MXPA98009853A - Cosas, laminated, multip layer - Google Patents

Abstract

A multiaxial pressing fabric that can be sewn onto a machine for the pressing section of a papermaking machine is made from a base fabric layer assembled spirally wound a strip of fabric in a plurality of continuous turns, each of which are in contact and linked to those adjacent. The resulting endless base fabric layer is flattened to produce first and second folds of fabric joined together in the folds at their widthwise edges, deposited between the first and second folds of the fabric of the flattened base layer. The seam rings extend outwardly between the unattached sections of the longitudinal threads between the first and second folds of the fabric. The first fold of the fabric, the base fabric that can be sewn onto the machine and the second fold of the machine are laminated between each other by the block of fiber fibrous material cut therethrough. The pressing fabric is joined in an endless manner during installation on a papermaking machine by directing a needle through the passageway formed by the interlacing of the seam rings at their edges to the anchor.

Description

COSAS, LAMINATED, MULTI-LAYERED FABRIC Background of the Invention 1. Field of the Invention The present invention relates to papermaking techniques. More specifically, the present invention relates to press fabrics for the press section of a paper machine. 2. Description of the Prior Art During the papermaking process, a network of cellulosic fibers is formed by depositing a fiber suspension, i.e., an aqueous dispersion of cellulose fibers, on a moving forming fabric in the forming section of a cellulose fiber. a machine to make paper. A large amount of water is drained from the suspension through the forming fabric, leaving the network of cellulosic fibers on the surface of the forming fabric. The newly formed network of cellulosic fibers comes from the forming section to a press section, which includes a series of clamping points of a press. The network of cellulosic fibers passes through the fastening points of the press supported by a press fabric, or, as is often the case, between two such press fabrics. At the points of attachment of the press, the network of cellulosic fibers is subjected to compressive forces which squeeze water from it, and which adhere the cellulosic fibers in the network together to transform the network of cellulosic fibers into a sheet of paper. The water is accepted by the cloth or press fabrics and, ideally, does not return to the sheet of paper. The sheet of paper finally proceeds to a drying section, which includes at least one series of rotating drying drums or cylinders, which are internally heated by steam. The newly formed paper sheet is directed in a serpentine path sequentially around each of a series of drums by means of a drying cloth, which holds the sheet of paper very close to the surfaces of the drums. The hot drums reduce the water content of the paper sheet to a desirable level through evaporation. It should be appreciated that the forming, pressing and drying fabrics take the form of endless bands on the papermaking machine and function in the form of conveyors. It should also be noted that papermaking is a continuous process, which proceeds at considerable speeds. That is, the fiber suspension is continuously deposited on the forming fabric in the forming section, while a freshly made sheet of paper is continuously rolled onto rolls after it leaves the drying section. The present invention relates specifically to the press fabrics used in the pressing section. Press fabrics play a critical role during the papermaking process. One of its functions, as explained above, is to support and transport the paper product that is being manufactured through the fastening points of the press. The press fabrics also take part in the finishing of the surface of the paper sheet. That is, the press fabrics are designed so that they have smooth surfaces and uniformly elastic structures, so that, during their passage through the clamping points of the press, they impart a smooth surface, free of marks to the paper. Perhaps more importantly, press fabrics accept large quantities of water extracted from the wet paper at the press attachment points. To perform this function, there must literally be some place, commonly known as empty volume, within the press fabric where the water can go, and the fabric must maintain adequate water permeability throughout its useful life. Finally, the press fabrics must be able to prevent the accepted water of the wet paper from returning and rewetting the paper that comes out above the clamping points of the press. Contemporary press fabrics are produced in a wide variety of styles designed to meet the requirements of the paper machines on which they are installed., for the grades of paper that are manufactured. In general, they comprise a woven base fabric in which a block of fibrous material of fine, non-woven fibrous material has been