supporting the paper web and the layer L16 of the side in contact with the machine, fabric 100 ', for example, as shown in figv.

Therefore, in the fabric 100 ', each of the threads 90 and 92 of the binder pair 88 extends over the threads 21 and 32 of the machine direction on the outer surface of the layer L14 of the side supporting the paper web. This type of tie pair is hereinafter referred to as a double transverse parallel (DCP) tie pair. Accordingly, the fabric 100 'has two interwoven layers of transverse threads and machine-made threads that are fastened together by a plurality of binder pairs of a double transverse parallel type, and within the rapport, two threads of each such binder pair extend over two threads of a machine direction on the outer surface of the side supporting layer L14 paper web.

Another fabric will now be described with reference to FIGS. 12A-D.

12A shows a portion or pattern of weaving of a binder pair 108 of fabric 200 that has a first layer 114 (side supporting the paper web) and second layer 116 (side in contact with the machine). Namely, FIG. 12A is a cross-sectional view showing a plurality of machine direction filaments 120-138 in a side layer 114 supporting a paper web, a plurality of machine direction filaments 140-158 in a side layer 116 in contact with a machine, and a tie pair 108 having transverse yarns 110 and 112 interwoven with yarns of machine direction. As shown in FIG. 12A, in the binder pair 108, the transverse thread 110 extends over the machine direction filaments 120, 128, 132 and 136 and under the machine direction filaments 122, 126, 130, 134 and 138 of the side layer supporting the paper web and passes under the thread 144 of the machine direction of the layer 116 of the side in contact with the machine. The transverse thread 112 passes over the machine direction threads 120, 124 and 128 and under the machine direction threads 122, 126, 130, 132, 136 and 138 of the machine layer of the side supporting the paper web and passes over and under the machine direction threads 152, 156 and 158 thread 154 machine direction layer 116 of the side in contact with the machine. In the fabric 200, a number of binder pairs 108 can be interlaced, as shown in FIG. 12C (view of the side of the fabric supporting the paper web) and FIG. 12D (view of the side of the fabric in contact with the machine).

Additionally, a number of binder pairs 106, each of which has transverse threads 160 and 162, can also be interwoven with machine-made yarns of fabric 200 and disposed in it alternately with binder pairs 108. Each of the binder pairs 106 (which may be called a binder pair with support weft (SSB)) may have transverse threads 160 and 162 that can be interwoven with machine direction threads of the tissue side supporting layer 114 of the paper web and the tissue side layer 116 in contact with the machine, as shown in FIG. 12V As seen in FIG. 12B, the transverse threads 160 and 162 do not extend over one or more common machine direction threads on the outer surface of the side supporting layer 114 of the paper web. Further, a number of transverse threads 170 can also be woven into fabrics 200 and arranged so that the corresponding threads from among the transverse threads 170 are located on both sides of the tie pairs 106 and 108 as, for example, shown in figs. The transverse threads may be similar to the transverse threads 62 and 64 shown in figs.

Therefore, in the fabric 200, each of the yarns 110 and 112 of the binder pair 108 extends over the machine direction yarns 120 on the outer surface of the paper web supporting layer 114. Thus, the binder pair 108 is a pair of double transverse parallel (DCP) type. Accordingly, the fabric 200 has two interwoven layers of transverse and machine-direction threads that are held together by a plurality of binder pairs of double transverse parallel type, wherein within the rapport, two threads of each such binder pair extend over two threads of machine direction on the outer surface of the side supporting layer 114 paper web. In addition, the location of the bonding elements in the fabric 200 makes it possible to obtain relatively high permeability.

Another fabric will now be described with reference to figa-D.