woven. The base fabrics can be woven from single filament yarns, a single folded filament, multiple filaments or folded multiple filaments, and can be single layer, multilayer, or laminated. The yarns are typically extruded from any synthetic polymer resins, such as polyamide and polyester resins, used for this purpose by those skilled in the coating techniques in paper machines. Woven base fabrics themselves take many different forms. For example, they may be of endless fabric, or flat fabric and subsequently converted to an endless form with a woven seam. Alternatively, they can be produced by a process commonly known as modified endless fabric, wherein the edges across the width of the base fabric are provided with sewing rings that use the yarns in the machine direction (MD) thereof. . In this process, the MD yarns are continuously woven from back to front and between the edges across the width of the fabric, at each edge returning back and forming a seam ring. A base fabric produced in this way is placed in endless form during its installation on a paper machine, and for this reason it is known as fabric that can be sewn on the machine. To place such a fabric in an endless form, the two edges in width are put together, the rings of the seam on the two edges intertwine with each other, and a pin or sewing needle is directed through the passage formed by the seams. sewing rings intertwined. In addition, the woven base fabrics can be laminated by placing one base fabric within the endless band formed by another, and by sewing a block of fibrous fiber material cut through both base fabrics to join them together. One or both of the woven base fabrics can be of the type that can be sewn onto the machine. In any case, the woven base fabrics are in the form of endless bands, or they can be sewn in such shapes, having a specific length, measured longitudinally around them, and a specific width, measured transversely therethrough. Because configurations of papermaking machines vary widely, manufacturers of coatings of papermaking machines are required to produce press fabrics, and other coatings of papermaking machines, with the dimensions required to conform to particular positions in the papermaking industry. the papermaking machines of their customers. Needless to say, this requirement makes it difficult to carry out the manufacturing process, since each press fabric must typically be made to order. In response to this need to produce press fabrics in a variety of lengths and widths more quickly and efficiently, in recent years press fabrics have been produced using a spiral technique described in U.S. Patent No. 5,360,656, commonly issued to Rexfelt et al. ., the teachings of which are incorporated here as a reference. U.S. Patent No. 5,360,656 shows a press fabric comprising a base fabric having one or more layers of cut fiber material sewn thereon. The base fabric comprises at least one layer composed of a spirally wound woven fabric strip, having a width that is smaller than the width of the base fabric. The base fabric has no end in the longitudinal or machine direction. The longitudinal strands of the spirally wound strip form an angle with the longitudinal direction of the press fabric. The woven fabric strip may be of flat fabric on a fabric which is narrower than those typically used in the production of coatings of papermaking machines. The base fabric comprises a plurality of spirally wound and joined turns of the relatively narrow woven fabric strip. The strip of fabric is woven of longitudinal (warp) and transverse (weft) threads. The adjacent turns of the spirally wound fabric strip can be brought into contact with each other, and the helical continuous seam thus produced, can be closed by sewing, knitting, melting or welding. Alternatively, the adjacent longitudinal side edge portions of the adjacent spiral turns can be arranged superimposed, as long as the edges have a reduced thickness, so as not to cause an increase in thickness in the area of the overlap. In addition, the separation between the longitudinal threads can be increased at the edges of the strip, so that, when the attached spiral turns are arranged superimposed, there can be a separation without change between the longitudinal threads in the area of the overlap. In any case, the result is a woven base fabric, which takes the form of an endless band and which has an internal surface, a longitudinal direction (of the machine) and a transverse direction (transverse to the machine). The side edges of the woven base fabric are then cut to join them parallel to their longitudinal (machine) direction. The angle between the machine direction of the woven base fabric and the helical continuous seam can be relatively small, that is, typically less than 10 °. For the same reason, the longitudinal (warp) threads of the woven fabric strip form the same relatively small angle with the longitudinal (machine) direction of the woven base fabric. Similarly, the transverse (warp) yarns of the woven fabric strip, which are perpendicular to the longitudinal (weft) yarns, form the same relatively small angle with the transverse direction (transverse to the machine) of the base fabric woven. In summary, neither the longitudinal (warp) nor transverse (weft) threads of the woven fabric strip align with the longitudinal (machine) or transverse (transverse to machine) directions in the woven base fabric. In the method shown in the United States Patent No. 5,360,656, the woven fabric strip is wound around two parallel rollers to assemble the woven base fabric. It should be recognized that endless base fabrics can be provided in a variety of widths and lengths by spirally winding a relatively narrow piece of woven fabric strips around two parallel rollers, the length of a particular endless base fabric being determined by the length of each turn. of the spiral of the strip of woven cloth, and the width is determined by the number of turns of the spiral of the strip of woven cloth. The prior need to weave full base fabrics of specific lengths and widths upon request can, therefore, be avoided. Instead, a narrow fabric of 20 inches (0.5 meters) could be used to produce a strip of woven fabric, but, for practical reasons, a conventional textile fabric having a width of 40 to 60 inches (1.0 a) may be preferred. 1.5 meters). U.S. Patent No. 5,360,656 also shows a press fabric comprising a base fabric having two layers, each composed of a spirally wound strip of nonwoven fabric. Both layers take the form of an endless band, one within the endless band formed by the other. Preferably, the strip of woven fabric wound spirally in one layer is spirally wound in a direction opposite to that of the strip of woven fabric in the other layer. That is, more specifically, that the strip spirally wound in one layer defines a right spiral, while the other layer defines a left spiral. In such a two-layer laminated base fabric, the longitudinal (warp) yarns of the woven fabric strip in each of the two layers, form relatively small angles with the longitudinal (machine) direction of the woven base fabric, and the longitudinal (warp) threads of the strip of woven fabric in one layer, form an angle with the longitudinal (warp) threads of the strip of woven fabric in the other layer. Similarly, the transverse (weft) yarns of the woven fabric strip in each of the two layers, form relatively small angles with the transverse direction (transverse to the machine) of the woven base fabric, and the transverse yarns ( weft) of the strip of woven fabric in one layer, form an angle with the transverse (weft) yarns of the woven fabric strip in the other layer. In summary, none of the longitudinal (warp) or transverse (weft) threads of the woven fabric strip in any layer align with the longitudinal (machine) or transverse (transverse to machine) directions of the base fabric . Furthermore, none of the longitudinal (warp) or transverse (weft) threads of the woven fabric strip in any one layer align with those of the other. As a consequence, the base fabrics shown in US Pat. No. 5,360,656 have no threads. in the direction of the machine or in the cross-machine direction defined. Instead, the yarn systems are in directions at oblique angles to the machine and transverse directions to the machine. A press fabric having such a base fabric for a multi-axial press fabric may be preferred. While the standard press fabrics of the prior art have three axes: one in the machine direction (MD), one in the cross machine direction (CD) and one in the Z direction, which is through the thickness of the fabric, a multiaxial press fabric not only has those three axes, but has at least two more axes, defined as directions of the yarn systems in their spirally wound layers. In addition, there are multiple flow paths in the Z direction in a multi-axial press fabric. As a result, a multiaxial press fabric has at least five axes. Due to its multi-axial structure, a multiaxial press fabric having more than one layer exhibits superior resistance to nesting and / or collapse in response to compression at a press clamping point during the papermaking process, compared to those with base fabric layers whose thread systems are parallel to each other. Because the multiaxial pressing fabrics of the above type have heretofore been produced in endless form only, their use has been limited to press sections having cantilevered press rolls and other components, which allow a press fabric to be pressed. Endless is installed from one side of the pressing section. However, its ease of manufacture and superior strength to compaction have contributed to a greater interest and an increasing need for a multiaxial pressing fabric that can be sewn endlessly during its installation on a pressing section, thus returning both such press fabric available for use in papermaking machines that lack cantilevered components. The present invention, a multiaxial press fabric that can be sewn onto the machine, has been developed to fill this need.