13A shows a portion or pattern of weaving of a binder pair 208 in a fabric that has a first layer 214 (side supporting the paper web) and a second layer 216 (side in contact with the machine). Namely, FIG. 13A shows a cross-section of a portion of fabric 300 depicting a plurality of machine-directed threads 220-238 in a side layer 214 supporting a paper web, a plurality of machine-oriented threads 240-258 in a side layer 216 in contact with the machine, and a binder pair 208 having transverse threads 210 and 212, interwoven with threads of machine direction. As shown in this drawing, the transverse thread 212 extends over the machine direction threads 220, 224, 228, 232 and 236 and under the machine direction threads 222, 226, 234 and 238 of the machine side layer 214 supporting the paper web and extends under the thread 250 of the layer 116 side in contact with the machine. The transverse thread 210 passes over the threads 228 and 232 of the machine direction and under the threads 230 and 234 of the layer 214 of the side supporting the paper web, and passes over the threads 242, 244, 246, 256 and 258 and under the thread of the machine direction 240 of the layer 216 of the side in contact with by car. A number of binder pairs 208 may be woven into fabric 300, as shown in FIG. 13C (view of the side of the fabric supporting the paper web) and FIG. 13D (view of the side of the fabric in contact with the machine).

Additionally, a number of binder pairs 206 can be interlaced in fabric 300 and arranged alternately with binder pairs 208. Each of the pairs 206 (which can be a binder pair with a supporting weft) can have transverse threads 260 and 262 that can be intertwined with threads machine direction of the layer 214 of the side of the fabric supporting the paper web, and the layer 216 of the side of the fabric in contact with the machine, as shown in figv. As shown in FIG. 13B, the transverse threads 260 and 262 do not extend over one or more of the same machine direction threads on the outer surface of the side supporting layer 214 of the paper web.

Further, several transverse threads 270 can also be woven into fabrics 300 and arranged so that corresponding threads from among the transverse threads 270 are located on both sides of the binder pairs 208 and the transverse pairs 206, for example, as shown in FIG. 13C. The transverse threads 270 may be similar to the transverse threads 62 and 64 shown in figs.

Therefore, in the fabric 300, each of the threads 210 and 212 of the binder pair 208 extends over the machine direction threads 228 and 232 on the outer surface of the side sheet supporting layer 214 of the paper web. Thus, the binder pair 208 is a pair of double transverse parallel type. Accordingly, the fabric 300 has two interwoven layers of cross-section and machine-direction threads that are fastened together by a plurality of double cross-parallel type tie pairs and tie webs with a support weft, wherein in the rapport, two threads of each double cross-parallel tie type pair pass over two machine threads directions on the outer surface of the layer 14 of the side supporting the paper web. Further, the arrangement of the bonding elements in the fabric 300 can provide a direct passage from the top to the bottom and, thus, can improve the internal wear resistance of the fabric compared to fabrics having other layouts.

Another fabric will be described below with reference to figa-D.

FIG. 14A shows a portion or pattern of weaving of a binder pair 308 of fabric 400, which has a first layer 314 (side supporting the paper web) and a second layer 316 (side in contact with the machine). Namely, FIG. 14A is a cross-sectional view illustrating a plurality of machine direction threads 320-338 in a side layer 314 supporting a paper web, a plurality of machine direction threads 340-358 in a machine side layer 316, and a tie pair 308 having transverse yarns 310 and 312 interwoven with yarns of machine direction. As shown, the transverse thread 312 passes over the machine direction threads 320, 324 and 328 and under the machine direction threads 322, 326 and 330 of the side layer 314 supporting the paper web, and also passes under the thread 354 of the side layer 316 in contact with the machine. The transverse thread 310 extends over the machine direction thread 328 and under the machine direction thread 330 of the side layer 314 supporting the paper web, and also passes over the machine direction threads 342, 344 and 346 and under the machine direction thread 340 of the side layer 316 in contact with the machine. A number of binder pairs 308 can be woven into fabric 400, as shown in FIG. 14C (view of the side of the fabric supporting the paper web) and FIG. 14D (view of the side of the fabric in contact with the machine).