Brief Description of the Invention Accordingly, the present invention is a multi-axial press fabric that can be sewn onto the machine for the press section of a paper machine. The press fabric comprises a first base fabric having a first fold of fabric and a second fold of fabric. The first base fabric is assembled from a layer of endless base fabric, which comprises a strip of fabric having a first side edge, a second side edge, a plurality of longitudinal threads and a plurality of transverse threads. The fabric strip is wound spirally into a plurality of contiguous turns, wherein the first side edge on a given turn of the first fabric strip comes into contact with the second side edge of an adjacent turn. Therefore, a continuous helical seam is formed which separates the adjacent turns of the fabric strip. This seam is closed by contacting the first and second edges with each other. The result is a base fabric layer in the form of an endless belt having a machine direction, a cross machine direction, an inner surface and an outer surface. The endless base fabric layer is flattened to produce the first and second folds of the fabric. The folds are joined together at their two edges widthwise in the folds produced when the endless base fabric layer is flattened. At least one transverse thread on each turn of the fabric strip is removed from the fold at each edge across the width of the flat endless base fabric layer. This provides unattached sections of longitudinal threads of the fabric strip. Alternatively, instead of actually flattening the endless base fabric layer to produce the folds, any two places can be marked, separated by one-half the distance around the endless base fabric layer, perhaps with a pointed marker of felt, with a web extending in the direction transverse to the machine through the endless base fabric layer, and at least one transverse thread of each turn of the strip of fabric removed from the bands marked to provide the sections not joined of the longitudinal threads of the fabric strip. A second base fabric is deposited between the first fold and the second fold. The second base fabric is a base fabric that can be sewn on the machine, which comprises longitudinal and transverse threads, the longitudinal threads form sewing threads along the two edges across the width thereof. The second base fabric has a length, exclusive of the seam rings, equal to that of the first fold and the second fold of the fabric. The second base fabric is placed between the first fold of the fabric and the second fold of the fabric, so that the seam rings on it extend outward between the unattached sections of the longitudinal threads between the first and second folds of the fabric, and are used to join the muitiaxial pressing fabric which can be sewn on the machine in the form of an endless band during its installation on a paper machine. At least one layer of block material of cut fiber fibrous material is sewn into one of the first and second folds of the fabric and through the second base fabric another of the first and second folds of the fabric to laminate the first fold of the fabric , the second base fabric and the second fold of the fabric together.

The present invention will now be described in a more detailed manner by frequently referring to the figures identified below.

BRIEF DESCRIPTION OF THE DRAWINGS Figure 1 is a schematic top plan view illustrating a method for manufacturing the base fabric layer of the multiaxial press fabric that can be sewn onto the machine of the present invention; Figure 2 is a top plan view of the finished base fabric layer; Figure 3 is a cross-sectional view taken as indicated by line 3-3 in Figure 1; Figure 4 is a top plan view of the base fabric layer in a flattened condition; Figure 5 is a perspective view of the base fabric layer as shown in Figure 4; Figure 6 is a schematic cross-sectional view of the flattened base fabric layer taken as indicated by line 6-6 in Figure 4; Figure 7 is a plan view of a portion of the surface of the base fabric layer; Figure 8 is a plan view of the portion of the surface of the base fabric layer shown in Figure 7 after the removal of some of its transverse yarns; Figure 9 is a schematic cross-sectional view, analogous to that provided in Figure 6, after the removal of the transverse threads; and Figures 10, 11 and 12 are cross-sectional, schematic views of the subsequent steps in manufacturing the multiaxial press fabric that can be sewn onto the machine of the present invention.

Detailed Description of the Preferred Modality Referring now to those figures, Figure 1 is a top plan view, schematic, illustrating a method for manufacturing the base fabric layer of the multi-axial press fabric that can be sewn on the machine of the present invention. The method can be practiced using an apparatus 10 comprising a first roller 12 and second roller 14, which are parallel to each other and which can be rotated in the directions indicated by the arrows. A strip of woven fabric 16 of a supply roll 18 is wound around the first roll 12 and the second roll 14 in a continuous spiral. It should be recognized that it may be necessary to move the supply roller 18 at an appropriate speed along the second roller 14 (to the right in Figure 1) when the fabric strip 16 is being wound around the rollers 12, 14.