In addition, a number of binder pairs 306 can be woven into fabric 400 and disposed therein alternately with binder pairs 308. Each of the binder pairs 306 (which may be a binder pair with a support weft) may have transverse threads 360 and 362, which may be interwoven with machine-made yarns of the fabric side layer 314 supporting the paper web and the fabric side layer 316 in contact with the machine, as shown in FIG. 14B. As shown in FIG. 14B, the transverse threads 360 and 362 do not extend over one or more of the same machine direction threads on the outer surface of the side layer 314 supporting the paper web.

Further, a certain number of transverse threads 370 can also be woven into fabric 400 and arranged so that the corresponding threads from among the transverse threads 370 are located on both sides of the tie pairs 306 and 308, for example, as shown in FIG. 14C. The transverse threads 370 may be similar to the transverse threads 62 and 64 shown in figs.

Therefore, each of the yarns 310 and 312 of the binder pair 308 extends over the yarn 328 of machine direction on the outer surface of the side sheet supporting layer 314 of the paper web. Thus, the binder pair 308 is a pair of double transverse parallel type.

Accordingly, fabric 400 has two interwoven layers of transverse threads and machine-made threads that are fastened together by a plurality of binder pairs of a double transverse parallel type and binder pairs with a supporting weft, wherein in the rapport two threads of each binder pair of a double transverse parallel type pass over only one machine thread directions on the outer surface of the side 314 supporting the paper web. As a result, the machine direction or warp yarns can be laid one above the other and a symmetrical contour of the connecting element can be obtained. Further, such an arrangement can minimize the number of intersections, reduce the marking level of the paper web, reduce the thickness, and improve crosslinkability compared to fabrics having other yarn arrangements.

In the above-described fabrics, the transverse threads of the binder pairs of the double transverse parallel type do not intersect each other when they pass below the intermediate upper thread of the machine direction. Instead, such threads are adjacent to each other as they pass over one or more of the same machine direction threads.

Although specific patterns for weaving yarns have been described above, the present invention is not limited to them. For example, other patterns of weaving of binder pairs, such as those shown in FIG. 15, contain in the rapport a combination of binder pairs of double transverse parallel type and binder pairs with a supporting weft. Namely, FIG. 15 shows a cross-section of a portion of fabric 500 that comprises a first layer 514 (side supporting the paper web) and a second layer 516 (side contacting the machine) having a plurality of machine direction threads and a number of binder pairs, each which comprises transverse threads 510 and 520. As shown in FIG. 15, each of the transverse threads 510 and 520 extends over machine threads 530 and 532. A pair of tie members in FIG. 15 comprise several double transverse parallel type portions 550 and type 540 portions bind pair with a supporting duck. Figure 16 shows a weaving pattern for a fabric in which binding pairs can be used. Additionally, weaving patterns for the upper layer (the side supporting the paper web) may be plain weaving patterns or other weaving patterns. Similarly, the bottom layer (the side in contact with the machine) can be woven on 4, 5 or 6 throats, or other configurations can be used.

17A shows a cross-section of yet another binder pair 630 in accordance with the invention, which forms part of a multilayer fabric 600. The binder yarns 610 and 620 together constitute a binder pair 630 that binds together the yarns of the layer L1 of the side supporting the paper web and the layer L2 of the side in contact with the machine. A pair of bonding elements 630 can be considered as a combination of the double-bend structure of the bonding element 30 described above and the double cross parallel type bonding elements also described above. The presented weave pattern of the pair 630 of binder yarns may be a rapport pattern that repeats in the transverse direction. The yarn 610 forms a double bend around the yarn 2-4, and this double bend provides the advantages mentioned earlier, that is, it improves the integrity of the resulting multilayer fabric, reducing the length of the binder threads through the fabric, increases the strength of the fabric seam, etc. In addition, the arrangement of the binder threads 610 and 620 together in places above the warp threads 11 and 17 gives, for example, a pair of binder elements of a double transverse parallel type with corresponding advantages.