The first roller 12 and the second roller 14 are spaced a distance D, which is determined with reference to the total length, C, required for the base fabric layer being manufactured, the total length, C, is measured longitudinally ( in the machine direction) around the endless belt shape of the layer, it should be understood that the total length, C, is essentially twice the length of the multiaxial press fabric that can be sewn onto the machine that is being manufactured The woven fabric strip 16, which has a width w, is wound spirally on the first and second rollers 12, 14 in a plurality of turns from the supply roll 18, which can be moved along the second roller 14 in the curl course. The successive turns of the fabric strip 16 are brought into contact with each other and joined together along the helical continuous seam 20 by stitching, knitting, melting or welding to produce the base fabric layer 22 as shown in FIG. Figure 2. When a sufficient number of turns of the strip of fabric 16 have been produced to produce the layer 22 with the desired width, that width is measured transversely (in the direction transverse to the machine) through the band shape. endless layer 22, the spiral winding concludes. The base fabric layer 22 thus obtained has an internal surface, an external surface, a machine direction and a line. direction transversal to the machine. Initially, the side edges of the base fabric layer 22, as will be apparent, will not be parallel to the machine direction thereof, and should be cut along the line 24 to provide the layer 22 with the desired width, and with two lateral edges parallel to the machine direction of its endless band shape. The fabric strip 16 can be woven from single filament, pleated filament or multi-filament synthetic polymeric resin yarns, such as polyester or polyamide, in the same way that other fabrics used in the yarn are woven. paper manufacturing industry. After being woven, it can be thermosetted in a conventional manner before being stored interim in a supply roll 18. The fabric strip 16 includes longitudinal threads and transverse threads, where, for example, the longitudinal threads can be threads of a single filament, folded, while the transverse threads can be single filament yarns. In addition, the cloth fabric 16 can be a single layer or multiple layer fabric. Alternatively, the fabric strip 16 can be woven and thermoset in a conventional manner, and fed directly to the apparatus 10 from a thermosetting unit without interim storage on a supply roller 18. It may also be possible to eliminate the thermosetting with the selection of the appropriate material and construction of the product (fabric, sizes and yarn numbers). Figure 3 is a cross section of the strip of fabric 16 taken according to what is indicated by line 3-3 in Figure 1. This comprises longitudinal threads 26 and transverse threads 28, both of which are represented as a woven fabric. monofilaments, interwoven in a single layer. More specifically, a flat fabric is shown, although, it will be understood, that the fabric strip 16 may be woven according to any of the fabric patterns commonly used to weave coatings for papermaking machines. Since the fabric strip 16 is wound spirally to assemble the base fabric layer 22, the longitudinal threads 26 and the transverse threads 28, do not align in the machine and cross machine directions, respectively, of the layer 22 Instead, the longitudinal threads 26 form a slight angle,?, Whose maude is a measure of the separation of the turns of the spiral from the fabric strip 16, with respect to the machine direction of the layer 22, as suggested by the plan view thereof shown in Figure 2. This angle, as noted above, is typically less than 10 °. Because the transverse threads 28 of the fabric strip 16 generally intersect the longitudinal threads 26 at an angle of 90 °, the transverse threads 28 produce the same light angle,?, With respect to the cross machine direction of the layer. 22. The woven fabric strip 16 has a first side edge 30 and a second side edge 32, which together define the width of the body of the woven fabric strip 16. When the fabric strip 16 is being wound spirally over the first and second rollers 12, 14, the first lateral edge of each turn comes into contact with the second lateral edge 32 of the immediately preceding turn. Once the base fabric layer 22 has been assembled, it can be thermoset before being removed from the apparatus 10. After the removal, it is flattened as shown in the plan view presented in Figure 4. This places the layer of base fabric 22 in the form of a two-fold length fabric, L, which is equal to half the total length, C, of the base fabric layer 22 when manufactured on the apparatus 10, and a width,. The seam 20 between the adjacent turns of the woven fabric strip 16 is inclined in one direction in the uppermost part of the two folds, and in the opposite direction to the lower crease, as suggested by the dashed lines in the Figure 4. The flattened base fabric layer 22 has two widthwise edges 36. Figure 5 is a perspective view of the base fabric layer 22 in a flattened condition. On the two edges width 36 of the base fabric layer 22 flattened, are the folds 38, which are aligned in the transverse direction or transverse direction of the machine thereof. Figure 6 is a cross-sectional, schematic view, taken as indicated by line 6-6 in Figure 4. In accordance with the present invention, a plurality of transverse threads. 28 of the fabric strip 16 and the segments thereof, are removed from the adjacent folds 38 to produce a first fold of fabric 40 and a second fold of cloth 42 joined together at their edges in width 36, by sections unattached longitudinal yarns 26. The provision of the unattached sections of the longitudinal yarns 26 on the two edges width 36 of the flattened base fabric layer 22 is complicated by two factors. The first, because the fabric strip 16 has a width smaller than the base fabric layer 22, its transverse yarns 28 do not extend the full width of the base fabric layer 22. The second, and most importantly, because the fabric strip 16 is wound spirally to produce the base fabric layer 22, its transverse yarns do not fall in the cross machine direction of the base fabric layer 22 and therefore are not parallel to the bends 38. Instead, as discussed above, the transverse yarns 28 form a slight angle,?, typically less than 10 °, with respect to the machine-transverse direction of the base fabric layer 22, Consequently, to provide the unattached sections of longitudinal threads 26 in the folds 38, the transverse threads 28 must be gradually removed from the folds 38 across the width, W, of the base fabric layer 22. For purposes of illustration , Figure 7 is a plan view of a portion of the surface of the base fabric layer 22 at a point on one of the folds 38 near the continuous spiral seam 20 between two turns of the adjacent spiral of the fabric strip 16 The longitudinal threads 26 and the transverse threads 28 are at slight angles with respect to the machine direction (MD) and the cross machine direction (CD), respectively. The fold 38, which is flattened during the removal of the neighboring cross wires 28, is represented by a dotted line in Figure 7. In practice, the base fabric layer 22 could be flattened, as described above, and the folds 38 in their two widthwise edges 36 marked in some way, so that their location could be clear when they were flattened, To provide the required non-union sections of the longitudinal threads 26 in fold 38, it is necessary to remove the transverse threads 28 of a region, defined by dotted lines 46, 48 equally spaced from fold 38 on opposite sides thereof. Because the transverse threads 28 are not parallel to the bend 38 or the dotted lines 46, 48, it is often necessary to remove only a portion of a given transverse thread 28, such as in the case of the transverse thread 50 in Figure 7, to make the space between the dotted lines 46, 48 of the transverse yarns 28. Figure 8 is a plan view of the same portion of the surface of the base fabric layer 22 as shown in Figure 7 after the removal of the transverse threads 28 of the central region around the fold 38. The unattached sections 44 of the longitudinal threads 26 extend between the dotted lines 46, 48 in the region of the fold 38. The portion of the transverse thread 50 which extends afterwards of the dotted line 46 has been removed, as noted above. After the removal of the transverse threads 28 from the central region around the fold 38, the base fabric layer 22 is again flattened so that the first fold of the fabric 40 and the second fold of the fabric 42 are interlaced * r between yes by the unattached sections 44 of the longitudinal threads 26. Figure 9 is a schematic, cross-sectional view analogous to that provided in FIG.