A pair of bonding elements 630 may be implemented in a multilayer fabric in the spaces between other bonding elements, such as the bonding pair 30 shown in FIG. 17B (which is the same as the bonding pair shown in FIG. 1). For example, if we consider in Fig.3 the view of the side in contact with the machine; the binder pair 630 may alternate so that the weaving pattern shown changes from top to bottom from 50, 30, 50, 30, 50, 30, 50, 30 ... to 50, 30, 50, 630, 50, 30, 50, 630. ... Alternatively, the binder pair 630 can be used as the only type of binder of the fabric.

Figa and 18B respectively show the connecting pairs 108 and 670, which can be used in another fabric 680 in accordance with the invention. So, the connecting elements 108 and 670 can be used in the fabric 680 alternately with each other, for example, through one. The pair of couples 108 is the same as that previously discussed in connection with figa, therefore, its description will not be repeated here. As shown in FIG. 18B, the binder pair 670 contains yarns 665 and 675. In the illustrated pattern, yarn 665 passes over yarns 1 and 2, then below the main yarn 3, is laid over yarn 4, 5, and 6 and then weaves yarn 17-20 top layer as shown. The thread 675 interweaves the threads 11-15, then passes over the threads 6 and 7, goes around the bottom of the thread 8 and passes over the threads 9 and 10, ending the pattern of rapport. Pairs of tie elements 108 and 670 can be used in fabric 680 in between spaces of weft threads, such as those shown in FIG. 2, or as shown in FIG. 6, to form a multilayer fabric 680.

Referring now to FIG. 19, another binder pair 730 is shown in cross section, forming in accordance with the invention a part of the multilayer fabric 700. The binder yarns 710 and 720 together form a binder pair 730 that also binds together the yarns of the layer L1 of the side supporting the paper web , and layer L2 of the side in contact with the machine. The tie pair 730 can be considered as a combination of the double-bend tie structure 30 described above and the double cross parallel type tie members also described above. The weaving pattern of the binder pair 730 shown may be a rapport pattern that repeats in the transverse direction. Thread 710 forms a double bend around threads 3-5, and this double bend provides the previously mentioned advantages. Thread 720 also forms a double bend around warp threads 8 and 10. Additionally, the close arrangement of the binder threads 710 and 720 in places above the warp threads 11 and 17, for example, gives the binder pair of a double transverse parallel type corresponding advantages. Note that the thread 720 sharply decreases from a level above the main thread 17 to a level below the main thread 8, which leads to further minimization of the length of the inner floor of the binder threads. As in the case of the binder pair 630, the binder pair 730 can be made in a multilayer fabric between the other binder elements, such as the binder pair 30 shown in FIG. 1 (or 17B), or any of those shown in FIGS. 11-18 . Alternatively, binder pair 730 can be used as the only type of binder element in fabric 700. As in the cases described above, the binder couple shown in FIG. 19 is used in fabric 700 in the spaces (not shown) between weft yarns not belonging to the binder elements such as those shown in FIG. 2 or FIG. 6.

It should further be noted that as further modifications of the embodiments described above, a number of binder pairs in a fabric can be woven so that two strands in such pairs are arranged in the same (or straight) order side by side for all such binder pairs. In addition, many binder pairs in the fabric can be woven so that two threads in such pairs are arranged side by side in alternating or reverse order. For example, in the above-described fabrics having binding pairs with a supporting weft, these pairs can be arranged to be direct or reverse.

In addition, although the embodiments of the present invention have been described as having binder pairs consisting of transverse threads that extend over one or two machine direction threads on the outer surface of the layer of the side supporting the paper web, the present invention is not limited to this. That is, other threading schemes may also be used. For example, there may be transverse threads that, within the rapport, extend over more than two machine direction threads on the outer surface of the layer of the side supporting the paper web. As another example, a binder pair may comprise two machine-directional threads that extend over one or more of the same transverse threads in a rapport. As another example, the binder yarns in the rapport may extend over one or more of the same yarns of the transverse (or machine) direction on the outer surface of the layer of the side in contact with the machine.