Figure 6, of one of the two edges in width 36 of the layer of the flattened base fabric 22. Referring to Figure 10, a base fabric that can be stitched on the machine 52 is then installed between the first fold of the fabric. fabric 40 and the second fold of the cloth 42 and against the unattached sections 44 of the longitudinal yarns 26. Stitches 54 may be made, for example, to connect the first fold of the cloth 40, the base cloth which can be sewn on the machine 52 and the second fold of the fabric 42 together. Alternatively, the first fold of the fabric, the base fabric that can be sewn onto the machine 52 and the second fold of the fabric 42 can be connected together by any other means used for such purpose by those skilled in the art. . The base fabric that can be sewn on the machine 52, comprises longitudinal threads 56 and transverse threads 58. The longitudinal threads 56 form seam rings 60 along each edge across the width of the base fabric that can be sewn onto the machine 52, which have a length, L, exclusive of the seaming rings 60, equal to that of the flattened base fabric layer 22, as shown in Figures 4 and 5. When the base fabric can be sewn over the machine 52 is installed between the first fold of the fabric 40 and the second fold of the fabric 42, this is forced against the unattached sections 44 of the longitudinal threads 26 on the two edges width 36 of the layer of base fabric flattened 22, so that the unattached sections 44 of the longitudinal threads 26 run between the adjacent seaming rings 60. Stitches 54 or other means are then used to connect the three layers comprising the first fold of the fabric 40, the fabric base that p it can be sewn on the machine 52 and the second fold of the fabric 42 together. The base fabric that can be sewn on the machine 52 can be produced by a modified endless weaving technique, wherein the weft yarns, which are finally the longitudinal yarns 56, are woven continuously back and forth through the fabric. the fabric, in each step through it forming a sewing ring 60 on one of the two edges across the width of the fabric being woven passing around a pin forming the ring. During the modified endless weaving process, the transverse yarns 58 of the base fabric that can be sewn on the machine 52 are the warp yarns. Various schemes, described and claimed in US Patent No. 3,815,645 of Codorniu, teachings of which are incorporated herein by reference, for weaving the base fabric that can be sewn onto the machine 52 by the modified endless fabric, are available and can be used in the practice of the present invention. The fabric that is being woven to provide the base fabric that can be sewn onto the machine 52 can be single or multi-layer, and can be woven of single filament, single bent filament or multiple filaments of a polymeric resin synthetic, such as polyester or polyamide. The weft yarns, which form the seaming rings 60 and are finally the longitudinal yarns 56, are preferably single filament yarns. Once the base fabric that can be stitched onto the machine 52 is secured within the flattened base fabric layer 22, the seaming rings 60 provided by it on the two width edges 36 are then interlaced with each other in a form well known to those skilled in the art. As shown in Figure 11, a needle 62 is directed through the passage defined by the interlocked seaming rings 60 to join the two edges across the width 36 of the flattened base fabric layer 22 together, thereby forming a 64 base fabric for a multiaxial press fabric that can be sewn on the machine.

The base fabric 64 can, at this point, again be thermoset. In any case, one or more layers of fibrous fiber material block material 66 are sewn in and through the first overlapping fabric fold 40, the base fabric that can be sewn onto the machine 52 and the second fabric fold 42 to join them between yes and completing the manufacture of the multiaxial pressing fabric that can be sewn on the machine 70. The cut fiber fibrous material block 66 is made of a polymeric resin material, and preferably is a polyamide or polyester resin. Upon completion of the fabrication of the multiaxial press fabric that can be sewn onto the machine 70, the needle 62 can be removed, and the block of cut fiber material 66 cut in the vicinity of the seam 68 for placing the press fabric 70 open for transport to a paper mill and for subsequent installation in a paper machine. The modifications to the foregoing are obvious to one skilled in the art, but do not lead the invention to be modified beyond the scope of the appended claims.

Claims (15)

1. CHAPTER RE IVINDICATORÍO Having described the invention, it is considered as a novelty and, therefore, what is contained in the following claims * Claims: 1. A multiaxial pressing fabric that can be sewn on the machine for the pressing section of a paper machine, the press fabric is characterized in that it comprises: a first base fabric, the first base fabric having a first cloth fold and a second cloth fold made from a layer of endless base cloth, the second layer endless base fabric comprises a strip of fabric having a first side edge, a second side edge, a plurality of longitudinal threads and a plurality of transverse threads, the fabric strip is wound spirally into a plurality of contiguous turns, wherein the The first lateral edge in a given turn of the first strip of fabric comes into contact with the second lateral edge of an adjacent turn thereof, thus forming a stitch With a helical continuous that separates the adjacent turns of the fabric strip, the continuous helical seam is closed by contacting the first and second side edges of the fabric strip together, thereby providing the base fabric layer in the form of a endless belt having a machine direction, a machine-transverse direction, an inner surface and an outer surface, the endless base fabric layer, is flattened to produce the first fold of the fabric and the second fold of the fabric having two edges in width, the first fold of the fabric and the second fold of the fabric are connected together in folds along the two edges in width, in at least one transverse thread in each of the turns of the strip of the fabric being removed in each of the folds at the two edges in width to provide unattached sections of longitudinal threads of the fabric strip in the folds; a second base fabric, the second base fabric is a base fabric that can be sewn on the machine comprising longitudinal and transverse threads, the longitudinal threads form seam rings along two edges across the width of the second base fabric, the second base fabric has a length, exclusive of the seam rings, equal to that of the first fabric fold and the second fold of the fabric of the first base fabric, the second base fabric is placed between the first fold of the fabric and the second fabric. second fold of the fabric, the sewing rings of the second base fabric extend outwardly between the unattached sections of the longitudinal threads between the first fold of the fabric and the second fold of the fabric; and at least one block layer of cut fiber fibrous material stitched into one of the first and second folds of the fabric and through the second base fabric to the other of the first and second folds of the fabric to laminate the first fold of the fabric, the second base fabric and the second fold of the fabric together.
2. 2. The multi-axial press fabric that can be sewn on the machine in accordance with the claim 1, characterized in that the strip of fabric is woven from longitudinal and transverse threads.
3. 3, The multiaxial pressing fabric that can be sewn on the machine in accordance with the claim 2, characterized in that the fabric strip is made of a single layer fabric.
4. 4. The multiaxial pressing fabric that can be sewn on the machine according to claim 2, characterized in that the strip of the fabric is made of a multilayer fabric.
5. 5. The multi-axial press fabric that can be sewn on the machine in accordance with the claim 1, characterized in that the longitudinal threads and the transverse threads of the fabric strip are made of a synthetic polymer resin.
6. 6. The multiaxial pressing fabric that can be sewn on a machine according to claim 1, characterized in that the base fabric layer has side edges cut in a direction parallel to the machine thereof.
7. 7. The multi-axial press fabric that can be sewn on a machine in accordance with the claim 1, characterized in that the fabric strip forms an angle of less than 10 ° with respect to the machine direction of the base fabric layer.
8. 8. The multi-axial press fabric that can be sewn on a machine in accordance with the claim 1, characterized in that it further comprises at least one block layer of cut fiber fibrous material stitched into the first and second folds of the fabric.
9. 9. The multi-axial press fabric that can be sewn on a machine in accordance with the claim 1, characterized in that the fibrous block of staple fiber material is made of a polymeric resin material.
10. 10. The multi-axial press fabric that can be sewn onto a machine according to claim 9, characterized in that the polymeric resin material is selected from the group consisting of polyamide and polyester resins.
11. 11. The multiaxial pressing fabric that can be sewn on a machine according to claim 1, characterized in that the second base fabric is sewn from longitudinal and transverse threads.
12. 12. The multiaxial pressing fabric that can be sewn on a machine according to claim 11, characterized in that the second base fabric is of a single layer fabric.
13. 13. The multiaxial pressing fabric that can be sewn on a machine in accordance with the claim II, characterized in that the second base fabric is made of a multilayer fabric.
14. 14. The multiaxial pressing fabric that can be sewn on a machine according to claim 1, characterized in that the longitudinal threads and the transverse threads of the second base fabric are made of synthetic polymeric resin.
15. 15. The multiaxial pressing fabric that can be sewn on a machine according to claim 1, characterized in that the longitudinal threads of the second base fabric are single filament threads. SUMMARY OF THE INVENTION A multiaxial pressing fabric that can be sewn onto a machine for the pressing section of a papermaking machine is made from a base fabric layer assembled by spirally winding a strip of fabric in a plurality of continuous turns, each of which is in contact and linked to those adjacent. The resulting endless base fabric layer is flattened to produce first and second folds of fabric joined together in the folds at their width edges. Crosswise threads are removed from each turn of the fabric strip in the folds at the edges in width to produce unattached sections of longitudinal threads. A base fabric that can be sewn on the machine, which has seam rings along its width edges, is deposited between the first and second folds of the fabric of the flattened base layer. The sewing rings extend outwardly between the unattached sections of the longitudinal threads between the first and second folds of the fabric. The first fold of the fabric, the base fabric that can be sewn on the machine and the second fold of the machine are laminated together by sewing the block of fibrous fiber material cut therethrough. The pressing fabric is joined in an endless manner during installation on a papermaking machine by directing a needle through the passage formed by the interlacing of the seam rings on their two edges in width.