In addition, although the invention has been described as being used for a papermaking process, it is not limited thereto. That is, this fabric can be used in other applications.

The fabric according to this invention may contain monofilament yarns. Cross threads may be polyester monofilaments and / or some threads may be polyester or polyamide monofilaments. The threads of the transverse and machine direction may have a circular cross-sectional shape with one or more than one diameter. Further, in addition to the round shape, one or more threads can have other cross-sectional shapes, such as a rectangular, elliptical or other non-circular shape.

It should be clear that the forms of the invention described above are examples only, and those skilled in the art can make many changes to the disclosed forms of carrying out the invention without departing from its scope and spirit, which are determined by the appended claims.

Claims (27)

1. Fabric containing: a first layer having machine direction (MD) yarns and transverse direction (CD) yarns interwoven with them; a second layer having machine direction (MD) yarns and transverse direction (CD) yarns interwoven with them; and a plurality of pairs of binder yarns of the first type for bonding together the first and second layer, which are intertwined so as to (i) be an integral part of the first layer and contribute to its structure, and (ii) not be an integral part of the second layer and not to contribute to its structure, with each pair of the first type includes the first and second binder threads; moreover, during the rapport, the first connecting thread of the pair of the first type is intertwined with the threads of the first layer as an integral part thereof and passes over the outer surfaces of two non-successive threads in the second layer. 2. The fabric according to claim 1, characterized in that it is suitable for at least one of the operations of the papermaking process, such as molding, pressing and drying. 3. The fabric according to claim 2, characterized in that the first layer is a layer of the side in contact with the paper web, and the second layer is the layer of the side in contact with the machine, the first binder thread passing over the outer surfaces of two non-consecutive threads in the layer of the side in contact with the machine. 4. The fabric according to claim 3, characterized in that the two non-successive threads in the layer of the side in contact with the machine have only one thread between themselves, over the outer surface of which the first binder thread does not pass. 5. The fabric according to claim 3, characterized in that during the rapport, the second binder yarn of the pair of the first type is woven as a unit with the yarns of the first layer or layer of the side supporting the paper web, and passes over the outer surfaces of two non-consecutive yarns in the second layer or layer of the side in contact with the machine. 6. The fabric according to claim 5, characterized in that the first and second binder yarns of a pair of the first type together form a plain weave pattern on the upper layer. 7. The fabric according to claim 2, characterized in that the first and second binder yarns are located essentially parallel to the threads of the transverse direction. 8. The fabric according to claim 2, characterized in that the first and second binder threads are located essentially parallel to the threads of the machine direction. 9. The fabric according to claim 2, characterized in that at least some of the threads of the machine and transverse directions are monofilament. 10. The fabric according to claim 2, characterized in that at least some of the threads of the machine direction are polyamide or polyester threads. 11. The fabric according to claim 2, characterized in that at least some of the threads of the transverse direction are polyamide or polyester threads. 12. The fabric according to claim 2, characterized in that at least some of the threads of the machine direction and the threads of the transverse direction have either round, or rectangular, or non-circular cross-sectional shape. 13. The fabric of claim 2, further comprising a plurality of pairs of binder yarns of the second type, each of which includes a first binder yarn and a second binder yarn for bonding together the first and second layers, the first and second binder yarns of at least one pair of the second type with the first and second layers so that they extend over at least one common thread on the outer surface of the first or second layer. 14. The fabric according to item 13, wherein the first layer is a layer of the side supporting the paper web, and the first binder thread and the second binder thread of at least one pair of the second type within rapport pass over two common threads on the outer surface of the side layer supporting the paper web. 15. The fabric according to item 13, wherein the pairs of binder yarns of the first type and pairs of binder yarns of the second type are arranged alternately, so that the corresponding pair of binder yarns of the first type is located between two pairs of binder yarns of the second type, and the corresponding pair of binder yarns of the second type located between two pairs of binder threads of the first type. 16. The fabric according to clause 15, wherein each of several pairs of binder threads of the first and second type is located respectively between two corresponding threads of the transverse direction, so that a pair of binder threads of the first type is located between two corresponding threads of the transverse direction, one of which is located next to a pair of binder threads of the second type, located next to another transverse thread, which is located next to another pair of binder threads of the first type, etc. 17. The fabric according to claim 2, characterized in that the first and second binder yarns of at least one pair of the first type are intertwined with the first and second layers so that during rapport they pass over at least one common thread on the outer surface of one of first and second layers. 18. The fabric of Claim 17, wherein the first layer is a layer of the side supporting the paper web, wherein the first and second binder yarns of at least one pair of the first type within rapport extend over two common yarns on the outer surface of said side layer, supporting paper web. 19. The fabric according to claim 2, characterized in that the pair of binder threads of the first type is actually a thread of the transverse direction in the first layer, and the fabric has a ratio of weft threads 3: 1, where the specified ratio of weft threads is the ratio of the number of threads of the transverse direction, together with indicated by the actual transverse thread in the first layer to the number of threads of the transverse direction in the second layer. 20. A fabric for use in a papermaking process, comprising: a first layer having machine direction (MD) yarns and transverse direction (CD) yarns interwoven with them; a second layer having machine direction (MD) yarns and transverse direction (CD) yarns interwoven with them; and a plurality of binder yarns for bonding together the first and second layer, which are intertwined with them so that (i) be an integral part of the first layer and contribute to its structure, and (ii) not be an integral part of the second layer and not to contribute to it structure; moreover, at least one of the binder yarns is interwoven with the yarns of the first fabric layer as an integral part thereof and during the rapport passes over the outer surfaces of two non-successive yarns in the second layer. 21. The fabric according to claim 20, characterized in that the first layer is a layer of the side supporting the paper web, and the second layer is the layer of the side in contact with the machine, and during rapport, at least the first binder thread passes over the outer surfaces of two non-following one after the other in the second layer or layer of the side in contact with the machine. 22. The fabric according to item 21, wherein the two non-successive threads in the layer of the side in contact with the machine have only one thread between themselves, at least one binder thread does not pass over the outer surface of the thread. 23. The fabric according to claim 20, characterized in that the two binder yarns are intertwined with the first and second layers so that during the rapport they pass over at least one common thread on the outer surface of the first or second layer. 24. The fabric according to claim 23, wherein the first layer is a layer of the side supporting the paper web, and within the rapport, said two binder yarns extend over two common threads on the outer surface of said layer of the side supporting the paper web. 25. A fabric for use in a papermaking process, comprising: a first layer having machine direction (MD) yarns and transverse direction (CD) yarns interwoven with them; a second layer having machine direction (MD) yarns and transverse direction (CD) yarns interwoven with them; and a plurality of pairs of binder yarns for bonding together the first and second layers intertwined with them so that (i) be an integral part of the first layer and contribute to its structure and (ii) not be an integral part of the second layer and not contribute to its structure wherein each pair of the first type includes a first and second binder yarn; moreover, the first connecting thread of the pair passes the interval corresponding only to two successive threads of the first layer and two successive threads of the second layer at a given location within the rapport; and the second connecting thread of the pair passes the interval corresponding to only one thread of the first layer and one thread of the second layer at a given location within the rapport. 26. The fabric according A.25, characterized in that the first and second binder yarns intersect when passing the interval between the threads of the upper and lower layers. 27. The fabric according to p. 26, wherein the first layer is a layer of the side supporting the paper web, and the second layer is a layer of the side in contact with the machine.

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